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Sample records for adrenocorticotropic hormone secretion

  1. Isolated double adrenocorticotropic hormone-secreting pituitary adenomas: A case report and review of the literature

    PubMed Central

    PU, JIUJUN; WANG, ZHIMING; ZHOU, HUI; ZHONG, AILING; JIN, KAI; RUAN, LUNLIANG; YANG, GANG

    2016-01-01

    Only a few cases of double or multiple pituitary adenomas have previously been reported in the literature; however, isolated double adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas are even more rare. The present study reports a rare case of a 50-year-old female patient who presented with typical clinical features of Cushing's disease and was diagnosed with isolated double ACTH-secreting pituitary adenomas. Endocrinological examination revealed an ACTH-producing pituitary adenoma, and preoperative magnetic resonance imaging (MRI) demonstrated a microadenoma with a lower intensity on the right side of the pituitary gland. The patient underwent endoscopic endonasal transsphenoidal surgery, which revealed another pituitary tumor in the left side of the pituitary gland. The two, clearly separated, pituitary adenomas identified in the same gland were completely resected. Immunohistochemistry and pathology revealed that the clearly separated double pituitary adenomas were positive for ACTH, thyroid-stimulating, growth and prolactin hormones. Postoperatively, the levels of ACTH and cortisol hormone decreased rapidly. The case reported in the present study is considerably rare, due to the presence of a second pituitary adenoma in the same gland, which was not detected by preoperative MRI scan, but was noticed during surgery. Intraoperative evaluation may be important in the identification of double or multiple pituitary adenomas. PMID:27347184

  2. [Neurotropic action of adrenocorticotropic hormone].

    PubMed

    Louis, J C; Anglard, P; Vincendon, G

    1986-02-01

    The adrenocorticotropic hormone (ACTH) is produced within the cell body of hypothalamic neurons by proteolytic cleavage of its large precursor molecule, pro-opiomelanocortin. These neurons distribute ACTH-containing nerve endings throughout the central nervous system. ACTH is able to evoke motor and behavioural responses and to modify neuronal metabolism. Since ACTH has been shown to regulate glucose uptake and utilization, its implication in the adaptative response to stress situations, such as cerebral hypoxia, deserves further investigations. PMID:3008142

  3. Pancreatic solitary fibrous tumor causing ectopic adrenocorticotropic hormone syndrome.

    PubMed

    Murakami, Keigo; Nakamura, Yasuhiro; Felizola, Saulo J A; Morimoto, Ryo; Satoh, Fumitoshi; Takanami, Kentaro; Katakami, Hideki; Hirota, Seiichi; Takeda, Yoshiyu; Meguro-Horike, Makiko; Horike, Shin-Ichi; Unno, Michiaki; Sasano, Hironobu

    2016-11-15

    Solitary fibrous tumors occasionally present with hypoglycemia because of the excessive release of insulin-like growth factor II. We report the first case of pancreatic solitary fibrous tumor causing ectopic adrenocorticotropic hormone syndrome. An 82-year-old Japanese man presented with lower limb edema, uncontrolled hypertension, hypokalemia, and baseline hypercortisolism. Distal pancreatectomy was performed after the clinical diagnosis of a neuroendocrine tumor with ectopic secretion of adrenocorticotropic hormone. On histological examination, the tumor showed spindle cells in a fascicular arrangement. The diagnosis of the solitary fibrous tumor was confirmed by the identification of the NAB2-STAT6 fusion gene and positive immuno-histochemical staining for STAT6 and CD34. Using quantitative real-time polymerase chain reaction, mRNA that encoded proopiomelanocortin, precursor of adrenocorticotropic hormone, was detected. Proopiomelanocortin production through the demethylation of the promoter region Domain IV was detected. Pancreatic solitary fibrous tumors represent a new cause of ectopic adrenocorticotropic hormone syndrome. PMID:27585487

  4. 21 CFR 862.1025 - Adrenocorticotropic hormone (ACTH) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Adrenocorticotropic hormone (ACTH) test system... Test Systems § 862.1025 Adrenocorticotropic hormone (ACTH) test system. (a) Identification. An adrenocorticotropic hormone (ACTH) test system is a device intended to measure adrenocorticotropic hormone in...

  5. 21 CFR 862.1025 - Adrenocorticotropic hormone (ACTH) test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Adrenocorticotropic hormone (ACTH) test system... Test Systems § 862.1025 Adrenocorticotropic hormone (ACTH) test system. (a) Identification. An adrenocorticotropic hormone (ACTH) test system is a device intended to measure adrenocorticotropic hormone in...

  6. 21 CFR 862.1025 - Adrenocorticotropic hormone (ACTH) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Adrenocorticotropic hormone (ACTH) test system... Test Systems § 862.1025 Adrenocorticotropic hormone (ACTH) test system. (a) Identification. An adrenocorticotropic hormone (ACTH) test system is a device intended to measure adrenocorticotropic hormone in...

  7. 21 CFR 862.1025 - Adrenocorticotropic hormone (ACTH) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Adrenocorticotropic hormone (ACTH) test system... Test Systems § 862.1025 Adrenocorticotropic hormone (ACTH) test system. (a) Identification. An adrenocorticotropic hormone (ACTH) test system is a device intended to measure adrenocorticotropic hormone in...

  8. 21 CFR 862.1025 - Adrenocorticotropic hormone (ACTH) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Adrenocorticotropic hormone (ACTH) test system... Test Systems § 862.1025 Adrenocorticotropic hormone (ACTH) test system. (a) Identification. An adrenocorticotropic hormone (ACTH) test system is a device intended to measure adrenocorticotropic hormone in...

  9. Nicotine self-administration diminishes stress-induced norepinephrine secretion but augments adrenergic-responsiveness in the hypothalamic paraventricular nucleus and enhances adrenocorticotropic hormone and corticosterone release

    PubMed Central

    Yu, Guoliang; Sharp, Burt M.

    2010-01-01

    Chronic nicotine self-administration augments the thalamo-pituitary-adrenal (HPA) responses to stress. Altered neuropeptide expression within corticotropin-releasing factor (CRF) neurons in the hypothalamic paraventricular nucleus (PVN) contributes to this enhanced HPA response to stress. Herein, we determined the role of norepinephrine, a primary regulator of CRF neurons, in the responses to footshock during nicotine self-administration. On day 12-15 of self-administration, microdialysis showed nicotine reduced PVN norepinephrine release by footshock (<50% of saline). Yet, the reduction in footshock-induced adrenocorticotropic hormone (ACTH) and corticosterone secretion due to intra-PVN prazosin (α1 adrenergic antagonist) was significantly greater in rats self-administering nicotine (2-fold) than saline. Additionally, PVN phenylephrine (α1 agonist) stimulated ACTH and corticosterone release to a similar extent in unstressed rats self-administering nicotine or saline. Nicotine self-administration also decreased footshock-induced c-Fos expression in the nucleus of the solitary tract (NTS)-A2/C2 catecholaminergic neurons that project to the PVN. Therefore, footshock-induced NTS activation and PVN norepinephrine input are both attenuated by nicotine self-administration, yet PVN CRF neurons are more responsive to α1 stimulation, but only during stress. This plasticity in noradrenergic regulation of PVN CRF neurons provides a new mechanism contributing to the HPA sensitization to stress by nicotine self-administration and smoking. PMID:20028457

  10. Opposite regulation of thrombospondin-1 and corticotropin-induced secreted protein/thrombospondin-2 expression by adrenocorticotropic hormone in adrenocortical cells.

    PubMed

    Lafeuillade, B; Pellerin, S; Keramidas, M; Danik, M; Chambaz, E M; Feige, J J

    1996-04-01

    Corticotropin-induced secreted protein (CISP) is a trimeric glycoprotein secreted by primary cultures of bovine adrenortical cells in response to adrenocorticotropic hormone (ACTH). This protein was recently purified in our laboratory, and its N-terminal amino-acid sequence revealed a significant similarity with thrombospondin-2 (TSP2). We report here the nucleotide sequence of a 386 bp RT-PCR fragment specific for CISP. The deduced protein sequence shares 84% identity with the N-terminal portion of mature human TSP2, suggesting that CISP is its bovine counterpart. Northern analysis of adrenocortical cell RNA using the above cDNA fragment as a probe revealed a 6.0 kb CISP/TSP2 mRNA whose abundance was increased nearly fivefold following a 24 h cell treatment with 10(-7) M ACTH. Under the same conditions, the expression of TSP1 mRNA was reduced by tenfold. The protein levels of TSP1 and CISP/TSP2 varied accordingly with their respective mRNA levels, as shown by immunoprecipitation and immunofluorescence experiments. Taken together, these data show that ACTH induces a dramatic shift in the pattern of adrenocortical cell thrombospondin expression from TSP1 to CISP/TSP2. This observation suggests that these two members of the thrombospondin family exert distinct biological functions in the adrenal cortex. This hypothesis is further supported by the observation that anti-CISP antibodies inhibit the maintenance of the morphological changes of bovine adrenocortical cells induced by ACTH, whereas anti-TSP1 antibodies do not. PMID:8698834

  11. Adrenocorticotropic hormone analog use for podocytopathies

    PubMed Central

    Filippone, Edward J; Dopson, Shirley J; Rivers, Denise M; Monk, Rebeca D; Udani, Suneel M; Jafari, Golriz; Huang, Solomon C; Melhem, Arafat; Assioun, Bassim; Schmitz, Paul G

    2016-01-01

    Background Adrenocorticotropic hormone is being increasingly studied for treatment of various glomerulopathies, most notably membranous nephropathy. Less data are available regarding its use in idiopathic nephrotic syndrome (INS) secondary to minimal change disease (MCD) or focal segmental glomerulosclerosis (FSGS). We report here our experience with H.P. Acthar® Gel (repository corticotropin injection) as first-line or subsequent therapy in patients with INS. Methods Data were taken from three patients with MCD and ten patients with FSGS from around the US, who were treated with Acthar Gel as initial or subsequent therapy. Treatment was solely at the discretion of the primary nephrologist without a specific protocol. A complete response (CR) was defined as final urine protein-to-creatinine ratio <500 mg/g and a partial response (PR) as 50% decrease without rise of serum creatinine. Side effects and tolerability were noted. Results All three patients with MCD received Acthar Gel as second-line or later immunosuppressive (IS) therapy and all responded (one CR and two PRs). Two of the ten patients with FSGS received Acthar Gel as first-line IS therapy, while the other eight had failed multiple agents. Four of the ten patients with FSGS had responses, including two CRs and two PRs. The three patients with MCD tolerated therapy well without side effects. Five patients with FSGS tolerated therapy well, while five had various steroid-like side effects, resulting in therapy discontinuation in two patients. Conclusion Acthar Gel is a viable alternative IS agent for treatment of INS in patients intolerant or resistant to conventional therapy. More data are needed to better define its appropriate place. PMID:27418857

  12. Generalised hyperpigmentation caused by ectopic adrenocorticotropic hormone syndrome with recurrent thymic neuroendocrine carcinoma.

    PubMed

    Moon, Hye-Rim; Won, Chong Hyun; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan

    2015-05-01

    Ectopic adrenocorticotropic hormone (ACTH) syndrome is a rare cause of generalised hyperpigmentation. The clinical features are due to the excessive ectopic secretion of adenocorticotropin by diverse neuroendocrine or non-endocrine tumours. Here, we describe a rare case of ectopic ACTH syndrome developing from recurring thymic neuroendocrine carcinoma, which first presented as generalised hyperpigmentation.

  13. Early hyperbaric oxygen therapy inhibits aquaporin 4 and adrenocorticotropic hormone expression in the pituitary gland of rabbits with blast-induced craniocerebral injury★

    PubMed Central

    Huo, Jian; Liu, Jiachuan; Wang, Jinbiao; Zhang, Yongming; Wang, Chunlin; Yang, Yanyan; Sun, Wenjiang; Xu, Shaonian

    2012-01-01

    In the present study, rabbits were treated with hyperbaric oxygen for 1 hour after detonator-blast- induced craniocerebral injury. Immunohistochemistry showed significantly reduced aquaporin 4 expression and adrenocorticotropic hormone expression in the pituitary gland of rabbits with craniocerebral injury. Aquaporin 4 expression was positively correlated with adrenocorticotropic hormone expression. These findings indicate that early hyperbaric oxygen therapy may suppress adrenocorticotropic hormone secretion by inhibiting aquaporin 4 expression. PMID:25624795

  14. Early hyperbaric oxygen therapy inhibits aquaporin 4 and adrenocorticotropic hormone expression in the pituitary gland of rabbits with blast-induced craniocerebral injury.

    PubMed

    Huo, Jian; Liu, Jiachuan; Wang, Jinbiao; Zhang, Yongming; Wang, Chunlin; Yang, Yanyan; Sun, Wenjiang; Xu, Shaonian

    2012-08-01

    In the present study, rabbits were treated with hyperbaric oxygen for 1 hour after detonator-blast- induced craniocerebral injury. Immunohistochemistry showed significantly reduced aquaporin 4 expression and adrenocorticotropic hormone expression in the pituitary gland of rabbits with craniocerebral injury. Aquaporin 4 expression was positively correlated with adrenocorticotropic hormone expression. These findings indicate that early hyperbaric oxygen therapy may suppress adrenocorticotropic hormone secretion by inhibiting aquaporin 4 expression.

  15. Ectopic Adrenocorticotropic Hormone and Corticotropin-Releasing Hormone Co-Secreting Tumors in Children and Adolescents Causing Cushing Syndrome: A Diagnostic Dilemma and How to Solve It

    PubMed Central

    Karageorgiadis, Alexander S.; Papadakis, Georgios Z.; Biro, Juliana; Keil, Meg F.; Lyssikatos, Charalampos; Quezado, Martha M.; Merino, Maria; Schrump, David S.; Kebebew, Electron; Patronas, Nicholas J.; Hunter, Maya K.; Alwazeer, Mouhammad R.; Karaviti, Lefkothea P.; Balazs, Andrea E.; Stratakis, Constantine A.

    2015-01-01

    Context: Ectopic ACTH/CRH syndrome is a rare cause of Cushing syndrome (CS), especially in children. The localization, work-up, and management of ACTH/CRH-secreting tumors are discussed. Setting: A retrospective study was conducted of patients under 21 years of age evaluated at the National Institutes of Health (NIH) for CS and diagnosed with ectopic ACTH/CRH-secreting tumors during the period 2009–2014. Patients: Seven patients with ectopic ACTH/CRH CS are included in this study with a median age 13.6 years (range 1–21), and 3 are female. Measurements: Clinical, biochemical, radiological features, treatment, and histological findings are described. Results: Seven patients were found to have ACTH/CRH-secreting tumors, all with neuroendocrine features. The site of the primary lesion varied: pancreas (3), thymus (2), liver (1), right lower pulmonary lobe (1). Patients underwent biochemical evaluation for CS, including diurnal serum cortisol and ACTH levels, urinary free cortisol levels (UFC), and CRH stimulation tests. All patients underwent radiological investigations including MRI, CT, and PET scan; imaging with octreotide and 68 gallium DOTATATE scans were performed in individual cases. Five patients underwent inferior petrosal sinus sampling; 4 patients had sampling for ACTH and CRH levels from additional sites. Three patients underwent trans-sphenoidal surgery (TSS), and 3 patients required bilateral adrenalectomy. Three patients (43%) died due to metastatic disease, demonstrating the high mortality rate. One of the unique findings in these seven patients is that in each case, their neuroendocrine tumors were ultimately proven to be co-secreting ACTH and CRH. This explains the enigmatic presentation, in which 3 patients initially thought to have Cushing's disease (CD) with corresponding pituitary hyperplasia underwent TSS prior to the correct localization of the causative tumor. Conclusions: Ectopic ACTH/CRH co-secreting tumors are extremely rare in children

  16. Severe Hypokalaemia, Hypertension, and Intestinal Perforation in Ectopic Adrenocorticotropic Hormone Syndrome.

    PubMed

    Kaya, Tezcan; Karacaer, Cengiz; Açikgöz, Seyyid Bilal; Aydemir, Yusuf; Tamer, Ali

    2016-01-01

    Ectopic adrenocorticotropic hormone (ACTH) syndrome is a rare cause of the Cushing's syndrome. The occurrence of the ectopic ACTH syndrome presenting with severe hypokalaemia, metabolic alkalosis, and hypertension has been highlighted in case reports. However, presentation with lower gastrointestinal perforation is not known. We report the case of a 70-year-old male patient with severe hypokalaemia, metabolic alkalosis, hypertension, and colonic perforation as manifestations of an ACTH-secreting small cell lung carcinoma. Ectopic ACTH syndrome should be kept in mind as a cause of hypokalaemia, hypertension, and intestinal perforation in patients with lung carcinoma. PMID:26894113

  17. Neuroendocrine carcinoma of the ampulla of Vater causing ectopic adrenocorticotropic hormone-dependent Cushing's syndrome

    PubMed Central

    KATO, AKIHISA; HAYASHI, KAZUKI; NAITOH, ITARU; SENO, KYOJI; OKADA, YUKIKO; BAN, TESSHIN; KONDO, HIROMU; NISHI, YUJI; UMEMURA, SHUICHIRO; HORI, YASUKI; NATSUME, MAKOTO; JOH, TAKASHI

    2016-01-01

    Ectopic adrenocorticotropic hormone (ACTH) is rarely secreted by neuroendocrine tumors. Although neuroendocrine tumors may occur at any site in the gastrointestinal system, they very rarely occur in the ampulla of Vater and have a poor prognosis. The present study described the first Cushing's syndrome as a result of ectopic ACTH arising from the ampulla of Vater neuroendocrine carcinoma. A 69-year-old female was admitted with clinical features of Cushing's syndrome, confirmed biochemically by hypokalemia, and elevated levels of ACTH and cortisol. In further investigations, a tumor of the ampulla of Vater and liver metastases were detected. Pathological analysis of the biopsy confirmed a neuroendocrine carcinoma, which was immunohistochemically positive for chromogranin A, synaptophysin, cluster of differentiation 56 and ACTH. Therefore, the present study diagnosed a functional and metastatic neuroendocrine carcinoma of the ampulla of Vater with ectopic ACTH production causing Cushing's syndrome. The patient succumbed to mortality 4 months later, despite administration of combined chemotherapy with irinotecan and cisplatin. PMID:27330779

  18. The effect of adrenocorticotropic hormone on inflammation due to tuberculin hypersensitivity and turpentine and on circulating antibody levels.

    PubMed

    OSGOOD, C K; FAVOUR, C B

    1951-11-01

    The treatment with adrenocorticotropic hormone of guinea pigs sensitized with heat-killed tubercle bacilli caused suppression of their skin reactivity to tuberculin. Similar animals treated with saline did not show this change. Normal guinea pigs treated with adrenocorticotropic hormone showed suppression of inflammation, but not necrosis, produced by intracutaneous oil of turpentine. There was slight, but probably not significant, diminution of inflammation during saline administration. Tuberculin complement-fixing antibody titers were not altered by either adrenocorticotropic hormone or saline administration. Adrenocorticotropic hormone produced marked eosinopenia and lymphopenia in guinea pigs.

  19. THE EFFECT OF ADRENOCORTICOTROPIC HORMONE ON INFLAMMATION DUE TO TUBERCULIN HYPERSENSITIVITY AND TURPENTINE AND ON CIRCULATING ANTIBODY LEVELS

    PubMed Central

    Osgood, Charles K.; Favour, Cutting B.

    1951-01-01

    The treatment with adrenocorticotropic hormone of guinea pigs sensitized with heat-killed tubercle bacilli caused suppression of their skin reactivity to tuberculin. Similar animals treated with saline did not show this change. Normal guinea pigs treated with adrenocorticotropic hormone showed suppression of inflammation, but not necrosis, produced by intracutaneous oil of turpentine. There was slight, but probably not significant, diminution of inflammation during saline administration. Tuberculin complement-fixing antibody titers were not altered by either adrenocorticotropic hormone or saline administration. Adrenocorticotropic hormone produced marked eosinopenia and lymphopenia in guinea pigs. PMID:14888823

  20. Adrenocorticotropic Hormone Suppresses Gonadotropin-Stimulated Estradiol Release from Zebrafish Ovarian Follicles

    PubMed Central

    Alsop, Derek; Ings, Jennifer S.; Vijayan, Mathilakath M.

    2009-01-01

    While stress is known to impact reproductive performance, the pathways involved are not entirely understood. Corticosteroid effects on the functioning of the hypothalamus-pituitary-gonadal axis are thought to be a key aspect of stress-mediated reproductive dysfunction. A vital component of the stress response is the pituitary secretion of adrenocorticotropic hormone (ACTH), which binds to the melanocortin 2 receptor (MC2R) in the adrenal glands and activates cortisol biosynthesis. We recently reported MC2R mRNA abundance in fish gonads leading to the hypothesis that ACTH may be directly involved in gonadal steroid modulation. Using zebrafish (Danio rerio) ovarian follicles, we tested the hypothesis that acute ACTH stimulation modulates cortisol and estradiol (E2) secretion. ACTH neither affected cortisol nor unstimulated E2 release from ovarian follicles. However, ACTH suppressed human chorionic gonadotropin (hCG)-stimulated E2 secretion in a dose-related manner, with a maximum decrease of 62% observed at 1 I.U. ACTH mL−1. This effect of ACTH on E2 release was not observed in the presence of either 8-bromo-cAMP or forskolin, suggesting that the mechanism(s) involved in steroid attenuation was upstream of adenylyl cyclase activation. Overall, our results suggest that a stress-induced rise in plasma ACTH levels may initiate a rapid down-regulation of acute stimulated E2 biosynthesis in the zebrafish ovary, underscoring a novel physiological role for this pituitary peptide in modulating reproductive activity. PMID:19649243

  1. Effect of adrenocorticotropic hormone (ACTH) and insulin on the phagocytic capacity of Tetrahymena.

    PubMed

    Köhidai, L; Lovas, B; Csaba, G

    1995-06-01

    Adrenocorticotropic hormone (ACTH) and insulin negatively influenced the phagocytic activity of Tetrahymena. The two hormones had diverse effects after 4 hr of treatments on no-test-particle containing, "0-cells". At this time the number of "0 cells" was significantly lower in the ACTH-treated groups, while in the insulin-treated groups there was an increase of "0-cells" compared to the control and to the results of the starting experiment. Considering previous results, when small molecular weight hormones, if did at all, positively influenced phagocytosis in Tetrahymena, the experiments call the attention to the differences caused by the size of the signal molecules. In the light of the literary data on hormone effects to phagocytosis in mammals and men, the similarity of the effects in species being very far from each other in evolution, could be concluded.

  2. Structure and ultrastructure of adrenocorticotropic hormone cells in goats in anoestrus, gestation and milk production.

    PubMed

    Navarro, J A; Gómez, M A; Sánchez, J; Gómez, S; Bernabé, A

    1991-01-01

    The structural and ultrastructural characteristics of adrenocorticotropic hormone cells in adult female goats in anoestrus, gestation and milk production were studied with an immunohistochemical method (peroxidase-antiperoxidase). Only one cellular type has been identified and is characterized by numerous secretory granules of different electron density and an average diameter of 275 nm. During pregnancy these cells increase in number and size, and there is a frequent presence of vacuoles. During lactation the number of size of the cells decreases but without reaching the state observed in anoestrus and the involution of the cytoplasmic vacuolizations which appear in pregnancy.

  3. Quantifying Pituitary-Adrenal Dynamics and Deconvolution of Concurrent Cortisol and Adrenocorticotropic Hormone Data by Compressed Sensing

    PubMed Central

    Faghih, Rose T.; Dahleh, Munther A.; Adler, Gail K.; Klerman, Elizabeth B.; Brown, Emery N.

    2015-01-01

    Pulsatile release of cortisol from the adrenal glands is governed by pulsatile release of adrenocorticotropic hormone (ACTH) from the anterior pituitary. In return, cortisol has a negative feedback effect on ACTH release. Simultaneous recording of ACTH and cortisol is not typical, and determining the number, timing, and amplitudes of pulsatile events from simultaneously recorded data is challenging because of several factors: (I) stimulator ACTH pulse activity, (II) kinematics of ACTH and cortisol, (III) the sampling interval, and (IV) the measurement error. We model ACTH and cortisol secretion simultaneously using a linear differential equations model with Gaussian errors and sparse pulsatile events as inputs to the model. We propose a novel framework for recovering pulses and parameters underlying the interactions between ACTH and cortisol. We recover the timing and amplitudes of pulses using compressed sensing, and employ generalized cross validation for determining the number of pulses. We analyze serum ACTH and cortisol levels sampled at 10-minute intervals over 24 hours from 10 healthy women. We recover physiologically plausible timing and amplitudes for these pulses and model the feedback effect of cortisol. We recover 15 to 18 pulses over 24 hours, which is highly consistent with the results of another cortisol data analysis approach. Modeling the interactions between ACTH and cortisol allows for accurate quantification of pulsatile events, and normal and pathological states. This could lay the basis for a more physiologically-based approach for administering cortisol therapeutically. The proposed approach can be adapted to deconvolve other pairs of hormones with similar interactions. PMID:25935025

  4. NFKB2 mutation in common variable immunodeficiency and isolated adrenocorticotropic hormone deficiency

    PubMed Central

    Shi, Chuan; Wang, Fen; Tong, Anli; Zhang, Xiao-Qian; Song, Hong-Mei; Liu, Zheng-Yin; Lyu, Wei; Liu, Yue-Hua; Xia, Wei-Bo

    2016-01-01

    Abstract Background Common variable immunodeficiency (CVID) with central adrenal insufficiency is a recently defined clinical syndrome caused by mutations in the nuclear factor kappa-B subunit 2 (NFKB2) gene. We present the first case of NFKB2 mutation in Asian population. Methods and Results An 18-year-old Chinese female with adrenocorticotropic hormone (ACTH) deficiency was admitted due to adrenal crisis and pneumonia. She had a history of recurrent respiratory infections since childhood and ectodermal abnormalities were noted during physical examination. Immunologic tests revealed panhypogammaglobulinemia and deficient natural killer (NK)-cell function. DNA sequencing of NFKB2 identified a heterozygous nonsense mutation (c.2563 A>T, p.855: Lys>∗) in the patient but not her parents. Conclusion Clinicians should be alert to comorbidities of adrenal insufficiency and ectodermal dysplasia in CVID patients as these might suggest a rare hereditary syndrome caused by NFKB2 mutation. PMID:27749582

  5. [A Case of an Adrenocorticotropic Hormone-Producing Pituitary Adenoma Removed via Electromagnetic-Guided Neuroendoscopy].

    PubMed

    Tomita, Yusuke; Kurozumi, Kazuhiko; Terasaka, Tomohiro; Inagaki, Kenichi; Otsuka, Fumio; Date, Isao

    2016-06-01

    The use of navigation systems is safe and reliable for neurological surgery. We performed endoscopic transsphenoidal surgery to totally resect an adrenocorticotropic hormone (ACTH)-producing pituitary adenoma associated with oculomotor nerve palsy. A 70-year-old woman developed right ptosis 4 months before admission. She developed anisocoria 2 months later and was referred to the department of neurology from clinic. Brain magnetic resonance imaging(MRI)showed an intrasellar tumor that partially invaded the right cavernous sinus, and she was then referred to our department. She exhibited a round face ("moon face") and central obesity. Laboratory test results showed a high urinary cortisol level and high serum ACTH level, and neither the serum cortisol nor ACTH level was suppressed by a low-dose dexamethasone test. We performed transsphenoidal surgery using high-dimensional endoscopy under electromagnetic navigation. The tumor invading the cavernous sinus was visualized via endoscopy and confirmed on navigation using a flexible needle probe. Postoperative MRI showed total removal of the tumor, and the serum ACTH level recovered to the normal range. The patient's right oculomotor palsy resolved within 1 week postoperatively. In summary, electromagnetic navigation was useful for total resection of a pituitary tumor invading the cavernous sinus, contributing to normalization of the ACTH level and improvement in neurological symptoms.

  6. [A Case of an Adrenocorticotropic Hormone-Producing Pituitary Adenoma Removed via Electromagnetic-Guided Neuroendoscopy].

    PubMed

    Tomita, Yusuke; Kurozumi, Kazuhiko; Terasaka, Tomohiro; Inagaki, Kenichi; Otsuka, Fumio; Date, Isao

    2016-06-01

    The use of navigation systems is safe and reliable for neurological surgery. We performed endoscopic transsphenoidal surgery to totally resect an adrenocorticotropic hormone (ACTH)-producing pituitary adenoma associated with oculomotor nerve palsy. A 70-year-old woman developed right ptosis 4 months before admission. She developed anisocoria 2 months later and was referred to the department of neurology from clinic. Brain magnetic resonance imaging(MRI)showed an intrasellar tumor that partially invaded the right cavernous sinus, and she was then referred to our department. She exhibited a round face ("moon face") and central obesity. Laboratory test results showed a high urinary cortisol level and high serum ACTH level, and neither the serum cortisol nor ACTH level was suppressed by a low-dose dexamethasone test. We performed transsphenoidal surgery using high-dimensional endoscopy under electromagnetic navigation. The tumor invading the cavernous sinus was visualized via endoscopy and confirmed on navigation using a flexible needle probe. Postoperative MRI showed total removal of the tumor, and the serum ACTH level recovered to the normal range. The patient's right oculomotor palsy resolved within 1 week postoperatively. In summary, electromagnetic navigation was useful for total resection of a pituitary tumor invading the cavernous sinus, contributing to normalization of the ACTH level and improvement in neurological symptoms. PMID:27270145

  7. Comparison of Ultraviolet Photodissociation and Collision Induced Dissociation of Adrenocorticotropic Hormone Peptides

    NASA Astrophysics Data System (ADS)

    Robotham, Scott A.; Brodbelt, Jennifer S.

    2015-09-01

    In an effort to better characterize the fragmentation pathways promoted by ultraviolet photoexcitation in comparison to collision induced dissociation (CID), six adrenocorticotropic hormone (ACTH) peptides in a range of charge states were subjected to 266 nm ultraviolet photodissociation (UVPD), 193 nm UVPD, and CID. Similar fragment ions and distributions were observed for 266 nm UVPD and 193 nm UVPD for all peptides investigated. While both UVPD and CID led to preferential cleavage of the Y-S bond for all ACTH peptides [except ACTH (1-39)], UVPD was far less dependent on charge state and location of basic sites for the production of C-terminal and N-terminal ions. For ACTH (1-16), ACTH (1-17), ACTH (1-24), and ACTH (1-39), changes in the distributions of fragment ion types ( a, b, c, x, y, z, and collectively N-terminal ions versus C-terminal ions) showed only minor changes upon UVPD for all charge states. In contrast, CID displayed significant changes in the fragment ion type distributions as a function of charge state, an outcome consistent with the dependence on the number and location of mobile protons that is not prominent for UVPD. Sequence coverages obtained by UVPD showed less dependence on charge state than those determined by CID, with the latter showing a consistent decrease in coverage as charge state increased.

  8. Vigabatrin Therapy for Infantile Spasms in a Case of Cardiofaciocutaneous Syndrome with Cardiac Hypertrophy Developing during Adrenocorticotropic Hormone Treatment.

    PubMed

    Hatori, Takayuki; Sugiyama, Yohei; Yamashita, Shinichiro; Hirakubo, Yuka; Nonaka, Kazuhito; Ichihashi, Ko

    2016-01-01

    In a patient with cardiofaciocutaneous syndrome complicated by intractable infantile spasms (West syndrome), cardiac hypertrophy developed during adrenocorticotropic hormone treatment. Various types of antiepileptic drugs, intravenous immunoglobulin, thyrotropin releasing hormone, and a ketogenic diet were ineffective in this case. However, vigabatrin both decreased clinical seizures and improved electroencephalogram findings. Although vigabatrin has not been approved for use in Japan, the results in the present case suggest that this drug should be considered as an alternative therapy for cases of infantile spasms associated with syndromes involving cardiomyopathy or its potential risk factors, such as cardiofaciocutaneous syndrome. PMID:27680485

  9. Adrenocorticotropic hormone gel in the treatment of systemic lupus erythematosus: A retrospective study of patients.

    PubMed Central

    Li, Xiao; Golubovsky, Josh; Hui-Yuen, Joyce; Shah, Ummara; Olech, Ewa; Lomeo, Rosalia; Singh, Vijay; Busch, Howard; Strandberg, Mary Jane; Strandberg, Kayla; Horowitz, Leslie; Askanase, Anca

    2016-01-01

    Objectives: Acthar Gel is a long-acting formulation of adrenocorticotropic hormone (ACTH) with anti-inflammatory effects thought to be mediated in part through melanocortin receptor activation. This study was initiated to understand the role of Acthar Gel in SLE treatment in rheumatology practices. Methods: This is a retrospective case series of nine adult female patients treated with Acthar Gel for at least six months at five academic centers. Treating physicians completed a one-page questionnaire on lupus medications, disease activity, and outcomes. Clinical response was defined using SLEDAI 2K and improvement in the clinical manifestation(s) being treated. Results: The most common clinical SLE manifestations/indications requiring therapy with Acthar Gel were arthritis, rash, and inability to taper corticosteroids. The mean SLEDAI 2K score at baseline was 5.8 ± 5.0 (range 0-16). Six patients were concomitantly treated with corticosteroids (mean dose 18.3mg/day). All patients were on background SLE medications including immunosuppressives. Seven of nine patients had an overall improvement, with a decrease in SLEDAI 2K from 5.8 ± 5.0 at baseline to 3.5 ± 2.7 (range 0-8); four of five patients had improvement or resolution in arthritis, and one of two patients had resolution of inflammatory rash. Four patients discontinued corticosteroids and one patient tapered below 50% of the initial dose by 3 months of treatment with Acthar Gel. No adverse events were reported. Conclusions: This study suggests a role for Acthar Gel as an alternative to corticosteroids in the treatment of SLE. Acthar Gel appears to be safe and well-tolerated after 6 months of treatment, with a significant reduction in disease activity. PMID:27158444

  10. The central anorexigenic mechanism of adrenocorticotropic hormone involves the caudal hypothalamus in chicks.

    PubMed

    Shipp, Steven L; Yi, Jiaqing; Dridi, Sami; Gilbert, Elizabeth R; Cline, Mark A

    2015-10-01

    Adrenocorticotropic hormone (ACTH), consisting of 39 amino acids, is most well-known for its involvement in an organism's response to stress. It also participates in satiety, as exogenous ACTH causes decreased food intake in rats. However, its anorexigenic mechanism is not well understood in any species and its effect on appetite is not reported in the avian class. Thus, the present study was designed to evaluate central ACTH's effect on food intake and to elucidate the mechanism mediating this response using broiler chicks. Chicks that received intracerebroventricular (ICV) injection of 1, 2, or 4 nmol of ACTH reduced food intake, under both ad libitum and 180 min fasted conditions. Water intake was also reduced in ACTH-injected chicks under both feeding conditions, but when measured without access to feed it was not affected. Blood glucose was not affected in either feeding condition. Following ACTH injection, c-Fos immunoreactivity was quantified in key appetite-associated hypothalamic nuclei including the ventromedial hypothalamus (VMH), dorsomedial hypothalamus, lateral hypothalamus (LH), arcuate nucleus (ARC) and the parvo- and magno-cellular portions of the paraventricular nucleus. ACTH-injected chicks had increased c-Fos immunoreactivity in the VMH, LH, and ARC. Hypothalamus was collected at 1h post-injection, and real-time PCR performed to measure mRNA abundance of some appetite-associated factors. Neuropeptide Y, pro-opiomelanocortin, glutamate decarboxylase 1, melanocortin receptors 2-5, and urocortin 3 mRNA abundance was not affected by ACTH treatment. However, expression of corticotropin releasing factor (CRF), urotensin 2 (UT), agouti-related peptide (AgRP), and orexin (ORX), and melanocortin receptor 1 (MC1R) mRNA decreased in the hypothalamus of ACTH-injected chicks. In conclusion, ICV ACTH causes decreased food intake in chicks, and is associated with VMH, LH, and ARC activation, and a decrease in hypothalamic mRNA abundance of CRF, UT, AgRP, ORX

  11. Effects of adrenocorticotropic hormone challenge and age on hair cortisol concentrations in dairy cattle.

    PubMed

    González-de-la-Vara, Marcela del Rosario; Valdez, Ricardo Arturo; Lemus-Ramirez, Vicente; Vázquez-Chagoyán, Juan Carlos; Villa-Godoy, Alejandro; Romano, Marta C

    2011-07-01

    Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle.

  12. Glucocorticosteroid concentrations in feces and hair of captive caribou and reindeer following adrenocorticotropic hormone challenge.

    PubMed

    Ashley, N T; Barboza, P S; Macbeth, B J; Janz, D M; Cattet, M R L; Booth, R K; Wasser, S K

    2011-07-01

    Climate change and industrial development are contributing to synchronous declines in Rangifer populations across the Arctic. Chronic stress has been implicated as a proximate factor associated with decline in free-ranging populations, but its role in Rangifer is unspecified. Analysis of glucocorticosteroid (GC) concentration in feces, and more recently in hair, is a non-invasive method for monitoring stress in wildlife. Adrenocorticotropic hormone (ACTH) released from the pituitary gland stimulates GC release from the adrenals and can be administered to reflect adrenal activation. In this study, we assessed concentrations of GC metabolites in feces and cortisol in hair of Alaskan caribou (Rangifer tarandus granti) and reindeer (R. t. tarandus) following ACTH treatment. We predicted that ACTH challenge would increase concentrations of fecal GCs, but not hair cortisol because steroid deposited into the hair shaft occurs over an extended period of time (months) and is likely insensitive to acute adrenal stimulation. Adult caribou (n=10; mean age, 6.5 years old) exhibited a peak increase in fecal GCs 8h following a 2 IU/kg dose of ACTH compared to pre-injection concentrations. In contrast, sub-adult reindeer (n=10, 0.8 years old) elicited a diminished response to the same dose. Quadrupling the dose (8 IU/kg) prolonged the fecal GC response in female reindeer, but male reindeer were unresponsive. Hair cortisol was unaffected by a single ACTH challenge. Further investigation is required to ascertain whether subspecific differences in adrenal sensitivity are attributed to age or sex differences, or historical selective pressures from semi-domestication and/or sedentary life cycle in reindeer.

  13. Effects of adrenocorticotropic hormone challenge and age on hair cortisol concentrations in dairy cattle

    PubMed Central

    del Rosario González-de-la-Vara, Marcela; Valdez, Ricardo Arturo; Lemus-Ramirez, Vicente; Vázquez-Chagoyán, Juan Carlos; Villa-Godoy, Alejandro; Romano, Marta C.

    2011-01-01

    Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle. PMID:22210998

  14. Limited Diagnostic Utility of Plasma Adrenocorticotropic Hormone for Differentiation between Adrenal Cushing Syndrome and Cushing Disease

    PubMed Central

    Hong, A Ram; Kim, Jung Hee; Hong, Eun Shil; Kim, I Kyeong; Park, Kyeong Seon; Ahn, Chang Ho; Kim, Sang Wan; Shin, Chan Soo

    2015-01-01

    Background Measurement of the plasma adrenocorticotropic hormone (ACTH) level has been recommended as the first diagnostic test for differentiating between ACTH-independent Cushing syndrome (CS) and ACTH-dependent CS. When plasma ACTH values are inconclusive, a differential diagnosis of CS can be made based upon measurement of the serum dehydroepiandrosterone sulfate (DHEA-S) level and results of the high-dose dexamethasone suppression test (HDST). The aim of this study was to assess the utility of plasma ACTH to differentiate adrenal CS from Cushing' disease (CD) and compare it with that of the HDST results and serum DHEA-S level. Methods We performed a retrospective, multicenter study from January 2000 to May 2012 involving 92 patients with endogenous CS. The levels of plasma ACTH, serum cortisol, 24-hour urine free cortisol (UFC) after the HDST, and serum DHEA-S were measured. Results Fifty-seven patients had adrenal CS and 35 patients had CD. The area under the curve of plasma ACTH, serum DHEA-S, percentage suppression of serum cortisol, and UFC after HDST were 0.954, 0.841, 0.950, and 0.997, respectively (all P<0.001). The cut-off values for plasma ACTH, percentage suppression of serum cortisol, and UFC after HDST were 5.3 pmol/L, 33.3%, and 61.6%, respectively. The sensitivity and specificity of plasma ACTH measurement were 84.2% and 94.3%, those of serum cortisol were 95.8% and 90.6%, and those of UFC after the HDST were 97.9% and 96.7%, respectively. Conclusion Significant overlap in plasma ACTH levels was seen between patients with adrenal CS and those with CD. The HDST may be useful in differentiating between these forms of the disease, especially when the plasma ACTH level alone is not conclusive. PMID:26248856

  15. Isolated Adrenocorticotropic Hormone or Thyrotropin Deficiency Following Mild Traumatic Brain Injury: Three Cases with Long-Term Follow-Up

    PubMed Central

    Baek, Cho-Ok; Kim, Yu Ji; Kim, Ji Hye

    2015-01-01

    Few studies have examined the clinical features and long-term outcomes of isolated pituitary hormone deficiencies after traumatic brain injury (TBI). Such deficiencies typically present at time intervals after TBI, especially after mild injuries such as concussions, which makes their diagnosis difficult without careful history taking. It is necessary to improve diagnosis and prevent life threatening or morbid conditions such as those that may occur in deficiencies of adrenocorticotropic hormone (ACTH) or thyroid-stimulating hormone (as known as thyrotropin, TSH), the two most important pituitary hormones in hypopituitarism treatment. Here, we report two cases of isolated ACTH deficiency and one case of isolated TSH deficiency. These patients presented at different time points after concussion and underwent long-term follow-ups. PMID:27169080

  16. Thyroid hormones and renin secretion.

    PubMed

    Ganong, W F

    Circulating angiotensin is produced by the action of renin from the kidneys on circulating angiotensinogen. There are other renin-angiotensin systems in various organs in the body, and recent observations raise the intriguing possibility that angiotensin II is produced by a totally intracellular pathway in the juxtaglomerular cells, the gonadotrops of the anterior pituitary, neurons, in the brain, salivary duct cells, and neuroblastoma cells. Circulating angiotensin II levels depend in large part on the plasma concentration of angiotensinogen, which is hormonally regulated, and on the rate of renin secretion. Renin secretion is regulated by an intrarenal baroreceptor mechanism, a macula densa mechanism, angiotensin II, vasopressin, and the sympathetic nervous system. The increase in renin secretion produced by sympathetic discharge is mediated for the most part by beta-adrenergic receptors, which are probably located on the juxtaglomerular cells. Hyperthyroidism would be expected to be associated with increased renin secretion in view of the increased beta-adrenergic activity in this condition, and hypothyroidism would be associated with decreased plasma renin activity due to decreased beta-adrenergic activity. Our recent research on serotonin-mediated increases in renin secretion that depend on the integrity of the dorsal raphe nucleus and the mediobasal hypothalamus has led us to investigate the effect of the pituitary on the renin response to p-chloroamphetamine. The response is potentiated immediately after hypophysectomy, but 22 days after the operation, it is abolished. This slowly developing decrease in responsiveness may be due to decreased thyroid function.

  17. Inhibition of Ubiquitin-specific Peptidase 8 Suppresses Adrenocorticotropic Hormone Production and Tumorous Corticotroph Cell Growth in AtT20 Cells

    PubMed Central

    Jian, Fang-Fang; Li, Yun-Feng; Chen, Yu-Fan; Jiang, Hong; Chen, Xiao; Zheng, Li-Li; Zhao, Yao; Wang, Wei-Qing; Ning, Guang; Bian, Liu-Guan; Sun, Qing-Fang

    2016-01-01

    Background: Two recent whole-exome sequencing researches identifying somatic mutations in the ubiquitin-specific protease 8 (USP8) gene in pituitary corticotroph adenomas provide exciting advances in this field. These mutations drive increased epidermal growth factor receptor (EGFR) signaling and promote adrenocorticotropic hormone (ACTH) production. This study was to investigate whether the inhibition of USP8 activity could be a strategy for the treatment of Cushing's disease (CD). Methods: The anticancer effect of USP8 inhibitor was determined by testing cell viability, colony formation, apoptosis, and ACTH secretion. The immunoblotting and quantitative reverse transcription polymerase chain reaction were conducted to explore the signaling pathway by USP8 inhibition. Results: Inhibition of USP8-induced degradation of receptor tyrosine kinases including EGFR, EGFR-2 (ERBB2), and Met leading to a suppression of AtT20 cell growth and ACTH secretion. Moreover, treatment with USP8 inhibitor markedly induced AtT20 cells apoptosis. Conclusions: Inhibition of USP8 activity could be an effective strategy for CD. It might provide a novel pharmacological approach for the treatment of CD. PMID:27569239

  18. Adrenocorticotropic hormone and cortisol levels in relation to inflammatory response and disease severity in children with meningococcal disease.

    PubMed

    van Woensel, J B; Biezeveld, M H; Alders, A M; Eerenberg, A J; Endert, E; Hack, E C; von Rosenstiel, I A; Kuijpers, T W

    2001-12-15

    This prospective observational study investigated the relationship of the hypothalamic-pituitary-adrenal axis to inflammatory markers and to disease severity in children with meningococcal disease. In total, 32 children were studied: 10 with distinct meningococcal meningitis (MM), 10 with MM and septic shock, and 12 with fulminant meningococcal septicemia (FMS). Levels of adrenocorticotropic hormone (ACTH) and interleukin (IL)-6, IL-8, and IL-10 were lowest in the MM group and dramatically elevated in the FMS group. Cortisol and C-reactive protein levels were highest in the MM group and relatively low in the FMS group. Levels of ACTH and inflammatory markers decreased within the first 24 h of admission, but cortisol levels did not fluctuate. Cortisol was significantly inversely correlated with IL-6, IL-8, and IL-10 (P < or =.04). These results suggest that the adrenal reserve in children is insufficient to handle the extreme conditions and stress associated with severe meningococcal disease.

  19. Cyclic AMP in female mouse brain is altered by the adrenocorticotropic hormone(4-9) analogue organon 2766.

    PubMed

    Schneider, D R; Felt, B T; Murphy, S; Goldman, H

    1981-09-01

    Cyclic AMP content was determined in 12 brain regions of young adult female mice at 30 min and at 24 h following an intraperitoneal injection of the tri-substituted adrenocorticotropic hormone(4-9) [ACTH(4-9)] analogue Organon 2766 [ORG 2766]. Animals were killed by focused 3.5 kW microwave radiation applied for 350 ms. Unlike previously reported responses in male mice, at 30 min post-injection there were no detectable differences in cyclic AMP content between the placebo and ORG 2766-treated animals. By contrast, 24 h after injection, the content of cyclic AMP was changed significantly in 8 of the 12 brain regions examined: medulla-pons, septal area, thalamus, hypothalamus, hippocampus, olfactory bulb, and parietal and occipital cortices. In most of the regions examined, differences consisted of 50% or greater reductions of tissue cyclic AMP content. The changes were unrelated to the estrus cycle of these animals.

  20. Unusual suspects: pulmonary opportunistic infections masquerading as tumor metastasis in a patient with adrenocorticotropic hormone-producing pancreatic neuroendocrine cancer.

    PubMed

    Chowdry, Rajasree P; Bhimani, Chandar; Delgado, Maria A; Lee, Daniel J; Dayamani, Priya; Sica, Gabriel L; Owonikoko, Taofeek K

    2012-11-01

    Pancreatic neuroendocrine tumors (p-NETs) are a rare group of neoplasms but with increasing incidence. The atypical complications that arise in the setting of functional endocrine tumors are underreported and therefore have not received sufficient attention and the necessary mention in the oncology literature. The clinical implications of these complications pose management challenges starting with the difficulty in establishing diagnosis, accurate staging and optimal treatment of the primary process. We present the case of a middle-aged woman diagnosed with adrenocorticotropic hormone-producing carcinoma arising from the pancreas whose case was complicated by excessive uncontrolled hypercortisolism and reactivation of pulmonary opportunistic infections that confounded her management. We believe that this case illustration will be of value to practicing oncologists and other groups of physicians who are called upon to participate in the multidisciplinary treatment of these relatively rare but highly challenging cases. PMID:23118805

  1. Unusual suspects: pulmonary opportunistic infections masquerading as tumor metastasis in a patient with adrenocorticotropic hormone-producing pancreatic neuroendocrine cancer

    PubMed Central

    Chowdry, Rajasree P.; Bhimani, Chandar; Delgado, Maria A.; Lee, Daniel J.; Dayamani, Priya; Sica, Gabriel L.

    2012-01-01

    Pancreatic neuroendocrine tumors (p-NETs) are a rare group of neoplasms but with increasing incidence. The atypical complications that arise in the setting of functional endocrine tumors are underreported and therefore have not received sufficient attention and the necessary mention in the oncology literature. The clinical implications of these complications pose management challenges starting with the difficulty in establishing diagnosis, accurate staging and optimal treatment of the primary process. We present the case of a middle-aged woman diagnosed with adrenocorticotropic hormone-producing carcinoma arising from the pancreas whose case was complicated by excessive uncontrolled hypercortisolism and reactivation of pulmonary opportunistic infections that confounded her management. We believe that this case illustration will be of value to practicing oncologists and other groups of physicians who are called upon to participate in the multidisciplinary treatment of these relatively rare but highly challenging cases. PMID:23118805

  2. Parathyroid hormone - Secretion and metabolism in vivo.

    NASA Technical Reports Server (NTRS)

    Habener, J. F.; Powell, D.; Murray, T. M.; Mayer, G. P.; Potts, J. T., Jr.

    1971-01-01

    Gel filtration and radioimmunoassay were used to determine the molecular size and immunochemical reactivity of parathyroid hormone present in gland extracts, in the general peripheral circulation, and in parathyroid effluent blood from patients with hyperparathyroidism, as well as from calves and from cattle. It was found that parathyroid hormone secreted from the parathyroids in man and cattle is at least as large as the molecule extracted from normal bovine glands. However, once secreted into the circulation the hormone is cleaved, and one or more fragments, immunologically, dissimilar to the originally secreted hormone, constitute the dominant form of circulating immunoreactive hormone.

  3. Dephosphorylation/inactivation of tyrosine hydroxylase at the median eminence of the hypothalamus is required for suckling-induced prolactin and adrenocorticotrop hormone responses.

    PubMed

    Fehér, Pálma; Oláh, Márk; Bodnár, Ibolya; Hechtl, Dániel; Bácskay, Ildikó; Juhász, Béla; Nagy, György M; Vecsernyés, Miklós

    2010-04-29

    We have recently found that dopamine (DA) released from terminals of the hypothalamic neuroendocrine dopamine (NEDA) neurons plays a role not only in prolactin (PRL), but also in adrenocorticotrop hormone (ACTH) secretion, without having any influence on alpha-melanocyte-stimulating hormone (alpha-MSH) release in lactating dams. The aim of our present studies was to further investigate this DAerg regulation of ACTH using consecutively applied physiological stimulation (suckling) and pharmacological inhibition of the rate-limiting enzyme of DA synthesis (tyrosine hydroxylase, TH) by alpha-methyl-p-tyrosine (alpha-MpT) that acutely affect secretion of these pituitary hormones during lactation. Following 4h separation period, two experimental groups were formed. In the first group, lactating rats were assembled with their litters for 60 min prior to alpha-MpT. In the second group, the alpha-MpT was injected first and 60 min later suckling stimulus was applied. Plasma samples were taken in every 15 min during the 90 min experimental period. Concentrations of plasma PRL, ACTH and alpha-MSH were measured by specific RIAs. Both stimuli applied in the first sequence, significantly elevated plasma PRL and ACTH levels in separated lactating dams, without having any effect on alpha-MSH secretion. Suckling applied in the first sequence was able to block the alpha-MpT-induced elevation of ACTH secretion, while PRL response was also significantly attenuated. alpha-MpT pretreatment prevented both PRL and ACTH responses to suckling stimulus. Investigating the dephosphorylation/inactivation of TH in the arcuate nucleus-ME (TIDA) regions, no pTH-immunoreactive perikarya or terminals can be found in continuously suckled dams. In contrast, after 4h separation of the mothers from their litters, pTH-immunoreactivity can be clearly visualized in the external zone of ME. In alpha-MpT pretreated mothers following 4h separation no pTH positive terminals are visible. No changes in the TH

  4. Sources of variation in plasma corticosterone and dehydroepiandrosterone in the male northern cardinal (Cardinalis cardinalis): I. Seasonal patterns and effects of stress and adrenocorticotropic hormone.

    PubMed

    Fokidis, H Bobby

    2016-09-01

    The secretion of steroids from the adrenal gland is a classic endocrine response to perturbations that can affect homeostasis. During an acute stress response, glucocorticoids (GC), such as corticosterone (CORT), prepare the metabolic physiology and cognitive abilities of an animal in a manner that promotes survival during changing conditions. Although GC functions during stress are well established, much less is understood concerning how adrenal androgens, namely dehydroepiandrosterone (DHEA) are influenced by stress. I conducted three field studies (one experimental and two descriptive) aimed at identifying how both CORT and DHEA secretion in free-living male northern cardinals (Cardinalis cardinalis), vary during acute stress; across different circulations (brachial vs. jugular); in response to ACTH challenge; and during the annual cycle. As predicted, restraint stress increased plasma CORT, but unexpectedly DHEA levels decreased, but the latter effect was only seen for blood sampled from the jugular vein, and not the brachial. The difference in DHEA between circulations may result from increased neural uptake of DHEA during stress. Injection with exogenous adrenocorticotropic hormone (ACTH) increased CORT concentrations, but failed to alter DHEA levels, thus suggesting ACTH is not a direct regulator of DHEA. Monthly field sampling revealed distinct seasonal patterns to both initial and restraint stress CORT and DHEA levels with distinct differences in the steroid milieu between breeding and non-breeding seasons. These data suggest that the CORT response to stress remains relatively consistent, but DHEA secretion is largely independent of the response by CORT. Although CORT functions have been well-studied in wild animals, little research exists for the role of DHEA and their variable relationship sets the stage for future experimental research addressing steroid stress responses. PMID:27255363

  5. Calcium calmodulin and hormone secretion.

    PubMed

    Brown, B L; Walker, S W; Tomlinson, S

    1985-08-01

    As long ago as 1970, it was proposed that Ca2+ can act as a 'second messenger' like cAMP (Rasmussen & Nagata, 1979). The recognition that calmodulin is a major Ca2+ binding protein in non-muscle cells has prompted the suggestion that calmodulin may serve an analogous role for Ca2+ to that served by protein kinase for cAMP (Wang & Waisman, 1979), or at least to the regulatory subunit of the cyclic nucleotide-dependent kinases. It is becoming clear that calmodulin probably does play a role in stimulus secretion coupling in endocrine cells. Nevertheless, some of the experimental approaches which have led to this rather tentative conclusion do induce some doubts, as we have attempted to indicate. Many of the pharmacological agents used in the studies cited in this review are not specific in their interaction with calmodulin. For example, the phenothiazines also inhibit phospholipid-sensitive protein kinase. The introduction of more specific drugs, such as the naphthalene sulphonamides, may lead to a clearer picture of the role of calmodulin in hormone secretion. Relationships probably exist between cyclic nucleotides, calcium, calmodulin, phosphatidylinositol (PI) turnover and phospholipids in the overall control of the secretory process (see Fig. 1). There is considerable evidence that calcium is the primary internal signal initiating exocytosis of hormone from many glands. However, it appears that cyclic nucleotides can modulate the calcium signal either positively or negatively and it is possible that cAMP and calcium can separately activate secretion. The presence of both calmodulin-activated adenylate cyclase and cyclic nucleotide phosphodiesterase in the same tissue would appear to suggest either spatial or temporal control mechanisms or that (diagram; see text) the calcium requirement for calmodulin activation differs between the two enzymes. The true explanation is probably far more complex and involves perhaps as yet unknown factors that can differentially

  6. Metabolic responses to adrenocorticotropic hormone (ACTH) vary with life-history stage in adult male northern elephant seals.

    PubMed

    Ensminger, David C; Somo, Derek A; Houser, Dorian S; Crocker, Daniel E

    2014-08-01

    Strong individual and life-history variation in serum glucocorticoids has been documented in many wildlife species. Less is known about variation in hypothalamic-pituitary-adrenal (HPA) axis responsiveness and its impact on metabolism. We challenged 18 free-ranging adult male northern elephant seals (NES) with an intramuscular injection of slow-release adrenocorticotropic hormone (ACTH) over 3 sample periods: early in the breeding season, after 70+ days of the breeding fast, and during peak molt. Subjects were blood sampled every 30 min for 2h post-injection. Breeding animals were recaptured and sampled at 48 h. In response to the ACTH injection, cortisol increased 4-6-fold in all groups, and remained elevated at 48 h in early breeding subjects. ACTH was a strong secretagogue for aldosterone, causing a 3-8-fold increase in concentration. Cortisol and aldosterone responses did not vary between groups but were correlated within individuals. The ACTH challenge produced elevations in plasma glucose during late breeding and molting, suppressed testosterone and thyroid hormone at 48 h in early breeding, and increased plasma non-esterified fatty acids and ketoacids during molting. These data suggest that sensitivity of the HPA axis is maintained but the metabolic impacts of cortisol and feedback inhibition of the axis vary with life history stage. Strong impacts on testosterone and thyroid hormone suggest the importance of maintaining low cortisol levels during the breeding fast. These data suggest that metabolic adaptations to extended fasting in NES include alterations in tissue responses to hormones that mitigate deleterious impacts of acute or moderately sustained stress responses.

  7. Metabolic responses to adrenocorticotropic hormone (ACTH) vary with life-history stage in adult male northern elephant seals.

    PubMed

    Ensminger, David C; Somo, Derek A; Houser, Dorian S; Crocker, Daniel E

    2014-08-01

    Strong individual and life-history variation in serum glucocorticoids has been documented in many wildlife species. Less is known about variation in hypothalamic-pituitary-adrenal (HPA) axis responsiveness and its impact on metabolism. We challenged 18 free-ranging adult male northern elephant seals (NES) with an intramuscular injection of slow-release adrenocorticotropic hormone (ACTH) over 3 sample periods: early in the breeding season, after 70+ days of the breeding fast, and during peak molt. Subjects were blood sampled every 30 min for 2h post-injection. Breeding animals were recaptured and sampled at 48 h. In response to the ACTH injection, cortisol increased 4-6-fold in all groups, and remained elevated at 48 h in early breeding subjects. ACTH was a strong secretagogue for aldosterone, causing a 3-8-fold increase in concentration. Cortisol and aldosterone responses did not vary between groups but were correlated within individuals. The ACTH challenge produced elevations in plasma glucose during late breeding and molting, suppressed testosterone and thyroid hormone at 48 h in early breeding, and increased plasma non-esterified fatty acids and ketoacids during molting. These data suggest that sensitivity of the HPA axis is maintained but the metabolic impacts of cortisol and feedback inhibition of the axis vary with life history stage. Strong impacts on testosterone and thyroid hormone suggest the importance of maintaining low cortisol levels during the breeding fast. These data suggest that metabolic adaptations to extended fasting in NES include alterations in tissue responses to hormones that mitigate deleterious impacts of acute or moderately sustained stress responses. PMID:24798580

  8. Effects of bupropion and pramipexole on cell proliferation in the hippocampus of adrenocorticotropic hormone-treated rats.

    PubMed

    Onoue, Yuka; Kuwatsuka, Keiko; Miyazaki, Ikuko; Asanuma, Masato; Kitamura, Yoshihisa; Sendo, Toshiaki

    2014-01-01

    The dopamine reuptake inhibitor bupropion and dopamine D2/3 receptor agonist pramipexole have been clinically proven to improve both depression and treatment-resistant depression. We examined its influence on the duration of immobility during the forced swim test in adrenocorticotropic hormone (ACTH)-treated rats and further analyzed the possible role of the dopamine nerve system in this effect. Bupropion and pramipexole significantly decreased the duration of immobility in normal and ACTH-treated rats. We previously demonstrated that the chronic administration of ACTH caused a significant decrease in hippocampal cell proliferation and neurogenesis. In this study, we used the mitotic marker 5-bromo-2'-deoxyridine to investigate the effects of bupropion and pramipexole on cell proliferation in the subgranular zone of the hippocampal dentate gyrus following chronic treatment with ACTH. The ACTH treatment for 14 d decreased adult hippocampal cell proliferation. The chronic administration of bupropion for 14 d blocked the loss of cell proliferation resulting from the chronic treatment with ACTH, whereas pramipexole did not. The administration of bupropion may have treatment-resistant antidepressive properties, which may be partly attributed to the normalization of hippocampal cell proliferation.

  9. Primary intracranial neuroendocrine tumor with ectopic adrenocorticotropic hormone syndrome: A rare and complicated case report and literature review

    PubMed Central

    LIU, HAILONG; ZHANG, MINGSHAN; WANG, XUAN; QU, YANMING; ZHANG, HONGWEI; YU, CHUNJIANG

    2016-01-01

    Neuroendocrine tumors (NETs) and ectopic adrenocorticotropic hormone (ACTH) syndrome are frequent in adult patients. However, primary intracranial NETs, exhibiting immunonegativity for ACTH, high serum ACTH level and treated with anterior skull base reconstruction, are rare and complicated. We herein present a case of a primary intracranial NET immunonegative for ACTH, resulting in ectopic ACTH syndrome. A 40-year-old woman presented with intermittent rhinorrhea, rapid weight gain, polydipsia, polyuria, hypertension, dimness, bilateral exophthalmus, diminution of vision in the left eye and pigmentation of the skin of the face and trunk. Computed tomography (CT) and magnetic resonance imaging scans revealed a sizeable enhancing tumor in the anterior cranial fossa, which infiltrated the sphenoid and ethmoid sinuses bilaterally, the left maxillary sinus and the nasal cavity. Abdominal CT scans revealed bilateral adrenal hyperplasia. The biochemical findings included hypokalemia and high glucose, cortisol, plasma ACTH, 24-h urinary free cortisol and testosterone levels. The neoplasm was exposed through a right frontal craniotomy, while anterior skull base reconstruction was performed during surgery. The intracranial surgery achieved gross removal of the tumor; however, part of the tumor remained in the nasal cavity. Histopathological examination of the surgical specimen confirmed the diagnosis of a low-grade small-cell NET, exhibiting immunonegativity for ACTH. A postoperative abdominal CT scan demonstrated bilateral regression of the adrenal gland hyperplasia and the serum ACTH level returned to normal after 16 days. To the best of our knowledge, there are no previous reports of primary intracranial NETs, immunohistochemically negative for ACTH, resulting in ectopic ACTH syndrome. PMID:27330775

  10. Regulation of rat adrenal vasoactive intestinal peptide content: effects of adrenocorticotropic hormone treatment and changes in dietary sodium intake.

    PubMed

    Hinson, J P; Renshaw, D; Carroll, M; Kapas, S

    2001-09-01

    Vasoactive intestinal peptide (VIP) is well established as a paracrine regulator of adrenal function. It is present in nerves supplying the adrenal cortex, although previous studies have found that the amount of VIP in the outer zones of the rat adrenal is not affected by ligating the splanchnic nerve supplying the adrenal gland. The present studies were designed to investigate the mechanisms involved in regulating the VIP content of the rat adrenal gland. This study examined the effects of changes in electrolyte balance and adrenocorticotropic hormone (ACTH) administration on the adrenal content of VIP as measured by radioimmunoassay. Rats on a low sodium diet had a significantly increased capsular/zona glomerulosa immunoreactive VIP (irVIP) level, while rats on a high sodium diet had suppressed levels relative to controls. Changes in dietary sodium did not affect inner zone/medullary VIP content. Administration of ACTH caused a decrease in irVIP levels in the capsular/zona glomerulosa portion of the adrenal gland but had no effect on the inner zone/medulla. Analysis of mRNA encoding VIP revealed a large increase in expression of VIP in the sodium-deplete group compared with the control, with no change in VIP expression in the sodium-loaded group. ACTH treatment was found to significantly decrease VIP mRNA levels in the capsular portion. Neither ACTH treatment nor changes in sodium intake affected inner zones/medullary VIP message. These data suggest that VIP in the capsule and zona glomerulosa region of the adrenal cortex is regulated in response to the physiological status of the animal, with changes in capsular/zona glomerulosa VIP correlating with changes in zona glomerulosa function.

  11. Efficacy and safety of adrenocorticotropic hormone treatment in glomerular diseases: a systematic review and meta-analysis

    PubMed Central

    Kittanamongkolchai, Wonngarm; Cheungpasitporn, Wisit; Zand, Ladan

    2016-01-01

    Background There is growing evidence that adrenocorticotropic hormone (ACTH) may be effective in treating various forms of glomerular diseases. However, the efficacy of treatment and frequency of adverse effects associated with the use of ACTH in glomerular diseases are unknown. A systematic review and meta-analysis of the literature was performed. Methods A literature search was performed using Medline, Embase, Google Scholar and the Cochrane Database of Systematic Reviews from inception through 18 July 2015. Studies assessing the efficacy and safety of ACTH treatment in adults with glomerular diseases were included. Results Of the 343 identified citations, 18 evaluated the drug efficacy and 12 evaluated the adverse effects. The most common glomerular diseases were membranous nephropathy (MN), primary focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD). The overall rate of complete remission in MN was 80% at 0–6 months, 69% at >6–12 months, 90% at >12–24 months and 95% beyond 24 months of follow-up. Fifty percent of primary FSGS and MCD patients treated with ACTH were in remission at 6 months, but the relapse rate was high after ACTH discontinuation (17%). Evidence of ACTH efficacy for other glomerular diseases was scarce. Edema was the most commonly reported adverse effect {incidence rate [IR] 0.10 [95% confidence interval (CI) 0.04–0.18]} followed by insomnia [IR 0.08 (95% CI 0.03–0.15)]. The dropout rate due to adverse events was 7%, mostly due to edema and weight gain. Conclusions ACTH is a well-tolerated therapy and is most promising when treating patients with MN. There may be a potential role for ACTH in patients with MCD and FSGS, but data are lacking. PMID:27274822

  12. Peripheral blood corticotropin-releasing factor, adrenocorticotropic hormone and cytokine (Interleukin Beta, Interleukin 6, tumor necrosis factor alpha) levels after high- and low-dose total-body irradiation in humans

    SciTech Connect

    Girinsky, T.A.; Pallardy, M.; Comoy, E.; Benassi, T.; Roger, R.; Ganem, G.; Socie, G.; Cossett, J.M.; Magdelenat, H.

    1994-09-01

    Total-body irradiation (TBI) induces an increase in levels of granulocytes and cortisol in blood. To explore the underlying mechanisms, we studied 26 patients who had TBI prior to bone marrow transplantation. Our findings suggest that only a high dose of TBI (10 Gy) was capable of activating the hypothalamopituitary area since corticotropin-releasing factor and blood adrenocorticotropic hormone levels increased at the end of the TBI. There was a concomitant increase in the levels of interleukin 6 and tumor necrosis factor in blood, suggesting that these cytokines might activate the hypothalamo-pituitary adrenal axis. Interleukin 1 was not detected. Since vascular injury is a common after radiation treatment, it is possible that interleukin 6 was secreted by endothelial cells. The exact mechanisms of the production of cyctokines induced by ionizing radiation remain to be determined. 25 refs., 1 fig.

  13. Concentrations of the adrenocorticotropic hormone, corticosterone and sex steroid hormones and the expression of the androgen receptor in the pituitary and adrenal glands of male turkeys (Meleagris gallopavo) during growth and development.

    PubMed

    Kiezun, J; Kaminska, B; Jankowski, J; Dusza, L

    2015-01-01

    Androgens take part in the regulation of puberty and promote growth and development. They play their biological role by binding to a specific androgen receptor (AR). The aim of this study was to evaluate the expression of AR mRNA and protein in the pituitary and adrenal glands, to localize AR protein in luteinizing hormone (LH)-producing pituitary and adrenocortical cells, to determine plasma concentrations of adrenocorticotropic hormone (ACTH) and corticosterone and the concentrations of corticosterone, testosterone (T), androstenedione (A4) and oestradiol (E2) in the adrenal glands of male turkeys at the age of 4, 8, 12, 16, 20, 24 and 28weeks. The concentrations of hormones and the expression of AR varied during development. The expression of AR mRNA and protein in pituitary increased during the growth. The increase of AR mRNA levels in pituitary occurred earlier than increase of AR protein. The percentage of pituitary cells expressing ARs in the population of LH-secreting cells increased in week 20. It suggests that AR expression in LH-producing pituitary cells is determined by the phase of development. The drop in adrenal AR mRNA and protein expression was accompanied by an increase in the concentrations of adrenal androgens. Those results could point to the presence of a compensatory mechanism that enables turkeys to avoid the potentially detrimental effects of high androgen concentrations. Our results will expand our knowledge of the role of steroids in the development of the reproductive system of turkeys from the first month of age until maturity.

  14. Concentrations of the adrenocorticotropic hormone, corticosterone and sex steroid hormones and the expression of the androgen receptor in the pituitary and adrenal glands of male turkeys (Meleagris gallopavo) during growth and development.

    PubMed

    Kiezun, J; Kaminska, B; Jankowski, J; Dusza, L

    2015-01-01

    Androgens take part in the regulation of puberty and promote growth and development. They play their biological role by binding to a specific androgen receptor (AR). The aim of this study was to evaluate the expression of AR mRNA and protein in the pituitary and adrenal glands, to localize AR protein in luteinizing hormone (LH)-producing pituitary and adrenocortical cells, to determine plasma concentrations of adrenocorticotropic hormone (ACTH) and corticosterone and the concentrations of corticosterone, testosterone (T), androstenedione (A4) and oestradiol (E2) in the adrenal glands of male turkeys at the age of 4, 8, 12, 16, 20, 24 and 28weeks. The concentrations of hormones and the expression of AR varied during development. The expression of AR mRNA and protein in pituitary increased during the growth. The increase of AR mRNA levels in pituitary occurred earlier than increase of AR protein. The percentage of pituitary cells expressing ARs in the population of LH-secreting cells increased in week 20. It suggests that AR expression in LH-producing pituitary cells is determined by the phase of development. The drop in adrenal AR mRNA and protein expression was accompanied by an increase in the concentrations of adrenal androgens. Those results could point to the presence of a compensatory mechanism that enables turkeys to avoid the potentially detrimental effects of high androgen concentrations. Our results will expand our knowledge of the role of steroids in the development of the reproductive system of turkeys from the first month of age until maturity. PMID:25776460

  15. Random Secretion of Growth Hormone in Humans

    NASA Astrophysics Data System (ADS)

    Prank, Klaus; Kloppstech, Mirko; Nowlan, Steven J.; Sejnowski, Terrence J.; Brabant, Georg

    1996-08-01

    In normal humans, growth hormone (GH) is secreted from a gland located adjacent to the brain (pituitary) into the blood in distinct pulses, but in patients bearing a tumor within the pituitary (acromegaly) GH is excessively secreted in an irregular manner. It has been hypothesized that GH secretion in the diseased state becomes random. This hypothesis is supported by demonstrating that GH secretion in patients with acromegaly cannot be distinguished from a variety of linear stochastic processes based on the predictability of the fluctuations of GH concentration in the bloodstream.

  16. Pre-emptive oral dexmethorphan reduces fentanyl-induced cough as well as immediate postoperative adrenocortico-tropic hormone and growth hormone level

    PubMed Central

    Mukherjee, Avik; Kundu, Asim Kumar; Ghosh, Sudipta; Choudhuri, Rajat; Bandopadhyay, Bijoy Kumar; Dasgupta, Sugata

    2011-01-01

    Background: Fentanyl-induced cough is not always benign and brief and can be remarkably troublesome, spasmodic, and explosive. Dextromethorphan, an opioid derivative with an antitussive action, may be effective in reducing the fentanyl-induced cough. Dextromethorphan, a N-methyl D aspartate receptor antagonist, may have some effect on diminishing the stress response to surgery. This study was undertaken to determine whether preoperative dextromethorphan could effectively attenuate its incidence, severity, and effect on postoperative stress hormone levels. Materials and Methods: Three hundred and twenty patients of American society of anesthesiologists I-II, aged 18–60 years, undergoing elective laparoscopic cholecystectomy or appendicectomy were randomly allocated into two groups (Group C, control; Group D, dextromethorphan) consisting of 160 patients each. Patients in Group D received dextromethorphan 40 mg orally and in Group C received placebo tablets 60 minutes before induction of anesthesia. The incidence of cough was recorded for 1 minute after fentanyl injection and graded as none (0), mild (1–2), moderate (3–5), and severe (>5 cough). Blood samples were collected for estimation of stress hormone levels before surgery and again at 1 hour and 24 hours postoperatively and compared. The appearance of adverse reactions was recorded. Results: The incidence of reflex fentanyl cough was lower in dextromethorphan group (3.9%) in comparison to placebo (59.8%). Five patients developed mild and one moderate cough in the dextromethorphan group. In the control group, 31 patients developed mild, 29 moderate, and 32 severe cough. The stress hormones were significantly higher at 1 hour and 24 hours postoperatively in both groups in comparison to its preoperative values. However, at 1 hour postoperatively, adrenocorticotropic hormone, epinephrine, and growth hormone values were significantly low in the dextromethorphan group (61.5 ± 21.1 pg/ ml, 142.1 ± 11.2 pg

  17. ACTH (Adrenocorticotropic Hormone) Test

    MedlinePlus

    ... disease , also called primary adrenal insufficiency: decreased cortisol production due to adrenal gland damage Secondary adrenal insufficiency: decreased cortisol production because of pituitary dysfunction Hypopituitarism : pituitary dysfunction or ...

  18. Transport mechanism of a new behaviorally highly potent adrenocorticotropic hormone (ACTH) analog, ebiratide, through the blood-brain barrier.

    PubMed

    Shimura, T; Tabata, S; Ohnishi, T; Terasaki, T; Tsuji, A

    1991-08-01

    The binding and internalization of a novel adrenocorticotropic hormone (ACTH) analog having a potent neuromodulating effect, ebiratide (H-Met(O2)-Glu-His-Phe-D-Lys-Phe-NH(CH2)8NH2), by isolated bovine brain capillaries, were examined. Metabolism of [5-125I-His]ebiratide occurred during a 30-min incubation with bovine brain capillaries at 37 degrees C. In the presence of 20 mM EDTA, added to inhibit this metabolism, the medium, after 30 min of incubation, contained 82.3 +/- 0.5% of the unchanged ebiratide. The total binding and acid-resistant binding of [125I]ebiratide increased with time and reached an equilibrium at about 15 min. The total binding and acid-resistant binding at 30 min (as the cell/medium ratios corrected with [14C]sucrose) were 13.07 +/- 0.86 and 5.00 +/- 0.18 microliters/mg of protein, respectively. The acid-resistant binding showed significant dependence on temperature and medium osmolarity. The [125I]ebiratide binding was significantly inhibited by dansylcadaverine, an endocytosis inhibitor. The saturable acid-resistant binding was obtained by the addition of unlabeled ebiratide (100 nM-5 mM), and the maximal internalization capacity (Bmax) at 30 min was 144.2 pmol/mg of protein, with the half-saturation constant (KD) of 62.1 microM. The nonsaturable acid-resistant binding [cell/medium ratio in the presence of the unlabeled compound (1 mM or more)] was 2.2 microliters/mg of protein. The acid-resistant binding was significantly inhibited by human ACTH, poly-L-lysine, protamine and E-2078, a basic peptide, but was not inhibited by poly-L-glutamate, insulin or transferrin. These results demonstrate that ebiratide is transported through the blood-brain barrier via a basic peptide-specific absorptive-mediated endocytosis.

  19. Efficacy of single serum cortisol reading obtained between 9 AM and 10 AM as an index of adrenal function in children treated with glucocorticoids or synthetic adrenocorticotropic hormone.

    PubMed

    Goto, Masahiro; Shibata, Nao; Hasegawa, Yukihiro

    2016-07-01

    To find a simple method to screen for iatrogenic childhood adrenal insufficiency, we retrospectively examined the results of CRH stimulation tests performed 212 times on 111 subjects (68 males; age at commencement of initial treatment ranged 0.0-19.8 yr; median age, 5.8 yr). Before the commencement of this study, 97 subjects had been treated with glucocorticoids and 14 subjects with West syndrome had been treated with synthetic adrenocorticotropic hormone. Duration of the primary treatment ranged from 15 to 2150 days. CRH stimulation tests were conducted between 09:00 AM and 10:00 AM and peak cortisol values less than 15 µg/dL were considered indicative of adrenal insufficiency. The receiver operating characteristic curve showed that the optimal basal serum cortisol cut-off values when screening for adrenal suppression ranged from 5.35 to 5.80 µg/dL depending on the primary disease. All subjects having a serum cortisol value of less than 2.3 µg/dL had insufficient adrenal function while all subjects having greater than 11 µg/dL had intact adrenal function. We concluded that single serum cortisol values obtained between 09:00 AM and 10:00 AM had the potential to serve as an index of adrenal function in children treated with glucocorticoids or synthetic adrenocorticotropic hormone. PMID:27507908

  20. Efficacy of single serum cortisol reading obtained between 9 AM and 10 AM as an index of adrenal function in children treated with glucocorticoids or synthetic adrenocorticotropic hormone

    PubMed Central

    Goto, Masahiro; Shibata, Nao; Hasegawa, Yukihiro

    2016-01-01

    Abstract. To find a simple method to screen for iatrogenic childhood adrenal insufficiency, we retrospectively examined the results of CRH stimulation tests performed 212 times on 111 subjects (68 males; age at commencement of initial treatment ranged 0.0–19.8 yr; median age, 5.8 yr). Before the commencement of this study, 97 subjects had been treated with glucocorticoids and 14 subjects with West syndrome had been treated with synthetic adrenocorticotropic hormone. Duration of the primary treatment ranged from 15 to 2150 days. CRH stimulation tests were conducted between 09:00 AM and 10:00 AM and peak cortisol values less than 15 µg/dL were considered indicative of adrenal insufficiency. The receiver operating characteristic curve showed that the optimal basal serum cortisol cut-off values when screening for adrenal suppression ranged from 5.35 to 5.80 µg/dL depending on the primary disease. All subjects having a serum cortisol value of less than 2.3 µg/dL had insufficient adrenal function while all subjects having greater than 11 µg/dL had intact adrenal function. We concluded that single serum cortisol values obtained between 09:00 AM and 10:00 AM had the potential to serve as an index of adrenal function in children treated with glucocorticoids or synthetic adrenocorticotropic hormone. PMID:27507908

  1. Profiling of adrenocorticotropic hormone and arginine vasopressin in human pituitary gland and tumor thin tissue sections using droplet-based liquid-microjunction surface-sampling-HPLC–ESI-MS–MS

    SciTech Connect

    Kertesz, Vilmos; Calligaris, David; Feldman, Daniel R.; Changelian, Armen; Laws, Edward R.; Santagata, Sandro; Agar, Nathalie Y. R.; Van Berkel, Gary J.

    2015-06-18

    Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections using a fully automated droplet-based liquid microjunction surface sampling-HPLC-ESI-MS/MS system for spatially resolved sampling, HPLC separation, and mass spectral detection. Excellent correlation was found between the protein distribution data obtained with this droplet-based liquid microjunction surface sampling-HPLC-ESI-MS/MS system and those data obtained with matrix assisted laser desorption ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland. AVP was most abundant in the posterior pituitary gland region (neurohypophysis) and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH secreting and non-secreting pituitary adenomas correlated with histopathological evaluation. ACTH was readily detected at significantly higher levels in regions of ACTH secreting adenomas and in normal anterior adenohypophysis compared to non-secreting adenoma and neurohypophysis. AVP was mostly detected in normal neurohypophysis as anticipated. This work demonstrates that a fully automated droplet-based liquid microjunction surface sampling system coupled to HPLC-ESI-MS/MS can be readily used for spatially resolved sampling, separation, detection, and semi-quantitation of physiologically-relevant peptide and protein hormones, such as AVP and ACTH, directly from human tissue. In addition, the relative simplicity, rapidity and specificity of the current methodology support the potential of this basic technology with further advancement for assisting surgical decision-making.

  2. Profiling of adrenocorticotropic hormone and arginine vasopressin in human pituitary gland and tumor thin tissue sections using droplet-based liquid-microjunction surface-sampling-HPLC–ESI-MS–MS

    DOE PAGES

    Kertesz, Vilmos; Calligaris, David; Feldman, Daniel R.; Changelian, Armen; Laws, Edward R.; Santagata, Sandro; Agar, Nathalie Y. R.; Van Berkel, Gary J.

    2015-06-18

    Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections using a fully automated droplet-based liquid microjunction surface sampling-HPLC-ESI-MS/MS system for spatially resolved sampling, HPLC separation, and mass spectral detection. Excellent correlation was found between the protein distribution data obtained with this droplet-based liquid microjunction surface sampling-HPLC-ESI-MS/MS system and those data obtained with matrix assisted laser desorption ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland.more » AVP was most abundant in the posterior pituitary gland region (neurohypophysis) and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH secreting and non-secreting pituitary adenomas correlated with histopathological evaluation. ACTH was readily detected at significantly higher levels in regions of ACTH secreting adenomas and in normal anterior adenohypophysis compared to non-secreting adenoma and neurohypophysis. AVP was mostly detected in normal neurohypophysis as anticipated. This work demonstrates that a fully automated droplet-based liquid microjunction surface sampling system coupled to HPLC-ESI-MS/MS can be readily used for spatially resolved sampling, separation, detection, and semi-quantitation of physiologically-relevant peptide and protein hormones, such as AVP and ACTH, directly from human tissue. In addition, the relative simplicity, rapidity and specificity of the current methodology support the potential of this basic technology with further advancement for assisting surgical decision-making.« less

  3. Effects of benzyl glucoside and chlorogenic acid from Prunus mume on adrenocorticotropic hormone (ACTH) and catecholamine levels in plasma of experimental menopausal model rats.

    PubMed

    Ina, Hiroji; Yamada, Kenji; Matsumoto, Kosai; Miyazaki, Toshio

    2004-01-01

    To investigate the effectiveness of benzyl beta-D-glucopyranoside (BG) and chlorogenic acid (CA), the constituents of the fruit of Prunus mume, for relieving tension in experimental menopausal model rats (M-rats) caused by ether stress, the effects of BG and CA on adrenocorticotropic hormone (ACTH) and catecholamine (adrenaline, noradrenaline, and dopamine) levels were examined in the plasma of M-rats. Caffeic acid, quinic acid, and rosmarinic acid, which are compounds structurally related to CA, were also examined. BG obviously recovered catecholamine levels decreased by ether stress and increased dopamine to high levels. On the other hand, CA significantly decreased the ACTH level increased by ether stress and showed the greatest effect of all compounds. These results suggest that BG and CA may contribute to relieving the tension in M-rats caused by ether stress.

  4. Pharmacological regulation of parathyroid hormone secretion.

    PubMed

    Nemeth, E F

    2002-01-01

    Parathyroid hormone (PTH) is the key endocrine factor regulating systemic Ca(2+) homeostasis. Elevated levels of circulating PTH increase bone turnover and, depending on the duration of elevation, will result in net anabolic or catabolic effects on the skeleton. Secretion of PTH from the parathyroid glands is regulated by small changes in circulating levels of Ca(2+) which are detected by a Ca(2+) receptor on the surface of parathyroid cells. This G protein-coupled receptor is the primary molecular entity used by parathyroid cells to regulate secretion of PTH. As such, the Ca(2+) receptor is a unique molecular target for new drugs capable of increasing or decreasing circulating levels of PTH. Compounds which activate the Ca(2+) receptor are termed calcimimetics and they inhibit the secretion of PTH; a calcimimetic compound is in late stage clinical trials for the treatment of both primary and secondary hyperparathyroidism. Conversely, calcilytic compounds, which are Ca(2+) receptor antagonists, stimulate secretion of PTH; a calcilytic compound is in early clinical development for the treatment of osteoporosis. PMID:12171519

  5. CXCL10/CXCR3 signaling mediates inhibitory action by interferon-gamma on CRF-stimulated adrenocorticotropic hormone (ACTH) release.

    PubMed

    Horiguchi, Kotaro; Fujiwara, Ken; Tsukada, Takehiro; Yoshida, Saishu; Higuchi, Masashi; Tateno, Kozue; Hasegawa, Rumi; Takigami, Shu; Ohsako, Shunji; Yashiro, Takashi; Kato, Takako; Kato, Yukio

    2016-05-01

    Secretion of hormones by the anterior pituitary gland can be stimulated or inhibited by paracrine factors that are produced during inflammatory reactions. The inflammation cytokine interferon-gamma (IFN-γ) is known to inhibit corticotropin-releasing factor (CRF)-stimulated adrenocorticotropin (ACTH) release but its signaling mechanism is not yet known. Using rat anterior pituitary, we previously demonstrated that the CXC chemokine ligand 10 (CXCL10), known as interferon-γ (IFN-γ) inducible protein 10 kDa, is expressed in dendritic cell-like S100β protein-positive (DC-like S100β-positive) cells and that its receptor CXCR3 is expressed in ACTH-producing cells. DC-like S100β-positive cells are a subpopulation of folliculo-stellate cells in the anterior pituitary. In the present study, we examine whether CXCL10/CXCR3 signaling between DC-like S100β-positive cells and ACTH-producing cells mediates inhibition of CRF-activated ACTH-release by IFN-γ, using a CXCR3 antagonist in the primary pituitary cell culture. We found that IFN-γ up-regulated Cxcl10 expression via JAK/STAT signaling and proopiomelanocortin (Pomc) expression, while we reconfirmed that IFN-γ inhibits CRF-stimulated ACTH-release. Next, we used a CXCR3 agonist in primary culture to analyze whether CXCL10 induces Pomc-expression and ACTH-release using a CXCR3 agonist in the primary culture. The CXCR3 agonist significantly stimulated Pomc-expression and inhibited CRF-induced ACTH-release, while ACTH-release in the absence of CRF did not change. Thus, the present study leads us to an assumption that CXCL10/CXCR3 signaling mediates inhibition of the CRF-stimulated ACTH-release by IFN-γ. Our findings bring us to an assumption that CXCL10 from DC-like S100β-positive cells acts as a local modulator of ACTH-release during inflammation.

  6. Sellar gangliocytoma with adrenocorticotropic and prolactin adenoma.

    PubMed

    Kissiedu, Juliana O; Prayson, Richard A

    2016-02-01

    We report a case of a 60-year-old man who presented with weight gain, headaches, dizziness, erectile dysfunction and decreased libido. He was found to have elevated adrenocorticotropic hormone (ACTH) and prolactin serum levels. The imaging studies revealed a 1.4 cm sella/suprasellar mass which was compressing the optic chiasm. Histologic slides of the lesion showed a pituitary adenoma, marked by a proliferation of biphenotypic appearing cells, associated with a gangliocytoma, and marked by a proliferation of atypical appearing neuronal cells arranged against a glial-appearing background. Pituitary adenoma-gangliocytomas are benign combination tumors that rarely occur in the sellar region. Adenomas in this setting are sometimes functional, and rare patients with mixed adenomas (adenomas secreting more than one hormone) have been reported. To our knowledge, there has been only one other report of a combined ACTH and prolactin-producing adenoma with gangliocytoma, reported in a patient who also had acromegaly. In our patient, the immunohistochemical stains demonstrated that the bulk of the adenoma cells stained with prolactin antibody, and scattered clusters of cells within the adenoma stained positively for ACTH. The adenoma did not stain with antibodies to any of the other anterior pituitary hormones. Postoperatively, the elevated prolactin and ACTH levels returned to normal levels and there was no evidence of residual tumor. Adequate sampling and immunohistochemistry are important in rendering a correct diagnosis and in identifying the hormone status of mixed adenoma-gangliocytomas.

  7. Sellar gangliocytoma with adrenocorticotropic and prolactin adenoma.

    PubMed

    Kissiedu, Juliana O; Prayson, Richard A

    2016-02-01

    We report a case of a 60-year-old man who presented with weight gain, headaches, dizziness, erectile dysfunction and decreased libido. He was found to have elevated adrenocorticotropic hormone (ACTH) and prolactin serum levels. The imaging studies revealed a 1.4 cm sella/suprasellar mass which was compressing the optic chiasm. Histologic slides of the lesion showed a pituitary adenoma, marked by a proliferation of biphenotypic appearing cells, associated with a gangliocytoma, and marked by a proliferation of atypical appearing neuronal cells arranged against a glial-appearing background. Pituitary adenoma-gangliocytomas are benign combination tumors that rarely occur in the sellar region. Adenomas in this setting are sometimes functional, and rare patients with mixed adenomas (adenomas secreting more than one hormone) have been reported. To our knowledge, there has been only one other report of a combined ACTH and prolactin-producing adenoma with gangliocytoma, reported in a patient who also had acromegaly. In our patient, the immunohistochemical stains demonstrated that the bulk of the adenoma cells stained with prolactin antibody, and scattered clusters of cells within the adenoma stained positively for ACTH. The adenoma did not stain with antibodies to any of the other anterior pituitary hormones. Postoperatively, the elevated prolactin and ACTH levels returned to normal levels and there was no evidence of residual tumor. Adequate sampling and immunohistochemistry are important in rendering a correct diagnosis and in identifying the hormone status of mixed adenoma-gangliocytomas. PMID:26314658

  8. Skin manifestations of hormone-secreting tumors.

    PubMed

    Jabbour, Serge A

    2010-01-01

    Endocrine and metabolic diseases, besides affecting other organs, can result in changes in cutaneous function and morphology and can lead to a complex symptomatology. Dermatologists may see some of these skin lesions first, either before the endocrinologist, or even after the internist or specialist has missed the right diagnosis. Because some skin lesions might reflect a life-threatening endocrine or metabolic disorder, identifying the underlying disorder is very important, so that patients can receive corrective rather than symptomatic treatment. In this issue, we will review various hormone-secreting tumors, including pituitary disorders (Cushing's syndrome and acromegaly), hyperthyroidism, glucagonoma, carcinoid syndrome, mastocytosis, and hyperandrogenism. We will focus on clinical manifestations, mainly cutaneous, followed by a brief discussion on how to make the diagnosis of each condition in addition to treatment options. PMID:21054708

  9. Seasonal and sex differences in responsiveness to adrenocorticotropic hormone contribute to stress response plasticity in red-sided garter snakes (Thamnophis sirtalis parietalis).

    PubMed

    Dayger, Catherine A; Lutterschmidt, Deborah I

    2016-04-01

    As in many vertebrates, hormonal responses to stress vary seasonally in red-sided garter snakes (Thamnophis sirtalis parietalis). For example, males generally exhibit reduced glucocorticoid responses to a standard stressor during the spring mating season. We asked whether variation in adrenal sensitivity to adrenocorticotropic hormone (ACTH) explains why glucocorticoid responses to capture stress vary with sex, season and body condition in red-sided garter snakes. We measured glucocorticoids at 0, 1 and 4 h after injection with ACTH (0.1 IU g(-1)body mass) or vehicle in males and females during the spring mating season and autumn pre-hibernation period. Because elevated glucocorticoids can influence sex steroids, we also examined androgen and estradiol responses to ACTH. ACTH treatment increased glucocorticoids in both sexes and seasons. Spring-collected males had a smaller integrated glucocorticoid response to ACTH than autumn-collected males. The integrated glucocorticoid response to ACTH differed with sex during the spring, with males having a smaller glucocorticoid response than females. Although integrated glucocorticoid responses to ACTH did not vary with body condition, we observed an interaction among season, sex and body condition. In males, ACTH treatment did not alter androgen levels in either season, but androgen levels decreased during the sampling period. Similar to previous studies, plasma estradiol was low or undetectable during the spring and autumn, and therefore any effect of ACTH treatment on estradiol could not be determined. These data provide support for a mechanism that partly explains how the hypothalamus-pituitary-adrenal (HPA) axis integrates information about season, sex and body condition: namely, variation in adrenal responsiveness to ACTH. PMID:26896543

  10. Blood plasma collected after adrenocorticotropic hormone administration during the preovulatory period in the sow negatively affects in vitro fertilization by disturbing spermatozoa function.

    PubMed

    González, R; Kumaresan, A; Bergqvist, A S; Sjunnesson, Y C B

    2015-04-15

    Successful fertilization is essential for reproduction and might be negatively affected by stressful events, which could alter the environment where fertilization occurs. The aim of the study was to determine whether an altered hormonal profile in blood plasma caused by adrenocorticotropic hormone (ACTH) administration could affect in vitro fertilization in the pig model. In experiment 1, gametes were exposed for 24 hours to plasma from ACTH-treated, non-ACTH-treated sows, or medium with BSA. Fertilization, cleavage, and blastocyst rates were lower in the ACTH group compared with the no ACTH or BSA control groups (P < 0.01). In experiment 2, the exposure of matured oocytes for 1 hour before fertilization to the same treatments did not have an impact on their ability to undergo fertilization or on embryo development. In experiment 3, spermatozoa were incubated for 0, 1, 4, and 24 hours under the same conditions. There was no effect of treatment on sperm viability. The percentage of acrosome-reacted spermatozoa remained higher in the ACTH group compared with the non-ACTH-treated group through the incubation period (P < 0.001). Protein tyrosine phosphorylation (PTP) patterns were also affected by treatment (P < 0.001). The presence of an atypical PTP pattern was higher in the ACTH group at all the analyzed time points compared with the BSA and no ACTH groups (P < 0.001). In conclusion, this altered environment may not affect oocyte competence but might affect the sperm fertilizing ability through alterations in the acrosome reaction and correct sequence of PTP patterns.

  11. Evaluation of Basal Serum Adrenocorticotropic Hormone and Cortisol Levels and Their Relationship with Nonalcoholic Fatty Liver Disease in Male Patients with Idiopathic Hypogonadotropic Hypogonadism

    PubMed Central

    Wang, Wen-Bo; She, Fei; Xie, Li-Fang; Yan, Wen-Hua; Ouyang, Jin-Zhi; Wang, Bao-An; Ma, Hang-Yun; Zang, Li; Mu, Yi-Ming

    2016-01-01

    Background: Prolonged gonadal hormone deficiency in patients with idiopathic hypogonadotropic hypogonadism (IHH) may produce adverse effects on the endocrine homeostasis and metabolism. This study aimed to compare basal serum adrenocorticotropic hormone (ACTH) and cortisol levels between male IHH patients and healthy controls. Moreover, this study compared the basal hypothalamic-pituitary-adrenal (HPA) axis in patients with and without nonalcoholic fatty liver disease (NAFLD), and also evaluated the relationship between basal HPA axis and NAFLD in male IHH patients. Methods: This was a retrospective case-control study involving 75 Chinese male IHH patients (mean age 21.4 ± 3.8 years, range 17–30 years) and 135 healthy controls after matching for gender and age. All subjects underwent physical examination and blood testing for serum testosterone, luteinizing hormone, follicle-stimulating hormone, ACTH, and cortisol and biochemical tests. Results: Higher basal serum ACTH levels (8.25 ± 3.78 pmol/L vs. 6.97 ± 2.81 pmol/L) and lower cortisol levels (366.70 ± 142.48 nmol/L vs. 452.82 ± 141.53 nmol/L) were observed in male IHH patients than healthy subjects (all P <0.05). IHH patients also showed higher metabolism parameters and higher prevalence rate of NAFLD (34.9% vs. 4.4%) than the controls (all P < 0.05). Basal serum ACTH (9.91 ± 4.98 pmol/L vs. 7.60 ± 2.96 pmol/L) and dehydroepiandrosterone sulfate (2123.7 ± 925.8 μg/L vs. 1417.1 ± 498.4 μg/L) levels were significantly higher in IHH patients with NAFLD than those without NAFLD (all P < 0.05). We also found that basal serum ACTH levels were positively correlated with NAFLD (r = 0.289, P <0.05) and triglyceride levels (r = 0.268, P < 0.05) in male IHH patients. Furthermore, NAFLD was independently associated with ACTH levels in male IHH patients by multiple linear regression analysis. Conclusions: The male IHH patients showed higher basal serum ACTH levels and lower cortisol levels than matched healthy

  12. Repeated administrations of adrenocorticotropic hormone during late gestation in pigs: maternal cortisol response and effects on fetal HPA axis and brain neurotransmitter systems.

    PubMed

    Otten, W; Kanitz, E; Tuchscherer, M; Brüssow, K-P; Nürnberg, G

    2008-02-01

    The present study examined the effects of repeated adrenocorticotropic hormone (ACTH) administrations to sows during late gestation on hypothalamic-pituitary-adrenocortical (HPA) axis and brain neurotransmitter systems in their fetuses. ACTH (100 IU per animal, Synacthen Depot, n=6) or saline (n=5) was administered intramuscularly to sows every 2nd day from gestational day (GD) 85 to GD 101. Blood samples were taken from sows repeatedly within 12h after ACTH application on GD 85 and GD 101. On GD 105, fetuses were recovered under general anaesthesia for the collection of blood and brain samples. Plasma cortisol concentrations in sows increased significantly within 2h after ACTH application and returned to control levels after 10h post-application, showing a similar response at the beginning and at the end of the 16-day stimulation period. On GD 101, a significant increase of plasma glucose and insulin concentrations was found in sows after administration of ACTH and after a following feeding time. Number and body weight of fetuses were not affected by the maternal ACTH treatment. Cortisol concentrations in the umbilical vein were significantly decreased in fetuses from ACTH sows and a similar trend was observed in the umbilical artery and in the vena cava cranialis. Glucocorticoid receptor (GR) binding in hippocampus and hypothalamus did not differ between treatments. However, in hippocampus, serotonergic activity was increased in fetuses from ACTH-treated mothers as shown by significantly elevated 5-hydroxytryptamine (5-HT) levels. In conclusion, repeated administrations of ACTH during late gestation resulted in a reproducible cortisol response of sows and reduced cortisol concentrations in the fetal umbilical vein after the treatment period. Although the number of sows used in this experiment was low and differences between treatments were limited these findings indicate that excessive glucocorticoid exposure during gestation alters serotonergic activity in

  13. [Glutamate neurotransmission, stress and hormone secretion].

    PubMed

    Jezová, D; Juránková, E; Vigas, M

    1995-11-01

    Glutamate neurotransmission has been investigated in relation to several physiological processes (learning, memory) as well as to neurodegenerative and other disorders. Little attention has been paid to its involvement in neuroendocrine response during stress. Penetration of excitatory amino acids from blood to the brain is limited by the blood-brain barrier. As a consequence, several toxic effects but also bioavailability for therapeutic purposes are reduced. A free access to circulating glutamate is possible only in brain structures lacking the blood-brain barrier or under conditions of its increased permeability. Excitatory amino acids were shown to stimulate the pituitary hormone release, though the mechanism of their action is still not fully understood. Stress exposure in experimental animals induced specific changes in mRNA levels coding the glutamate receptor subunits in the hippocampus and hypothalamus. The results obtained with the use of glutamate receptor antagonists indicate that a number of specific receptor subtypes contribute to the stimulation of ACTH release during stress. The authors provided also data on the role of NMDA receptors in the control of catecholamine release, particularly in stress-induced secretion of epinephrine. These results were the first piece of evidence on the involvement of endogenous excitatory amino acids in neuroendocrine activation during stress. Neurotoxic effects of glutamate in animals are well described, especially after its administration in the neonatal period. In men, glutamate toxicity and its use as a food additive are a continuous subject of discussions. The authors found an increase in plasma cortisol and norepinephrine, but not epinephrine and prolactin, in response to the administration of a high dose of glutamate. It cannot be excluded that these effects might be induced even by lower doses in situations with increased vulnerability to glutamate action (age, individual variability). (Tab. 1, Fig. 6, Ref. 44

  14. In-vivo blood-brain barrier transport of a novel adrenocorticotropic hormone analogue, ebiratide, demonstrated by brain microdialysis and capillary depletion methods.

    PubMed

    Shimura, T; Tabata, S; Terasaki, T; Deguchi, Y; Tsuji, A

    1992-07-01

    The transport of ebiratide, a novel adrenocorticotropic hormone (ACTH) analogue, [H-Met-(O2)-Glu-His-Phe-D-Lys-Phe-NH(CH2)8-NH2], through the blood-brain barrier was directly demonstrated in-vivo. [125I]Ebiratide (16.9 MBq mL-1) or [14C]sucrose (29.2 MBq mL-1) known to be restrictively transported through the blood-brain barrier was infused into the rat internal carotid artery at a flow rate of 50 microL min-1 for 10 min, and after 15 min infusion the distribution volume of each compound in the brain parenchyma was determined by the capillary depletion method. The distribution volume of [125I]ebiratide was 167.8 +/- 62.2 microL (g brain)-1, which was about seven times higher than that of [14C]sucrose (24.9 +/- 4.0 microL g brain)-1, indicating the uptake of ebiratide into brain parenchymal cells. During the infusion into the internal carotid artery, brain microdialysis was simultaneously performed to directly collect the brain interstitial fluid as the dialysate. Radioactivity was detected in the dialysate during the [125I]ebiratide infusion and HPLC analysis of the dialysate revealed that the intact ebiratide accounted for greater than or equal to 80% total radioactivity. The concentrations of [125I]ebiratide and [14C]sucrose in the brain interstitial fluid were estimated based on the relative recovery obtained in the in-vitro recovery study. The brain interstitial fluid/internal carotid arterial blood concentration ratio for [125I]ebiratide was determined to be 1.47 x 10(-2) +/- 0.17 x 10(-2) and was about eight times higher than that for [14C]sucrose (1.92 x 10(-3) +/- 0.36 x 10(-3)), indicating significant transport of ebiratide to the brain interstitial fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. High-end normal adrenocorticotropic hormone and cortisol levels are associated with specific cardiovascular risk factors in pediatric obesity: a cross-sectional study

    PubMed Central

    2013-01-01

    Background The hypothalamic-pituitary-adrenal (HPA) axis, and in particular cortisol, has been reported to be involved in obesity-associated metabolic disturbances in adults and in selected populations of adolescents. The aim of this study was to investigate the association between morning adrenocorticotropic hormone (ACTH) and cortisol levels and cardiovascular risk factors in overweight or obese Caucasian children and adolescents. Methods This cross-sectional study of 450 obese children and adolescents (aged 4 to 18 years) was performed in a tertiary referral center. ACTH, cortisol, cardiovascular risk factors (fasting and post-challenge glucose, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, and hypertension) and insulin resistance were evaluated. All analyses were corrected for confounding factors (sex, age, puberty, body mass index), and odds ratios were determined. Results ACTH and cortisol levels were positively associated with systolic and diastolic blood pressure, triglycerides, fasting glucose and insulin resistance. Cortisol, but not ACTH, was also positively associated with LDL-cholesterol. When adjusted for confounding factors, an association between ACTH and 2 h post-oral glucose tolerance test glucose was revealed. After stratification according to cardiovascular risk factors and adjustment for possible confounding factors, ACTH levels were significantly higher in subjects with triglycerides ≥90th percentile (P <0.02) and impaired fasting glucose or glucose tolerance (P <0.001). Higher cortisol levels were found in subjects with blood pressure ≥95th percentile and LDL-cholesterol ≥90th percentile. Overall, the highest tertiles of ACTH (>5.92 pmol/l) and cortisol (>383.5 nmol/l) although within the normal range were associated with increases in cardiovascular risk factors in this population. Conclusions In obese children and adolescents, high morning ACTH and cortisol levels are associated

  16. Nonlinear analysis and prediction of pulsatile hormone secretion

    SciTech Connect

    Prank, K. |; Kloppstech, M.; Nowlan, S.J.; Harms, H.M.; Brabant, G.; Hesch, R.; Sejnowski, T.J.

    1996-06-01

    Pulsatile hormone secretion is observed in almost every hormonal system. The frequency of episodic hormone release ranges from approximately 10 to 100 pulses in 24 hours. This temporal mode of secretion is an important feature of intercellular information transfer in addition to a dose-response dependent regulation. It has been demonstrated in a number of experiments that changes in the temporal pattern of pulsatile hormone secretion specifically regulate cellular and organ function and structure. Recent evidence links osteoporosis, a disease characterized by loss of bone mass and structure, to changes in the dynamics of pulsatile parathyroid hormone (PTH) secretion. In our study we applied nonlinear and linear time series prediction to characterize the secretory dynamics of PTH in both healthy human subjects and patients with osteoporosis. Osteoporotic patients appear to lack periods of high predictability found in normal humans. In contrast to patients with osteoporosis patients with hyperparathyroidism, a condition which despite sometimes reduced bone mass has a preserved bone architecture, show periods of high predictability of PTH secretion. Using stochastic surrogate data sets which match certain statistical properties of the original time series significant nonlinear determinism could be found for the PTH time series of a group of healthy subjects. Using classical nonlinear analytical techniques we could demonstrate that the irregular pattern of pulsatile PTH secretion in healthy men exhibits characteristics of deterministic chaos. Pulsatile secretion of PTH in healthy subjects seems to be a first example of nonlinear determinism in an apparently irregular hormonal rhythm in human physiology. {copyright} {ital 1996 American Institute of Physics.}

  17. Regulation of human growth hormone secretion and its disorders.

    PubMed

    Kato, Yuzuru; Murakami, Yoshio; Sohmiya, Motoi; Nishiki, Masateru

    2002-01-01

    Growth hormone (GH) secretion from anterior pituitary is regulated by the hypothalamus and the mediators of GH actions. Major regulatory factors include GH releasing hormone (GHRH), somatostatin (SRIF), GH releasing peptide (ghrerin) and insulin-like growth factor (IGF-I). The principal physiological regulation mechanisms of GH secretion are neural endogenous rhythm, sleep, stress, exercise, and nutritional and metabolic signals. GH deficiency results from various hereditary or acquired causes, which may be isolated or combined with other pituitary hormone deficiencies. GH deficiency can be treated with recombinant human GH, which results in accelerating growth in children and normalization of intermediary metabolism in adults. GH hypersecretion mostly results from a pituitary tumor and causes acromegaly or gigantism. Hypersecretion of GH can be treated by transshenoidal surgery. Medical treatment with octreotide and analogs is also effective to reduce GH secretion in combination with or without the surgery. PMID:11838603

  18. [Pituitary hormone secretion induced by optokinetic stimulation (author's transl)].

    PubMed

    Mang, W L; Scherer, H; Eversmann, T; Gottsmann, M

    1978-08-01

    A slight optokinetic stimulation induces a significant increase of serum levels of antidiuretic hormone 1,1 +/- 0.8 pg/ml (mean +/- SD) to 3,3 +/- 1,9 pg/ml (mean +/- SD). Serum levels of gGH and cortisol remain unchanged, whereas serum prolactin levels decrease slightly. The ADH secretion seems to be the most sensitive hormonal parameter of the stimulation of the vestibular nuclei induced either by the optokinetic stimulation or by the Coriolis effect.

  19. Control of Pituitary Thyroid-stimulating Hormone Synthesis and Secretion by Thyroid Hormones during Xenopus Metamorphosis

    EPA Science Inventory

    Serum thyroid hormone (TH) concentrations in anuran larvae rise rapidly during metamorphosis. Such a rise in an adult anuran would inevitably trigger a negative feedback response resulting in decreased synthesis and secretion of thyroid-stimulating hormone (TSH) by the pituitary....

  20. Silent pituitary macroadenoma co-secreting growth hormone and thyroid stimulating hormone.

    PubMed

    Sen, Orhan; Ertorer, M Eda; Aydin, M Volkan; Erdogan, Bulent; Altinors, Nur; Zorludemir, Suzan; Guvener, Nilgun

    2005-04-01

    Silent pituitary adenomas are a group of tumors showing heterogenous morphological features with no hormonal function observed clinically. To date no explanation has been provided as to why these tumors remain "silent". We report a case of a silent macroadenoma with both growth hormone (GH) and thyroid stimulating hormone (TSH) staining and secretion but with no clinical manifestations, in particular, the absence of features of acromegaly or hyperthyroidism. The relevant literature is reviewed. PMID:15851094

  1. Purification and cultivation of human pituitary growth hormone secreting cells

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.

    1978-01-01

    The maintainance of actively secreting human pituitary growth hormone cells (somatotrophs) in vitro was studied. The primary approach was the testing of agents which may be expected to increase the release of the human growth hormone (hGH). A procedure for tissue procurement is described along with the methodologies used to dissociate human pituitary tissue (obtained either at autopsy or surgery) into single cell suspensions. The validity of the Biogel cell column perfusion system for studying the dynamics of GH release was developed and documented using a rat pituitary cell system.

  2. Purification and cultivation of human pituitary growth hormone secreting cells

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.

    1979-01-01

    Efforts were directed towards maintenance of actively secreting human pituitary growth hormone cells (somatotrophs) in vitro. The production of human growth hormone (hGH) by this means would be of benefit for the treatment of certain human hypopituitary diseases such as dwarfism. One of the primary approaches was the testing of agents which may logically be expected to increase hGH release. The progress towards this goal is summarized. Results from preliminary experiments dealing with electrophoresis of pituitary cell for the purpose of somatotroph separation are described.

  3. Oncological emergencies: syndrome of inappropriate antidiuretic hormone secretion (SIADH).

    PubMed

    Matwiejczuk, Sylwester; Püsküllüoğlu, Miroslawa; Zygulska, Aneta L

    2014-01-01

    Excessive secretion of vasopressin in the course of Syndrome of Inappropriate Antidiuretic Hormone Secretion is a common cause of hyponatremia in cancer patients. Clinical symptoms depend on the cause, rate of change of sodium level and their absolute values. Treatment options include fluid restrictions, intravenous administration of hypertonic sodium chloride solutions, loop diuretics and vaptans. The sodium level should not be adjusted too fast, because it may lead to irreversible brain damage. The article presents pathophysiology, diagnostics and recommendations of management of this oncological emergency.

  4. Vesicle-Mediated Steroid Hormone Secretion in Drosophila melanogaster.

    PubMed

    Yamanaka, Naoki; Marqués, Guillermo; O'Connor, Michael B

    2015-11-01

    Steroid hormones are a large family of cholesterol derivatives regulating development and physiology in both the animal and plant kingdoms, but little is known concerning mechanisms of their secretion from steroidogenic tissues. Here, we present evidence that in Drosophila, endocrine release of the steroid hormone ecdysone is mediated through a regulated vesicular trafficking mechanism. Inhibition of calcium signaling in the steroidogenic prothoracic gland results in the accumulation of unreleased ecdysone, and the knockdown of calcium-mediated vesicle exocytosis components in the gland caused developmental defects due to deficiency of ecdysone. Accumulation of synaptotagmin-labeled vesicles in the gland is observed when calcium signaling is disrupted, and these vesicles contain an ABC transporter that functions as an ecdysone pump to fill vesicles. We propose that trafficking of steroid hormones out of endocrine cells is not always through a simple diffusion mechanism as presently thought, but instead can involve a regulated vesicle-mediated release process. PMID:26544939

  5. Effects of hypothalamic dopamine on growth hormone-releasing hormone-induced growth hormone secretion and thyrotropin-releasing hormone-induced prolactin secretion in goats.

    PubMed

    Jin, Jin; Hashizume, Tsutomu

    2015-06-01

    The aim of the present study was to clarify the effects of hypothalamic dopamine (DA) on the secretion of growth hormone (GH) in goats. The GH-releasing response to an intravenous (i.v.) injection of GH-releasing hormone (GHRH, 0.25 μg/kg body weight (BW)) was examined after treatments to augment central DA using carbidopa (carbi, 1 mg/kg BW) and L-dopa (1 mg/kg BW) in male and female goats under a 16-h photoperiod (16 h light, 8 h dark) condition. GHRH significantly and rapidly stimulated the release of GH after its i.v. administration to goats (P < 0.05). The carbi and L-dopa treatments completely suppressed GH-releasing responses to GHRH in both male and female goats (P < 0.05). The prolactin (PRL)-releasing response to an i.v. injection of thyrotropin-releasing hormone (TRH, 1 μg/kg BW) was additionally examined in male goats in this study to confirm modifications to central DA concentrations. The treatments with carbi and L-dopa significantly reduced TRH-induced PRL release in goats (P < 0.05). These results demonstrated that hypothalamic DA was involved in the regulatory mechanisms of GH, as well as PRL secretion in goats.

  6. Episodic leptin release is independent of luteinizing hormone secretion.

    PubMed

    Sir-Petermann, T; Maliqueo, M; Palomino, A; Vantman, D; Recabarren, S E; Wildt, L

    1999-11-01

    Several studies suggest that leptin modulates hypothalamic-pituitary-gonadal axis functions. Leptin may stimulate release of gonadotrophin releasing hormone (GnRH) from the hypothalamus and of gonadotrophins from the pituitary. A synchronicity of luteinizing hormone (LH) and leptin pulses has been described in healthy women and in patients with polycystic ovarian syndrome, suggesting that leptin may modulate the episodic secretion of LH. However, it has not been established whether LH regulates the episodic secretion of leptin. To further examine LH-leptin interactions, we studied the episodic fluctuations of circulating LH and leptin in two patients with Kallmann's syndrome (KS) before and on day 7 of pulsatile GnRH administration, and compared these with those observed in the early follicular phase of 10 regularly menstruating women divided into two control groups according to the body mass index of each patient. To assess episodic hormone secretion, blood samples were collected at 10 min intervals for 6 h, before and on day 7 of GnRH administration in KS patients, and during days 3-7 of the follicular phase in normally cycling women. LH and leptin concentrations were measured in all samples. For pulse analysis, the cluster algorithm was used. Before treatment, an apulsatile pattern with no endogenous LH pulsations was observed in both KS patients. However, leptin pulses were assessed in both women. During GnRH administration, pulsatile LH activity was achieved in both patients with pulse characteristics similar to those of the respective control group. Serum leptin concentrations and leptin pulsatile patterns were not modified. These results suggest that circulating leptin is probably not modulated by pulsatile GnRH-LH secretion.

  7. Neuroendocrine regulation of thyroid-stimulating hormone secretion in amphibians.

    PubMed

    Okada, Reiko; Kobayashi, Tetsuya; Yamamoto, Kazutoshi; Nakakura, Takashi; Tanaka, Shigeyasu; Vaudry, Hubert; Kikuyama, Sakae

    2009-04-01

    The hypothalamic peptides thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH), and corticotropin-releasing factor (CRF), which have been postulated as acting as thyroid-stimulating hormone (TSH)-releasing hormone in amphibians, were tested for their activity by employing a recently developed radioimmunoassay for bullfrog (Rana catesbeiana) TSH. CRF markedly stimulated the release of TSH from both adult and larval bullfrog pituitary cells. Both TRH and GnRH moderately stimulated the release of TSH from adult pituitary cells but not from larval ones. The release of TSH was also enhanced by bullfrog hypothalamic extracts. The hypothalamic extract-evoked release of TSH was markedly reduced by a CRF receptor antagonist, suggesting that CRF and/or CRF-related peptides are the main TSH-releasing factors occurring in the bullfrog hypothalamus. Experiments using CRF receptor agonists and antagonists revealed that CRF acts through the type 2 receptor. With regard to other hypothalamic substances that influence the release of TSH, pituitary adenylate cyclase-activating polypeptide and vasoactive intestinal polypeptide were found to be potent stimulators and somatostatin an inhibitor of TSH release. Thus, it becomes clear that the main regulatory peptides controlling TSH secretion in amphibians are different from those in mammals. Triiodothyronine did not affect the basal release of TSH from the pituitary of either larval or adult bullfrogs but suppressed the CRF-induced release of TSH, suggesting that negative feedback by thyroid hormone is functioning both in larvae and adults.

  8. Influence of prostaglandins and thyrotropin releasing hormone (TRH) on hormone secretion and growth in wether lambs.

    PubMed

    Davis, S L; Anfinson, M S; Klindt, J; Ohlson, D L

    1977-06-01

    A series of experiments were conducted in ewes and whether (castrate male) lambs to evaluate the influence of prostaglandins on secretion of anabolic hormones and to determine if repeated injections of prostaglandin (PG) F2alpha would chronically influence the secretion of these hormones and perhaps growth rate as well. A single intravenous injection of PGA1 and PGB1 (100 microgram/kg) exerted no significant (P greater than .10) influence on plasma concentrations of prolactin (PRL), growth hormone (GH) or thyrotropin (TSH) in ewes. PGA1, but not PGB1, stimulated an increase in the plasma concentration of insulin. Infusion of PGF2alpha for 5.5 hr into ewes resulted in increased (P less than .05) plasma concentrations of both GH and ARL while TSH and insulin were not significantly influenced. Prostaglandin F2alpha, when injected subcutaneously into wether lambs (10 mg twice weekly) stimulated (P less than .05) plasma GH concentrations after the first injection, but not after 3 weeks of treatment. Changes in plasma PRL or TSH were not observed consistently in the lambs treated chronically with PGF2alpha or TRH. Prostaglandin F2alpha, in the present studies, and PGE1 in previously reported studies (1-3), has been demonstrated to be stimulatory to the secretion of PRL and GH. In contrast, PGA1 and PGB1, which lack an 11-hydroxyl group, failed to influence the secretion of either PRL or GH. It would, therefore, appear that the 11-hydroxyl group is a structural requirement for prostaglandins to influence the secretion of these two hormones in sheep. Treatment with thyrotropin releasing hormone (TRH), alone or in combination with PGF 2alpha, significantly (P less than .05) increased growth rate (average daily gains) while PGF2alpha did not, despite the fact that both compounds exerted similar effects on plasma GH.

  9. Localization of the genes encoding the melanocortin-2 (Adrenocorticotropic hormone) and melanocortin-3 receptors to chromosomes 18p11. 2 and 20q13. 2-q13. 3 by fluorescence in situ hybridization

    SciTech Connect

    Gantz, I.; Tashiro, Takao; Konda, Yoshitaka; Shimoto, Yoshimasa; Miwa, Hiroto; Munzert, G.; Barcroft, C.; Glover, T.; Yamada, Tadataka )

    1993-10-01

    Adrenocorticotropic hormone (ACTH) and [alpha]-, [beta]-, and [gamma]-melanocyte-stimulating hormone (MSH) are products of propiomelanocortin post-translational processing. These compounds are collectively labeled as melanocortins (MC). Aside from their established effects on the regulation of the adrenal cortex (ACTH) and melanocytes ([alpha]-MSH), the melanocortins have been implicated in a broad array of physiological events. Melanocortins mediate their effects through cell membrane receptors belonging to the superfamily of seven transmembrane G-protein-linked receptors. Using the technique of polymerase chain reaction with primers based on conserved areas of the seven transmembrane G-protein-linked receptor family, the authors recently isolated an [open quotes]orphan[close quotes] subfamily of this receptor group. Within the past year, two of these receptors were identified as specific for [alpha]-MSH (MC1) and ACTH (MC2). They have recently described a third melanocortin receptor (MC3) that appears to recognize the core heptapeptide sequence of melanocortins with equal potency and efficacy and identified its presence in the brain, placenta, and gut. Using the FISH technique, they localized the ACTH and the melanocortin-3 receptors to chromosome loci 18p11.2 and 20q12.3-q13.2, respectively. 19 refs., 1 fig.

  10. Control of pituitary thyroid-stimulating hormone synthesis and secretion by thyroid hormones during Xenopus metamorphosis.

    PubMed

    Sternberg, Robin M; Thoemke, Kara R; Korte, Joseph J; Moen, Scott M; Olson, Jessica M; Korte, Lisa; Tietge, Joseph E; Degitz, Sigmund J

    2011-09-15

    We used ex vivo and in vivo experiments with Xenopus laevis tadpoles to examine the hypothesis that the set-point for negative feedback on pituitary thyroid-stimulating hormone (TSH) synthesis and secretion by thyroid hormones (THs) increases as metamorphosis progresses to allow for the previously documented concomitant increase in serum TH concentrations and pituitary TSH mRNA expression during this transformative process. First, pituitaries from climactic tadpoles were cultured for up to 96 h to characterize the ability of pituitary explants to synthesize and secrete TSHβ in the absence of hypothalamic and circulating hormones. Next, pituitary explants from tadpoles NF stages 54-66 were exposed to physiologically-relevant concentrations of THs to determine whether stage-specific differences exist in pituitary sensitivity to negative feedback by THs. Finally, in vivo exposures of tadpoles to THs were conducted to confirm the results of the ex vivo experiments. When pituitaries from climactic tadpoles were removed from the influence of endogenous hormones, TSHβ mRNA expression increased late or not at all whereas the rate of TSHβ secreted into media increased dramatically, suggesting that TSH secretion, but not TSH mRNA expression, is under the negative regulation of an endogenous signal during the climactic stages of metamorphosis. Pituitaries from pre- and prometamorphic tadpoles were more sensitive to TH-induced inhibition of TSHβ mRNA expression and secretion than pituitaries from climactic tadpoles. The observed decrease in sensitivity of pituitary TSHβ mRNA expression to negative feedback by THs from premetamorphosis to metamorphic climax was confirmed by in vivo experiments in which tadpoles were reared in water containing THs. Based on the results of this study, a model is proposed to explain the seemingly paradoxical, concurrent rise in serum TH concentrations and pituitary TSH mRNA expression during metamorphosis in larval anurans.

  11. Encoding and decoding mechanisms of pulsatile hormone secretion.

    PubMed

    Walker, J J; Terry, J R; Tsaneva-Atanasova, K; Armstrong, S P; McArdle, C A; Lightman, S L

    2010-12-01

    Ultradian pulsatile hormone secretion underlies the activity of most neuroendocrine systems, including the hypothalamic-pituitary adrenal (HPA) and gonadal (HPG) axes, and this pulsatile mode of signalling permits the encoding of information through both amplitude and frequency modulation. In the HPA axis, glucocorticoid pulse amplitude increases in anticipation of waking, and, in the HPG axis, changing gonadotrophin-releasing hormone pulse frequency is the primary means by which the body alters its reproductive status during development (i.e. puberty). The prevalence of hormone pulsatility raises two crucial questions: how are ultradian pulses encoded (or generated) by these systems, and how are these pulses decoded (or interpreted) at their target sites? We have looked at mechanisms within the HPA axis responsible for encoding the pulsatile mode of glucocorticoid signalling that we observe in vivo. We review evidence regarding the 'hypothalamic pulse generator' hypothesis, and describe an alternative model for pulse generation, which involves steroid feedback-dependent endogenous rhythmic activity throughout the HPA axis. We consider the decoding of hormone pulsatility by taking the HPG axis as a model system and focussing on molecular mechanisms of frequency decoding by pituitary gonadotrophs.

  12. Sociosexual stimuli and gonadotropin-releasing hormone/luteinizing hormone secretion in sheep and goats.

    PubMed

    Hawken, P A R; Martin, G B

    2012-08-01

    Sociosexual stimuli have a profound effect on the physiology of all species. Sheep and goats provide an ideal model to study the impact of sociosexual stimuli on the hypothalamic-pituitary-gonadal axis because we can use the robust changes in the pulsatile secretion of luteinizing hormone as a bioassay of gonadotropin-releasing hormone secretion. We can also correlate these changes with neural activity using the immediate early gene c-fos and in real time using changes in electrical activity in the mediobasal hypothalamus of female goats. In this review, we will update our current understanding of the proven and potential mechanisms and mode of action of the male effect in sheep and goats and then briefly compare our understanding of sociosexual stimuli in ungulate species with the "traditional" definition of a pheromone.

  13. Ultrastructural study of mixed growth hormone & prolactin secreting pituitary adenomas.

    PubMed

    Sarkar, C; Dinda, A K; Roy, S; Kochupillai, N; Kharbanda, K; Tandon, P N

    1992-08-01

    An ultrastructural study was done on 15 mixed growth hormone (GH) and prolactin (PRL)-secreting pituitary adenomas surgically removed from acromegalic patients with hyper-prolactinaemia, in order to see whether the 2 hormones were present in the same cell or in different cells. Double labelling immunogold technique was used for simultaneous ultrastructural localization of GH and PRL. It was found that each neoplastic cell in these 15 tumours (30 to 50 cells were studied in each case) contained 4 populations of granules viz., (i) granules positive for only GH; (ii) granules positive for only PRL; (iii) granules positive for both GH and PRL; and (iv) granules negative for both GH and PRL (unlabelled). Though the relative percentage of these 4 types of granules varied from cell to cell even within the same tumour, the major population (49.9 to 96%) was constituted by the mixed granules showing labelling for both GH and PRL. Almost all the cells examined from each tumour appeared to be mammosomatotrophs. Thus, the study indicated that mammosomatotroph adenomas are perhaps more common among mixed GH and PRL--secreting pituitary adenomas than previously believed. It could be important to recognize these tumours from the therapeutic point of view.

  14. A priming effect of gonadotrophin releasing hormone on luteinizing hormone secretion in the boar.

    PubMed Central

    Liptrap, R M; Doble, E

    1982-01-01

    The possibility that gonadotrophin releasing hormone (GnRH) can prime the anterior pituitary to a second dose of GnRH resulting in a greatly enhanced secretion of luteinizing hormone was examined in three adult boars. Four experiments were conducted: saline injection followed one hour later by a second saline injection (control); 1 microgram of synthetic GnRH injection followed one hour later by saline injection; saline injection followed one hour later by GnRH injection; GnRH injection followed one hour later by a second GnRH injection. Immunoassayable levels of plasma luteinizing hormone resulting from GnRH plus GnRH treatment were significantly greater than the sum obtained when values from GnRH plus saline and saline plus GnRH were added. Testosterone values in plasma reached maximal concentrations about 60 minutes after peak values of luteinizing hormone were achieved. The results suggest that the first dose of GnRH, in addition to stimulating release of luteinizing hormone can also sensitize the gonadotrophs to a second dose of GnRH causing a significantly greater release of luteinizing hormone. PMID:6751507

  15. [TREATMENT OF SHORT STATURE PATIENTS WITH NOPMAL GROWTH HORMONE SECRETION OF HYPOPHIS].

    PubMed

    Sprinchuk, N A; Samson, O J; Bol'shova, E V

    2014-12-01

    The article presents the treatment outcome in 86 children with short stature associated with different endocrine pathology and saved growth hormone secretion (congenital adrenal hyperplasia chondrodystrophy, Turner syndrome, idiopathic short stature, syndrome biologically inactive growth hormone and other genetically determined pathology). This study extends prior knowledge about the outcomes of the treatment with recombinant growth hormone and luteinizing hormone--releasing hormone analogue (alone or in combination) in short patients with poor prognosis of final height. PMID:26638471

  16. Cholinergic and VIPergic effects on thyroid hormone secretion in the mouse

    SciTech Connect

    Ahren, B.

    1985-07-01

    The thyroid gland is known to harbor cholinergic and VIPergic nerves. In the present study, the influences of cholinergic stimulation by carbachol, cholinergic blockade by methylatropine and stimulation with various VIP sequences on basal, TSH-induced and VIP-induced thyroid hormone secretion were investigated in vivo in mice. The mice were pretreated with /sup 125/I and thyroxine; the subsequent release of /sup 125/I is an estimation of thyroid hormone secretion. It was found that basal radioiodine secretion was inhibited by both carbachol and methylatropine. Furthermore, TSH-induced radioiodine secretion was inhibited already by a low dose of carbachol. Moreover, a high dose of carbachol could inhibit VIP-induced radioiodine secretion. Methylatropine did not influence TSH- or VIP-stimulated radioiodine secretion, but counteracted the inhibitory action of carbachol on TSH- and VIP-induced radioiodine release. In addition, contrary to VIP, six various synthesized VIP fragments had no effect on basal or stimulated radioiodine release. It is concluded that basal thyroid hormone secretion is inhibited by both cholinergic activation and blockade. Furthermore, TSH-induced thyroid hormone secretion is more sensitive to inhibition with cholinergic stimulation than is VIP-induced thyroid hormone secretion. In addition, the VIP stimulation of thyroid hormone secretion seems to require the full VIP sequence.

  17. Trifluoperazine inhibits thyrotropin-releasing hormone-stimulated TSH secretion.

    PubMed

    Zofková, I; BednárJ

    1986-09-01

    In previous work changes of the thyrotropic secretion after administration of some substances affecting the calcium content in the cytosol were demonstrated. The object of the present investigation was to assess the hormonal response to the administration of trifluoperazine, a psychopharmaceutical preparation, the main mechanism of its action being the inactivation of the cytosol receptor for the calcium signal - calmodulin. The poor utilization of intracellular calcium of the secretory cell is then the factor which inhibits secretion proper. The thyrotropic secretory reserve (delta TSH) was assessed in the same subjects before and after trifluoperazine administration by the TRH test as the difference of values at rest and TRH-stimulated TSH levels during the 20th, 30th, 40th and 60th minute following intravenous administration of 200 micrograms TRH. It was revealed that this calmodulin antagonist administered for one week in amounts of 6-12 mg per day by mouth significantly inhibits the secretory response of TSH to TRH in healthy subjects during the 20th and 40th min. (P less than 0.05). The reproducibility of the TRH test repeated in a group of subjects not treated with trifluoperazine, however, under equal conditions and after the same time intervals as in the experiment with trifluoperazine was very satisfactory and thus physiological inhibition caused by repeated TRH administration could be ruled out. The inhibition of the secretory TSH response to TRH can be therefore considered the consequence of the direct effect of trifluoperazine on the thyrotropic secretory mechanism. Trifluoperazine significantly reduced serum calcium levels and raised phosphate levels, while it did not affect the blood levels of magnesium.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Gigantism caused by growth hormone secreting pituitary adenoma.

    PubMed

    Rhee, Noorisaem; Jeong, Kumi; Yang, Eun Mi; Kim, Chan Jong

    2014-06-01

    Gigantism indicates excessive secretion of growth hormones (GH) during childhood when open epiphyseal growth plates allow for excessive linear growth. Case one involved a 14.7-year-old boy presented with extreme tall stature. His random serum GH level was 38.4 ng/mL, and failure of GH suppression was noted during an oral glucose tolerance test (OGTT; nadir serum GH, 22.7 ng/mL). Magnetic resonance imaging (MRI) of the brain revealed a 12-mm-sized pituitary adenoma. Transsphenoidal surgery was performed and a pituitary adenoma displaying positive immunohistochemical staining for GH was reported. Pituitary MRI scan was performed 4 months after surgery and showed recurrence/residual tumor. Medical treatment with a long-acting somatostatin analogue for six months was unsuccessful. As a result, secondary surgery was performed. Three months after reoperation, the GH level was 0.2 ng/mL and insulin-like growth factor 1 was 205 ng/mL. Case two involved a 14.9-year-old boy, who was referred to our department for his tall stature. His basal GH level was 9.3 ng/mL, and failure of GH suppression was reported during OGTT (nadir GH, 9.0 ng/mL). Pituitary MRI showed a 6-mm-sized pituitary adenoma. Surgery was done and histopathological examination demonstrated a pituitary adenoma with positive staining for GH. Three months after surgery, the GH level was 0.2 ng/mL and nadir GH during OGTT was less than 0.1 ng/mL. Pituitary MRI scans showed no residual tumor. We present two cases of gigantism caused by a GH-secreting pituitary adenoma with clinical and microscopic findings. PMID:25077093

  19. Gigantism caused by growth hormone secreting pituitary adenoma

    PubMed Central

    Rhee, Noorisaem; Jeong, Kumi; Yang, Eun Mi

    2014-01-01

    Gigantism indicates excessive secretion of growth hormones (GH) during childhood when open epiphyseal growth plates allow for excessive linear growth. Case one involved a 14.7-year-old boy presented with extreme tall stature. His random serum GH level was 38.4 ng/mL, and failure of GH suppression was noted during an oral glucose tolerance test (OGTT; nadir serum GH, 22.7 ng/mL). Magnetic resonance imaging (MRI) of the brain revealed a 12-mm-sized pituitary adenoma. Transsphenoidal surgery was performed and a pituitary adenoma displaying positive immunohistochemical staining for GH was reported. Pituitary MRI scan was performed 4 months after surgery and showed recurrence/residual tumor. Medical treatment with a long-acting somatostatin analogue for six months was unsuccessful. As a result, secondary surgery was performed. Three months after reoperation, the GH level was 0.2 ng/mL and insulin-like growth factor 1 was 205 ng/mL. Case two involved a 14.9-year-old boy, who was referred to our department for his tall stature. His basal GH level was 9.3 ng/mL, and failure of GH suppression was reported during OGTT (nadir GH, 9.0 ng/mL). Pituitary MRI showed a 6-mm-sized pituitary adenoma. Surgery was done and histopathological examination demonstrated a pituitary adenoma with positive staining for GH. Three months after surgery, the GH level was 0.2 ng/mL and nadir GH during OGTT was less than 0.1 ng/mL. Pituitary MRI scans showed no residual tumor. We present two cases of gigantism caused by a GH-secreting pituitary adenoma with clinical and microscopic findings. PMID:25077093

  20. Gigantism caused by growth hormone secreting pituitary adenoma.

    PubMed

    Rhee, Noorisaem; Jeong, Kumi; Yang, Eun Mi; Kim, Chan Jong

    2014-06-01

    Gigantism indicates excessive secretion of growth hormones (GH) during childhood when open epiphyseal growth plates allow for excessive linear growth. Case one involved a 14.7-year-old boy presented with extreme tall stature. His random serum GH level was 38.4 ng/mL, and failure of GH suppression was noted during an oral glucose tolerance test (OGTT; nadir serum GH, 22.7 ng/mL). Magnetic resonance imaging (MRI) of the brain revealed a 12-mm-sized pituitary adenoma. Transsphenoidal surgery was performed and a pituitary adenoma displaying positive immunohistochemical staining for GH was reported. Pituitary MRI scan was performed 4 months after surgery and showed recurrence/residual tumor. Medical treatment with a long-acting somatostatin analogue for six months was unsuccessful. As a result, secondary surgery was performed. Three months after reoperation, the GH level was 0.2 ng/mL and insulin-like growth factor 1 was 205 ng/mL. Case two involved a 14.9-year-old boy, who was referred to our department for his tall stature. His basal GH level was 9.3 ng/mL, and failure of GH suppression was reported during OGTT (nadir GH, 9.0 ng/mL). Pituitary MRI showed a 6-mm-sized pituitary adenoma. Surgery was done and histopathological examination demonstrated a pituitary adenoma with positive staining for GH. Three months after surgery, the GH level was 0.2 ng/mL and nadir GH during OGTT was less than 0.1 ng/mL. Pituitary MRI scans showed no residual tumor. We present two cases of gigantism caused by a GH-secreting pituitary adenoma with clinical and microscopic findings.

  1. Cadmium effects on hypothalamic activity and pituitary hormone secretion in the male.

    PubMed

    Lafuente, A; Esquifino, A I

    1999-11-22

    Cadmium specifically modify amine metabolism at the central nervous system and pituitary hormone secretions. Thus, the physiological functions controlled by these hormones can be modulated by cadmium. This xenobiotic is associated with deleterious effects on the gonadal function and with changes in the secretory pattern of other pituitary hormones like prolactin, ACTH, GH or TSH. The observed changes in pituitary hormone secretion do not correlate with the modifications of central nervous system metabolism of the neurotransmitters involved in their regulation. The accumulative data indicates the existence of a disruption in the regulatory mechanisms of the hypothalamic-pituitary axis. The physiological significance of these effects remains to be elucidated.

  2. A Rare Corticotroph-Secreting Tumor with Coexisting Prolactin and Growth Hormone Staining Cells

    PubMed Central

    Kannan, Subramanian; Staugaitis, Susan M.; Weil, Robert J.; Hatipoglu, Betul

    2012-01-01

    Pituitary adenomas can express and secrete different hormones. Expression of pituitary hormones in nonneoplastic pituitary cells is regulated by different transcription factors. Some pituitary adenomas show plurihormonal expression. The most commonly reported plurihormonal adenomas are composed of somatotrophs, lactotrophs, thyrotrophs and gonadotrophs. Pituitary adenomas composed of both corticotroph and somatolactotroph secreting cells are not common because transcription factors regulating the expression of these hormones are different. We report a rare case of pituitary adenoma with concomitant corticotroph, prolactin, and growth hormone staining cells, review literature on similar cases, and discuss possible biological mechanisms underlying these plurihormonal tumors. PMID:23320206

  3. Peptide T bolus normalizes the growth hormone secretion pattern in two children with AIDS.

    PubMed

    Barbey-Morel, Charlotte; McDonnell, Kevin; Pert, Candace B; Adams, MerriBeth; Farrand, Dean; Ruff, Michael R; Lumpkin, Michael D

    2002-12-01

    In humans, HIV infection reduces growth hormone (GH) secretion contributing to AIDS wasting. In rats, the HIV envelope protein gp120 alone blocks GH secretion both in vitro and in vivo through GH-releasing hormone receptors. Peptide T, a modified octapeptide derived from gp120, normalizes GH secretion. We now report that an intravenous bolus of peptide T normalizes nocturnal GH secretion in two out of three children with AIDS. These results, coupled with the lack of toxicity of this experimental AIDS therapeutic, justify clinical trials for AIDS wasting and pediatric AIDS. A clinical and basic science update on peptide T appears in Current HIV Research. PMID:12535709

  4. Oxidative stress impact on growth hormone secretion in the eye

    PubMed Central

    Šarić, Borna; Šarić, Vlatka Brzović; Barberić, Monika; Predović, Jurica; Rumenjak, Vlatko; Cerovski, Branimir

    2015-01-01

    Aim To evaluate the influence of oxidative stress on extrapituitary growth hormone (GH) secretion in the eye and to analyze the interdependence between eye and serum GH levels under normal and hypoxic conditions. Methods Pars plana vitrectomy (PPV) was performed in 32 patients with developed proliferative diabetic retinopathy (PDR) and 49 non-diabetic controls, both of whom required this procedure as part of their regular treatment in the period from April 2013 to December 2014. During PPV, vitreous samples were taken and blood was simultaneously collected from the cubital vein. GH levels in serum and vitreous samples were measured by electrochemical luminescence assay. Oxidative stress was measured by enzyme-linked immunosorbent assay of advanced oxidation protein products (AOPP) and lipid hydroperoxide (LPO) in serum and vitreous. Results Serum AOPP levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group) and LPO levels were significantly higher only in PDR group (P < 0.001). There was a significant positive correlation between serum and vitreous LPO levels in PDR group (r = 0.909; P < 0.001). Serum GH levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group). Serum GH levels were significantly higher in PDR group than in controls (P = 0.012). Vitreous GH values were slightly higher in PDR group, but the difference was not significant. Conclusion Our study confirms that GH production in the eye is autonomous and independent of oxidative stress or pituitary GH influence. PMID:26321025

  5. Transformation of a Microprolactinoma into a Mixed Growth Hormone and Prolactin-Secreting Pituitary Adenoma

    PubMed Central

    Dessimoz, Cédric; Browaeys, Patrick; Maeder, Philippe; Lhermitte, Benoît; Pitteloud, Nelly; Momjian, Shahan; Pralong, François P.

    2012-01-01

    Combined prolactin (PRL) and growth hormone (GH) secretion by a single pituitary tumor can occur in approximately 5% of cases. However, in all previously reported patients, combined secretion of both hormones was present at the time of diagnosis. Here we describe a patient initially diagnosed with a pure prolactin-secreting microadenoma, who experienced the progressive apparition of symptomatic autonomous GH secretion while on intermittent long term dopamine agonist therapy. She was operated on, and immunohistochemical analysis of tumor tissue confirmed the diagnosis of pituitary adenoma with uniform co-staining of all cells for both GH and PRL. This patient represents the first documented occurrence of asynchronous development of combined GH and PRL secretion in a pituitary adenoma. Although pathogenic mechanisms implicated remain largely speculative, it emphasizes the need for long term hormonal follow up of patients harboring prolactinomas. PMID:22654846

  6. Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone antagonist-treated male rats.

    PubMed

    Tena-Sempere, M; Pinilla, L; Aguilar, E

    1995-03-01

    The pituitary component of the feedback mechanisms exerted by testicular factors on gonadotropin secretion was analyzed in adult male rats treated with a potent gonadotropin-releasing hormone (GnRH) antagonist. In order to discriminate between androgens and testicular peptides, groups of males were orchidectomized (to eliminate androgens and non-androgenic testicular factors) or injected with ethylene dimethane sulfonate (EDS), a selective toxin for Leydig cells (to eliminate selectively androgens) and treated for 15 days with vehicle or the GnRH antagonist Ac-D-pClPhe-D-pClPhe-D-Trp-Ser-Tyr-D-Arg-Leu-Arg-Pro-D-Ala-+ ++NH2CH3COOH (Org.30276, 5 mg/kg/72 hours). Serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured 7 and 14 days after the beginning of treatment. We found that: in males treated with GnRH antagonist, orchidectomy or EDS treatment did not induce any increase in LH secretion; and orchidectomy, but not EDS treatment, increased FSH secretion in GnRH-treated males. The present results show that negative feedback of testicular factors on LH secretion is mediated completely through changes in GnRH actions. In contrast, a part of the inhibitory action of the testis on FSH secretion is exerted directly at the pituitary level. It can be hypothesized that non-Leydig cell testicular factor(s) inputs at different levels of the hypothalamic-pituitary axis in controlling LH and FSH secretion.

  7. Diminished growth hormone secretion in blind males after L-dopa stimulation.

    PubMed

    Fatranská, M; Jurcovicová, J; Németh, S; Vigas, M

    1988-12-01

    Growth hormone secretion after L-dopa administration (1000 mg p.o.) was investigated in young adult normal and blind volunteers. The average increment of plasma growth hormone after L-dopa stimulation in the blind was below the criterion for a positive response (less than 5 ng ml-1). The control volunteers showed normal response. After L-dopa stimulation there was a significantly diminished growth hormone response in the young adult blind compared to control volunteers. PMID:3243205

  8. A study of cell electrophoresis as a means of purifying growth hormone secreting cells

    NASA Technical Reports Server (NTRS)

    Plank, Lindsay D.; Hymer, W. C.; Kunze, M. Elaine; Marks, Gary M.; Lanham, J. Wayne

    1983-01-01

    Growth hormone secreting cells of the rat anterior pituitary are heavily laden with granules of growth hormone and can be partialy purified on the basis of their resulting high density. Two methods of preparative cell electrophoresis were investigated as methods of enhancing the purification of growth hormone producing cells: density gradient electrophoresis and continuous flow electrophoresis. Both methods provided a two- to four-fold enrichment in growth hormone production per cell relative to that achieved by previous methods. Measurements of electrophoretic mobilities by two analytical methods, microscopic electrophoresis and laser-tracking electrophoresis, revealed very little distinction between unpurified anterior pituitary cell suspensions and somatotroph-enriched cell suspensions. Predictions calculated on the basis of analytical electrophoretic data are consistent with the hypothesis that sedimentation plays a significant role in both types of preparative electrophoresis and the electrophoretic mobility of the growth hormone secreting subpopulation of cells remains unknown.

  9. Nonlinear dynamics in pulsatile secretion of parathyroid hormone in normal human subjects

    NASA Astrophysics Data System (ADS)

    Prank, Klaus; Harms, Heio; Brabant, Georg; Hesch, Rolf-Dieter; Dämmig, Matthias; Mitschke, Fedor

    1995-03-01

    In many biological systems, information is transferred by hormonal ligands, and it is assumed that these hormonal signals encode developmental and regulatory programs in mammalian organisms. In contrast to the dogma of endocrine homeostasis, it could be shown that the biological information in hormonal networks is not only present as a constant hormone concentration in the circulation pool. Recently, it has become apparent that hormone pulses contribute to this hormonal pool, which modulates the responsiveness of receptors within the cell membrane by regulation of the receptor synthesis, movement within the membrane layer, coupling to signal transduction proteins and internalization. Phase space analysis of dynamic parathyroid hormone (PTH) secretion allowed the definition of a (in comparison to normal subjects) relatively quiet ``low dynamic'' secretory pattern in osteoporosis, and a ``high dynamic'' state in hyperparathyroidism. We now investigate whether this pulsatile secretion of PTH in healthy men exhibits characteristics of nonlinear determinism. Our findings suggest that this is conceivable, although on the basis of presently available data and techniques, no proof can be established. Nevertheless, pulsatile secretion of PTH might be a first example of nonlinear deterministic dynamics in an apparently irregular hormonal rhythm in human physiology.

  10. Increased secretion of growth hormone, prolactin, antidiuretic hormone, and cortisol induced by the stress of motion sickness.

    PubMed

    Eversmann, T; Gottsmann, M; Uhlich, E; Ulbrecht, G; von Werder, K; Scriba, P C

    1978-01-01

    The stress of motion sickness was experimentally provoked by Coriolis effect. Significant and reproducible increases from the basal serum level (delta mean +/- S.E.) of antidiuretic hormone delta - ADH: 48.2 +/- 4.6 pg/ml; p less than 0.0005), of growth hormone (delta - hGH: 10.0 +/- 1.2 ng/ml; p less than 0.0005), of prolactin (delta - hPRL: 186.5 +/- 29.9 muU/ml; p less than 0.0005), and of cortisol (delta - F; 12.3 +/- 0.9 microgram%; p less than 0.0005) were observed, whereas the luteinizing hormone levels did not change significantly. The stimulation of hormone secretion induced by different degrees of motion sickness seems to correlate with the severity of motion sickness. The secretion of antidiuretic hormones is the most sensitive indicator for the stress of motion sickness whereas growth hormone, prolactin, and cortisol responses to the stress of motion sickness are more delayed and less pronounced.

  11. Purification and cultivation of human pituitary growth hormone secreting cells

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.

    1984-01-01

    A multiphase study was conducted to examine the properties of growth hormone cells. Topics investigated included: (1) to determine if growth hormone (GH) cells contained within the rat pituitary gland can be separated from the other hormone producing cell types by continuous flow electrophoresis (CFE); (2) to determine what role, if any, gravity plays in the electrophoretic separation of GH cells; (3) to compare in vitro GH release from rat pituitary cells previously exposed to microgravity conditions vs release from cells not exposed to microgravity; (4) to determine if the frequency of different hormone producing pituitary cell types contained in cell suspensions can be quantitated by flow cytometry; and (5) to determine if GH contained within the human post mortem pituitary gland can be purified by CFE. Specific experimental procedures and results are included.

  12. Stimulatory and inhibitory effects of neuropeptide Y on growth hormone secretion in acromegaly in vivo.

    PubMed

    Watanobe, H; Tamura, T

    1997-02-01

    It has been reported that neuropeptide Y (NPY) affects growth hormone (GH) secretion in several animal species. With respect to the role of NPY in regulating GH release in humans, one previous study has reported that NPY inhibited GH secretion from cultured GH-secreting pituitary adenoma cells in vitro. However, since it has yet to be explored whether NPY affects GH secretion in acromegaly in vivo, in this study we attempted to examine the effect of intravenous (i.v.) bolus injection of 100 microg of human NPY on plasma GH levels in 15 patients with active acromegaly, trying to find a possible correlation among GH responses to NPY, thyrotropin-releasing hormone (TRH;500 microg, i.v.), luteinizing hormone-releasing hormone (LHRH;100 microg, i.v.), and bromocriptine (Br;2.5 mg, per os). NPY significantly increased GH secretion (more than twice the basal level) in 4 (27%) patients, and all of them were responsive to LHRH and non-responsive to Br. In contrast, 3 (20%) acromegalics showed a significant decrease in GH levels (less than half the baseline) after NPY, and all these patients were responsive to both TRH and Br. From these results, we hypothesize that the NPY-induced increase in GH release may be a feature of somatotroph-like pituitary adenoma causing acromegaly, whereas the NPY-induced decrease in GH secretion may be a feature of lactotroph-like adenoma.

  13. Effect of single-dose radiation on cell survival and growth hormone secretion by rat anterior pituitary cells

    SciTech Connect

    Hochberg, Z.; Kuten, A.; Hertz, P.; Tatcher, M.; Kedar, A.; Benderly, A.

    1983-06-01

    Cranial irradiation has been shown to impair growth hormone secretion in children. In this study a cell culture of dispersed rat anterior pituitary cells was exposed to single doses of radiation in the range of 100 to 1500 rad. Survival curves were obtained for the different anterior pituitary cell lines, and growth hormone secretion was measured in the tissue culture medium. Both survival and growth hormone secretion curves showed an initial shoulder in the range of 0 to 300 rad, followed by a decline between 300 to 750 rad. It is concluded that growth hormone secreting acidophilic pituicytes are sensitive to radiation at single doses greater than 300 rad.

  14. Gastric bypass alters both glucose-dependent and glucose-independent regulation of islet hormone secretion

    PubMed Central

    Salehi, Marzieh; Woods, Stephen C.; D’Alessio, David A.

    2015-01-01

    Aims Roux-en-Y gastric bypass surgery (GB) is characterized by accentuated, but short-lived postprandial elevations of blood glucose and insulin. This profile has been attributed to effects of relative hyperglycemia to directly stimulate β-cells and an augmented incretin effect. We hypothesized additional glucose-independent stimulation of insulin secretion in GB subjects. Methods Fifteen subjects with prior GB, and six matched obese non-surgical controls, and seven lean individuals were recruited. Islet hormones were measured before and after meal ingestion during hyperinsulinemic hypoglycemic clamps to minimize the direct effects of glycemia and glucose-dependent gastrointestinal hormones on insulin secretion. Results The GB subjects had less suppression of fasting β-cell secretion during the insulin clamp compared to controls. In addition, meal-induced insulin secretion increased in the GB subjects but not controls during fixed sub-basal glycemia. In contrast the glucagon responses to hypoglycemia and meal ingestion were lower in the GB subjects than controls. Conclusions Among subjects with GB the response of insulin and glucagon secretion to decreasing blood glucose is blunted, but meal-induced insulin secretion is stimulated even at fixed systemic sub-basal glycemia. These findings indicate that following GB islet hormone secretion is altered as a result of factors beyond circulatory glucose levels. PMID:26316298

  15. Novel structures in secreting the androgenic gland hormone.

    PubMed

    Negishi, S; Hasegawa, Y; Nakajima, Y

    2001-12-01

    The secretory granules in the androgenic gland of the terrestrial isopod Armadillidium vulgare, which have been indistinct for long time because of vulnerable structures, were revealed by using the rapid-freezing and freeze-substitution method. The fine structure of the androgenic gland is conspicuous by the distribution of numerous particular organelles in the cytoplasm consisting of the endoplasmic reticulum and the Golgi complex, and by having a number of highly organized structures developed between the androgenic gland cells. The structures connect to the intercellular space, which is seen as intercellular canaliculi for exporting the androgenic gland hormone. The plasma membranes near the particular structure of the intercellular canaliculi in the androgenic gland are often specialized to form cellular junctions. The secretory granules including the electron-dense materials, which are supposed to be peptides of androgenic gland hormone, are distributed beside the particular structure of the intercellular canaliculi. Some of the granules are seen to fuse with the plasma membranes. This observation suggests that, in the Armadillidium vulgare, the secretory granules containing androgenic gland hormone are transferred to the extracellular space through the intercellular canaliculi particularly developed for exporting the peptide hormone. This is the first evidence to show the secretory mechanism of the androgenic gland hormone in the Isopoda. PMID:11911080

  16. Expression of receptors for luteinizing hormone, gastric-inhibitory polypeptide, and vasopressin in normal adrenal glands and cortisol-secreting adrenocortical tumors in dogs.

    PubMed

    Galac, S; Kars, V J; Klarenbeek, S; Teerds, K J; Mol, J A; Kooistra, H S

    2010-07-01

    Hypercortisolism caused by an adrenocortical tumor (AT) results from adrenocorticotropic hormone (ACTH)-independent hypersecretion of glucocorticoids. Studies in humans demonstrate that steroidogenesis in ATs may be stimulated by ectopic or overexpressed eutopic G protein-coupled receptors. We report on a screening of 23 surgically removed, cortisol-secreting ATs for the expression of receptors for luteinizing hormone (LH), gastric-inhibitory polypeptide (GIP), and vasopressin (V(1a), V(1b), and V(2)). Normal adrenal glands served as control tissues. Abundance of mRNA for these receptors was quantified using quantitative polymerase chain reaction (QPCR), and the presence and localization of these receptors were determined by immunohistochemistry. In both normal adrenal glands and ATs, mRNA encoding for all receptors was present, although the expression abundance of the V(1b) receptor was very low. The mRNA expression abundance for GIP and V(2) receptors in ATs were significantly lower (0.03 and 0.01, respectively) than in normal adrenal glands. The zona fasciculata of normal adrenal glands stained immunonegative for the GIP receptor. In contrast, islands of GIP receptor-immunopositive cells were detected in about half of the ATs. The zona fasciculata of both normal adrenal glands and AT tissue were immunopositive for LH receptor; in ATs in a homogenous or heterogenous pattern. In normal adrenal glands, no immunolabeling for V(1b)R and V(2) receptor was present, but in ATs, V(2) receptor-immunopositive cells were detected. In conclusion, QPCR analysis did not reveal overexpression of LH, GIP, V(1a), V(1b), or V(2) receptors in the ATs. However, the ectopic expression of GIP and V(2) receptor proteins in tumorous zona fasciculata tissue may play a role in the pathogenesis of canine cortisol-secreting ATs.

  17. Infarction of a growth hormone-secreting macroadenoma during a TRH test.

    PubMed

    Lever, E G; Butler, J; Moore, P; Cox, T C; Maccabe, J J

    1986-06-01

    Pituitary infarction occurring immediately after TRH injection (200 micrograms) is reported in a patient with gigantism due to a growth hormone-secreting pituitary macroadenoma. Evidence of infarction was seen in CSF and in serial CT scans. Regression of symptoms and sign of acromegaly, abolition of abnormal growth hormone secretion, and virtually complete anterior and partial posterior pituitary failure rapidly followed. The infarction was probably initiated by a hypertensive response to TRH. TRH testing in acromegalic subjects may require smaller doses of TRH to avoid unwanted pressor responses. PMID:3090811

  18. Antibody that blocks stimulation of cortisol secretion by adrenocorticotrophic hormone in Addison's disease

    PubMed Central

    Kendall-Taylor, Pat; Lambert, Ann; Mitchell, Robert; Robertson, William R

    1988-01-01

    To investigate whether Addison's disease may in some cases be due to the blocking of adrenocorticotrophic hormone's action at the adrenal cortex by antibodies IgG isolated from a woman with Addison's disease associated with the autoimmune polyglandular syndrome type I was studied. Its effects on guinea pig adrenal cells in vitro were investigated and compared with those of IgG from three normal subjects and IgG obtained commercially. IgG from the patient inhibited the stimulation of cortisol secretion by adrenocorticotrophic hormone by 77 (SD 2)% and 57 (12)% at concentrations of 0·5 and 0·05 g/l, respectively; IgG prepared five months after she had started treatment with replacement steroids inhibited cortisol secretion by 74 (1)% (0·5 g/l) and 51 (15)% (0·05 g/l). The other IgGs had no inhibitory effects. The IgG from the patient and that obtained commercially did not inhibit the stimulation of cortisol secretion by dibutyryl cyclic adenosine monophosphate or precursors of cortisol. None of the IgGs bound to adrenocorticotrophic hormone. These results suggest that the IgG from the patient acted against the receptor for adrenocorticotrophic hormone, and its presence may explain the patient's raised concentrations of adrenocorticotrophic hormone, failure to respond to exogenous adrenocorticotrophic hormone, and normal basal cortisol concentrations. Addison's disease may thus in some instances be a receptor antibody disease. PMID:2839266

  19. Taste signaling elements expressed in gut enteroendocrine cells regulate nutrient-responsive secretion of gut hormones.

    PubMed

    Kokrashvili, Zaza; Mosinger, Bedrich; Margolskee, Robert F

    2009-09-01

    Many of the receptors and downstream signaling elements involved in taste detection and transduction are also expressed in enteroendocrine cells where they underlie the chemosensory functions of the gut. In one well-known example of gastrointestinal chemosensation (the "incretin effect"), it is known that glucose that is given orally, but not systemically, induces secretion of glucagon-like peptide 1 and glucose-dependent insulinotropic peptide (the incretin hormones), which in turn regulate appetite, insulin secretion, and gut motility. Duodenal L cells express sweet taste receptors, the taste G protein gustducin, and several other taste transduction elements. Knockout mice that lack gustducin or the sweet taste receptor subunit T1r3 have deficiencies in secretion of glucagon-like peptide 1 and glucose-dependent insulinotropic peptide and in the regulation of plasma concentrations of insulin and glucose in response to orally ingested carbohydrate-ie, their incretin effect is dysfunctional. Isolated small intestine and intestinal villi from gustducin null mice displayed markedly defective glucagon-like peptide 1 secretion in response to glucose, indicating that this is a local circuit of sugar detection by intestinal cells followed by hormone secretion from these same cells. Modulating hormone secretion from gut "taste cells" may provide novel treatments for obesity, diabetes, and malabsorption syndromes. PMID:19571229

  20. Regulation of Gonadotropin-Releasing Hormone Secretion by Cannabinoids

    PubMed Central

    GAMMON, C. MICHAEL; FREEMAN, G. MARK; XIE, WEIHUA; PETERSEN, SANDRA L.; WETSEL, WILLIAM C.

    2005-01-01

    Cannabinoids (CBs) exert untoward effects on reproduction by reducing LH secretion and suppressing gonadal function. Recent evidence suggests these effects are due primarily to hypothalamic dysfunction; however, the mechanism is obscure. Using immortalized hypothalamic GnRH neurons, we find these cells produce and secrete at least two different endocannabinoids. Following release, 2-arachidonyl monoacylglycerol and anandamide are rapidly transported into GnRH neurons and are degraded to other lipids by fatty-acid amide hydrolase. The immortalized GnRH neurons also possess CB1 and CB2 receptors that are coupled to Gi/Go proteins whose activation leads to inhibition of GnRH secretion. In perifusion experiments, CBs block pulsatile release of GnRH. When a CB receptor agonist is delivered into the third ventricle of adult female mice, estrous cycles are prolonged by at least 2 days. Although in situ hybridization experiments suggest either that GnRH neurons in vivo do not possess CB1 receptors or that they are very low, transcripts are localized in close proximity to these neurons. Inasmuch as GnRH neurons in vivo possess G protein receptors that are coupled to phospholipase C and increased intracellular Ca2+, these same neurons should also be able to synthesize endocannabinoids. These lipids, in turn, could bind to CB receptors on neighboring cells and perhaps, GnRH neurons, to exert feedback control over GnRH function. This network could serve as a novel mechanism for regulating GnRH secretion where reproductive functions as diverse as the onset of puberty, timing of ovulation, duration of lactational infertility, and initiation/persistence of menopause may be affected. PMID:16020480

  1. Purification and Cultivation of Human Pituitary Growth Hormones Secreting Cells

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.; Todd, P.; Grindeland, R.; Lanham, W.; Morrison, D.

    1985-01-01

    The rat and human pituitary gland contains a mixture of hormone producing cell types. The separation of cells which make growth hormone (GH) is attempted for the purpose of understanding how the hormone molecule is made within the pituitary cell; what form(s) it takes within the cell; and what form(s) GH assumes as it leaves the cell. Since GH has a number of biological targets (e.g., muscle, liver, bone), the assessment of the activities of the intracellular/extracellular GH by new and sensitive bioassays. GH cells contained in the mixture was separated by free flow electrophoresis. These experiments show that GH cells have different electrophoretic mobilities. This is relevant to NASA since a lack of GH could be a prime causative factor in muscle atrophy. Further, GH has recently been implicated in the etiology of motion sickness in space. Continous flow electrophoresis experiment on STS-8 showed that GH cells could be partially separated in microgravity. However, definitive cell culture studies could not be done due to insufficient cell recoveries.

  2. Synthesis of the Growth Hormone Secretion Mechanism Using Nonlinear Analysis and CAD Tools.

    PubMed

    Shell, J R

    2005-01-01

    The goal of this paper is to present a hardware realization of the feed-forward and feedback hypothalamic-pituitary growth hormone (GH) secretion mechanism based on a bio-mathematical nonlinear delay differential equation model developed by Farhy et al. (2003) and Veldhuis et al. (2001). Behavioral modeling is implemented through Verilog hardware descriptive language (HDL) to simulate the antagonistic and stimulatory interaction of growth hormone, growth hormone releasing hormone (GHRH) and somatotropin release inhibiting factor (SRIF). The model is synthesized using computer aided design (CAD) tools and is promulgated through a combinational complex programmable logic device (CPLD)/field programmable grid array (FPGA) Xilinx XSA-50 microchip. The microchip sequentially displays the decimal equivalents of the time changing hormonal concentration levels of the biomathematical model.

  3. Transient pituitary hypothyroidism in a patient with ectopic adrenocorticotrophic hormone secretion.

    PubMed

    Rodríguez-Espinosa, J; Urgell, E; Montesinos, J; Domingo, P; Webb, S M

    2000-05-01

    We report the case of a 55-year-old woman who presented with hypercortisolism secondary to ectopic adrenocorticotrophic hormone secretion and severe non-thyroidal illness syndrome (NTIS) due to metastatic small cell lung carcinoma associated with severe infections. The patient initially showed hormonal profiles of pituitary hypothyroidism and gonadal hypofunction. After decrease in cortisol production following treatment with chemotherapy and metyrapone, serum thyroid hormones and thyroid-stimulating hormone (TSH) concentrations normalized. Study of the relative contributions of cortisol and pro-inflammatory cytokines (interleukin-6 and tumour necrosis factor alpha) to the overall variability in thyroid function tests disclosed a significant and independent effect of serum cortisol on serum TSH concentrations; the variability in free thyroid hormone concentration was explained only by changes in TSH concentration. These observations indicate that cortisol could be the major determinant of changes in serum TSH concentrations in clinical conditions accompanied by hypercortisolism, as occurs in NTIS.

  4. Acute Effect of Manganese on Hypothalamic Luteinizing Hormone Releasing Hormone Secretion in Adult Male Rats: Involvement of Specific Neurotransmitter Systems

    PubMed Central

    Prestifilippo, Juan Pablo; Fernández-Solari, Javier; De Laurentiis, Andrea; Mohn, Claudia Ester; de la Cal, Carolina; Reynoso, Roxana; Dees, W. Les; Rettori, Valeria

    2008-01-01

    Manganese chloride (MnCl2) is capable of stimulating luteinizing hormone releasing hormone (LHRH) secretion in adult male Sprague-Dawley rats through the activation of the hypothalamic nitric oxide/cyclic guanosine monophosphate (cGMP)/protein kinase G pathway. The present study aimed to determine the involvement of specific neurotransmitters involved in this action. Our results indicate that dopamine, but not glutamic acid and prostaglandinds, mediates the MnCl2 stimulated secretion of LHRH from medial basal hypothalami in vitro, as well as increases the activity of nitric oxide synthase. Furthermore, a biphasic response was observed in that gamma aminobutyric acid (GABA) release was also increased, which acts to attenuate the MnCl2 action to stimulate LHRH secretion. Although it is clear that manganese (Mn+2) can acutely induce LHRH secretion in adult males, we suggest that the additional action of MnCl2 to release GABA, a LHRH inhibitor, may ultimately contribute to suppressed reproductive function observed in adult animals following exposure to high chromic levels of Mn+2. PMID:18603625

  5. Abdominal pain and syndrome of inappropriate antidiuretic hormone secretion as clinical presentation of acute intermittent porphyria.

    PubMed

    Valle Feijóo, M L; Bermúdez Sanjurjo, J R; González Vázquez, L; Rey Martínez, M; de la Fuente Aguado, J

    2015-01-01

    Acute intermittent porphyria (AIP) is a rare condition characterized by abdominal pain and a wide range of nonspecific symptoms. We report the case of a woman with abdominal pain and syndrome of inappropriate antidiuretic hormone secretion (SIADH) as clinical presentation of AIP. The diagnosis was achieved through the etiologic study of the SIADH.

  6. Luteinizing hormone secretion as influenced by age and estradiol in the prepubertal gilt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to determine if there is an age related reduction in the sensitivity of the negative feedback action of estradiol on luteinizing hormone (LH) secretion in the prepubertal gilt. Ovariectomized gilts at 90 (n = 12), 150 (n = 11) or 210 (n = 12) days of age received estradiol ...

  7. Dysgeusia in symptomatic syndrome of inappropriate antidiuretic hormone secretion: think of lung cancer

    PubMed Central

    Singh, Nishith K; Hayes, Shelbi; Hahs, Seth; Varney, Andrew

    2009-01-01

    The case of a 60-year-old woman who presented with marked dysgeusia to all food and symptomatic syndrome of inappropriate antidiuretic hormone secretion (SIADH) is described. She eventually turned out to have metastatic small cell lung cancer. The case study explores the interesting constellation of dysgeusia, SIADH and lung cancer. PMID:21686989

  8. Ethanol-induced alterations in the posttranslational processing, but not secretion of luteinizing hormone-releasing hormone in vitro.

    PubMed

    Uddin, S; Wilson, T; Emanuele, M A; Williams, D; Kelley, M R; Emanuele, N

    1996-05-01

    The effects of ethanol (EtOH) on the male hypothalamic pituitary reproductive axis are multiple and varied. Although direct gonadal toxicity has been reported, hypothalamic-pituitary perturbations have also been noted. The difficulty of sampling the hypothalamus has made direct investigation of EtOH-induced alterations on luteinizing hormone-releasing hormone (LHRH) fraught with interpretation problems. To circumvent this, we have conducted a series of experiments exploring the effect of 200 mg% EtOH in vitro on GT1-7 cells, a newly developed LHRH secreting neural cell line. Cell lines were treated with EtOH-containing or EtOH-free media for 2, 6, 24, or 48 hr. EtOH caused no significant change in LHRH secretion at any time point, although there was a trend to increased secretion after 2 hr EtOH exposure when compared with control. Significantly increased total (i.e., cellular plus secreted) pro-LHRH coupled with significantly reduced cellular LHRH after 6 hr only of EtOH exposure suggested that EtOH caused a transient decrease in processing from bioinactive pro-LHRH to bioactive LHRH. However, even at this time point, LHRH secretion from these EtOH-exposed cells was no different than from control cells. Steady-state LHRH mRNA levels were not changed by EtOH at any time point. These findings are concordant with previous in vitro data using hypothalamic tissue that has similarly demonstrated no effect of EtOH on LHRH secretion. Taken together with the in vivo demonstration that EtOH reduces hypothalamic-pituitary portal blood levels of LHRH, these data indicate that EtOH exerts its effect either at an extrahypothalamic locus and/or on non-LHRH-producing cells within the hypothalamus.

  9. Adrenal insufficiency in a child following unilateral excision of a dual-hormone secreting phaeochromocytoma

    PubMed Central

    Sjoeholm, Annika; Li, Cassandra; Leem, Chaey; Lee, Aiden; Stack, Maria P; Hofman, Paul L

    2015-01-01

    Summary Phaeochromocytomas are a rare clinical entity, with dual hormone-secreting lesions particularly uncommon, seen in <1%. ACTH is the most common hormone co-produced, and is potentially lethal if not diagnosed. We present the case of a previously well 10-year-old boy, who presented acutely with a hypertensive crisis and was found to have a unilateral, non-syndromic phaeochromocytoma. Medical stabilization of his hypertension was challenging, and took 3 weeks to achieve, before proceeding to unilateral adrenalectomy. Post-operatively the child experienced severe fatigue and was subsequently confirmed to have adrenal insufficiency. He improved markedly with hydrocortisone replacement therapy, which is ongoing 6 months post-operatively. In retrospect this likely represents unrecognized, sub-clinical ACTH-dependent Cushing's syndrome secondary to an ACTH/or precursor dual-hormone secreting phaeochromocytoma. At follow-up, his hypertension had resolved, there was no biochemical evidence of recurrence of the phaeochromocytoma, and genetic analysis was indicative of a sporadic lesion. Learning points Dual hormone secreting phaeochromocytomas with ACTH/or a precursor may cause secondary adrenal insufficiency following surgical removal.The concurrent features of Cushing's syndrome can be mild and easily overlooked presenting diagnostic and management pitfalls.As concomitant syndromes of hormone excess are rare in phaeochromocytomas; the diagnosis requires a high index of suspicion.Serial/diurnal cortisol levels, ACTH measurement +/− low dose dexamethasone suppression (when clinically stable, appropriate adrenergic blockade in place, and well supervised), can all be considered as needed. PMID:26113981

  10. Cerebral salt wasting syndrome distinct from the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

    PubMed

    Yamaki, T; Tano-oka, A; Takahashi, A; Imaizumi, T; Suetake, K; Hashi, K

    1992-01-01

    Two cases with pituitary tumour developed postoperative hyponatraemia which was not caused by inappropriate secretion of antidiuretic hormone. The one case with non-functioning macro-adenoma showed severe hyponatraemia (116 mEq/l) on day 11 after trans-sphenoidal surgery in association with diabetes insipidus (DI). The patients was treated by aqueous pitressin and saline administration to control urinary output and keep positive salt balance at the same time. The other case with GH-producing macro-adenoma showed progressive negative sodium balance with the total loss of 644 mEq resulting in hyponatraemia of 133 mEq/l. This was corrected by additional salt intake. The plasma atrial natriuretic polypeptide (ANP), antidiuretic hormone (ADH) as well as aldosterone levels were normal in the latter case. These patients were considered to manifest primary salt wasting disorder, which should be clearly differentiated from the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

  11. [Thyroid-stimulating hormone-secreting pituitary adenoma].

    PubMed

    Tóth, M; Rácz, K; Kiss, R; Fütö, L; Varga, I; Karlinger, K; Dékány, E; Czirják, S; Pásztor, E; Gláz, E

    1994-12-01

    A 40-year-old male patient with a 2 years history of recurring hyperthyroidism is presented with clinical hyperthyroidism and diffuse goiter. Despite thyreostatic treatment and surgical thyroid ablation the hyperthyroidism recurred. The patient had laboratory evidence of hyperthyroidism and his serum TSH was persistently and enormously elevated (T4:214 nmol/l, T3:6.9 nmol/l, TSH:218 mIU/l)> Computed tomography and magnetic resonance imaging confirmed a pituitary mass of 7 cm in a-p diameter, with supra-, parasellar and sphenoidal extension. The pituitary adenoma was partially resected by transsphenoidal surgery, which failed to result in a substantial decrease in the serum thyrotropin level. Pituitary irradiation and a long-term somatostatin analog octreotide treatment (300-600 micrograms/die) combined with bromocriptine therapy resulted in a significant, but still incomplete suppression of thyrotropin secretion (TSH level about 15 mIU/l) and persisting mild hyperthyroidism. The size of the adenoma was unchanged during the two years of highdose octreotide treatment period. According to our best knowledge this is the first reported case of a thyrotropin-secreting pituitary adenoma in Hungary. PMID:7991245

  12. Ghrelin suppresses nocturnal secretion of luteinizing hormone (LH) and thyroid stimulating hormone (TSH) in patients with major depression.

    PubMed

    Kluge, Michael; Schmidt, Doreen; Uhr, Manfred; Steiger, Axel

    2013-09-01

    Major depression is associated with various endocrine disturbances. Apart from the well-known hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, also the function of the hypothalamic-pituitary-gonadal (HPG) axis and of the hypothalamic-pituitary-thyroid (HPT) axis may be altered compared to healthy subjects. The orexigenic hormone ghrelin is involved in mood regulation and may have antidepressant effects. In addition, it has been shown to suppress secretion of luteinizing hormone (LH) and thyroid stimulating hormone (TSH) in healthy subjects. Aim of this study was therefore to test the effect of ghrelin on the activity of the HPG and HPT axis in patients with major depression. Therefore, secretion profiles of LH and TSH were determined in 14 unmedicated patients with major depression (7 women) twice, receiving 50 μg ghrelin or placebo at 2200, 2300, 0000, and 0100 h. LH secretion after ghrelin injection as assessed by the AUC (4.05 ± 1.18 mlIU min/ml) was significantly (P = 0.049) lower than after placebo injection (4.75 ± 1.33 mlIU min/ml) during the predefined intervention period (2220-0200 h). In addition, LH pulses occurred significantly (P = 0.045) less frequently after ghrelin injection (3.2 ± 1.4) than after placebo injection (3.9 ± 1.7). Mean TSH plasma levels were significantly lower at 0240 h and from 0320 until 0420 h after ghrelin injection than after placebo injection. In conclusion, ghrelin suppressed nocturnal secretion of LH and TSH in patients with major depression. However, these effects were weaker than previously shown in healthy subjects.

  13. Relative roles of follicle-stimulating hormone and luteinizing hormone in the control of inhibin secretion in normal men.

    PubMed Central

    McLachlan, R I; Matsumoto, A M; Burger, H G; de Kretser, D M; Bremner, W J

    1988-01-01

    The glycoprotein hormone inhibin is produced by the Sertoli cells of the testis under the influence of follicle-stimulating hormone (FSH) and is postulated in turn to inhibit FSH secretion. Luteinizing hormone (LH) is not recognized to have an important role in the control of inhibin secretion in any species. To determine the relative roles of FSH and LH in the control of inhibin secretion in man, we examined the effects of selective FSH and LH replacement on serum inhibin levels in normal men whose endogenous gonadotropins were suppressed by testosterone (T). After a 3-mo control period, nine men received 200 mg T enanthate i.m. weekly for 3-9 mo. During T treatment, serum LH and FSH levels were markedly suppressed and serum inhibin levels fell to 40% of control values. While continuing T, 3-5 mo of treatment with purified hFSH (n = 4) or hLH (n = 4) increased the respective serum gonadotropin level into the upper normal range and significantly increased inhibin levels back to 64 and 55% of control values, respectively. Supraphysiological LH replacement with high doses of human chorionic gonadotropin (n = 3) returned serum inhibin levels to 63% of control values. In no case did inhibin levels return fully to control levels. In conclusion, serum inhibin levels fell during gonadotropin suppression and were partially and approximately equally restored by either FSH or LH treatment. FSH presumably acts directly on the Sertoli cell to increase inhibin secretion whereas LH may act via increases in intratesticular T levels and/or other factor(s). Images PMID:3138288

  14. Episodic hormone secretion: a comparison of the basis of pulsatile secretion of insulin and GnRH

    PubMed Central

    Satin, Leslie S.

    2015-01-01

    Rhythms govern many endocrine functions. Examples of such rhythmic systems include the insulin-secreting pancreatic beta-cell, which regulates blood glucose, and the gonadotropin-releasing hormone (GnRH) neuron, which governs reproductive function. Although serving very different functions within the body, these cell types share many important features. Both GnRH neurons and beta-cells, for instance, are hypothesized to generate at least two rhythms endogenously: (1) a burst firing electrical rhythm and (2) a slower rhythm involving metabolic or other intracellular processes. This review discusses the importance of hormone rhythms to both physiology and disease and compares and contrasts the rhythms generated by each system. PMID:24610206

  15. In vitro impact of pegvisomant on growth hormone-secreting pituitary adenoma cells

    PubMed Central

    Cuny, Thomas; Zeiller, Caroline; Bidlingmaier, Martin; Défilles, Céline; Roche, Catherine; Blanchard, Marie-Pierre; Theodoropoulou, Marily; Graillon, Thomas; Pertuit, Morgane; Figarella-Branger, Dominique; Enjalbert, Alain; Brue, Thierry

    2016-01-01

    Pegvisomant (PEG), an antagonist of growth hormone (GH)-receptor (GHR), normalizes insulin-like growth factor 1 (IGF1) oversecretion in most acromegalic patients unresponsive to somatostatin analogs (SSAs) and/or uncontrolled by transsphenoidal surgery. The residual GH-secreting tumor is therefore exposed to the action of circulating PEG. However, the biological effect of PEG at the pituitary level remains unknown. To assess the impact of PEG in vitro on the hormonal secretion (GH and prolactin (PRL)), proliferation and cellular viability of eight human GH-secreting tumors in primary cultures and of the rat somatolactotroph cell line GH4C1. We found that the mRNA expression levels of GHR were characterized in 31 human GH-secreting adenomas (0.086 copy/copy β-Gus) and the GHR was identified by immunocytochemistry staining. In 5/8 adenomas, a dose-dependent inhibition of GH secretion was observed under PEG with a maximum of 38.2±17% at 1μg/mL (P<0.0001 vs control). A dose-dependent inhibition of PRL secretion occurred in three mixed GH/PRL adenomas under PEG with a maximum of 52.8±11.5% at 10μg/mL (P<0.0001 vs control). No impact on proliferation of either human primary tumors or GH4C1 cell line was observed. We conclude that PEG inhibits the secretion of GH and PRL in primary cultures of human GH(/PRL)-secreting pituitary adenomas without effect on cell viability or cell proliferation. PMID:27267119

  16. In vitro impact of pegvisomant on growth hormone-secreting pituitary adenoma cells.

    PubMed

    Cuny, Thomas; Zeiller, Caroline; Bidlingmaier, Martin; Défilles, Céline; Roche, Catherine; Blanchard, Marie-Pierre; Theodoropoulou, Marily; Graillon, Thomas; Pertuit, Morgane; Figarella-Branger, Dominique; Enjalbert, Alain; Brue, Thierry; Barlier, Anne

    2016-07-01

    Pegvisomant (PEG), an antagonist of growth hormone (GH)-receptor (GHR), normalizes insulin-like growth factor 1 (IGF1) oversecretion in most acromegalic patients unresponsive to somatostatin analogs (SSAs) and/or uncontrolled by transsphenoidal surgery. The residual GH-secreting tumor is therefore exposed to the action of circulating PEG. However, the biological effect of PEG at the pituitary level remains unknown. To assess the impact of PEG in vitro on the hormonal secretion (GH and prolactin (PRL)), proliferation and cellular viability of eight human GH-secreting tumors in primary cultures and of the rat somatolactotroph cell line GH4C1. We found that the mRNA expression levels of GHR were characterized in 31 human GH-secreting adenomas (0.086 copy/copy β-Gus) and the GHR was identified by immunocytochemistry staining. In 5/8 adenomas, a dose-dependent inhibition of GH secretion was observed under PEG with a maximum of 38.2±17% at 1μg/mL (P<0.0001 vs control). A dose-dependent inhibition of PRL secretion occurred in three mixed GH/PRL adenomas under PEG with a maximum of 52.8±11.5% at 10μg/mL (P<0.0001 vs control). No impact on proliferation of either human primary tumors or GH4C1 cell line was observed. We conclude that PEG inhibits the secretion of GH and PRL in primary cultures of human GH(/PRL)-secreting pituitary adenomas without effect on cell viability or cell proliferation. PMID:27267119

  17. Breast cancer presenting with the syndrome of inappropriate secretion of antidiuretic hormone after simple mastectomy.

    PubMed

    Hashida, H; Honda, T; Morimoto, H; Sasaki, T; Aibara, Y; Yamanaka, M

    2001-09-01

    A 71-year-old woman showed disorientation 7 days after simple mastectomy for right breast cancer. Computed tomography of the brain was normal. The level of serum sodium was very low (110 mEq/l), while the urine sodium level was normal. The osmolality of urine was higher (342 mosmol/kg) than that of serum (220 mosmol/kg). These data suggested a syndrome of inappropriate secretion of antidiuretic hormone. A fluid restriction, infusion of hypertonic saline and administration of diuretics gradually increased the level of serum sodium. Subsequently, disorientation disappeared. This is a rare case of the syndrome of inappropriate secretion of antidiuretic hormone caused by simple mastectomy, a relatively minor surgical procedure.

  18. Changes in plasma growth hormone (GH) and secretion patterns of GH and luteinizing hormone in buffaloes (Bubalus bubalis) during growth.

    PubMed

    Mondal, Mohan; Prakash, B S

    2004-08-01

    To assess the changes of plasma growth hormone (GH) and secretion patterns of GH and luteinizing hormone (LH) during growth in buffaloes, six growing female Murrah buffalo calves (mean age 6+/-0.9 months and body weight 66+/-6 kg) were selected. Plasma samples were collected twice a week for 52 weeks for GH and LH assay. To examine for pulsatile secretion samples were collected at 15 minutes interval for 9 hr at weeks 6 and 42 for GH and LH measurements. Plasma progesterone was also estimated in twice-a-week samples to assess whether any of the buffalo had begun ovarian cyclicity. The body weight of all animals was recorded at weekly interval. Plasma GH concentration decreased (P < 0.01) only up to week 29 and showed an increasing trend (P < 0.01) thereafter. The ratio of plasma GH to body weight declined (P < 0.01) throughout the entire experimental period. Plasma GH showed a declining trend only up to when the animals attained 155 kg body weight and thereafter showed an increasing trend (P < 0.01). Plasma GH revealed distinct pulsatile patterns of release, with a mean of 6 and 5 pulses in the 6-week and 42-week samples, respectively. The plasma LH concentrations around the 42-week time period were significantly higher (P < 0.01) than at the 6-week time period, and they exhibited pulsatility. No animal reached puberty until the end of the experiment. In summary, plasma GH levels have a definite pattern of change during growth and patterns of secretion of plasma GH and LH also have a relation with body weight in this species of animal. PMID:15554346

  19. Physiological significance of the rhythmic secretion of hypothalamic and pituitary hormones.

    PubMed

    Gan, Earn-Hui; Quinton, Richard

    2010-01-01

    The various hypothalamic-pituitary-end-organ/gland axes are central to the regulation of mammalian homeostasis. These have a core role in integrating the response of both endocrine and nervous systems to external and internal stimuli, by means of multi-level signalling through negative and positive feedback loops. The content of these hormonal signals is overwhelmingly conveyed in a rhythmic secretory pattern (frequency modulation of signal) that is energetically more efficient in transmitting neuroendocrine signals than the alternatives (modulation of signal by amplitude or by total area-under-curve). These rhythmic neuroendocrine secretions are individually distinct but the majority display a common feature of low-level basal secretion with superimposed pulsatile rhythms. The underlying mechanisms contributing to this unique rhythmic secretion are complicated and incompletely understood, but are beginning to be better defined as a result of several elegant studies performed in recent years. In some cases, signal transduction in the target tissue is critically dependent upon a pulsatile input, but in others the observed pulsatility is a downstream echo of obligate pulsatility exhibited by a higher-level control hormone. Thus, the gonads are presented with a pulsatile gonadotrophin signal, not because this is essential to gonadotrophin action (the same level of stimulation can be elicited by a continuous input), but as a downstream consequence of pulsatile GnRH-mediated stimulation of pituitary gonadotrophs. By contrast, rhythmicity of signal is embedded at all levels of the hypothalamo-pituitary-adrenal axis. Hypothalamic-pituitary rhythmic secretions are influenced by various internal and external inputs such as age, gender, sleep and wakefulness, food intake, light (photoperiod) or exposure to stress. Understanding the physiological significance of the rhythmic secretion of hypothalamic and pituitary hormones has the potential to provide insights into disease

  20. Failure of ethanol metabolites to alter gonadotropin secretion or luteinizing hormone synthesis in vitro.

    PubMed

    Uddin, S; Kirsteins, L; LaPaglia, N; Emanuele, N V; Lawrence, A M; Kelley, M R; Emanuele, M A

    1995-08-01

    The impact of ethanol on the male reproductive axis are multiple and varied, with both gonadal and control hypothalamic-pituitary pertubations being reported. There appears to be a discrepancy, however, between the in vivo and in vitro effects of ethanol on hypothalamic luteinizing hormones releasing hormone (LHRH) and the pituitary gonadotropins luteinizing hormone (LH) and follicle stimulating hormone (FSH). While in vivo data suggests a decrease in LHRH release after EtOH, in vitro studies find no effect on secretion. Similarly, in vivo acute EtOH profoundly diminishes LH synthesis and secretion, while in vitro impaired release with no alteration in the transcription of beta LH has been found. A potential exploration for these discrept results could be the in vivo metabolism of EtOH into acetaldehyde and acetate, or the subsequent formation of salsolinol, a product of acetate combining with dopamine. To test this possibility, a series of in vitro experiments were conducted exposing dispensed anterior pituitary cells from male rats to different doses of acetaldehyde, acetate or salsolinol for varying amounts of time for which gonadotropin secretion and beta LH mRNA levels were assessed. The results demonstrated no effect of either acetaldehyde or acetate on basal or LHRH stimulated LH release, FSH release or steady-state beta LH mRNA levels. These data suggest that the metabolites of EtOH, which occur in vivo but not in vitro, are not responsible for the discrepant gonadotropin changes reported between the in vivo and in vitro setting. Other potential mechanisms to explain this phenomenon include differences in the molarity of EtOH, hyperprolactinemia and suprapituitary influences including hypothalamic LHRH, catecholamines, excitatory amino acids, substance P and beta endorphin.

  1. A control system formulation of the mechanism that controls the secretions of serum group hormone in humans during sleep

    NASA Technical Reports Server (NTRS)

    Howard, J. C.; Young, D. R.

    1975-01-01

    Plasma growth hormone concentrations during sleep were determined experimentally. An elevated level of plasma growth hormone was observed during the initial phase of sleep and remained elevated for approximately 3 hr before returning to the steady-state level. Moreover, subsequent to a prolonged interruption of sleep, of the order of 2-3 hr, an elevated level of plasma growth hormone was again observed during the initial phase of resumed sleep. A control system formulation of the mechanism that controls the secretions of serum growth hormone in humans was used to account for the growth hormone responses observed.

  2. Decreased hypothalamic gonadotropin-releasing hormone secretion in male marathon runners.

    PubMed

    MacConnie, S E; Barkan, A; Lampman, R M; Schork, M A; Beitins, I Z

    1986-08-14

    Hypogonadotropic hypogonadism due to a deficiency in hypothalamic gonadotropin-releasing hormone is common in female athletes ("hypothalamic amenorrhea"). It is not known, however, whether a similar phenomenon occurs in male athletes. We investigated the integrity of the hypothalamic-pituitary-gonadal axis in six highly trained male marathon runners (who were running 125 to 200 km per week). The mean (+/- SEM) frequency of spontaneous luteinizing hormone pulses was diminished in the runners, as compared with healthy controls (2.2 +/- 0.48 vs. 3.6 +/- 0.24 pulses per eight hours, P less than 0.05). The amplitude of the pulses was also low in the runners (0.9 +/- 0.24 vs. 1.6 +/- 0.15 mlU per milliliter; P less than 0.05), and the responses of luteinizing hormone to gradually increasing doses of exogenous gonadotropin-releasing hormone were decreased. Plasma testosterone levels were similar in the two groups and increased equally in response to an intramuscular injection of 2000 units of human chorionic gonadotropin. During short-term intense physical exercise (a treadmill run at 72 percent of maximal oxygen consumption for two hours), the plasma gonadotropin levels in the athletes remained stable, but significant elevations in plasma levels of cortisol, prolactin, and testosterone occurred. We conclude that highly trained male athletes, like their female counterparts, may have a deficiency of hypothalamic gonadotropin-releasing hormone. This condition may be caused by the prolonged, repetitive elevations of gonadal steroids and other hormones known to suppress gonadotropin-releasing hormone secretion that are elicited by their daily exercise.

  3. Increased prolactin secretion and thyrotrophin response to thyrotrophin releasing hormone in Klinefelter's syndrome.

    PubMed

    Kumanov, P

    1995-01-01

    The reports published thus far on prolactin and thyrotrophin secretion in patients with Klinefelter's syndrome are controversial. The aim of the present study was to investigate the interrelation between prolactin on one hand, and hormones of the hypothalamic-pituitary-gonadal axis and thyrotrophin, on the other, in males with Klinefelter's syndrome. Fifteen patients with Klinefelter's syndrome, aged between 17 and 43 years, and 15 healthy males, aged 22-35 years, were studied. Mean +/- SD basal serum prolactin levels were 529.6 +/- 174.6 mU l-1 in the patients, and 270.1 +/- 113.0 mU l-1 in the control group (P < 0.001). Following 200 micrograms thyrotrophin releasing hormone, an enhanced prolactin response was seen in the males with Klinefelter's syndrome. There was no evidence of any of the well-known causes of hyperprolactinaemia. The response of thyrotrophin to thyrotrophin releasing hormone was more pronounced in Klinefelter patients in comparison with controls. Presumably, in Klinefelter's syndrome both alterations--of prolactin and thyrotrophin secretion--may be caused by decrease of testosterone levels or they could reflect a disturbance in neuroendocrine regulation with some neurotransmitter imbalance.

  4. Diurnal variations of hormonal secretion, alertness and cognition in extreme chronotypes under different lighting conditions

    PubMed Central

    Maierova, L.; Borisuit, A.; Scartezzini, J.-L.; Jaeggi, S. M.; Schmidt, C.; Münch, M.

    2016-01-01

    Circadian rhythms in physiology and behavior are modulated by external factors such as light or temperature. We studied whether self-selected office lighting during the habitual waking period had a different impact on alertness, cognitive performance and hormonal secretion in extreme morning and evening chronotypes (N = 32), whose preferred bed- and wake-up times differed by several hours. The self-selected lighting condition was compared with constant bright light and a control condition in dim light. Saliva samples for hormonal analyses, subjective ratings of alertness, wellbeing, visual comfort and cognitive performance were regularly collected. Between the self-selected and the bright, but not the dim lighting condition, the onset of melatonin secretion in the evening (as marker for circadian phase) was significantly different for both chronotypes. Morning chronotypes reported a faster increase in sleepiness during the day than evening chronotypes, which was associated with higher cortisol secretion. Wellbeing, mood and performance in more difficult cognitive tasks were better in bright and self-selected lighting than in dim light for both chronotypes, whereas visual comfort was best in the self-selected lighting. To conclude, self-selection of lighting at work might positively influence biological and cognitive functions, and allow for inter-individual differences. PMID:27646174

  5. Dolomite supplementation improves bone metabolism through modulation of calcium-regulating hormone secretion in ovariectomized rats.

    PubMed

    Mizoguchi, Toshihide; Nagasawa, Sakae; Takahashi, Naoyuki; Yagasaki, Hiroshi; Ito, Michio

    2005-01-01

    Dolomite, a mineral composed of calcium magnesium carbonate (CaMg (CO3)2), is used as a food supplement that supplies calcium and magnesium. However, the effect of magnesium supplementation on bone metabolism in patients with osteoporosis is a matter of controversy. We examined the effects of daily supplementation with dolomite on calcium metabolism in ovariectomized (OVX) rats. Dolomite was administered daily to OVX rats for 9 weeks. The same amount of magnesium chloride as that supplied by the dolomite was given to OVX rats as a positive control. Histological examination revealed that ovariectomy decreased trabecular bone and increased adipose tissues in the femoral metaphysis. Dolomite or magnesium supplementation failed to improve these bone histological features. Calcium content in the femora was decreased in OVX rats. Neither calcium nor magnesium content in the femora in OVX rats was significantly increased by dolomite or magnesium administration. Urinary deoxypyridinoline excretion was significantly increased in OVX rats, and was not affected by the magnesium supplementation. Serum concentrations of magnesium were increased, and those of calcium were decreased, in OVX rats supplemented with dolomite or magnesium. However, there was a tendency toward decreased parathyroid hormone secretion and increased calcitonin secretion in OVX rats supplemented with dolomite or magnesium. Serum 1,25-dihydroxyvitamin D(3) and osteocalcin levels were significantly increased in the supplemented OVX rats. These results suggest that increased magnesium intake improves calcium metabolism in favor of increasing bone formation, through the modulation of calcium-regulating hormone secretion.

  6. Diurnal variations of hormonal secretion, alertness and cognition in extreme chronotypes under different lighting conditions.

    PubMed

    Maierova, L; Borisuit, A; Scartezzini, J-L; Jaeggi, S M; Schmidt, C; Münch, M

    2016-01-01

    Circadian rhythms in physiology and behavior are modulated by external factors such as light or temperature. We studied whether self-selected office lighting during the habitual waking period had a different impact on alertness, cognitive performance and hormonal secretion in extreme morning and evening chronotypes (N = 32), whose preferred bed- and wake-up times differed by several hours. The self-selected lighting condition was compared with constant bright light and a control condition in dim light. Saliva samples for hormonal analyses, subjective ratings of alertness, wellbeing, visual comfort and cognitive performance were regularly collected. Between the self-selected and the bright, but not the dim lighting condition, the onset of melatonin secretion in the evening (as marker for circadian phase) was significantly different for both chronotypes. Morning chronotypes reported a faster increase in sleepiness during the day than evening chronotypes, which was associated with higher cortisol secretion. Wellbeing, mood and performance in more difficult cognitive tasks were better in bright and self-selected lighting than in dim light for both chronotypes, whereas visual comfort was best in the self-selected lighting. To conclude, self-selection of lighting at work might positively influence biological and cognitive functions, and allow for inter-individual differences. PMID:27646174

  7. Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation

    NASA Technical Reports Server (NTRS)

    Grindeland, Richard E.; Roy, R. R.; Edgerton, V. R.; Gosselink, K. L.; Grossman, E. J.; Sawchenko, P. E.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    Growth hormone (GH) secretion is stimulated by aerobic and resistive exercise and inhibited by exposure to actual or simulated (bedrest, hindlimb suspension) microgravity. Moreover, hypothalamic growth hormone-releasing factor (GRF) and preproGRF mRNA are markedly decreased in spaceflight rats. These observations suggest that reduced sensory input from inactive muscles may contribute to the reduced secretion of GH seen in "0 G". Thus, the aim of this study was to determine the effect of muscle sensory nerve stimulation on secretion of GH. Fed male Wistar rats (304 +/- 23 g) were anesthetized (pentobarbital) and the right peroneal (Pe), tibial (T), and sural (S) nerves were cut. Electrical stimulation of the distal (D) or proximal (P) ends of the nerves was implemented for 15 min. to mimic the EMG activity patterns of ankle extensor muscles of a rat walking 1.5 mph. The rats were bled by cardiac puncture and their anterior pituitaries collected. Pituitary and plasma bioactive (BGH) and immunoactive (IGH) GH were measured by bioassay and RIA.

  8. Dolomite supplementation improves bone metabolism through modulation of calcium-regulating hormone secretion in ovariectomized rats.

    PubMed

    Mizoguchi, Toshihide; Nagasawa, Sakae; Takahashi, Naoyuki; Yagasaki, Hiroshi; Ito, Michio

    2005-01-01

    Dolomite, a mineral composed of calcium magnesium carbonate (CaMg (CO3)2), is used as a food supplement that supplies calcium and magnesium. However, the effect of magnesium supplementation on bone metabolism in patients with osteoporosis is a matter of controversy. We examined the effects of daily supplementation with dolomite on calcium metabolism in ovariectomized (OVX) rats. Dolomite was administered daily to OVX rats for 9 weeks. The same amount of magnesium chloride as that supplied by the dolomite was given to OVX rats as a positive control. Histological examination revealed that ovariectomy decreased trabecular bone and increased adipose tissues in the femoral metaphysis. Dolomite or magnesium supplementation failed to improve these bone histological features. Calcium content in the femora was decreased in OVX rats. Neither calcium nor magnesium content in the femora in OVX rats was significantly increased by dolomite or magnesium administration. Urinary deoxypyridinoline excretion was significantly increased in OVX rats, and was not affected by the magnesium supplementation. Serum concentrations of magnesium were increased, and those of calcium were decreased, in OVX rats supplemented with dolomite or magnesium. However, there was a tendency toward decreased parathyroid hormone secretion and increased calcitonin secretion in OVX rats supplemented with dolomite or magnesium. Serum 1,25-dihydroxyvitamin D(3) and osteocalcin levels were significantly increased in the supplemented OVX rats. These results suggest that increased magnesium intake improves calcium metabolism in favor of increasing bone formation, through the modulation of calcium-regulating hormone secretion. PMID:15750692

  9. Diurnal variations of hormonal secretion, alertness and cognition in extreme chronotypes under different lighting conditions.

    PubMed

    Maierova, L; Borisuit, A; Scartezzini, J-L; Jaeggi, S M; Schmidt, C; Münch, M

    2016-09-20

    Circadian rhythms in physiology and behavior are modulated by external factors such as light or temperature. We studied whether self-selected office lighting during the habitual waking period had a different impact on alertness, cognitive performance and hormonal secretion in extreme morning and evening chronotypes (N = 32), whose preferred bed- and wake-up times differed by several hours. The self-selected lighting condition was compared with constant bright light and a control condition in dim light. Saliva samples for hormonal analyses, subjective ratings of alertness, wellbeing, visual comfort and cognitive performance were regularly collected. Between the self-selected and the bright, but not the dim lighting condition, the onset of melatonin secretion in the evening (as marker for circadian phase) was significantly different for both chronotypes. Morning chronotypes reported a faster increase in sleepiness during the day than evening chronotypes, which was associated with higher cortisol secretion. Wellbeing, mood and performance in more difficult cognitive tasks were better in bright and self-selected lighting than in dim light for both chronotypes, whereas visual comfort was best in the self-selected lighting. To conclude, self-selection of lighting at work might positively influence biological and cognitive functions, and allow for inter-individual differences.

  10. Thyrotropin-Releasing Hormone is not Required for Thyrotropin Secretion in the Perinatal Rat

    PubMed Central

    Theodoropoulos, Theodor; Braverman, Lewis E.; Vagenakis, Apostolos G.

    1979-01-01

    To determine the role of thyrotropin-releasing hormone (TRH) in the regulation of thyroid-stimulating hormone (TSH) secretion in the perinatal period, a physiological approach of neutralizing circulating TRH in the fetal and early neonatal rat was employed. TRH-antiserum (TRH-AS) raised in rabbits and administered daily to low iodine-propylthiouracil (LID-PTU)-fed pregnant rats from days 12 to 19 of gestation markedly impaired the rise in serum TSH to LID-PTU when compared with normal rabbit serum-treated controls. In contrast, fetal serum TSH was unaffected by TRH-AS. The binding capacity of TRH-AS in the fetal serum (111 ng/ml) far exceeded circulating TRH in the fetus. Similarly, acute TRH-AS administration to the pregnant rat fed LID-PTU markedly decreased the serum TSH concentration in the mother, but not in the fetus, 60 min after TRH-AS administration. Chronic TRH-AS administration to neonatal rats whose nursing mothers were fed LID-PTU was in-effective in decreasing the elevated serum TSH in the neonate through day 8 of life, whereas a slight but significant decrease in serum TSH was observed on day 10. Chronic daily TRH-AS administration to neonatal rats through day 10 of life had no effect on the later development of the hypothalamic-pituitary-thyroid axis. These findings suggest that TRH does not participate in TSH regulation during the perinatal life in the rat and that thyroid hormones are probably the main regulators of TSH secretion during this period. Placental TRH is not important in regulating TSH secretion in the fetal rat. Furthermore, TRH “deprivation” during neonatal life does not prevent normal later development of the hypothalamic-pituitary-thyroid axis. PMID:108290

  11. Effects of alcohol on pulsatile luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion in the adult male rat

    SciTech Connect

    Badger, T.M.; Abdallah, M.M.; Hayden, J.B. )

    1989-02-09

    To determine possible hypothalamic actions of alcohol on hormone secretion, the effects of acute intragastric alcohol on plasma LH and FSH pulsations were studied. One jugular and one intragastric cannula were surgically implanted into adult male Sprague Dawley rats. Eight days later, rats were bilaterally castrated at 1400 h and infused intragastrically with either saline or 3 g/kg ethanol between 0700 h 0800 h the next days. Blood samples (300 microliters) were collected every 5 min for 3 h (starting at 0800 h), centrifuged and the plasma was frozen for LH and FSH radioimmunoassay. The blood cells were resuspended in saline and returned to the animal immediately following the next sample collection. While the mean plasma LH or FSH concentration did not vary significantly between the alcohol-treated and saline-treated rats, the mean LH (but not FSH) pulse frequency was lower in ethanol-treated rats (3.3 {plus minus} 0.25 pulses/3 h) than saline-treated controls (7.2 {plus minus} 0.3 pulses/3 h). In addition, mean area under the OH pulses were significantly greater in ethanol-treated than saline controls. These data suggest that: (1) ethanol acts to reduce the frequency of LHRH release for the hypothalamus and increase the area under each LH pulse; and (2) LH and FSH secretion are differentially regulated.

  12. Human longevity is characterised by high thyroid stimulating hormone secretion without altered energy metabolism

    PubMed Central

    Jansen, S. W.; Akintola, A. A.; Roelfsema, F.; van der Spoel, E.; Cobbaert, C. M.; Ballieux, B. E.; Egri, P.; Kvarta-Papp, Z.; Gereben, B.; Fekete, C.; Slagboom, P. E.; van der Grond, J.; Demeneix, B. A.; Pijl, H.; Westendorp, R. G. J.; van Heemst, D.

    2015-01-01

    Few studies have included subjects with the propensity to reach old age in good health, with the aim to disentangle mechanisms contributing to staying healthier for longer. The hypothalamic-pituitary-thyroid (HPT) axis maintains circulating levels of thyroid stimulating hormone (TSH) and thyroid hormone (TH) in an inverse relationship. Greater longevity has been associated with higher TSH and lower TH levels, but mechanisms underlying TSH/TH differences and longevity remain unknown. The HPT axis plays a pivotal role in growth, development and energy metabolism. We report that offspring of nonagenarians with at least one nonagenarian sibling have increased TSH secretion but similar bioactivity of TSH and similar TH levels compared to controls. Healthy offspring and spousal controls had similar resting metabolic rate and core body temperature. We propose that pleiotropic effects of the HPT axis may favour longevity without altering energy metabolism. PMID:26089239

  13. Usefulness of urinary growth hormone (GH) measurement for evaluating endogenous GH secretion in acromegaly.

    PubMed

    Mauri, M; Picó, A M; Alfayate, R; Dominguez, J R; Cámara, R; Miralles, C

    1993-01-01

    We investigated the relationship between urinary growth hormone (u-GH) and spontaneous 24-hour plasma GH secretion in 15 acromegalic patients. To measure u-GH, we have developed a method based on concentrating the sample by centrifugal ultrafiltration and then performing an immunoradiometric assay using commercially available reagents. u-GH correlated well with the integrated concentration of plasma GH (r = 0.66, p < 0.02). Additionally, u-GH excretion in acromegalic patients was significantly higher than in the control group (190 +/- 100 vs. 3.89 +/- 0.56 pg/min, mean +/- SEM, p < 0.001). Immunoreactive u-GH showed the same elution pattern in Sephadex G-75 as standard or labeled hGH, proving that the substance measured in urine is authentic GH. In conclusion, u-GH appears to be a simple, noninvasive and inexpensive test for evaluating GH secretion in active acromegaly.

  14. Role of obestatin on growth hormone secretion: An in vitro approach

    SciTech Connect

    Pazos, Yolanda; Alvarez, Carlos J.P.; Camina, Jesus P.; Al-Massadi, Omar; Seoane, Luisa M.; Casanueva, Felipe F.

    2009-12-25

    Obestatin, the ghrelin-associated peptide, showed to activate MAPK signaling with no effect on Akt nor cell proliferating activity in rat tumor somatotroph cells (growth cells, GC). A sequential analysis of the obestatin transmembrane signaling pathway indicated a route involving the consecutive activation of G{sub i}, PI3k, novel PKC{epsilon}, and Src for ERK1/2 activation. Furthermore, obestatin treatment triggers growth hormone (GH) release in the first 30 min, being more acute at 15 min. At 1 h, obestatin treated cells showed the same levels in GH secretion than controls. Added to this functionality, obestatin was secreted by GC cells. Based on the capacity to stimulate GH release from somatotroph cells, obestatin may act directly in the pituitary through an autocrine/paracrine mechanism.

  15. Selective optogenetic activation of arcuate kisspeptin neurons generates pulsatile luteinizing hormone secretion.

    PubMed

    Han, Su Young; McLennan, Timothy; Czieselsky, Katja; Herbison, Allan E

    2015-10-20

    Normal reproductive functioning in mammals depends upon gonadotropin-releasing hormone (GnRH) neurons generating a pulsatile pattern of gonadotropin secretion. The neural mechanism underlying the episodic release of GnRH is not known, although recent studies have suggested that the kisspeptin neurons located in the arcuate nucleus (ARN) may be involved. In the present experiments we expressed channelrhodopsin (ChR2) in the ARN kisspeptin population to test directly whether synchronous activation of these neurons would generate pulsatile luteinizing hormone (LH) secretion in vivo. Characterization studies showed that this strategy targeted ChR2 to 70% of all ARN kisspeptin neurons and that, in vitro, these neurons were activated by 473-nm blue light with high fidelity up to 30 Hz. In vivo, the optogenetic activation of ARN kisspeptin neurons at 10 and 20 Hz evoked high amplitude, pulse-like increments in LH secretion in anesthetized male mice. Stimulation at 10 Hz for 2 min was sufficient to generate repetitive LH pulses. In diestrous female mice, only 20-Hz activation generated significant increments in LH secretion. In ovariectomized mice, 5-, 10-, and 20-Hz activation of ARN kisspeptin neurons were all found to evoke LH pulses. Part of the sex difference, but not the gonadal steroid dependence, resulted from differential pituitary sensitivity to GnRH. Experiments in kisspeptin receptor-null mice, showed that kisspeptin was the critical neuropeptide underlying the ability of ARN kisspeptin neurons to generate LH pulses. Together these data demonstrate that synchronized activation of the ARN kisspeptin neuronal population generates pulses of LH. PMID:26443858

  16. Selective optogenetic activation of arcuate kisspeptin neurons generates pulsatile luteinizing hormone secretion.

    PubMed

    Han, Su Young; McLennan, Timothy; Czieselsky, Katja; Herbison, Allan E

    2015-10-20

    Normal reproductive functioning in mammals depends upon gonadotropin-releasing hormone (GnRH) neurons generating a pulsatile pattern of gonadotropin secretion. The neural mechanism underlying the episodic release of GnRH is not known, although recent studies have suggested that the kisspeptin neurons located in the arcuate nucleus (ARN) may be involved. In the present experiments we expressed channelrhodopsin (ChR2) in the ARN kisspeptin population to test directly whether synchronous activation of these neurons would generate pulsatile luteinizing hormone (LH) secretion in vivo. Characterization studies showed that this strategy targeted ChR2 to 70% of all ARN kisspeptin neurons and that, in vitro, these neurons were activated by 473-nm blue light with high fidelity up to 30 Hz. In vivo, the optogenetic activation of ARN kisspeptin neurons at 10 and 20 Hz evoked high amplitude, pulse-like increments in LH secretion in anesthetized male mice. Stimulation at 10 Hz for 2 min was sufficient to generate repetitive LH pulses. In diestrous female mice, only 20-Hz activation generated significant increments in LH secretion. In ovariectomized mice, 5-, 10-, and 20-Hz activation of ARN kisspeptin neurons were all found to evoke LH pulses. Part of the sex difference, but not the gonadal steroid dependence, resulted from differential pituitary sensitivity to GnRH. Experiments in kisspeptin receptor-null mice, showed that kisspeptin was the critical neuropeptide underlying the ability of ARN kisspeptin neurons to generate LH pulses. Together these data demonstrate that synchronized activation of the ARN kisspeptin neuronal population generates pulses of LH.

  17. Cannabinoid CB1 receptor mediates glucocorticoid effects on hormone secretion induced by volume and osmotic changes.

    PubMed

    Ruginsk, S G; Uchoa, E T; Elias, L L K; Antunes-Rodrigues, J

    2012-02-01

    The present study provides the first in vivo evidence that the cannabinoid CB(1) receptor mediates the effects of dexamethasone on hormone release induced by changes in circulating volume and osmolality. Male adult rats were administered with the CB(1) receptor antagonist rimonabant (10 mg/Kg, p.o.), followed or not in 1 hour by dexamethasone (1 mg/Kg, i.p.). Extracellular volume expansion (EVE, 2 mL/100 g of body weight, i.v.) was performed 2 hours after dexamethasone or vehicle treatment using either isotonic (I-EVE, 0.15 mol/L) or hypertonic (H-EVE, 0.30 mol/L) NaCl solution. Five minutes after EVE, animals were decapitated and trunk blood was collected for all plasma measurements. Rimonabant potentiated oxytocin (OT) secretion induced by H-EVE and completely reversed the inhibitory effects of dexamethasone in response to the same stimulus. These data suggest that glucocorticoid modulation of OT release is mediated by the CB(1) receptor. Although dexamethasone did not affect vasopressin (AVP) secretion induced by H-EVE, the administration of rimonabant potentiated AVP release in response to the same stimulus, supporting the hypothesis that the CB(1) receptor regulates AVP secretion independently of glucocorticoid-mediated signalling. Dexamethasone alone did not affect atrial natriuretic peptide (ANP) release stimulated by I-EVE or H-EVE. However, pretreatment with rimonabant potentiated ANP secretion induced by H-EVE, suggesting a possible role for the CB(1) receptor in the control of peripheral factors that modulate cardiovascular function. Rimonabant also reversed the inhibitory effects of dexamethasone on H-EVE-induced corticosterone secretion, reinforcing the hypothesis that the CB(1) receptor may be involved in the negative feedback exerted by glucocorticoids on the activity of the hypothalamic-pituitary-adrenal axis. Collectively, the results of the present study indicate that the CB(1) receptor modulates neurohypophyseal hormone secretion and

  18. Syndrome of Inappropriate Antidiuretic Hormone Secretion and Cerebral/Renal Salt Wasting Syndrome: Similarities and Differences

    PubMed Central

    Oh, Ji Young; Shin, Jae Il

    2015-01-01

    Hyponatremia (sodium levels of <135 mEq/L) is one of the most common electrolyte imbalances in clinical practice, especially in patients with neurologic diseases. Hyponatremia can cause cerebral edema and brain herniation; therefore, prompt diagnosis and proper treatment is important in preventing morbidity and mortality. Among various causes of hyponatremia, diagnosing syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cerebral/renal salt wasting syndrome (C/RSW) is difficult due to many similarities. SIADH is caused by excess of renal water reabsorption through inappropriate antidiuretic hormone secretion, and fluid restriction is the treatment of choice. On the other hand, C/RSW is caused by natriuresis, which is followed by volume depletion and negative sodium balance and replacement of water and sodium is the mainstay of treatment. Determinating volume status in hyponatremic patients is the key point in differential between SIADH and C/RSW. However, in most situations, differential diagnosis of these two diseases is difficult because they overlap in many clinical and laboratory aspects, especially to assess differences in volume status of these patients. Although distinction between the SIADH and C/RSW is difficult, improvement of hypouricemia and an increased fractional excretion of uric acid after the correction of hyponatremia in SIADH, not in C/RSW, may be one of the helpful points in discriminating the two diseases. In this review, we compare these two diseases regarding the pathophysiologic mechanisms, diagnosis, and therapeutic point of view. PMID:25657991

  19. Effect of copper deficiency on the content and secretion of pancreatic islet hormones

    SciTech Connect

    Bhathena, S.J.; Voyles, N.R.; Timmers, K.I.; Fields, M.; Kennedy, B.W.; Recant, L.

    1986-03-01

    Experimental copper (Cu) deficiency in rats is characterized by glucose intolerance and hyperlipemia. Its severity is increased by dietary fructose (F) as compared to starch (S). Since islet hormones are intimately involved in carbohydrate metabolism the authors studied the effects of Cu deficiency on their content and secretion. Rats were fed Cu deficient (CuD) (0.6 ..mu..g Cu/g) or Cu supplemented (6.0 ..mu..g Cu/g) diets with either 62% F or S for 7 weeks after weaning. Feeding CuD diets decreased plasma insulin (I) (P < 0.001) but not plasma glucagon (G). F feeding compared to S magnified the effects of Cu deficiency. Total pancreatic content of I in CuD rats was increased threefold (P < 0.001). Total somatostatin content increased significantly only in the pancreas of CuD rats fed F. Although total G content was not altered in CuD rats, when G was expressed per g protein or g wet weight, significant increases were found in CuD rats fed F. Thus, of the islet hormones, the major effect of Cu deficiency was on I. When pancreata were perfused in vitro with high glucose, pancreas from CuD rats had reduced insulin response. Thus, cellular functions dependent on Cu are involved in maintaining the ability of the islets of Langerhans to secrete I in a normal fashion.

  20. Endogenous opiates modulate the pulsatile secretion of biologically active luteinizing hormone in man.

    PubMed

    Veldhuis, J D; Rogol, A D; Johnson, M L

    1983-12-01

    We studied the secretion of physiological pools of immunoreactive and biologically active luteinizing hormone in response to endogenous pulses of gonadotropin-releasing hormone (GNRH) in eugonadal men. Concentrations of immunoactive and bioactive luteinizing hormone (LH) were determined in blood drawn at 20-min intervals for 8 h in eight normal men under two conditions: (a) after placebo, in order to evaluate spontaneous LH pulsations in the basal state, and (b) after administration of the opiate-receptor antagonist, naltrexone, which is believed to amplify the pulsatile release of endogenous GNRH. Spontaneous and naltrexone-stimulated secretion of LH occurred in pulses of high biological activity, as measured in the RICT (rat interstitial cell testosterone bioassay), i.e., bioactive:immunoactive LH ratios within both spontaneous and naltrexone-stimulated LH pulses were higher than corresponding interpulse ratios (P less than 0.001). Quantitative characterization of the pulsatile release of bioactive LH revealed the following specific effects of opiate-receptor blockade: increased 8-h mean and integrated serum concentrations of bioactive LH (P less than 0.002), enhanced pulse frequency of bioactive LH release (P less than 0.001), and augmented peak amplitude of bio-LH pulses (P less than 0.01). Moreover, this increase in episodic secretion of bioactive LH was associated with increased 8-h mean and integrated serum testosterone concentrations in these men (P less than 0.05). We conclude the following: (a) LH is normally released in spontaneous pulses of high biological activity in men; (b) when the endogenous GNRH signal is amplified by opiate-receptor blockade, the pituitary gland releases more frequent bioactive LH pulses, which are of high amplitude and contain a high bioactive:immunoactive LH ratio. This increase in pulsatile release of bioactive LH quantitated in the RICT assay in vitro is reflected by acutely increased serum testosterone concentrations in vivo

  1. Hypothalamic Effects of Tamoxifen on Oestrogen Regulation of Luteinising Hormone and Prolactin Secretion in Female Rats.

    PubMed

    Aquino, N S S; Araujo-Lopes, R; Batista, I A R; Henriques, P C; Poletini, M O; Franci, C R; Reis, A M; Szawka, R E

    2016-01-01

    Oestradiol (E2) acts in the hypothalamus to regulate luteinising hormone (LH) and prolactin (PRL) secretion. Tamoxifen (TX) has been extensively used as a selective oestrogen receptor modulator, although its neuroendocrine effects remain poorly understood. In the present study, we investigated the hypothalamic effects of TX in rats under low or high circulating E2 levels. Ovariectomised (OVX) rats treated with oil, E2 or TX, or E2 plus TX, were evaluated for hormonal secretion and immunohistochemical analyses in hypothalamic areas. Both E2 and TX reduced LH levels, whereas TX blocked the E2 -induced surges of LH and PRL. TX prevented the E2 -induced expression of progesterone receptor (PR) in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC), although it did not alter PR expression in OVX rats. TX blocked the E2 induction of c-Fos in AVPV neurones, consistent with the suppression of LH surge. However, TX failed to prevent E2 inhibition of kisspeptin expression in the ARC. In association with the blockade of PRL surge, TX increased the phosphorylation of tyrosine hydroxylase (TH) in the median eminence of OVX, E2 -treated rats. TX also precluded the E2 -induced increase in TH expression in the ARC. In all immunohistochemical analyses, TX treatment in OVX rats caused no measurable effect on the hypothalamus. Thus, TX is able to prevent the positive- but not negative-feedback effect of E2 on the hypothalamus. TX also blocks the effects of E2 on tuberoinfundibular dopaminergic neurones and PRL secretion. These findings further characterise the anti-oestrogenic actions of TX in the hypothalamus and provide new information on the oestrogenic regulation of LH and PRL. PMID:26563816

  2. Tyrphostin-23 enhances steroid-hormone secretion from dispersed human and rat adrenocrotical cells.

    PubMed

    Andreis, P G; Neri, G; Tortorella, C; Gottardo, L; Nussdorfer, G G

    2000-08-01

    Tyrphostin-23 is commonly used as inhibitor of tyrosine kinase (TK). We found that tyrphostin-23 concentration-dependently increased basal steroid-hormone secretion from dispersed human and rat adrenocortical cells, the maximal effective concentration being 10(-5) M. Tyrphostin-23 (10(-5) M) enhanced 10(-9) M angiotensin-II- and endothelin-1-stimulated secretion of human and rat adrenocortical cells, but not the secretory response to 10(-9) M ACTH However, it increased the response to lower concentrations (10(-12) or 10(-11) M) of ACTH. The secretagogue effect of tyrphostin-23 on dispersed rat adrenocortical cells was abolished by either the adenylate cyclase inhibitor SQ-22536 (10(-4) M) or the protein kinase A (PKA) inhibitor H-89 (10(-5) M). Tyrphostin-23 (10(-5) M) raised basal cyclic-AMP release by dispersed rat adrenocortical cells, but in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX, 10(-3) M) it was ineffective. Both tyrphostin-23 and IBMX increased cyclic-AMP release by rat adrenocortical cells in response to 10(-10) M ACTH, and their effects were not additive. Taken together, our findings suggest that tyrphostin-23, acting as an inhibitor of phosphodiesterases in adrenocortical cells, increases the intracellular concentration of cyclic-AMP available for PKA activation thereby stimulating steroid-hormone secretion. They also stress that caution must be used in interpreting the results of studies aimed at investigating the possible cross-talk between adenylate cyclase- and TK-dependent signaling cascades. PMID:11019898

  3. Salicylic Acid, a Plant Defense Hormone, Is Specifically Secreted by a Molluscan Herbivore

    PubMed Central

    Kästner, Julia; von Knorre, Dietrich; Himanshu, Himanshu; Erb, Matthias; Baldwin, Ian T.; Meldau, Stefan

    2014-01-01

    Slugs and snails are important herbivores in many ecosystems. They differ from other herbivores by their characteristic mucus trail. As the mucus is secreted at the interface between the plants and the herbivores, its chemical composition may play an essential role in plant responses to slug and snail attack. Based on our current knowledge about host-manipulation strategies employed by pathogens and insects, we hypothesized that mollusks may excrete phytohormone-like substances into their mucus. We therefore screened locomotion mucus from thirteen molluscan herbivores for the presence of the plant defense hormones jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA). We found that the locomotion mucus of one slug, Deroceras reticulatum, contained significant amounts of SA, a plant hormone that is known to induce resistance to pathogens and to suppress plant immunity against herbivores. None of the other slugs and snails contained SA or any other hormone in their locomotion mucus. When the mucus of D. reticulatum was applied to wounded leaves of A. thaliana, the promotor of the SA-responsive gene pathogenesis related 1 (PR1) was activated, demonstrating the potential of the mucus to regulate plant defenses. We discuss the potential ecological, agricultural and medical implications of this finding. PMID:24466122

  4. Impaired thyrotrophin secretion following the administration of thyrotrophin-releasing hormone in type II diabetes mellitus.

    PubMed Central

    Small, M.; Cohen, H. N.; MacLean, J. A.; Beastall, G. H.; MacCuish, A. C.

    1986-01-01

    Serum thyrotrophin has been measured before and after the intravenous administration of 200 micrograms of thyrotrophin-releasing hormone in 91 white subjects (33 stable diabetic patients and 58 healthy controls), none of whom had any clinical evidence of thyroid or pituitary dysfunction. Seven of the diabetic subjects failed to achieve a rise of serum thyrotrophin of greater than 2 mU/l above basal concentrations, as compared with only one of the control subjects (P = 0.006). The difference in response between diabetics and controls was confined to patients with Type II (non-insulin-dependent) diabetes: thus 5 of 13 Type II patients and 2 of 20 Type I (insulin-dependent) patients failed to show a normal response to thyrotrophin releasing hormone injection. No significant effect of glycaemic control on thyrotrophin responses was noted. These results suggest that Type II diabetes mellitus may be a cause of impaired thyrotrophin secretion in patients with no clinical evidence of pituitary disease. The mechanism for this impaired pituitary hormone release remains to be clarified. PMID:3095820

  5. Meal induced gut hormone secretion is altered in aerobically trained compared to sedentary young healthy males.

    PubMed

    Lund, Michael Taulo; Taudorf, Lærke; Hartmann, Bolette; Helge, Jørn Wulff; Holst, Jens Juel; Dela, Flemming

    2013-11-01

    Postprandial insulin release is lower in healthy aerobically trained (T) compared to untrained (UT) individuals. This may be mediated by a lower release of the two incretin hormones [glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)] in T. The aim of this study was to assess and compare gut hormone response and satiety changes after a liquid meal intake in young, healthy T and UT males. Postprandial gut hormone release and subjective feelings of hunger, satiety, fullness and prospective food consumption were assessed before and frequently for the following 3 h after a 200 ml liquid meal (1,260 kJ and 27, 41 and 32 energy % as protein, carbohydrates and fat, respectively) in ten T and ten UT young, healthy male subjects. The insulin and GIP responses were markedly lower in T than UT and correlated during the first 30 min after the liquid meal. Baseline GLP-1 concentration was higher in T versus UT, but the response in the following 3 h after a liquid meal was similar in T and UT. Satiety measures did not differ between groups throughout the test. It is possible that in aerobically T subjects, a lower GIP release is partly responsible for a lower postprandial incretin stimulated insulin secretion.

  6. Human growth hormone and prolactin secreting pituitary adenomas analyzed by in situ hybridization.

    PubMed

    Lloyd, R V; Cano, M; Chandler, W F; Barkan, A L; Horvath, E; Kovacs, K

    1989-03-01

    Acidophilic pituitary adenomas commonly produce growth hormone (GH) or prolactin (PRL), according to studies employing immunohistochemical and ultrastructural methods. To examine this question, in situ hybridization with oligonucleotide probes was done on routinely processed tissues received in the pathology laboratory to analyze for the presence of GH and PRL messenger RNA (mRNA) in 4 normal pituitaries, 10 prolactinomas, and 16 GH-secreting adenomas. Most acidophilic cells in normal pituitaries expressed either GH or PRL hormone and the respective mRNAs, but GH mRNA and PRL hormone were also detected in some of the same cells. Patients with a clinical diagnosis of prolactinoma had cells with only PRL mRNA in their tumors, while most (14 of 16) patients with a clinical diagnosis of acromegaly or gigantism had both GH and PRL mRNAs in their tumors. The GH adenomas varied in these studies. In situ hybridization was helpful in characterizing the adenoma from a patient with acromegaly who had immunoreactive PRL, but no immunoreactive GH in the resected tumor; in situ hybridization analysis revealed mRNAs for both GH and PRL in the same tumor cells. Our findings indicate that pituitary adenomas from patients with acromegaly commonly express PRL mRNA. It is concluded that in situ hybridization provides new information about the clinical biology and the histopathologic classification of pituitary adenomas. PMID:2466405

  7. Hormonal control in a state of decreased activation: potentiation of arginine vasopressin secretion.

    PubMed

    O'Halloran, J P; Jevning, R; Wilson, A F; Skowsky, R; Walsh, R N; Alexander, C

    1985-10-01

    Behaviorally induced stress is associated with increased arginine vasopressin (AVP) secretion. In this report we describe a phasic conditioned response of AVP secretion yielding 2.6-7.1 times normal plasma concentration of this hormone in association with a physiological state of decreased activation, that associated with the mental technique of "transcendental meditation" (TM) in long-term practitioners (6-8 years of regular elicitation). Such a very large phasic response of AVP was previously unknown in the normal physiology of AVP. This elevation was not accompanied by elevation of plasma osmolality. Unstylized ordinary eyes closed rest in a separate group of subjects studied in the same manner was associated with normal plasma AVP concentration. Galvanic skin resistance (GSR) increased during both TM and rest with significantly larger increase associated with TM. Other measures of activation, including muscle metabolism, and the Spielberger Anxiety Inventory indicated marked relaxation in association with TM. In previous research it has been shown that blood pressure does not change acutely during this behavior. These observations indicate that neither stress nor operation of other usual homeostatic control mechanisms are responsible for elevated for AVP in the meditators. It is speculated that the apparently unique mechanism of TM-induced AVP secretion may be more specifically related to the behavioral effects of meditation.

  8. Syndrome of Inappropriate Secretion of Antidiuretic Hormone Associated with Localized Herpes Zoster Ophthalmicus

    PubMed Central

    Wang, Chih-Chiang; Shiang, Jeng-Chuan; Chen, Jiann-Tomg

    2010-01-01

    The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with localized herpes zoster is rarely reported and may be under-appreciated. We describe two diabetic men with herpes zoster ophthalmicus (HZO) who developed hyponatremia (114 and 116 mmol/L) during acute illness. Both were euvolemic and had elevated urine osmolality (435 and 368 mmol/kg.H2O) and sodium (Na+) concentration (61 and 63 mmol/L) along with normal cardiac, renal, liver, and endocrine function consistent with the diagnosis of SIADH. Thorough investigation for other causes of SIADH, including detailed physical examination, laboratory studies, and computed tomography of the brain, chest, and abdomen, were negative. Despite antiviral therapy (acyclovir) for herpes zoster, ophthalmoplegia, keratitis, and post-herpetic neuralgia (PHN) developed. Even with fluid restriction and high salt diet, SIADH lasted for 3 to 4 months and resolved concomitantly with resolution of PHN, suggesting an association between SIADH and HZO. These two cases raise the potential for herpes zoster infection, especially HZO, to involve the regulatory pathway of ADH secretion, contributing to SIADH. The presence of PHN, which reflects greater neural damage may, at least in part, explain the prolonged ADH secretion and hyponatremia. PMID:20878495

  9. [Alteration of thyroid hormone secretion after long-term exposure to low doses of endocrine disruptor DDT].

    PubMed

    Iaglova, N V; Iaglov, V V

    2014-01-01

    Endocrine disruptors are exogenous substances that exhibit hormone-like action and consequently disrupt homeostatic action of endogenous hormones. DDT is the most common disruptor. The objective was to evaluate changes in thyroid hormone secretion after long-term exposure to low doses of DDT. The experiment was performed on male Wistar rats. The rats were given DDT at doses of 1.89±0.86 мg/kg/day and 7.77±0.17 мg/kg/day for 6 and 10 weeks. Dose dependent increase of serum total thyroxine, total triiodthyronine, and thyroid peroxidase was revealed after 6 weeks exposure. After 10 weeks free thyroxine secretion was reduced. Such alterations of the thyroid status are typical for iodine deficient goiter. The data obtained indicate that the main mechanism of DDT action includes disruption of thyroxine secretion by thyrocytes, but not inhibition of deiodinase activity and decrease of blood thyroid binding proteins. PMID:25552505

  10. [Alteration of thyroid hormone secretion after long-term exposure to low doses of endocrine disruptor DDT].

    PubMed

    Iaglova, N V; Iaglov, V V

    2014-01-01

    Endocrine disruptors are exogenous substances that exhibit hormone-like action and consequently disrupt homeostatic action of endogenous hormones. DDT is the most common disruptor. The objective was to evaluate changes in thyroid hormone secretion after long-term exposure to low doses of DDT. The experiment was performed on male Wistar rats. The rats were given DDT at doses of 1.89±0.86 мg/kg/day and 7.77±0.17 мg/kg/day for 6 and 10 weeks. Dose dependent increase of serum total thyroxine, total triiodthyronine, and thyroid peroxidase was revealed after 6 weeks exposure. After 10 weeks free thyroxine secretion was reduced. Such alterations of the thyroid status are typical for iodine deficient goiter. The data obtained indicate that the main mechanism of DDT action includes disruption of thyroxine secretion by thyrocytes, but not inhibition of deiodinase activity and decrease of blood thyroid binding proteins.

  11. Sex steroids modulate luteinizing hormone-releasing hormone secretion in a cholinergic cell line from the basal forebrain.

    PubMed

    Martínez-Morales, J R; López-Coviella, I; Hernández-Jiménez, J G; Reyes, R; Bello, A R; Hernández, G; Blusztajn, J K; Alonso, R

    2001-01-01

    The function of a particular neuronal population is in part determined by its neurotransmitter phenotype. We have found that a neuronal-derived septal cell line (SN56), known for its cholinergic properties, also synthesizes and releases luteinizing hormone-releasing hormone. In addition, these cells express the messenger RNAs encoding estrogen and progesterone receptors. The activation of these receptors by their respective ligands cooperatively modulates the depolarization-induced release of luteinizing hormone-releasing hormone in these cells. We have also found that a number of septal neurons in postnatal (1-week-old) mice are immunoreactive to both choline acetyltransferase and luteinizing hormone-releasing hormone. These results indicate that both neurotransmitters, acetylcholine and luteinizing hormone-releasing hormone, may co-exist in septal neurons of the CNS and that they could be modulated by gonadal hormones, and suggest that luteinizing hormone-releasing hormone could be involved in some of the actions of sex steroids on cholinergic neurotransmission.

  12. Novel role for anti-Müllerian hormone in the regulation of GnRH neuron excitability and hormone secretion.

    PubMed

    Cimino, Irene; Casoni, Filippo; Liu, Xinhuai; Messina, Andrea; Parkash, Jyoti; Jamin, Soazik P; Catteau-Jonard, Sophie; Collier, Francis; Baroncini, Marc; Dewailly, Didier; Pigny, Pascal; Prescott, Mel; Campbell, Rebecca; Herbison, Allan E; Prevot, Vincent; Giacobini, Paolo

    2016-01-01

    Anti-Müllerian hormone (AMH) plays crucial roles in sexual differentiation and gonadal functions. However, the possible extragonadal effects of AMH on the hypothalamic-pituitary-gonadal axis remain unexplored. Here we demonstrate that a significant subset of GnRH neurons both in mice and humans express the AMH receptor, and that AMH potently activates the GnRH neuron firing in mice. Combining in vivo and in vitro experiments, we show that AMH increases GnRH-dependent LH pulsatility and secretion, supporting a central action of AMH on GnRH neurons. Increased LH pulsatility is an important pathophysiological feature in many cases of polycystic ovary syndrome (PCOS), the most common cause of female infertility, in which circulating AMH levels are also often elevated. However, the origin of this dysregulation remains unknown. Our findings raise the intriguing hypothesis that AMH-dependent regulation of GnRH release could be involved in the pathophysiology of fertility and could hold therapeutic potential for treating PCOS.

  13. Direct effects of catecholamines, thyrotropin-releasing hormone, and somatostatin on growth hormone and prolactin secretion from adenomatous and nonadenomatous human pituitary cells in culture.

    PubMed Central

    Ishibashi, M; Yamaji, T

    1984-01-01

    To determine the mechanism and the site of action of catecholamines as well as hormones including thyrotropin-releasing hormone (TRH)1 and somatostatin on pituitary hormone release in patients with acromegaly and in normal subjects, the effects of these substances on growth hormone (GH) and prolactin (PRL) secretion from adenomatous and nonadenomatous human pituitary cells in culture were examined. When dopamine (0.01-0.1 microM) or bromocriptine (0.01-0.1 microM) was added to the culture media, a significant inhibition of GH and PRL secretion from adenoma cells from acromegalic patients was observed. This inhibition was blocked by D2 receptor blockade with metoclopramide or sulpiride, but not by D1 receptor blockade. Similarly, dopamine suppressed GH and PRL release by nonadenomatous pituitary cells in a dose-dependent manner, which was again blocked by D2 receptor blockade. The minimum effective concentration of dopamine required for a significant inhibition of PRL secretion (0.01 microM) was lower than that for GH release (0.1 microM). Norepinephrine, likewise, caused a suppression of PRL secretion from adenomatous and nonadenomatous pituitary cells. This effect was blocked by sulpiride, phentolamine, however, was ineffective. When TRH was added to the media, both GH and PRL secretion were enhanced in adenoma cells, while only the stimulation of PRL release was observed in nonadenomatous pituitary cells. Coincubation of TRH and dopamine resulted in variable effects on GH and PRL secretion. Somatostatin consistently lowered GH and PRL secretion in both adenomatous and nonadenomatous pituitary cells and completely blocked the TRH-induced stimulation of GH and PRL secretion from adenoma cells. Opioid peptides (1 microM) failed to affect hormone release. These results suggest that no qualitative difference in GH and PRL responses to dopaminergic agonists or to somatostatin exists between adenoma cells of acromegalic patients and normal pituitary cells, and that the

  14. Evidence for the secretion of decidual luteotropin: a prolactin-like hormone produced by rat decidual cells.

    PubMed

    Herz, Z; Khan, I; Jayatilak, P G; Gibori, G

    1986-06-01

    Rat decidual tissue contains a PRL-like hormone named decidual luteotropin. We have recently revealed some of its physiological and biochemical characteristics. However, because rat decidual tissue contains specific binding sites for PRL, it was important to demonstrate that the hormone found in the tissue is not locally stored and structurally transformed PRL but a hormone actively synthesized by the rat decidual tissue. Decidual explants or decidual cells obtained from day 9 pseudopregnant rats were incubated for different times under either static conditions or continuously perifused with medium at a rate of 1 ml/h. Levels of decidual luteotropin were measured by a specific radioreceptor assay using luteal membranes as source of receptors and [125I]iodo-ovine(o)PRL as a tracer. In the static incubation, no proof of hormone production was obtained; levels of decidual luteotropin in medium and tissue or cells at the end of the incubation were similar to levels found in either cells or tissue before incubation. In sharp contrast, decidual cells perifused with media secreted large amounts of hormone. This may suggest that an inhibitor of decidual luteotropin production was being removed from the culture by the perifusion. For the first 4 h of perifusion, no hormone was produced. However by the fifth hour, cells began to actively release decidual luteotropin. Secretion of the hormone increased with time and reached maximal values between 7-15 h of perifusion. During the 15 h of perifusion, decidual cells released approximately 1000 times more decidual luteotropin than the amount they originally contained. A dose-response increase in hormone secretion was obtained with increased concentrations of decidual cells. The net amount of decidual luteotropin released into the medium over an 18-h period was approximately 6.5 micrograms/30 X 10(6) cells, 3.5 micrograms/10 X 10(6) cells, and 0.5 micrograms/2 X 10(6) cells. A similar profile of decidual luteotropin release was

  15. Influence of daily calcium and vitamin D supplementation on parathyroid hormone secretion.

    PubMed

    Reginster, J Y; Zegels, B; Lejeune, E; Micheletti, M C; Taquet, A N; Albert, A

    2001-02-01

    Calcium and vitamin D supplementation have been shown to reduce secondary hyperparathyroidism and play a role in age-related osteoporosis. In order to define the optimal regimen of calcium and vitamin D supplementation to produce the maximal inhibition of parathyroid hormone secretion, we compared the administration of a calcium-vitamin D supplement as a single morning dose with the administration of two divided doses at 6-hour intervals. Twelve healthy male volunteers were assigned to three investigational procedures, which were alternated at weekly intervals. After a 'blank' control procedure, when they were not exposed to any supplements, they received one of two calcium-vitamin D supplement regimens: either two doses of Orocal D3 (500 mg calcium and 400 IU vitamin D3) with a 6-hour interval between doses, or one water-soluble effervescent powder pack of Cacit vitamin D3, taken in the morning (1000 mg calcium and 880 IU vitamin D3). During the three procedures (control and the two calcium-vitamin D supplementation protocols), veinous blood was drawn every 60 minutes for up to 9 hours, for serum calcium and parathyroid hormone measurements. The order of administration of the two calcium and vitamin D supplementation regimens was allocated by randomization. No significant changes in serum calcium were observed during the study. During the first 6 hours following calcium-vitamin D supplementation, a statistically significant decrease in serum parathyroid hormone was observed with both regimens, compared with baseline and the control procedure. During this first period, no differences were observed between the two treatment regimens. However, between the 6th and the 9th hour, serum parathyroid hormone levels remained significantly decreased compared to baseline with the twice-daily Orocal D3 administration, while they returned to baseline values with the once-daily Cacit D3 preparation. During this period, the percentage decrease in serum parathyroid hormone

  16. Syndrome of inappropriate antidiuretic hormone secretion: Revisiting a classical endocrine disorder

    PubMed Central

    Pillai, Binu P.; Unnikrishnan, Ambika Gopalakrishnan; Pavithran, Praveen V.

    2011-01-01

    Hyponatremia occurs in about 30% of hospitalized patients and syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common cause of hyponatremia. SIADH should be differentiated from other causes of hyponatremia like diuretic therapy, hypothyroidism and hypocortisolism. Where possible, all attempts should be made to identify and rectify the cause of SIADH. The main problem in SIADH is fluid excess, and hyponatremia is dilutional in nature. Fluid restriction is the main stay in the treatment of SIADH; however, cerebral salt wasting should be excluded in the clinical setting of brain surgeries, subarachnoid hemorrhage, etc. Fluid restriction in cerebral salt wasting can be hazardous. Sodium correction in chronic hyponatremia (onset >48 hours) should be done slowly to avoid deleterious effects in brain. PMID:22029026

  17. The effects of vasoactive intestinal peptide on adrenal steroid hormone secretion

    SciTech Connect

    Cunningham, L.A.

    1988-01-01

    Vasoactive intestinal peptide (VIP)-immunoreactive nerve fibers have been demonstrated in the rat adrenal cortex in close association with zona glomerulosa cells. We have studied the effects of VIP on steroid hormone secretion from the outer zones of the normal rat adrenal cortex. Intact capsule-glomerulosa preparations, consisting of the capsule, zona glomerulosa, and a small portion of the zona fasciculata were perifused in vitro. The secretory responsiveness was assessed by measuring aldosterone and corticosterone release following stimulation with the physiological secretagogues ACTH and angiotensin II. The distribution of adrenal VIP receptors was assessed by in vitro autoradiography of {sup 125}I-VIP binding. {sup 125}I-VIP (0.75 and 2.0 nM) binding was concentrated in the capsule and zone glomerulosa, coincident with the distribution of VIP nerve fibers which aborize extensively in this region. The specificity of this binding was demonstrated using unlabelled VIP, ACTH and angiotensin II.

  18. Luteinizing hormone secretion in hemidecorticate female rats under several experimental conditions.

    PubMed

    Fernandes, G A; Antunes-Rodrigues, J; Covian, M R

    1978-01-01

    Luteinizing hormone (LH) secretion by the anterior pituitary gland was investigated in hemidecorticate (HD) rats under several conditions. Higher plasma and lower pituitary LH levels were observed in HD rats in the afternoon of proestrus, after unilateral ovariectomy, and at the 7th and 14th days after bilateral castration. The ovarian hypertrophy observed in HD rats did not differ from control. When hormonal substitutive therapy was started 3 days after bilateral ovariectomy, larger doses of estradiol benzoate (EB) were required to reduce plasma LH levels in control than in HD animals. The increase in pituitary weight was, however, significantly higher in the HD castrated group. When substitutive therapy started at the 7th and 14th days after castration no significant differences between the 2 experimental groups were observed. The results of substitutive therapy suggest that hemidecortication induces an increase in the sensitivity of hypothalamic-pituitary axis to estrogen negative feedback. This change in sensitivity is clearly seen in HD rats during the first few days after castration. These results suggest that hemidecortication may release the hypothalamus from inhibitory influences coming from rhinencephalic or cortical structures, thus rendering the preoptic-suprachiasmatic complex (POA-SCH) more sensitive to LH-releasing mechanisms.

  19. Acromegaloidism with normal growth hormone secretion associated with X-tetrasomy.

    PubMed

    Alvarez-Vázquez, Paula; Rivera, Alberto; Figueroa, Irene; Páramo, Concepción; García-Mayor, Ricardo V

    2006-01-01

    We reported a case of a 26-year-old female who was referred to our clinic with the diagnosis of possible acromegaly. She was born from a term pregnancy by forceps delivery. The patient was diagnosed as having hip luxation at one month and spoke her first word at 15 months. She had been diagnosed at the age of 9 years old as having perinatal encephalopathy with intellectual and motor affectation. Since this period of time she has undergone an insidious change in her appearance, mainly comprising progressive coarsening of the face. For this reason she was submitted to our clinic with presumed acromegaly. Dynamic tests of growth hormone secretion ruled out such a diagnosis. The Patient was considered as having "acromegaloidism", a term used for patients whom manifest clinical features of acromegaly but do not present a demonstrable growth hormone hypersecretion. Subsequently cytogenetic evaluation revealed an infrequent chromosome pattern: X-Tetrasomy. In the present article a differential diagnosis of acromegaloidism and the potential role of genes present on X-chromosome involved in human growth such as SHOX gene are discussed. Overdosification of SHOX gene might explain tall stature of girls with X-tetrasomy. Our observation suggested that X-tetrasomy should be considered in the differential diagnosis of acromegaloidism. Furthermore, this may lead to the identification of new genes in the X-chromosome that are important for growth of facial structures. PMID:16832583

  20. Acetylcholine is an autocrine or paracrine hormone synthesized and secreted by airway bronchial epithelial cells.

    PubMed

    Proskocil, Becky J; Sekhon, Harmanjatinder S; Jia, Yibing; Savchenko, Valentina; Blakely, Randy D; Lindstrom, Jon; Spindel, Eliot R

    2004-05-01

    The role of acetylcholine (ACh) as a key neurotransmitter in the central and peripheral nervous system is well established. However, the role of ACh may be broader because ACh may also function as an autocrine or paracrine signaling molecule in a variety of nonneuronal tissues. To begin to establish ACh of nonneuronal origin as a paracrine hormone in lung, we have examined neonatal and adult monkey bronchial epithelium for the components involved in nicotinic cholinergic signaling. Using immunohistochemistry and RT-PCR, we have demonstrated in lung bronchial epithelial cells (BECs) expression of choline acetyltransferase, the vesicular ACh transporter, the choline high-affinity transporter, alpha7, alpha4, and beta2 nicotinic ACh receptor (nAChR) subunits, and the nAChR accessory protein lynx1. Confocal microscopy demonstrates that these factors are expressed in epithelial cells and are clearly distinct from neighboring nerve fibers. Confirmation of RNA identity has been confirmed by partial sequence analysis of PCR products and by cDNA cloning. Primary culture of BECs confirms the synthesis and secretion of ACh and the activity of cholinesterases. Thus, ACh meets all the criteria for an autocrine/paracrine hormone in lung bronchial epithelium. The nonneuronal cholinergic signaling pathway in lung provides a potentially important target for cholinergic drugs. This pathway may also explain some of the effects of nicotine on fetal development and also provides additional mechanisms by which smoking affects lung cancer growth and development. PMID:14764638

  1. Development of Gonadotropin-Releasing Hormone-Secreting Neurons from Human Pluripotent Stem Cells.

    PubMed

    Lund, Carina; Pulli, Kristiina; Yellapragada, Venkatram; Giacobini, Paolo; Lundin, Karolina; Vuoristo, Sanna; Tuuri, Timo; Noisa, Parinya; Raivio, Taneli

    2016-08-01

    Gonadotropin-releasing hormone (GnRH) neurons regulate human puberty and reproduction. Modeling their development and function in vitro would be of interest for both basic research and clinical translation. Here, we report a three-step protocol to differentiate human pluripotent stem cells (hPSCs) into GnRH-secreting neurons. Firstly, hPSCs were differentiated to FOXG1, EMX2, and PAX6 expressing anterior neural progenitor cells (NPCs) by dual SMAD inhibition. Secondly, NPCs were treated for 10 days with FGF8, which is a key ligand implicated in GnRH neuron ontogeny, and finally, the cells were matured with Notch inhibitor to bipolar TUJ1-positive neurons that robustly expressed GNRH1 and secreted GnRH decapeptide into the culture medium. The protocol was reproducible both in human embryonic stem cells and induced pluripotent stem cells, and thus provides a translational tool for investigating the mechanisms of human puberty and its disorders. PMID:27426041

  2. Magnesium modulates parathyroid hormone secretion and upregulates parathyroid receptor expression at moderately low calcium concentration

    PubMed Central

    Rodríguez-Ortiz, Maria E.; Canalejo, Antonio; Herencia, Carmen; Martínez-Moreno, Julio M.; Peralta-Ramírez, Alan; Perez-Martinez, Pablo; Navarro-González, Juan F.; Rodríguez, Mariano; Peter, Mirjam; Gundlach, Kristina; Steppan, Sonja; Passlick-Deetjen, Jutta; Muñoz-Castañeda, Juan R.; Almaden, Yolanda

    2014-01-01

    Background The interest on magnesium (Mg) has grown since clinical studies have shown the efficacy of Mg-containing phosphate binders. However, some concern has arisen for the potential effect of increased serum Mg on parathyroid hormone (PTH) secretion. Our objective was to evaluate the direct effect of Mg in the regulation of the parathyroid function; specifically, PTH secretion and the expression of parathyroid cell receptors: CaR, the vitamin D receptor (VDR) and FGFR1/Klotho. Methods The work was performed in vitro by incubating intact rat parathyroid glands in different calcium (Ca) and Mg concentrations. Results Increasing Mg concentrations from 0.5 to 2 mM produced a left shift of PTH–Ca curves. With Mg 5 mM, the secretory response was practically abolished. Mg was able to reduce PTH only if parathyroid glands were exposed to moderately low Ca concentrations; with normal–high Ca concentrations, the effect of Mg on PTH inhibition was minor or absent. After 6-h incubation at a Ca concentration of 1.0 mM, the expression of parathyroid CaR, VDR, FGFR1 and Klotho (at mRNA and protein levels) was increased with a Mg concentration of 2.0 when compared with 0.5 mM. Conclusions Mg reduces PTH secretion mainly when a moderate low calcium concentration is present; Mg also modulates parathyroid glands function through upregulation of the key cellular receptors CaR, VDR and FGF23/Klotho system. PMID:24103811

  3. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas.

    PubMed

    Wang, Ji-Wen; Li, Ying; Mao, Zhi-Gang; Hu, Bin; Jiang, Xiao-Bing; Song, Bing-Bing; Wang, Xin; Zhu, Yong-Hong; Wang, Hai-Jun

    2014-01-01

    Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4-6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits. PMID:24421637

  4. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas

    PubMed Central

    Wang, Ji-wen; Li, Ying; Mao, Zhi-gang; Hu, Bin; Jiang, Xiao-bing; Song, Bing-bing; Wang, Xin; Zhu, Yong-hong; Wang, Hai-jun

    2014-01-01

    Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4–6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits. PMID:24421637

  5. Effect of gonadotropin-releasing hormone II receptor (GnRHR-II) knockdown on testosterone secretion in the boar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unlike the classical gonadotropin-releasing hormone (GnRH-I), the second mammalian GnRH isoform (GnRH-II; His5, Trp7, Tyr8) is a poor stimulator of gonadotropin secretion. In addition, GnRH-II is ubiquitously expressed, with transcript levels highest in tissues outside of the brain. A receptor speci...

  6. Thyroid-stimulating Hormone (TSH): Measurement of Intracellular, Secreted, and Circulating Hormone in Xenopus laevis and Xenopus tropicalis.

    EPA Science Inventory

    Thyroid Stimulating Hormone (TSH) is a hormone produced in the pituitary that stimulates the thyroid gland to grow and produce thyroid hormone (TH). The concentration of TH controls developmental changes that take place in a wide variety of organisms. Many use the metaphoric ch...

  7. Sex steroid hormones do not enhance the direct stimulatory effect of kisspetin-10 on the secretion of growth hormone from bovine anterior pituitary cells.

    PubMed

    Ezzat Ahmed, Ahmed; Saito, Hayato; Sawada, Tatsuru; Yaegashi, Tomoyoshi; Jin, Jin; Sawai, Ken; Yamashita, Tetsuro; Hashizume, Tsutomu

    2011-02-01

    The aims of the present study were to clarify the effect of kisspeptin10 (Kp10) on the secretion of growth hormone (GH) from bovine anterior pituitary (AP) cells, and evaluate the ability of sex steroid hormones to enhance the sensitivity of somatotrophic cells to Kp10. AP cells prepared from 8-11-month-old castrated calves were incubated for 12 h with estradiol (E(2), 10(-8) mol/L),progesterone (P(4), 10(-8) mol/L), testosterone (T, 10(-8) mol/L), or vehicle only (control), and then for 2 h with Kp10. The amount of GH released in the medium was measured by a time-resolved fluoroimmunoassay. Kp10 (10(-6) or 10(-5) mol/L) significantly stimulated the secretion of GH from the AP cells regardless of steroid treatments (P < 0.05), and E(2), P(4), and T had no effect on this response. The GH-releasing response to growth hormone-releasing hormone (GHRH, 10(-8) mol/L) was significantly greater than that to Kp10 (P < 0.05). The present results suggest that Kp10 directly stimulates the release of GH from somatotrophic cells and sex steroid hormones do not enhance the sensitivity of these cells to Kp10. Furthermore, they suggest that the GH-releasing effect of Kp10 is less potent than that of GHRH.

  8. Glucocorticoid stimulates expression of corticotropin-releasing hormone gene in human placenta

    SciTech Connect

    Robinson, B.G.; Emanuel, R.L.; Frim, D.M.; Majzoub, J.A. )

    1988-07-01

    Primary cultures of purified human cytotrophoblasts have been used to examine the expression of the corticotropin-releasing hormone (CRH) gene in placenta. The authors report here that glucocorticoids stimulate placental CRH synthesis and secretion in primary cultures of human placenta. This stimulation is in contrast to the glucocorticoid suppression of CRH expression in hypothalamus. The positive regulation of CRH by glucocorticoids suggests that the rise in CRH preceding parturition could result from the previously described rise in fetal glucocorticoids. Furthermore, this increase in placental CRH could stimulate, via adrenocorticotropic hormone, a further rise in fetal glucocorticoids, completing a positive feedback loop that would be terminated by delivery.

  9. Development of syndrome of inappropriate antidiuretic hormone secretion (SIADH) after Onyx embolisation of a cavernous carotid fistula.

    PubMed

    Chen, Tsinsue; Kalani, M Yashar S; Ducruet, Andrew F; Albuquerque, Felipe C; McDougall, Cameron G

    2016-01-01

    Patients with cavernous carotid fistulas (CCFs) can present with pituitary hypoperfusion and hypopituitarism; however, there are no previous reports of pituitary or hormonal abnormalities developing after CCF embolisation in an asymptomatic patient. We describe a patient with no hormonal abnormalities who developed syndrome of inappropriate antidiuretic hormone (SIADH) secretion after CCF embolisation. The patient had bilateral indirect CCFs, which were completely embolised via a transvenous approach, and was neurologically stable postoperatively and discharged. In the subsequent 2 weeks the patient was readmitted twice for acute hyponatraemia and a tonic-clonic seizure. Laboratory studies revealed severe SIADH. Clinical status and sodium levels improved after treatment. One year later the patient was weaned off all medications and remained neurologically stable. SIADH may be a delayed phenomenon after CCF embolisation. Given the proximity of embolised vessels to the pituitary's vascular supply, CCF treatment may result in flow disturbance, ischaemia and hormonal abnormalities. PMID:27001597

  10. Experiment K-7-22: Growth Hormone Regulation Synthesis and Secretion in Microgravity. Part 3; Plasma Analysis Hormone Measurements

    NASA Technical Reports Server (NTRS)

    Grindeland, R. E.; Popova, I. A.; Grossman, E.; Rudolph, I.

    1994-01-01

    Plasma from space flight and tail suspended rats was analyzed for a number of constituents in order to evaluate their metabolic status and endocrine function. The data presented here cover plasma hormone measurements. Corticosterone, thyroxine, and testosterone were measured by radioimmunoassay. Prolactin and growth hormone were measured by double antibody immunoassays using hormones and antisera prepared in house. Data were evaluated by analysis of variance.

  11. Digestive physiology of the pig symposium: G protein-coupled receptors in nutrient chemosensation and gastrointestinal hormone secretion.

    PubMed

    Liou, A P

    2013-05-01

    The gastrointestinal tract is a highly effective and efficient organ system that digests and absorbs nutrients, contributes to the regulation of glucose homeostasis, and signals postprandial satiety. A network of enteroendocrine cells orchestrates these events through the release of neuropeptide hormones secreted in response to the specific nutrient components within the intraluminal milieu. Nutrient chemosensing by these cells is mediated by cell membrane proteins that have been localized to hormone-producing cells. However, functional studies of the nutrient detection abilities of the endocrine cell population have been limited due to its rare and singly distributed cell type. Recent technological advances have enabled investigations with primary endocrine cells that promise to enhance our current understanding of enteroendocrine cell biology. This review focuses on a particular subset of chemosensing receptors, the G protein-coupled receptors (GPCR), that have been identified as putative nutrient sensors of the major macronutrients, lipids, proteins, and carbohydrates by enteroendocrine cells. The contributions of these receptors in directly activating and stimulating hormone secretion in several subsets of enteroendocrine cells will be discussed, based on evidence gathered by functional studies in animal models, in vitro studies in endocrine cell lines, and newly described findings in primary endocrine cells. Key insights in chemosensory detection and hormone secretion from enteroendocrine cells may help further the studies in larger animal models and guide the formulation of feed or supplements to influence the gastrointestinal signals regulating optimal food intake, absorptive capacity, and growth. PMID:23230119

  12. Effects of Hypergravity Rearing on Growth Hormone (GH) Secretion In Preweanling Rats

    NASA Technical Reports Server (NTRS)

    Baer, L. A.; Chowdhury, J. H.; Wade, C. E.; Ronca, A. E.; Dalton, Bonnie (Technical Monitor)

    2002-01-01

    We previously reported that rat pups reared at 1.5-g, 1.75 or 2.0-g hypergravity weigh 6-15% less than 1.0-g controls. To account for these findings. we measured the lactational hormones, prolaction (Prl) and oxytocin (OT), in the pups' mothers. Gravity related differences in Prl were not observed whereas OT of lactating dams was significantly reduced relative to controls. Milk transfer from dam to pup was not impaired in hypergravity-reared litters tested at 1-g. Together, these findings suggest that impaired lactation and milk transfer do not account for reduced body masses of postnatal rats reared in hypergravity. In the present study, we analyzed growth hormone (GH) secretion and maternal licking in pups reared in hypergravity and in 1.0-g controls. Recent reports using dwarfing phenotypes in mouse mutants have provided evidence for postnatal dependence on GH and insulin-like growth factors (IGFs). Beginning on Gestational day (G)11 of the rats' 22 day pregnancy, rat dams and their litters were exposed to either 1.5-g, 1.75-g or 2.0-g. On Postnatal day (P)10, we measured plasma GH using enzyme immunoassay (EIA). Contrary to our hypothesis, GH was significantly elevated in pups reared at 2.0-g relative to 1.0-g controls. Pup-oriented behaviors of the hypergravity dams were also changed, possibly accounting for the increase in pup GH. GH alone does not appear to play a role in reduced body weights of hypergravity-reared pups.

  13. General seizures revealing macro-adenomas secreting prolactin or prolactin and growth hormone in men

    PubMed Central

    Chentli, Farida; Akkache, Lina; Daffeur, Katia; Azzoug, Said

    2014-01-01

    Background: Epilepsy is a heterogeneous condition with numerous etiologies. Pituitary tumors are rarely responsible for generalized convulsions except when they are very large. Apart from anecdotic cases, only one study concerning epilepsy frequency in male macroprolactinomas is available in Medline. Our aim was to analyze epilepsy frequency and conditions under which seizures appear and disappear in men harboring macroprolactinomas or somatolactotroph adenomas. Materials and Methods: We retrospectively analyzed 90 men with macro-adenomas (>1 cm) secreting prolactin (PRL) (n = 82) or both PRL and growth hormone (n = 8) to look for generalized seizures. We took into account familial and personal medical history, clinical examination, routine and hormonal analyzes, and radiological assessment based on cerebral magnetic resonance imaging. Results: Between 1992 and 2012, we collected eight cases (8.9%): Seven were hospitalized for recent generalized seizures; one had epilepsy after conventional radiotherapy given in 1992 because of neurosurgery failure and resistance to bromocriptine. Their median age was 33.75 years (22-58), median PRL was 9,198 ng/ml and median tumor height was 74 mm (41-110). The temporal lobe was invaded in six cases. After tumor reduction, epilepsy disappeared and never relapsed after a follow-up varying between 1 and 20 years. Conclusion: Epilepsy, which is a life-threatening condition, can be the first presentation in men with prolactinomas or somatolactotroph adenomas, especially those involving the supra sellar area, and the brain. Convulsions can also appear after radiotherapy. That one should be avoided, if possible, before tumor reduction by surgery or medical treatment. PMID:24944932

  14. pNET co-secreting GHRH and calcitonin: ex vivo hormonal studies in human pituitary cells

    PubMed Central

    Rubinfeld, Hadara; Lysyy, Lyudmila; Schiller, Tal; Raverot, Véronique; Shimon, Ilan; Knobler, Hilla

    2016-01-01

    Summary Acromegaly due to ectopic GHRH secretion from a neuroendocrine tumor (NET) is rare and comprises <1% of all acromegaly cases. Herein we present a 57-year-old woman with clinical and biochemical features of acromegaly and a 6 cm pancreatic NET (pNET), secreting GHRH and calcitonin. Following surgical resection of the pancreatic tumor, IGF1, GH and calcitonin normalized, and the clinical features of acromegaly improved. In vitro studies confirmed that the tumor secreted large amounts of both GHRH and calcitonin, and incubation of pNET culture-derived conditioned media stimulated GH release from a cultured human pituitary adenoma. This is a unique case of pNET secreting both GHRH and calcitonin. The ability of the pNET-derived medium to stimulate in vitro GH release from a human pituitary-cell culture, combined with the clinical and hormonal remission following tumor resection, confirmed the ectopic source of acromegaly in this patient. Learning points Signs, symptoms and initial work-up of acromegaly due to ectopic GHRH secretion are similar to pituitary-dependent acromegaly. However, if no identifiable pituitary lesion is found, somatostatin receptor scan and further imaging (CT, MRI) should be performed.Detection of GHRH in the blood and in the tumor-derived medium supports the diagnosis of ectopic GHRH secretion.Functional bioactivity of pNET-secreted GHRH can be proved in vitro by releasing GH from human pituitary cells. PMID:26904199

  15. Growth hormone is secreted by normal breast epithelium upon progesterone stimulation and increases proliferation of stem/progenitor cells.

    PubMed

    Lombardi, Sara; Honeth, Gabriella; Ginestier, Christophe; Shinomiya, Ireneusz; Marlow, Rebecca; Buchupalli, Bharath; Gazinska, Patrycja; Brown, John; Catchpole, Steven; Liu, Suling; Barkan, Ariel; Wicha, Max; Purushotham, Anand; Burchell, Joy; Pinder, Sarah; Dontu, Gabriela

    2014-06-01

    Using in vitro and in vivo experimental systems and in situ analysis, we show that growth hormone (GH) is secreted locally by normal human mammary epithelial cells upon progesterone stimulation. GH increases proliferation of a subset of cells that express growth hormone receptor (GHR) and have functional properties of stem and early progenitor cells. In 72% of ductal carcinoma in situ lesions, an expansion of the cell population that expresses GHR was observed, suggesting that GH signaling may contribute to breast cancer development.

  16. Severe hyponatremia caused by nab-paclitaxel-induced syndrome of inappropriate antidiuretic hormone secretion

    PubMed Central

    Neuzillet, Cindy; Babai, Samy; Kempf, Emmanuelle; Pujol, Géraldine; Rousseau, Benoît; Le-Louët, Hervé; Christophe Tournigand

    2016-01-01

    Abstract Incidence of pancreatic ductal adenocarcinoma (PDAC) is increasing. Most patients have advanced disease at diagnosis and therapeutic options in this setting are limited. Gemcitabine plus nab-paclitaxel regimen was demonstrated to increase survival compared with gemcitabine monotherapy and is therefore indicated as first-line therapy in patients with metastatic PDAC and performance status Eastern Cooperative Oncology Group (ECOG) 0-2. The safety profile of gemcitabine and nab-paclitaxel combination includes neutropenia, fatigue, and neuropathy as most common adverse events of grade 3 or higher. No case of severe hyponatremia associated with the use of nab-paclitaxel for the treatment of PDAC has been reported to date. We report the case of a 72-year-old Caucasian man with a metastatic PDAC treated with gemcitabine and nab-paclitaxel regimen, who presented with a severe hyponatremia (grade 4) caused by a documented syndrome of inappropriate antidiuretic hormone secretion (SIADH). This SIADH was attributed to nab-paclitaxel after a rigorous imputability analysis, including a rechallenge procedure with dose reduction. After dose and schedule adjustment, nab-paclitaxel was pursued without recurrence of severe hyponatremia and with maintained efficacy. Hyponatremia is a rare but potentially severe complication of nab-paclitaxel therapy that medical oncologists and gastroenterologists should be aware of. Nab-paclitaxel-induced hyponatremia is manageable upon dose and schedule adaptation, and should not contraindicate careful nab-paclitaxel reintroduction. This is of particular interest for a disease in which the therapeutic options are limited. PMID:27368013

  17. Disorders of water metabolism: diabetes insipidus and the syndrome of inappropriate antidiuretic hormone secretion.

    PubMed

    Verbalis, Joseph G

    2014-01-01

    Disorders of body fluids are among the most commonly encountered problems in the practice of clinical medicine. This is in large part because many different disease states can potentially disrupt the finely balanced mechanisms that control the intake and output of water and solute. It therefore behooves clinicians treating such patients to have a good understanding of the pathophysiology, the differential diagnosis and the management of these disorders. Since body water is the primary determinant of the osmolality of the extracellular fluid (ECF), disorders of body water homeostasis can be divided into hypoosmolar disorders, in which there is an excess of body water relative to body solute, and hyperosmolar disorders, in which there is a deficiency of body water relative to body solute. The classical hyperosmolar disorder is diabetes insipidus (DI), and the classical hypoosmolar disorder is the syndrome of inappropriate antidiuretic hormone secretion (SIADH). This chapter first reviews the regulatory mechanisms underlying water and sodium metabolism, the two major determinants of body fluid homeostasis. The major disorders of water metabolism causing hyperosmolality and hypoosmolality, DI and SIADH, are then discussed in detail, including the pathogenesis, differential diagnosis and treatment of these disorders.

  18. Embolization of metastatic neuroendocrine tumor resulting in clinical manifestations of syndrome of inappropriate secretion of antidiuretic hormone (SIADH)

    PubMed Central

    Yarmohammadi, Hooman; Erinjeri, Joseph P.; Brown, Karen T.

    2016-01-01

    Complications after hepatic artery embolization are usually minor and transient. We report a patient with pancreatic neuroendocrine tumor with hepatic metastases that repeatedly developed clinical findings of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) with hyponatremia (sodium less than 130 mEq/L), low plasma osmolarity (lower than 275 mOsm/kg) and high urine osmolarity (above 500 mOsm/kg) after every session of hepatic artery embolization. PMID:25805538

  19. Space weightlessness and hormonal changes in human subjects and experimental animals

    NASA Technical Reports Server (NTRS)

    Grindeland, R. E.

    1982-01-01

    Data from spaceflight and bed rest studies are briefly described and the difficulties in interpreting these results are discussed. Growth hormone, prolactin, adrenocorticotropic hormone, cortisol, insulin, aldosterone, and other hormones are addressed.

  20. Effects on steroid hormones secretion resulting from the acute stimulation of sectioning the superior ovarian nerve to pre-pubertal rats

    PubMed Central

    2012-01-01

    In the adult rat, neural signals arriving to the ovary via the superior ovarian nerve (SON) modulate progesterone (P4), testosterone (T) and estradiol (E2) secretion. The aims of the present study were to analyze if the SON in the pre-pubertal rat also modulates ovarian hormone secretion and the release of follicle stimulating hormone (FSH) and luteinizing (LH) hormone. P4, T, E2, FSH and LH serum levels were measured 30 or 60 minutes after sectioning the SON of pre-pubertal female rats. Our results indicate that the effects on hormone levels resulting from unilaterally or bilaterally sectioning the SON depends on the analyzed hormone, and the time lapse between surgery and autopsy, and that the treatment yielded asymmetric results. The results also suggest that in the pre-pubertal rat the neural signals arriving to the ovaries via the SON regulate the enzymes participating in P4, T and E2 synthesis in a non-parallel way, indicating that the mechanisms regulating the synthesis of each hormone are not regulated by the same signals. Also, that the changes in the steroids hormones are not explained exclusively by the modifications in gonadotropins secretion. The observed differences in hormone levels between rats sacrificed 30 and 60 min after surgery reflect the onset of the compensatory systems regulating hormones secretion. PMID:23110668

  1. Obesity in transgenic female mice with constitutively elevated luteinizing hormone secretion.

    PubMed

    Kero, Jukka T; Savontaus, Eriika; Mikola, Maarit; Pesonen, Ullamari; Koulu, Markku; Keri, Ruth A; Nilson, John H; Poutanen, Matti; Huhtaniemi, Ilpo T

    2003-10-01

    Transgenic (TG) female mice, expressing a chimeric bovine luteinizing hormone (LH) beta-subunit/human chorionic gonadotropin beta-subunit COOH-terminal extension (bLHbeta-CTP) gene, produce high levels of circulating LH and serve as a model for functional ovarian hyperandrogenism and follicular cysts. We report here that obesity is a typical feature of these female mice. The mean body weight of the bLHbeta-CTP females was significantly higher than in controls at, and beyond 5 wk of age, and at 5 mo, it was 32% increased. At this age, the amount of white adipose tissue in the bLHbeta-CTP females was significantly increased, as reflected by the weight difference of the retroperitoneal fat pad. In addition, the expression of leptin mRNA in white adipose tissue of the TG females was elevated about twofold. Serum leptin and insulin levels, and food intake, were also increased significantly in the TG females. Brown adipose tissue (BAT) thermogenic activity, as measured by GDP binding to BAT mitochondria, was reduced (P < 0.05). Ovariectomy at the age of 3 wk totally prevented the development of obesity. In summary, the present results show that intact female bLHbeta-CTP mice are obese, have increased food consumption, and reduced BAT thermogenic activity. The weight gain can be explained partly by elevated androgens but is probably also contributed to the increased adrenal steroidogenesis. Hence, the bLHbeta-CTP mice provide a useful model for studying obesity related to elevated LH secretion, with consequent alterations in ovarian and adrenal function.

  2. Stimulation of murine biliary cholesterol secretion by thyroid hormone is dependent on a functional ABCG5/G8 complex

    PubMed Central

    Bonde, Ylva; Plösch, Torsten; Kuipers, Folkert; Angelin, Bo; Rudling, Mats

    2012-01-01

    Abstract Secretion of cholesterol into bile is important for the elimination of cholesterol from the body. Thyroid hormone (TH) increases biliary cholesterol secretion and hepatic gene expression of adenosine triphosphate (ATP)-binding cassette, subfamily G (WHITE), member 5 (ABCG5) and ATP-binding cassette, subfamily G (WHITE), member 8 (ABCG8), two half-transporters that act as a heterodimeric complex promoting sterol secretion. In addition, nuclear liver x receptor-alpha (LXRa), also regulated by TH, induces gene expression of ABCG5/G8. We here investigated if the TH-induced stimulation of biliary cholesterol secretion is mediated by the ABCG5/G8 complex in vivo, and if so, whether LXRa is involved. Mice homozygous for disruption of Abcg5 (Abcg5−/−) or Lxra (Lxra−/−) and their wild-type counterparts were treated with triiodothyronine (T3) for 14 days and compared to untreated mice of corresponding genetic backgrounds. Bile was collected by gallbladder cannulation, and liver samples were analyzed for gene expression levels. Basal biliary cholesterol secretion in Abcg5−/− mice was 72% lower than in Abcg5+/+ mice. T3 treatment increased cholesterol secretion 3.1-fold in Abcg5+/+ mice, whereas this response was severely blunted in Abcg5−/− mice. In contrast, biliary cholesterol secretion in T3-treated Lxra+/+ and Lxra−/− mice was increased 3.5- and 2.6-fold, respectively, and did not differ significantly. Conclusions: TH-induced secretion of cholesterol into bile is largely dependent on an intact ABCG5/G8 transporter complex, whereas LXRa is not critical for this effect. (HEPATOLOGY 2012;56:1828–1837) PMID:22829162

  3. Central neurogenic diabetes insipidus, syndrome of inappropriate secretion of antidiuretic hormone, and cerebral salt-wasting syndrome in traumatic brain injury.

    PubMed

    John, Cynthia A; Day, Michael W

    2012-04-01

    Central neurogenic diabetes insipidus, syndrome of inappropriate secretion of antidiuretic hormone, and cerebral salt-wasting syndrome are secondary events that affect patients with traumatic brain injury. All 3 syndromes affect both sodium and water balance; however, they have differences in pathophysiology, diagnosis, and treatment. Differentiating between hypernatremia (central neurogenic diabetes insipidus) and the 2 hyponatremia syndromes (syndrome of inappropriate secretion of antidiuretic hormone, and cerebral salt-wasting syndrome) is critical for preventing worsening neurological outcomes in patients with head injuries.

  4. Gonadotropins in the Russian Sturgeon: Their Role in Steroid Secretion and the Effect of Hormonal Treatment on Their Secretion.

    PubMed

    Yom-Din, Svetlana; Hollander-Cohen, Lian; Aizen, Joseph; Boehm, Benjamin; Shpilman, Michal; Golan, Matan; Hurvitz, Avshalom; Degani, Gad; Levavi-Sivan, Berta

    2016-01-01

    In the reproduction process of male and female fish, pituitary derived gonadotropins (GTHs) play a key role. To be able to specifically investigate certain functions of Luteinizing (LH) and Follicle stimulating hormone (FSH) in Russian sturgeon (Acipenser gueldenstaedtii; st), we produced recombinant variants of the hormones using the yeast Pichia pastoris as a protein production system. We accomplished to create in vitro biologically active heterodimeric glycoproteins consisting of two associated α- and β-subunits in sufficient quantities. Three dimensional modelling of both GTHs was conducted in order to study the differences between the two GTHs. Antibodies were produced against the unique β-subunit of each of the GTHs, in order to be used for immunohistochemical analysis and to develop an ELISA for blood and pituitary hormone quantification. This detection technique revealed the specific localization of the LH and FSH cells in the sturgeon pituitary and pointed out that both cell types are present in substantially higher numbers in mature males and females, compared to immature fish. With the newly attained option to prevent cross-contamination when investigating on the effects of GTH administration, we compared the steroidogeneic response (estradiol and 11-Keto testosterone (11-KT) in female and males, respectively) of recombinant stLH, stFSH, and carp pituitary extract in male and female sturgeon gonads at different developmental stages. Finally, we injected commercially available gonadotropin releasing hormones analog (GnRH) to mature females, and found a moderate effect on the development of ovarian follicles. Application of only testosterone (T) resulted in a significant increase in circulating levels of 11-KT whereas the combination of GnRH + T did not affect steroid levels at all. The response pattern for estradiol demonstrated a similar situation. FSH levels showed significant increases when GnRH + T was administered, while no changes were present in

  5. Gonadotropins in the Russian Sturgeon: Their Role in Steroid Secretion and the Effect of Hormonal Treatment on Their Secretion

    PubMed Central

    Yom-Din, Svetlana; Hollander-Cohen, Lian; Aizen, Joseph; Boehm, Benjamin; Shpilman, Michal; Golan, Matan; Hurvitz, Avshalom; Degani, Gad; Levavi-Sivan, Berta

    2016-01-01

    In the reproduction process of male and female fish, pituitary derived gonadotropins (GTHs) play a key role. To be able to specifically investigate certain functions of Luteinizing (LH) and Follicle stimulating hormone (FSH) in Russian sturgeon (Acipenser gueldenstaedtii; st), we produced recombinant variants of the hormones using the yeast Pichia pastoris as a protein production system. We accomplished to create in vitro biologically active heterodimeric glycoproteins consisting of two associated α- and β-subunits in sufficient quantities. Three dimensional modelling of both GTHs was conducted in order to study the differences between the two GTHs. Antibodies were produced against the unique β-subunit of each of the GTHs, in order to be used for immunohistochemical analysis and to develop an ELISA for blood and pituitary hormone quantification. This detection technique revealed the specific localization of the LH and FSH cells in the sturgeon pituitary and pointed out that both cell types are present in substantially higher numbers in mature males and females, compared to immature fish. With the newly attained option to prevent cross-contamination when investigating on the effects of GTH administration, we compared the steroidogeneic response (estradiol and 11-Keto testosterone (11-KT) in female and males, respectively) of recombinant stLH, stFSH, and carp pituitary extract in male and female sturgeon gonads at different developmental stages. Finally, we injected commercially available gonadotropin releasing hormones analog (GnRH) to mature females, and found a moderate effect on the development of ovarian follicles. Application of only testosterone (T) resulted in a significant increase in circulating levels of 11-KT whereas the combination of GnRH + T did not affect steroid levels at all. The response pattern for estradiol demonstrated a similar situation. FSH levels showed significant increases when GnRH + T was administered, while no changes were present in

  6. Gonadotropins in the Russian Sturgeon: Their Role in Steroid Secretion and the Effect of Hormonal Treatment on Their Secretion.

    PubMed

    Yom-Din, Svetlana; Hollander-Cohen, Lian; Aizen, Joseph; Boehm, Benjamin; Shpilman, Michal; Golan, Matan; Hurvitz, Avshalom; Degani, Gad; Levavi-Sivan, Berta

    2016-01-01

    In the reproduction process of male and female fish, pituitary derived gonadotropins (GTHs) play a key role. To be able to specifically investigate certain functions of Luteinizing (LH) and Follicle stimulating hormone (FSH) in Russian sturgeon (Acipenser gueldenstaedtii; st), we produced recombinant variants of the hormones using the yeast Pichia pastoris as a protein production system. We accomplished to create in vitro biologically active heterodimeric glycoproteins consisting of two associated α- and β-subunits in sufficient quantities. Three dimensional modelling of both GTHs was conducted in order to study the differences between the two GTHs. Antibodies were produced against the unique β-subunit of each of the GTHs, in order to be used for immunohistochemical analysis and to develop an ELISA for blood and pituitary hormone quantification. This detection technique revealed the specific localization of the LH and FSH cells in the sturgeon pituitary and pointed out that both cell types are present in substantially higher numbers in mature males and females, compared to immature fish. With the newly attained option to prevent cross-contamination when investigating on the effects of GTH administration, we compared the steroidogeneic response (estradiol and 11-Keto testosterone (11-KT) in female and males, respectively) of recombinant stLH, stFSH, and carp pituitary extract in male and female sturgeon gonads at different developmental stages. Finally, we injected commercially available gonadotropin releasing hormones analog (GnRH) to mature females, and found a moderate effect on the development of ovarian follicles. Application of only testosterone (T) resulted in a significant increase in circulating levels of 11-KT whereas the combination of GnRH + T did not affect steroid levels at all. The response pattern for estradiol demonstrated a similar situation. FSH levels showed significant increases when GnRH + T was administered, while no changes were present in

  7. [The effect of low doses of nakom on the hormonal secretion of the hypothalamo-hypophyseal-adrenal system in patients with infantile cerebral palsy].

    PubMed

    Brin, I L; Mashilov, K V

    1996-01-01

    The levels of hormones of hypothalamo-hypophyseal-adrenal system were measured in 14 10-14 year old children with infantile cerebral paralysis (ICP) with central catecholaminergic motor insufficiency. Contents of adrenocorticotropic hormone (ACTH), hydrocortisone (HC), somatotropic hormone, prolactin (P) were examined before and during Nacome administration (62.5 mg once daily in the morning). 110 patients of the same age with ICP and 18 children with acquired encephalopathy (EP) formed the control group. The elevations of ACTH, HC and P were revealed in spastic forms of ICP. Meanwhile nearly normal hormonal levels were observed in hyperkinetic forms of ICP and EP. The more pronounced effect was noted in "dopamine-dependent" children in which the drug's administration resulted in normalization of clinical and biochemical indices. Hyperkinetic phenomena revealed the connection between the character of neuromotor dyskinesias and the state of hypothalamo-hypophyseal-adrenal axis which is regulated by dopamine. The data obtained show hypofunction of dopaminergic neurotransmitter cerebral systems in patients with ICP that plays important pathogenetic role in development of disease with systemic manifestations. PMID:9281279

  8. Blood, pituitary, and brain renin-angiotensin systems and regulation of secretion of anterior pituitary gland.

    PubMed

    Ganong, W F

    1993-07-01

    In addition to increasing blood pressure, stimulating aldosterone and vasopressin secretion, and increasing water intake, angiotensin II affects the secretion of anterior pituitary hormones. Some of these effects are direct. There are angiotensin II receptors on lactotropes and corticotropes in rats, and there may be receptors on thyrotropes and other secretory cells. Circulating angiotensin II reaches these receptors, but angiotensin II is almost certainly generated locally by the pituitary renin-angiotensin system as well. There are also indirect effects produced by the effects of brain angiotensin II on the secretion of hypophyseotropic hormones. In the anterior pituitary of the rat, the gonadotropes contain renin, angiotensin II, and some angiotensin-converting enzyme. There is debate about whether these cells also contain small amounts of angiotensinogen, but most of the angiotensinogen is produced by a separate population of cells and appears to pass in a paracrine fashion to the gonadotropes. An analogous situation exists in the brain. Neurons contain angiotensin II and probably renin, but most angiotensin-converting enzyme is located elsewhere and angiotensinogen is primarily if not solely produced by astrocytes. Angiotensin II causes secretion of prolactin and adrenocorticotropic hormone (ACTH) when added to pituitary cells in vitro. Paracrine regulation of prolactin secretion by angiotensin II from the gonadotropes may occur in vitro under certain circumstances, but the effects of peripheral angiotensin II on ACTH secretion appear to be mediated via the brain and corticotropin-releasing hormone (CRH). In the brain, there is good evidence that locally generated angiotensin II causes release of norepinephrine that in turn stimulates gonadotropin-releasing hormone-secreting neurons, increasing circulating luteinizing hormone. In addition, there is evidence that angiotensin II acts in the arcuate nuclei to increase the secretion of dopamine into the portal

  9. The role of sexual steroid hormones in the direct stimulation by Kisspeptin-10 of the secretion of luteinizing hormone, follicle-stimulating hormone and prolactin from bovine anterior pituitary cells.

    PubMed

    Ezzat, A Ahmed; Saito, H; Sawada, T; Yaegashi, T; Goto, Y; Nakajima, Y; Jin, J; Yamashita, T; Sawai, K; Hashizume, T

    2010-09-01

    The aims of the present study were to clarify the effect of Kisspeptin-10 (Kp10) on the secretion of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) from bovine anterior pituitary (AP) cells and evaluate the ability of sex steroids to enhance the sensitivity of gonadotropic and lactotropic cells to Kp10. AP cells prepared from 7-week-old male calves were incubated for 12h with estradiol (E(2); 10(-8)M), progesterone (P(4); 10(-8)M), testosterone (T; 10(-8)M), or vehicle only (control), and then for 2h with Kp10 (10(-6)M). The amounts of LH, FSH and PRL released into the culture medium after the 2-h incubation period were examined. Kp10 significantly stimulated the secretion of LH from the AP cells treated with E(2) and T (P<0.05), but not from the P(4)-treated cells. In contrast, Kp10 had no effect on the secretion of FSH regardless of the steroid treatment. Kp10 significantly stimulated the secretion of PRL (P<0.05), the sexual steroid hormones having no effect. The LH- or FSH-releasing response to gonadotropin-releasing hormone (GnRH; 10(-8)M) and PRL-releasing response to thyrotropin-releasing hormone (TRH; 10(-8)M) were significantly greater than those to Kp10 (P<0.05). The present results suggest that E(2) and T, but not P(4), enhance the sensitivity of gonadotropic cells to the secretion of LH in response to Kp10. However, Kp10 had no stimulatory effect on the secretion of FSH regardless of the effect of sex steroids. Kp10 directly stimulates the secretion of PRL from the pituitary cells, and sex steroids do not enhance the sensitivity of lactotropic cells to Kp10. Furthermore, the LH- and FSH-releasing effect and the PRL-releasing effect of Kp10 are less potent than that of GnRH and TRH, respectively.

  10. Thyrotropin-induced hyperthyroidism caused by selective pituitary resistance to thyroid hormone. A new syndrome of "inappropriate secretion of TSH".

    PubMed Central

    Gershengorn, M C; Weintraub, B D

    1975-01-01

    An 18-yr-old woman with clinical and laboratory features of hyperthyroidism had persistently elevated serum levels of immunoreative thyrotropin (TSH). During 11 yr of follow-up there had been no evidence of a pituitary tumor. After thyrotropin-releasing hormone (TRH), there was a marked increase in TSH and secondarily in triiodothyronine (T3), the latter observation confirming the biologic activity of the TSH. Exogenous T3 raised serum T3 and several measurements of peripheral thyroid hormone effect, while decreasing serum TSH, thyroxine (T4), and thyroidal radioiodine uptake. After T3, the TRH-stimulated TSH response was decreased but was still inappropriate for the elevated serum T3 levels. Dexamethasone reduced serum TSH but did not inhibit TRH stimulation of TSH. Propylthiouracil reduced serum T4 and T3 and raised TSH. This patient represents a new syndrome of TSH-induced hyperthyroidism, differing from previous reports in the absence of an obvious pituitary tumor and in the responsiveness of the TSH to TRH stimulation and thyroid hormone suppression. This syndrome appears to be caused by a selective, partial resistance of the pituitary to the action of thyroid hormone. This case is also compared with previous reports in the literature of patients with elevated serum levels of immunoreactive TSH in the presence of elevated total and free thyroid hormones. A classification of these cases, termed "inappropriate secretion of TSH," is proposed. PMID:1159077

  11. The Physiological Role of Thyrotropin-Releasing Hormone in the Regulation of Thyroid-Stimulating Hormone and Prolactin Secretion in the Rat

    PubMed Central

    Harris, Arthur R. C.; Christianson, Dana; Smith, M. Susan; Fang, Shih-Lieh; Braverman, Lewis E.; Vagenakis, Apostolos G.

    1978-01-01

    The physiological role of thyrotropin-releasing hormone (TRH) in the regulation of thyrotropin (thyroid-stimulating hormone, TSH) and prolactin (Prl) secretion has been assumed but not proven. Stimulation of their release requires pharmacologic doses of TRH. Lesions of the hypothalamus usually induce an inhibition of TSH secretion and an increase in Prl. To determine whether TRH is essential for TSH and Prl secretion in the rat, 0.1 ml of TRH antiserum (TRH-Ab) or normal rabbit serum was administered to normal, thyroidectomized, cold-exposed, and proestrus rats through indwelling atrial catheter. Serum samples were obtained before and at frequent intervals thereafter. Serum TSH concentrations in normal, thyroidectomized, cold-exposed, and proestrus rats were not depressed in specimens obtained up to 24 h after injection of normal rabbit serum. In contrast, serum TSH was significantly decreased after the administration of TRH-Ab in all normal (basal, 41±8 μU/ml [mean±SE]; 30 min, 6±2; 45 min, 8±3; 75 min, 4±2); thyroidectomized (basal, 642±32 μU/ml; 30 min, 418±32; 60 min, 426±36; 120 min, 516±146); coldstressed (basal, 68±19 μU/ml; 30 min, 4±3; 180 min, 16±8); and proestrus (basal, 11 a.m., 57±10 μU/ml; 1 p.m., 20±3; 3 p.m., 13±4; 5 p.m., 19±3) rats. However, 0.1 ml of TRH-Ab had no effect on basal Prl concentrations in normal or thyroidectomized rats and did not prevent the Prl rise in rats exposed to cold (basal, 68±7 ng/ml; 15 min, 387±121; 30 min, 212±132; 60 min, 154±114), or the Prl surge observed on the afternoon of proestrus (basal 11 a.m., 23±2 ng/ml; 1 p.m., 189±55; 3 p.m., 1,490±260; 5 p.m., 1,570±286). These studies demonstrate that TRH is required for TSH secretion in the normal, cold-exposed and proestrus rat and contributes, at least in part, to TSH secretion in the hypothyroid rat, but is not required for Prl secretion in these states. PMID:413840

  12. Hyperpolarization of the Membrane Potential Caused by Somatostatin in Dissociated Human Pituitary Adenoma Cells that Secrete Growth Hormone

    NASA Astrophysics Data System (ADS)

    Yamashita, Naohide; Shibuya, Naohiko; Ogata, Etsuro

    1986-08-01

    Membrane electrical properties and the response to somatostatin were examined in dissociated human pituitary adenoma cells that secrete growth hormone (GH). Under current clamp condition with a patch electrode, the resting potential was -52.4 ± 8.0 mV, and spontaneous action potentials were observed in 58% of the cells. Under voltage clamp condition an outward K+ current, a tetrodotoxin-sensitive Na+ current, and a Ca2+ current were observed. Cobalt ions suppressed the Ca2+ current. The threshold of Ca2+ current activation was about -60 mV. Somatostatin elicited a membrane hyperpolarization associated with increased membrane permeability in these cells. The reversal potential of somatostatin-induced hyperpolarization was -78.4 ± 4.3 mV in 6 mM K+ medium and -97.2 ± 6.4 mV in 3 mM K+ medium. These reversal potential values and a shift with the external K+ concentration indicated that membrane hyperpolarization was caused by increased permeability to K+. The hyperpolarized membrane potential induced by somatostatin was -63.6 ± 5.9 mV in the standard medium. This level was subthreshold for Ca2+ and Na+ currents and was sufficient to inhibit spontaneous action potentials. Hormone secretion was significantly suppressed by somatostatin and cobalt ions. Therefore, we suggest that Ca2+ entering the cell through voltage-dependent channels are playing an important role for GH secretion and that somatostatin suppresses GH secretion by blocking Ca2+ currents. Finally, we discuss other possibilities for the inhibitory effect of somatostatin on GH secretion.

  13. Combined Use of Etomidate and Dexmedetomidine Produces an Additive Effect in Inhibiting the Secretion of Human Adrenocortical Hormones

    PubMed Central

    Gu, Hongbin; Zhang, Mazhong; Cai, Meihua; Liu, Jinfen

    2015-01-01

    Background The direct effects of etomidate were investigated on the secretion of cortisol and its precursors by dispersed cells from the adrenal cortex of human of animals. Dexmedetomidine (DEX) is an anesthetic agent that may interfere with cortisol secretion via an unknown mechanism, such as involving inhibition of 11β-hydroxylase and the cholesterol side-chain cleavage enzyme system. The aim of this study was to determine whether dexmedetomidine (DEX) has a similar inhibitory effect on adrenocortical function, and whether combined use of etomidate (ETO) and DEX could produce a synergistic action in inhibiting the secretion of human adrenocortical hormones. Material/Methods Human adrenocortical cells were exposed to different concentrations of ETO and DEX. The dose-effect model between the ETO concentration and the mean secretion of cortisone (CORT) and aldosterone (ALDO) per hour was estimated. Results Hill’s equation well-described the dose-effect correlation between the ETO concentration and the amount of ALDO and CORT secretion. When the DEX concentration was introduced into the model by using E0 (basal secretion) as the covariate, the goodness of fit of the ETO-CORT dose-effect model was improved significantly and the objective function value was reduced by 4.55 points (P<0.05). The parameters of the final ETO-ALDO pharmacodynamics model were EC50=9.74, Emax=1.20, E0=1.33, and γ=18.5; the parameters of the final ETO-CORT pharmacodynamics model were EC50=9.49, Emax=8.16, E0=8.57, and γ=37.0. In the presence of DEX, E0 was 8.57–0.0247×(CDEX–4.6), and the other parameters remained unchanged. All parameters but γ were natural logarithm conversion values. Conclusions Combined use of DEX and ETO reduced ETO’s inhibitory E0 (basal secretion) of CORT from human adrenocortical cells in a dose-dependent manner, suggesting that combined use of ETO and DEX produced an additive effect in inhibiting the secretion of human adrenocortical hormones. PMID

  14. Naloxone does not reverse the inhibitory effect of morphine on luteinizing hormone secretion in prepubescent male rats.

    PubMed

    Cicero, T J; Nock, B; O'Connor, L

    1993-01-01

    Morphine and naloxone exert age-dependent effects on secretion of luteinizing hormone (LH) in the male rat. Morphine suppresses LH secretion at very early stages of development, well before puberty, whereas naloxone does not increase LH until after puberty. The mechanisms underlying these age-dependent effects of opiates on the hypothalamic-pituitary-gonadal axis in pre- and postpubertal rats are poorly understood at the present time. The purpose of the present studies was to examine one plausible explanation of these effects: that morphine and naloxone act through different receptors in the pubescent male rat than they do in adults to influence LH secretion. Specifically, we examined whether naloxone blocks the effects of morphine on LH in prepubescent and adult rats which would be anticipated if both drugs were exerting their effects on LH via the same opiate receptor. Surprisingly, we found that naloxone did not reverse the effects of morphine on serum LH levels in the prepubescent animal, although it fully reversed this effect in adults. This non-naloxone-reversible effect of morphine appeared to be specific to LH, since naloxone antagonized morphine's effects on several other hormones (e.g., prolactin and corticosterone) and completely attenuated morphine's antinociceptive activity in prepubescent rats. Additionally, naloxone precipitated a withdrawal syndrome in the prepubescent morphine-dependent animal that was quantitatively and qualitatively the same as in adults.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Leptin directly acts within the hypothalamus to stimulate gonadotropin-releasing hormone secretion in vivo in rats

    PubMed Central

    Watanobe, Hajime

    2002-01-01

    It is still not known whether leptin, an adipocyte-derived hormone, acts directly within the hypothalamus to stimulate the gonadotropin-releasing hormone (GnRH)-luteinizing hormone (LH) system. In order to address this question, the present study examined the effects of direct intrahypothalamic perfusions with leptin on the in vivo release of GnRH in ovarian steroid-primed ovariectomized rats utilizing the push-pull perfusion technique. Both α-melanocyte-stimulating hormone (α-MSH) and neuropeptide Y were also measured in the hypothalamic perfusates. In normally fed animals, the leptin infusion was without effect on the release of these three hypothalamic peptides and also without effect on plasma LH and prolactin (PRL), whether leptin was infused into the medial preoptic area (where the majority of GnRH neuronal cell bodies exist) or the median eminence-arcuate nucleus complex (where axon terminals of GnRH neurons are located). In contrast, in 3-day fasted rats leptin was effective in stimulating the secretion of GnRH, α-MSH, and LH, regardless of the site of perfusion. These three hormones were increased in a temporal order of α-MSH, GnRH and LH. Irrespective of the site of perfusion, leptin was without effect on the release of neuropeptide Y. Only when leptin was infused into the median eminence-arcuate nucleus complex was PRL secretion also stimulated, although its onset was 1 h behind that of LH. The leptin-induced elevations of GnRH, α-MSH, LH and PRL were all dose-dependently stimulated by subnormal (1.0 ng ml−1) and normal (3.0 ng ml−1) concentrations of leptin, but at higher concentrations (10 ng ml−1) it did not produce additional effects. Leptin infusion into the anterior hypothalamic area, a control site equidistant from both the medial preoptic area and the median eminence-arcuate nucleus complex, did not produce a significant change in any of the hormones in either the fed or fasted rats. These results demonstrate for the first time that

  16. Influence of daily regimen calcium and vitamin D supplementation on parathyroid hormone secretion.

    PubMed

    Reginster, J-Y; Zegels, B; Lejeune, E; Micheletti, M C; Kvsaz, A; Seidel, L; Sarlet, N

    2002-02-01

    Calcium and vitamin D supplementation has been shown to reduce secondary hyperparathyroidism and play a role in the management of senile osteoporosis. In order to define the optimal regimen of calcium and vitamin D supplementation to produce the maximal inhibition of parathyroid hormone secretion, we have compared the administration of a similar amount of Ca and vitamin D, either as a single morning dose or split in two doses, taken 6 hours apart. Twelve healthy volunteers were assigned to three investigational procedures, at weekly intervals. After a blank control procedure, when they were not exposed to any drug intake, they received two calcium-vitamin D supplement regimens including either two doses of Orocal D3 (500 mg Ca and 400 IU vitamin D) 6 hours apart or one water-soluble effervescent powder pack of Cacit D3 in a single morning dose (1000 mg Ca and 880 IU vitamin D). During the three procedures (control and the two calcium-vitamin D supplementations), venous blood was drawn every 60 minutes for up to 9 hours, for serum Ca and serum PTH measurements. The order of administration of the two Ca and vitamin D supplementation sequences was allocated by randomization. No significant changes in serum Ca were observed during the study. During the 6 hours following Ca and vitamin D supplementation, a statistically significant decrease in serum PTH was observed with both regimens, compared with baseline and with the control procedure. Over this period of time, no differences were observed between the two treatment regimens. However, between the sixth and the ninth hour, serum PTH levels were still significantly decreased compared with baseline with split dose Orocal D3 administration, while they returned to baseline value with the Cacit D3 preparation. During this period, the percentage decrease in serum PTH compared with baseline was significantly more pronounced with Orocal D3 than with Cacit D3 (P = 0.0021). We therefore conclude that the administration of two

  17. Glucagon-like peptide-1 stimulates luteinizing hormone-releasing hormone secretion in a rodent hypothalamic neuronal cell line.

    PubMed Central

    Beak, S A; Heath, M M; Small, C J; Morgan, D G; Ghatei, M A; Taylor, A D; Buckingham, J C; Bloom, S R; Smith, D M

    1998-01-01

    To examine the influence of the putative satiety factor (GLP-1) on the hypothalamo-pituitary-gonadal axis, we used GT1-7 cells as a model of neuronal luteinizing hormone- releasing hormone (LHRH) release. GLP-1 caused a concentration-dependent increase in LHRH release from GT1-7 cells. Specific, saturable GLP-1 binding sites were demonstrated on these cells. The binding of [125I]GLP-1 was time-dependent and consistent with a single binding site (Kd = 0.07+/-0.016 nM; binding capacity = 160+/-11 fmol/mg protein). The specific GLP-1 receptor agonists, exendin-3 and exendin-4, also showed high affinity (Ki = 0.3+/-0.05 and 0.32+/-0.06 nM, respectively) as did the antagonist exendin-(9-39) (Ki = 0.98+/-0.24 nM). At concentrations that increased LHRH release, GLP-1 (0.5-10 nM) also caused an increase in intracellular cAMP in GT1-7 cells (10 nM GLP-1: 7.66+/-0.4 vs. control: 0.23+/-0.02 nmol/mg protein; P < 0.001). Intracerebroventricular injection of GLP-1 at a single concentration (10 microg) produced a prompt increase in the plasma luteinizing hormone concentration in male rats (GLP-1: 1.09+/-0.11 vs. saline: 0.69+/-0.06 ng/ml; P < 0.005). GLP-1 levels in the hypothalami of 48-h-fasted male rats showed a decrease, indicating a possible association of the satiety factor with the low luteinizing hormone levels in animals with a negative energy balance. PMID:9502775

  18. Effect of gonadotropin secretion rate on the radiosensitivity of the rat luteinizing hormone-releasing hormone neuron and gonadotroph

    SciTech Connect

    Winterer, J.; Barnes, K.M.; Lichter, A.S.; Deluca, A.M.; Loriaux, D.L.; Cutler, G.B. Jr.

    1988-03-01

    To test the hypothesis that the functional state of hypothalamic LHRH neurons and pituitary gonadotrophs might alter their radiosensitivity, we determined the experimental conditions under which the gonadotropin response to castration could be impaired by a single dose of cranial irradiation. Single doses of cranial irradiation greater than 2000 rads were lethal to unshielded rats. Shielding of the oropharynx and esophagus allowed the animals to survive doses up to 5000 rads. Doses between 2000 and 5000 rads had no effect on basal gonadotropin levels for as long as 3 months after irradiation. Irradiation caused a dose- and time-dependent impairment, however, in the gonadotropin response to castration. Impairment of the gonadotropin levels of castrate animals occurred in animals that were irradiated either before or after castration. However, rats irradiated in the castrate state showed a decreased susceptibility to irradiation damage. Additionally, stimulation of the pituitary by LHRH agonist (LHRHa) 3 h before irradiation significantly reduced the impairment of gonadotropin secretion 12-20 weeks after irradiation (P less than 0.05). Thus, increased functional activity of the rat hypothalamus or pituitary at the time of irradiation, induced by either castration or acute LHRHa administration, was associated with some protection against the gonadotropin-lowering effect of irradiation. Based upon these data, we hypothesize that stimulation of gonadotropin secretion at the time of therapeutic cranial irradiation in humans might protect against subsequent impairment of gonadotropin secretion.

  19. Music increase altruism through regulating the secretion of steroid hormones and peptides.

    PubMed

    Fukui, Hajime; Toyoshima, Kumiko

    2014-12-01

    Music is well known for its effect on human behavior especially of their bonding and empathy towards others. Music provokes one's emotion and activates mirror neurons and reward system. It also regulates social hormones such as steroid hormones or peptides, and increases empathy, pro-sociality and altruism. As a result, it improves one's reproductive success. PMID:25459139

  20. Music increase altruism through regulating the secretion of steroid hormones and peptides.

    PubMed

    Fukui, Hajime; Toyoshima, Kumiko

    2014-12-01

    Music is well known for its effect on human behavior especially of their bonding and empathy towards others. Music provokes one's emotion and activates mirror neurons and reward system. It also regulates social hormones such as steroid hormones or peptides, and increases empathy, pro-sociality and altruism. As a result, it improves one's reproductive success.

  1. Effects of acute unilateral ovariectomy to pre-pubertal rats on steroid hormones secretion and compensatory ovarian responses

    PubMed Central

    2011-01-01

    In the present study we analyzed the existence of asymmetry in the secretion of steroid hormones in pre-pubertal female rats treated with unilateral ovariectomy (ULO) or unilateral perforation of the abdominal wall (sham-surgery). Treated rats were sacrificed at different times after surgery. Since sham-surgery had an apparent effect on the age of first vaginal estrous (FVE) and serum levels hormone, the results of the sham surgery groups were used to assess the effects of their respective surgery treatment groups. On the day of FVE, compensatory ovulation (CO) and compensatory ovarian hypertrophy (COH) were similar in animals with ULO, regardless of the ovary remaining in situ. In ULO treated animals, progesterone (P4) levels were higher than in animals with sham-surgery one hour after treatment but lower in rats sacrificed at FEV. Left-ULO resulted in lower testosterone (T) concentration 48 and 72 hours after surgery. In rats with Right-ULO lower T concentrations were observed in rats sacrificed one or 72 hours after surgery, and at FVE. ULO (left or right) resulted in lower estradiol (E2) concentrations one or 72 hours after treatment. In rats with Left-ULO, E2 levels were higher 48 hours after surgery and at FVE. Left-ULO resulted in higher levels of follicle stimulating hormone (FSH) five hours after surgery and at FVE. FSH levels were higher in rats with Right-ULO sacrificed on FVE. The present results suggest that in the pre-pubertal rat both ovaries have similar capacities to secrete P4, and that the right ovary has a higher capacity to secrete E2. Taken together, the present results support the idea that the effects of ULO result from the decrease in glandular tissue and changes in the neural information arising from the ovary. PMID:21450102

  2. Experiment K-7-22: Growth Hormone Regulation Synthesis and Secretion in Microgravity. Part 1; Growth Hormone Regulation Synthesis and Secretion in Microgravity

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.; Grindeland, R.; Vale, W.; Sawchenko, P.; Ilyina-Kakueva, E. I.

    1994-01-01

    Changes in the musculoskeletal, immune, vascular, and endocrine system of the rat occur as a result of short-term spaceflight. Since pituitary gland growth hormone (GH) plays a role in the control of these systems, and since the results of an earlier spaceflight mission (Spacelab 3, 1985) showed that GH cell function was compromised in a number of post-flight tests, we repeated and extended the 1985 experiment in two subsequent spaceflights: the 12.5 day mission of Cosmos 1887 (in 1987) and the 14 day mission of Cosmos 2044 (in 1989). The results of these later two flight experiments are the subject of this report. They document repeatable and significant changes in the GH cell system of the spaceflown rat in several post-flight tests.

  3. Abnormal secretion of reproductive hormones and antioxidant status involved in quinestrol-induced reproductive toxicity in adult male rat.

    PubMed

    Li, Jian; Wang, Hongwei; Zhang, Jiliang; Zhou, Bianhua; Si, Lifang; Wei, Lan; Li, Xiang

    2014-02-01

    This study aimed to evaluate the effects of quinestrol, a synthetic oestrogen homologue with reproductive toxicity, on the secretion of reproductive hormones and antioxidant status in adult male rat. Our results showed that quinestrol exposure significantly decreased the weight of the testis, epididymides, seminal vesicle, and prostate, as well as the sperm counts in the cauda epididymis of rats. Quinestrol significantly reduced the size of seminiferous tubules and the total number of spermatogenic cells. Serum testosterone, follitropin, and lutropin were also significantly reduced in a dose-related manner after quinestrol exposure. Meanwhile, the activity of superoxide dismutase, glutathione peroxidase, and total antioxide capacity significantly decreased, whereas the malondialdehyde and nitric oxide concentrations significantly increased in the testes. These findings revealed that endocrine disorders of reproductive hormones and oxidative stress may be involved in reproductive toxicity induced by quinestrol in adult male rats. PMID:24183492

  4. Stimulation of thyroid hormone secretion by thyrotropin in beluga whales, Delphinapterus leucas.

    PubMed

    St Aubin, D J

    1987-07-01

    Bovine thyroid stimulating hormone administered to three beluga whales, Delphinapterus leucas, was effective in producing an increase in circulating levels of triiodothyronine and thyroxine. A single dose of 10 I.U. of thyroid stimulating hormone resulted in a 145% increase in triiodothyronine and a 35% increase in thyroxine after nine hours in a whale tested within two hours after capture. The response was less pronounced in an animal tested with the same does on two occasions after four and eight weeks in captivity. In the third whale, 10 I.U. of thyroid stimulating hormone given on each of three consecutive days produced a marked increase in triiodothyronine and thyroxine. The elevation of thyroxine concentration persisted for at least two days after the last injection of thyroid stimulating hormone. A subsequent decrease in thyroxine to levels below baseline signalled the suppression of endogenous thyroid stimulating hormone. This preliminary study helps to establish a protocol for testing thyroid function in cetaceans. PMID:3651900

  5. Stimulation of thyroid hormone secretion by thyrotropin in beluga whales, Delphinapterus leucas.

    PubMed

    St Aubin, D J

    1987-07-01

    Bovine thyroid stimulating hormone administered to three beluga whales, Delphinapterus leucas, was effective in producing an increase in circulating levels of triiodothyronine and thyroxine. A single dose of 10 I.U. of thyroid stimulating hormone resulted in a 145% increase in triiodothyronine and a 35% increase in thyroxine after nine hours in a whale tested within two hours after capture. The response was less pronounced in an animal tested with the same does on two occasions after four and eight weeks in captivity. In the third whale, 10 I.U. of thyroid stimulating hormone given on each of three consecutive days produced a marked increase in triiodothyronine and thyroxine. The elevation of thyroxine concentration persisted for at least two days after the last injection of thyroid stimulating hormone. A subsequent decrease in thyroxine to levels below baseline signalled the suppression of endogenous thyroid stimulating hormone. This preliminary study helps to establish a protocol for testing thyroid function in cetaceans.

  6. Transgenic mice expressing the human growth hormone gene provide a model system to study human growth hormone synthesis and secretion in non-tumor-derived pituitary cells: differential effects of dexamethasone and thyroid hormone.

    PubMed

    Vakili, Hana; Jin, Yan; Nagy, James I; Cattini, Peter A

    2011-10-15

    Growth hormone (GH) is regulated by pituitary and hypothalamic factors as well as peripheral endocrine factors including glucocorticoids and thyroid hormone. Studies on human GH are limited largely to the assessment of plasma levels in endocrine disorders. Thus, insight into the regulation of synthesis versus secretion has come mainly from studies done on non-human GH and/or pituitary tumor cells. However, primate and non-primate GH gene loci have differences in their structure and, by extension, regulation. We generated transgenic (171hGH/CS-TG) mice containing the intact hGH1 gene and locus control region, including sequences required for integration-independent and preferential pituitary expression. Here, we show hGH co-localizes with mouse (m) GH in somatotrophs in situ and in primary pituitary cells. Dexamethasone treatment increased hGH and mGH, as well as GH releasing hormone (GHRH) receptor RNA levels, and hGH release was stimulated by GHRH treatment. By contrast, triiodothyronine decreased or had no effect on hGH and mGH production, respectively, and the negative effect on hGH was also seen in the presence of dexamethasone. Thus, 171hGH/CS-TG mouse pituitary cultures represent a model system to investigate hormonal control of hGH synthesis and secretion.

  7. Clinical guidelines for management of diabetes insipidus and syndrome of inappropriate antidiuretic hormone secretion after pituitary surgery.

    PubMed

    Lamas, Cristina; del Pozo, Carlos; Villabona, Carles

    2014-04-01

    Changes in water metabolism and regulation of vasopressin (AVP) or antidiuretic hormone (ADH) are common complications of pituitary surgery. The scarcity of studies comparing different treatment and monitoring strategies for these disorders and the lack of prior clinical guidelines makes it difficult to provide recommendations following a methodology based on grades of evidence. This study reviews the pathophysiology of diabetes insipidus and inappropriate ADH secretion after pituitary surgery, and is intended to serve as a guide for their diagnosis, differential diagnosis, treatment, and monitoring.

  8. Gene expression in the brain-pituitary adipose tissue axis and luteinising hormone secretion during pubertal development in the gilt.

    PubMed

    Barb, C R; Hausman, G J; Rekaya, R

    2006-01-01

    The occurrence of puberty in the female is due to the interplay of central and peripheral mechanisms in which the hypothalamic-pituitary-ovarian axis regulates growth and gonadal function, as well as adipocyte hormone secretion. Hypothalamic GnRH mRNA expression increased at 3.5 months of age and declined by 6 months of age. Concomitant with the age related reduction in the oestrogen negative feedback on LH secretion was a decline in hypothalamic oestrogen receptor-alpha (ERalpha) expression and increased expression of repressor of ER activity gene (REA) at 210 days of age. Hypothalamic proopiomelanocortin expression increased at 6 months of age followed by increased expression of progesterone receptor (PR) membrane compliment-1 and steroid membrane binding protein gene at 210 days of age. This represents development of the endogenous opioid peptide-progesterone dependent LH inhibitory pathway. Adipose tissue leptin and insulin like growth factor-I (IGF-I) gene expression increased with age and adiposity. Pituitary transcription factors, steroidogenic factor 1 (SF1) and Lhx3, and LHbeta and FSHbeta gene expression increased with age. These results identify key hypothalamic and pituitary genes associated with changes in LH secretion and growth during pubertal development and adipose tissue genes and secreted proteins related to maturation of the neuroendocrine axis and puberty.

  9. The effect of chronic ethanol ingestion on growth hormone secretion and hepatic sexual dimorphism in male rats

    SciTech Connect

    Lechner, P.S.

    1992-01-01

    The effect of chronic ethanol ingestion on the activities of several sexually dimorphic hepatic proteins was investigated in male rats by feeding a nutritionally adequate liquid diet supplemented with either ethanol or dextrimaltose. Two androgen-responsive proteins served as markers of masculine hepatic function. A high capacity, moderate affinity male estrogen-binding protein (MEB) is found only in male rat liver cytosol and this activity was significantly reduced in all animals consuming ethanol at a dose of 5% by volume. The estrogen metabolizing enzyme estrogen 2-hydroxylase was also significantly reduced in male rats fed ethanol. Two proteins having higher activity in female compared to male liver were chosen as indicators of feminization: ceruloplasmin and 5[alpha]-reductase. Ceruloplasmin activity was increased after long term feeding of ethanol, but not after shorter durations of alcohol consumption. The 5a-reductase activity was not significantly affected by any of the alcohol feeding studies. Serum testosterone levels were not significantly decreased after ethanol consumption. After 30 or 60 days of ethanol ingestion, serum estradiol was elevated 34% and 40%. The reversibility of ethanol effects was determined by a gradual withdrawal of alcohol from the diet. The effect of ethanol consumption on sex-specific patterns of growth hormone secretion was examined. The secretory pattern of alcohol-fed rats was not feminized; after ethanol ingestion, the frequency of growth hormone pulses was unchanged. An increase in pulse height and mean growth hormone concentration was observed after 60 days of ethanol consumption. This results constitutes a change away from rather than toward the characteristics of a female secretory pattern. The feminization of activities of the male estrogen binding protein and of estrogen 2-hydroxylase in male rat liver after chronic ethanol consumption are not apparently related to a feminization of growth hormone secretion pattern.

  10. [Influence of nutrition on hormone secretion. I. Study in Agua Preta (author's transl)].

    PubMed

    Chaves, N; Guimarães, E D; Aguiar, F; Viana, T; Matos, E; Basto de Medeiros, R; Martins, G C; Bazante, M O; Pimenta, P P

    1975-01-01

    A positive correlation between the circulating growth hormone levels and the nutritional status was reported in 9 children of both sexes, aged 1 to 6 years, suffering from 2nd degree malnutrition. The mean serum insulin levels, the mean urinary 17-KS and 17-OHCS levels were low before the dietary therapy. No significant correlation between the levels of these hormones and the nutritional status was found. The hormone levels gradually returned to normal after the dietary therapy and the nutritional status of the children improved, according to the observed biochemical, clinical and anthropometric data.

  11. Copeptin as a marker for arginine-vasopressin/antidiuretic hormone secretion in the diagnosis of paraneoplastic syndrome of inappropriate ADH secretion.

    PubMed

    Wuttke, A; Dixit, K C; Szinnai, G; Werth, S C; Haagen, U; Christ-Crain, M; Morgenthaler, N; Brabant, G

    2013-12-01

    Direct measurement of arginine-vasopressin/antidiuretic hormone (AVP/ADH) concentrations is not included in the standard diagnostic procedures for paraneoplastic syndrome of inappropriate ADH secretion (SIADH). Here, we evaluate the potential of copeptin measurement as a surrogate marker of AVP/ADH secretion for the direct diagnosis of suspected SIADH in cancer patients. Forty-six unselected cancer patients with serum sodium concentrations permanently below 135 mmol/L were included in this study. We compared standard diagnostic criteria for SIADH to the measurement of plasma copeptin in relation to osmolality. Normative data for comparison were constructed from 24 healthy controls studied under basal conditions, experimental dehydration, and hypotonic hypervolemia as well as from 222 hospital patients with no suspicion of an altered ADH regulation. Log transformation of copeptin revealed a linear relationship to plasma osmolality in the controls (R = 0.495, p < 0.001). Compared to these normative data, copeptin levels in most cancer patients were inappropriately high for plasma osmolality and were not significantly correlated. These results, suggestive for paraneoplastic SIADH, could be confirmed by conventional diagnostic procedures for SIADH. Current strategies to diagnose SIADH are difficult to perform under outpatients conditions. Our approach allows screening from a single plasma sample for true paraneoplastic ADH oversecretion and thus rapid selection for a specific therapy with an AVP receptor antagonist.

  12. Effect of therapy with a new glucocorticoid, deflazacort, on linear growth and growth hormone secretion after renal transplantation.

    PubMed

    Ferraris, J R; Fainstein Day, P; Gutman, R; Granillo, E; Ramirez, J; Ruiz, S; Pasqualini, T

    1992-11-01

    Deflazacort is an oxazoline compound derived from prednisolone with similar antiinflammatory effects but fewer side effects. We studied changes in kidney function, growth velocity, weight/height ratio, and growth hormone secretion before and a year after substitution of deflazacort for methylprednisone in nine patients aged 9 to 15 years, 4 years after renal transplantation; all were in Tanner pubertal stage 1. Methylprednisone (mean +/- SEM: 0.2 +/- 0.02 mg/kg per day) was replaced by deflazacort (0.3 +/- 0.03 mg/kg per day) for a mean period of 15 months. Serum creatinine and calculated creatinine clearance did not change significantly during deflazacort treatment. Growth velocity increased from 1.5 +/- 0.3 to 3.2 +/- 0.5 cm/yr (p < 0.005) in the nine patients. Weight/height ratio decreased from 28.4% +/- 8.5% to 16% +/- 6.7% (p < 0.005). Cushingoid appearance decreased in all patients. Mean spontaneous growth hormone secretion increased from 2.5 +/- 0.4 to 4.4 +/- 1.2 ng/ml (p < 0.05). Our findings indicate that immunosuppressive treatment with deflazacort is as effective as methylprednisone and is associated with fewer side effects.

  13. Ectopic acromegaly due to a growth hormone-secreting neuroendocrine-differentiated tumor developed from ovarian mature cystic teratoma.

    PubMed

    Ozkaya, Mesut; Sayiner, Zeynel Abidin; Kiran, Gurkan; Gul, Kamile; Erkutlu, Ibrahim; Elboga, Umut

    2015-06-01

    Acromegaly is a clinical syndrome caused by the overproduction of growth hormone (GH) and also known as a rare disease. Clinical, biochemical, and radiological features are often indistinguishable between GH-producing hypophysis adenomas and ectopic GH-releasing hormone (GHRH)-producing tumors. A 40-year-old woman presented to us with her growing feet, hands especially fingers, and enlarging nose. Biochemical diagnosis of acromegaly was made by measuring insulin-like growth factor-1 (IGF-1) level and glucose-suppressed GH estimation. Her spot IGF-1 level was 1300 ng/ml (90-226 ng/ml). The basal GH was 30 ng/l, and 60- and 120-min GH levels after 75-g oral glucose load were 29 and 40 ng/l, respectively. Magnetic resonance imaging (MRI) of pituitary was normal. There was no pituitary adenoma or pituitary hyperplasia. Extrapituitary ectopic hypersecretion of GH or GHRH-secreting tumor search was done by high-resolution computed tomography (CT) of chest and whole abdomen. Abdomen CT revealed 9.5 × 8 cm pelvic mass, which included calcific regions and solid component. The specimen's immunohistochemical staining with GH was positive but interestingly GHRH was negative. According to immunohistochemical staining, the patient's diagnosis was ectopic acromegaly due to a GH-secreting neuroendocrine-differentiated tumor developed from an ovarian mature cystic teratoma. Herein, we present excellent illustration of an unusual and confusing clinical scenario of ectopic acromegaly.

  14. Hormones

    MedlinePlus

    Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work ... glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, ...

  15. Curcumin inhibits ACTH- and angiotensin II-stimulated cortisol secretion and Ca(v)3.2 current.

    PubMed

    Enyeart, Judith A; Liu, Haiyan; Enyeart, John J

    2009-08-01

    Adrenocorticotropic hormone and angiotensin II stimulate cortisol secretion from bovine adrenal zona fasciculata cells by the activation of adenylate cyclase and phospholipase C-coupled receptors. Curcumin (1- 20 muM), a compound found in the spice turmeric, inhibited cortisol secretion stimulated by ACTH, AngII, and 8CPT-cAMP. Curcumin also suppressed ACTH-stimulated increases in mRNAs coding for steroid acute regulatory protein and CYP11a1 steroid hydroxylase. In whole cell patch clamp recordings from AZF cells, curcumin at slightly higher concentrations also inhibited Ca(v)3.2 current. These results identify curcumin as an effective inhibitor of ACTH- and AngII-stimulated cortisol secretion. The inhibition of Ca(v)3.2 current by curcumin may contribute to its suppression of secretion.

  16. Control of luteinizing hormone and testosterone secretion in a flexibly breeding male passerine, the Rufous-winged Sparrow, Aimophila carpalis.

    PubMed

    Deviche, Pierre; Small, Thomas; Sharp, Peter; Tsutsui, Kazuyoshi

    2006-12-01

    Rufous-winged Sparrows, Aimophila carpalis, reside in the Sonoran desert and although testicular development is initiated in the spring under the influence of increasing day length, breeding occurs opportunistically in summer in association with heavy rainfall or "monsoon". The aim of this study in free-living male Rufous-winged Sparrows was to establish the relationship between concentrations of plasma luteinizing hormone (LH) and testosterone (T), and breeding associated with heavy rainfall, and to investigate whether breeding is mediated by changes in pituitary gland sensitivity to gonadotropin releasing hormone-I (GnRH) and the recently discovered avian gonadotropin-inhibitory hormone (GnIH). Concentrations of plasma LH and T were relatively low until mid-summer, but increased rapidly and transiently immediately prior to the monsoon which occurred after the summer solstice, when day lengths were decreasing. At this time the birds came into full breeding condition. An injection of chicken GnRH (10 ng) increased plasma LH within 2 min when given before or during the monsoon. An injection of GnIH (1 microg) did not affect plasma LH within 2 min during the monsoon and did not decrease GnRH-elicited LH secretion before or during the monsoon. No experimental treatment affected plasma T concentrations. The data suggest in male Rufous-winged Sparrows that the seasonal increase in plasma LH associated with summer monsoon results from increased stimulation of the pituitary gland by GnRH, rather than from a change in the responsiveness of the gland to GnRH, and that GnIH does not play an acute role in this mechanism. However, a possible chronic role for GnIH in the seasonal control of LH synthesis and secretion through an inhibitory effect on the hypothalamic GnRH system remains to be investigated.

  17. Improving Effect of the Acute Administration of Dietary Fiber-Enriched Cereals on Blood Glucose Levels and Gut Hormone Secretion

    PubMed Central

    2016-01-01

    Dietary fiber improves hyperglycemia in patients with type 2 diabetes through its physicochemical properties and possible modulation of gut hormone secretion, such as glucagon-like peptide 1 (GLP-1). We assessed the effect of dietary fiber-enriched cereal flakes (DC) on postprandial hyperglycemia and gut hormone secretion in patients with type 2 diabetes. Thirteen participants ate isocaloric meals based on either DC or conventional cereal flakes (CC) in a crossover design. DC or CC was provided for dinner, night snack on day 1 and breakfast on day 2, followed by a high-fat lunch. On day 2, the levels of plasma glucose, GLP-1, glucose-dependent insulinotropic polypeptide (GIP), and insulin were measured. Compared to CC, DC intake exhibited a lower post-breakfast 2-hours glucose level (198.5±12.8 vs. 245.9±15.2 mg/dL, P<0.05) and a lower incremental peak of glucose from baseline (101.8±9.1 vs. 140.3±14.3 mg/dL, P<0.001). The incremental area under the curve (iAUC) of glucose after breakfast was lower with DC than with CC (P<0.001). However, there were no differences in the plasma insulin, glucagon, GLP-1, and GIP levels. In conclusion, acute administration of DC attenuates postprandial hyperglycemia without any significant change in the representative glucose-regulating hormones in patients with type 2 diabetes (ClinicalTrials.gov. NCT 01997281). PMID:26839476

  18. Loss of a neural AMP-activated kinase mimics the effects of elevated serotonin on fat, movement, and hormonal secretions.

    PubMed

    Cunningham, Katherine A; Bouagnon, Aude D; Barros, Alexandre G; Lin, Lin; Malard, Leandro; Romano-Silva, Marco Aurélio; Ashrafi, Kaveh

    2014-06-01

    AMP-activated protein kinase (AMPK) is an evolutionarily conserved master regulator of metabolism and a therapeutic target in type 2 diabetes. As an energy sensor, AMPK activity is responsive to both metabolic inputs, for instance the ratio of AMP to ATP, and numerous hormonal cues. As in mammals, each of two genes, aak-1 and aak-2, encode for the catalytic subunit of AMPK in C. elegans. Here we show that in C. elegans loss of aak-2 mimics the effects of elevated serotonin signaling on fat reduction, slowed movement, and promoting exit from dauer arrest. Reconstitution of aak-2 in only the nervous system restored wild type fat levels and movement rate to aak-2 mutants and reconstitution in only the ASI neurons was sufficient to significantly restore dauer maintenance to the mutant animals. As in elevated serotonin signaling, inactivation of AAK-2 in the ASI neurons caused enhanced secretion of dense core vesicles from these neurons. The ASI neurons are the site of production of the DAF-7 TGF-β ligand and the DAF-28 insulin, both of which are secreted by dense core vesicles and play critical roles in whether animals stay in dauer or undergo reproductive development. These findings show that elevated levels of serotonin promote enhanced secretions of systemic regulators of pro-growth and differentiation pathways through inactivation of AAK-2. As such, AMPK is not only a recipient of hormonal signals but can also be an upstream regulator. Our data suggest that some of the physiological phenotypes previously attributed to peripheral AAK-2 activity on metabolic targets may instead be due to the role of this kinase in neural serotonin signaling. PMID:24921650

  19. Experiment K-7-22: Growth Hormone Regulation Synthesis and Secretion in Microgravity. Part 2; Hypothalamic Growth Hormone-Releasing Factor, Somatostatin Immunoreactivity, and Messenger RNA Levels in Microgravity

    NASA Technical Reports Server (NTRS)

    Sawchenko, P. E.; Arias, C.; Krasnov, I.; Grindeland, R. E.; Vale, W.

    1994-01-01

    Immunohistochemical analyses of hypothalamic hormones carried out on tissue from rats flown on an earlier flight (Cosmos 1887) suggested preferential effects on hypophysiotropic principles involved in the regulation of growth hormone secretion and synthesis. We found that staining in the median eminence for peptides that provide both stimulatory (growth hormone-releasing factor, or GRF) and inhibitory (somatostatin, SS) influences on growth hormone secretion were depressed in flight animals relative to synchronous controls, while staining for other neuroendocrine peptides, cortocotropin-releasing factor and arginine vasopressin, were similar in these two groups. While this suggests some selective impact of weightlessness on the two principal central nervous system regulators of growth hormone dynamics, the fact that both GRF- and SS-immunoreactivity (IR) appeared affected in the same direction is somewhat problematic, and makes tentative any intimation that effects on CNS control mechanisms may be etiologically significant contributors to the sequelae of reduced growth hormone secretion seen in prolonged space flight. To provide an additional, and more penetrating, analysis we attempted in hypothalamic material harvested from animals flown on Cosmos 2044 to complement immunohistochemical analyses of GRF and SS staining with quantitative, in situ assessments of messenger RNAs encoding the precursors for both these hormones.

  20. Oral phosphorus supplementation secondarily increases circulating fibroblast growth factor 23 levels at least partially via stimulation of parathyroid hormone secretion.

    PubMed

    Takasugi, Satoshi; Akutsu, Miho; Nagata, Masashi

    2014-01-01

    Oral phosphorus supplementation stimulates fibroblast growth factor 23 (FGF23) secretion; however, the underlying mechanism remains unclear. The aim of this study was to investigate the involvement of parathyroid hormone (PTH) in increased plasma FGF23 levels after oral phosphorus supplementation in rats. Rats received single dose of phosphate with concomitant subcutaneous injection of saline or human PTH (1-34) after treatment with cinacalcet or its vehicle. Cinacalcet is a drug that acts as an allosteric activator of the calcium-sensing receptor and reduces PTH secretion. Plasma phosphorus and PTH levels significantly increased 1 h after oral phosphorus administration and returned to basal levels within 3 h, while plasma FGF23 levels did not change up to 2 h post-treatment, but rather significantly increased at 3 h after administration and maintained higher levels for at least 6 h compared with the 0 time point. Plasma PTH and FGF23 levels were significantly lower in the cinacalcet-treated rats than in the vehicle-treated rats. Plasma phosphorus levels were significantly higher in the cinacalcet-treated rats than in the vehicle-treated rats at 2, 3, 4, and 6 h after oral phosphorus administration. Furthermore, rats treated with cinacalcet+human PTH (1-34) showed transiently but significantly higher plasma FGF23 levels at 3 h after oral phosphorus administration compared with cinacalcet-treated rats. These results suggest that oral phosphorus supplementation secondarily increases circulating FGF23 levels at least partially by stimulation of PTH secretion.

  1. Pulsatile and sexually dimorphic secretion of luteinizing hormone in the human infant on the day of birth.

    PubMed

    de Zegher, F; Devlieger, H; Veldhuis, J D

    1992-11-01

    Experimental evidence indicates that the hypothalamic-pituitary-gonadal axis is operational and sexually dimorphic in the mammalian fetus and newborn. We examined the dynamics of human luteinizing hormone (LH) secretion in five male and three female infants on the day of birth, after 34-41 wk of gestation. The infants were polycythemic, and blood samples were obtained every 20 min for 160 to 360 min during a therapeutic, standardized, isovolumetric, partial exchange transfusion. Serum LH was measured by an immunoradiometric assay that does not cross-react with human chorionic gonadotropin. The serum profiles of LH presented a striking sex dimorphism with elevated LH levels in male compared with female newborns. Deconvolution analysis of all male LH profiles was consistent with a high-frequency, pulsatile secretory pattern. Testosterone, measured in a pooled serum sample of each infant, was 10-fold higher in male than in female newborns. These results document pulsatile and sexually dimorphic secretion of LH in the human infant as early as the first day of postnatal life. It is possible that the augmented LH secretion in the male newborn participates in the neonatal rise of the serum testosterone concentration.

  2. Ketoconazole inhibition of testicular secretion of testosterone and displacement of steroid hormones from serum transport proteins.

    PubMed Central

    Grosso, D S; Boyden, T W; Pamenter, R W; Johnson, D G; Stevens, D A; Galgiani, J N

    1983-01-01

    In vivo perfusion of canine testes with ketoconazole inhibited the stimulation of testosterone production by human chorionic gonadotropin in a dose-dependent manner. Ketoconazole also selectively displaced steroids from serum-binding globulins. Dihydrotestosterone and estradiol binding to sex hormone-binding globulin were inhibited by ketoconazole. Cortisol binding to corticosteroid-binding globulin was unaffected. The concentrations of ketoconazole that inhibited human chorionic gonadotropin stimulation of testicular androgen production and displaced sex steroids from sex hormone-binding globulin were in the range of blood levels found in patients on higher therapeutic dosage regimens. Suppression of testicular testosterone synthesis and displacement of estrogens from sex hormone-binding globulin may decrease the androgen/estrogen ratio of the blood and contribute to the development of gynecomastia that has been reported in some ketoconazole-treated patients. PMID:6301363

  3. Could the improvement of obesity-related co-morbidities depend on modified gut hormones secretion?

    PubMed Central

    Finelli, Carmine; Padula, Maria Carmela; Martelli, Giuseppe; Tarantino, Giovanni

    2014-01-01

    Obesity and its associated diseases are a worldwide epidemic disease. Usual weight loss cures - as diets, physical activity, behavior therapy and pharmacotherapy - have been continuously implemented but still have relatively poor long-term success and mainly scarce adherence. Bariatric surgery is to date the most effective long term treatment for morbid obesity and it has been proven to reduce obesity-related co-morbidities, among them nonalcoholic fatty liver disease, and mortality. This article summarizes such variations in gut hormones following the current metabolic surgery procedures. The profile of gut hormonal changes after bariatric surgery represents a strategy for the individuation of the most performing surgical procedures to achieve clinical results. About this topic, experts suggest that the individuation of the crosslink among the gut hormones, microbiome, the obesity and the bariatric surgery could lead to new and more specific therapeutic interventions for severe obesity and its co-morbidities, also non surgical. PMID:25469034

  4. Active immunization of gilts against gonadotropin-releasing hormone: effects on secretion of gonadotropins, reproductive function, and responses to agonists of gonadotropin-releasing hormone.

    PubMed

    Esbenshade, K L; Britt, J H

    1985-10-01

    Sexually mature gilts were actively immunized against gonadotropin-releasing hormone (GnRH) by conjugating GnRH to bovine serum albumin, emulsifying the conjugate in Freund's adjuvant, and giving the emulsion as a primary immunization at Week 0 and as booster immunizations at Weeks 10 and 14. Antibody titers were evident by 2 wk after primary immunization and increased markedly in response to booster immunizations. Active immunization against GnRH caused gonadotropins to decline to nondetectable levels, gonadal steroids to decline to basal levels, and the gilts to become acyclic. Prolactin concentrations in peripheral circulation were unaffected by immunization against GnRH. The endocrine status of the hypothalamic-pituitary-ovarian axis was examined by giving GnRH and two agonists to GnRH and by ovariectomy. An i.v. injection of 100 micrograms GnRH caused release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in control animals, but not in gilts immunized against GnRH. In contrast, administration of 5 micrograms D-(Ala6, des-Gly-NH2(10] ethylamide or 5 micrograms D-(Ser-t-But6, des-Gly-NH2(10] ethylamide resulted in immediate release of LH and FSH in both control and GnRH-immunized gilts. Circulating concentrations of LH and FSH increased after ovariectomy in the controls, but remained at nondetectable levels in gilts immunized against GnRH. Prolactin concentrations did not change in response to ovariectomy. We conclude that cyclic gilts can be actively immunized against GnRH and that this causes cessation of estrous cycles and inhibits secretion of LH, FSH, and gonadal steroids.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Neural Mechanism by which Gravitational Stimuli and Stress Affect the Secretion of Renin and Other Hormones

    NASA Technical Reports Server (NTRS)

    Ganong, W. F.; Gotoh, E.; Alper, R. H.

    1985-01-01

    The serotonin-releasing drug p-chloroamphetamine (PCA), as well as L-propranolol and chloriasondamine were used in a study which established that the pathway from the hypothalamus to the kidneys is sympathetic. Which hypothalamic nuclei mediate the response to PCA is being investigated experiments are being conducted to determine a readily reproducible psychological stimulus to renin secretion that can be used in rats. The effects of equithesin, urethane, and inactin on plasma renin activity were examined in preparation for tilting experiments. The relation of vasopressin-secreting neurons in the brain sem to PCA response was explored in Brattleboro rats that are congenitally unable to produce vasopressin in their hypothalami.

  6. Anorexigenic effects of miglitol in concert with the alterations of gut hormone secretion and gastric emptying in healthy subjects.

    PubMed

    Kaku, H; Tajiri, Y; Yamada, K

    2012-04-01

    Although the α-glucosidase inhibitor miglitol (MG) has been reported to have anorexigenic effects, the mechanism remains to be elucidated. The objective of this study was to explore the effects of MG on appetite in relation to concomitant changes in postprandial gut hormone levels. This randomized open-label crossover study included 20 healthy volunteers. The effects of 50 mg MG on glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and ghrelin levels were assessed in conjunction with a simultaneous determination of appetite scores using visual analogue scales (VAS) over 3 h after the ingestion of a 592 kcal test cookie. Additionally, the gastric emptying rate (GER) was measured using breath ¹³CO₂ appearance in 10 subjects. 12 subjects were administered 50 mg MG thrice a day for 1 week, and alterations of the gut hormone levels and the VAS scores for appetite were evaluated. MG pre-administration resulted in a significant enhancement of GLP-1 and PYY responses induced by the cookie ingestion. Following MG administration, ghrelin level declined at 1 h, with a persistent suppression during the postprandial phase in contrast to the restoration to the basal level without MG. Furthermore, MG pre-administration suppressed appetite and maintained satiety evaluated using a VAS rating with concomitant inhibition of GER after cookie ingestion. One-week administration of MG did not influence either gut hormone levels before a meal or VAS rating during a whole day. These observations suggest that MG exerts an anorexigenic effects with concomitant alterations of gut hormone secretions and gastric emptying after meal ingestion. PMID:22351480

  7. Neural mechanisms by which gravitational stimuli and stress affect the secretion of renin and other hormones

    NASA Technical Reports Server (NTRS)

    Ganong, William F.

    1987-01-01

    The present goal is to determine by the production of discrete lesions the parts of the hypothalamus and brainstem that are involved in serotonin-mediated increases in renin secretion. A variety of stimuli which act in different ways to increase renin stimuli were developed and standardized. The experiments with p-chloroamphetamine (PCA) demonstrated that there is a serotonergic pathway which projects from the dorsal raphe nuclei to the paraventricular nuclei and the vetromedial nuclei of the hypothalamus; that projection from paraventricular nuclei to the brainstem and spinal cord may be oxytocinergic; and that the pathway from the spinal cord to the renin secreting cells is sympathetic. The demonstration that paraventicular lesions lower circulating renin substrate is important because it raises the possibility that substrate secretion is under neural control, either via the pituitary or by direct neural pathways. The discovery that lesions of the ventromedial nuclei appear to abolish the increase in renin secretion produced by many different stimuli without affecting the concentration of renin substrate in the plasma makes the position of the hypothalamus in the regulation of fluid and electrolyte balance more prominent than previously suspected.

  8. Effects of RFRP2 and RF9 on secretion of luteinizing hormone in prepubertal gilts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In most mammals, the RF-amide related peptide (RFRP) pre-pro-protein contains cleavage sites for 2 peptides (RFRP1 and RFRP3). Our laboratory did not observe RFRP3-induced suppression of LH secretion in gilts. However, the porcine sequence encodes an additional peptide (RFRP2) with an amidated C-ter...

  9. Hypothalamic Prolactin Regulation of Luteinizing Hormone Secretion in the Female Rat.

    PubMed

    Grachev, Pasha; Li, Xiao Feng; Goffin, Vincent; O'Byrne, Kevin T

    2015-08-01

    Prolactin (PRL) levels increase in response to long-term antipsychotic treatment that disrupts reproductive function. Recent evidence suggests that activation of central PRL receptors (PRLR) inhibits LH secretion and in ovariectomized rats. However, the mechanisms involved, the mode of LH secretion affected and relevance to hyperprolactinemia remain unknown. We therefore investigated the contribution of central PRL/PRLR signaling to the control of estradiol-induced surges of LH and PRL and pulsatile LH secretion under basal and hyperprolactinemic conditions. First, by subjecting ovariectomized estradiol-primed rats intracerebroventricularly administered with PRL to frequent blood sampling, we demonstrated that acute activation of hypothalamic PRLR disrupts pulsatile LH secretion. Pretreatment (intracerebroventricularly) with the pure PRLR antagonist, Δ1-9-G129R-hPRL, or the γ-aminobutyric acid receptor type A antagonist, bicuculline, blocked this effect. Next, we revealed that sustained blockade of hypothalamic PRLR using Δ1-9-G129R-hPRL augmented the magnitude of LH surges induced by estradiol benzoate and progesterone treatment and suppressed the concomitant surges of PRL. Finally, we determined that acute antagonism of central PRLR is insufficient to normalize the duration of the LH pulse interval prolonged as a result of hyperprolactinemia induced by chronic exposure to the atypical antipsychotic sulpiride. These data serve as the first evidence to suggest that PRL signaling through hypothalamic PRLR inhibits pulsatile secretion of LH in a γ-aminobutyric acid receptor type A-dependent fashion and tonically restrains the magnitude of the LH surge. Furthermore, our results indicate that transient blockade of hypothalamic PRL/PRLR signaling is not an effective strategy for restoring LH pulsatility perturbed by chronic hyperprolactinemia.

  10. Steroid secretion in polycystic ovarian disease after ovarian suppression by a long-acting gonadotropin-releasing hormone agonist.

    PubMed

    Chang, R J; Laufer, L R; Meldrum, D R; DeFazio, J; Lu, J K; Vale, W W; Rivier, J E; Judd, H L

    1983-05-01

    The principal glandular source of increased serum androgens in polycystic ovarian disease (PCO) is controversial), since complete separation of ovarian from adrenal function has not been achieved. The purpose of this study was to determine whether a long-acting GnRH agonist could be used to selectively inhibit ovarian steroid secretion in PCO and ovulatory women. Each of five typical PCO patients and six ovulatory subjects on day 2 of their menstrual cycles received D-Trp6-Pro9-NEt-LHRH (GnRH-a; 100 micrograms) for 28 consecutive days. Their results were compared to basal serum hormone values in eight oophorectomized women. In response to GnRH-a, PCO and normal subjects exhibited sharp and sustained rises of LH and gradual decreases in FSH. These levels were clearly less than basal levels seen in oophorectomized women. Episodic LH release was significantly attenuated in both groups at the end of GnRH-a treatment. After the administration of agonist, serum estradiol (E2), estrone (E1), androstenedione (A), and testosterone (T) were suppressed to castrate levels in both groups. The decrements of E2 and E1 in PCO were gradual and continuous compared to initial dramatic rises, which reached peaks at 14 days, and subsequent abrupt falls in the ovulatory controls. Serum A and T declined steadily in both groups. Basal serum dehydroepiandrosterone and dehydroepiandrosterone sulfate, but not cortisol, levels were elevated in PCO subjects. The 24-h secretion patterns and responses to ACTH of these hormones in PCO and ovulatory subjects were unaltered by GnRH-a administration. These data demonstrate that 1) in PCO subjects, GnRH-a induced complete suppression of ovarian steroid secretion, as circulating levels at the end of treatment were comparable to those seen in our oophorectomy subjects; 2) elevated A and T levels in PCO patients were derived primarily from the ovary; and 3) adrenal steroid secretion was unaltered by GnRH-a in both PCO and normal women.

  11. GPR142 Controls Tryptophan-Induced Insulin and Incretin Hormone Secretion to Improve Glucose Metabolism

    PubMed Central

    Efanov, Alexander M.; Fang, Xiankang; Beavers, Lisa S.; Wang, Xuesong; Wang, Jingru; Gonzalez Valcarcel, Isabel C.; Ma, Tianwei

    2016-01-01

    GPR142, a putative amino acid receptor, is expressed in pancreatic islets and the gastrointestinal tract, but the ligand affinity and physiological role of this receptor remain obscure. In this study, we show that in addition to L-Tryptophan, GPR142 signaling is also activated by L-Phenylalanine but not by other naturally occurring amino acids. Furthermore, we show that Tryptophan and a synthetic GPR142 agonist increase insulin and incretin hormones and improve glucose disposal in mice in a GPR142-dependent manner. In contrast, Phenylalanine improves in vivo glucose disposal independently of GPR142. Noteworthy, refeeding-induced elevations in insulin and glucose-dependent insulinotropic polypeptide are blunted in Gpr142 null mice. In conclusion, these findings demonstrate GPR142 is a Tryptophan receptor critically required for insulin and incretin hormone regulation and suggest GPR142 agonists may be effective therapies that leverage amino acid sensing pathways for the treatment of type 2 diabetes. PMID:27322810

  12. Prolonged stimulation of corticosterone secretion by corticotropin-releasing hormone in rats exhibiting high preference for dietary fat

    USGS Publications Warehouse

    Herminghuysen, D.; Plaisance, K.; Pace, R. M.; Prasad, C.

    1998-01-01

    Through the secretion of corticosterone, the hypothalamo-pituitary-adrenal (HPA) axis is thought to play an important role in the regulation of caloric intake and dietary fat preference. In an earlier study, we demonstrated a positive correlation between urinary corticosterone output and dietary fat preference. Furthermore, dietary fat preference was augmented following chronic but not acute hypercorticosteronemia produced by exogenous corticosterone administration. These observations led us to explore whether the HPA axis of rats exhibiting high preference for fat may have exaggerated sensitivity to corticotropin-releasing hormone (CRH). The results of these studies show a delayed and blunted but more prolonged corticosterone response to CRH in the fat-preferring rats compared with that of the carbohydrate-preferring rats.

  13. Tianeptine interferes with microtubule organization and hormone secretion of pheochromocytoma cells.

    PubMed

    Makani, Vishruti; Hall, James; Qamar, Khola; Jain, Priyanka; Jang, Yonggil; Hensley, Kenneth; Park, Joshua J

    2013-12-01

    Pheochromocytoma originates from chromaffin cells in the adrenal medulla and sympathetic paraganglia. 36-53% of pheochromocytoma becomes malignant and, thereafter, resistant to conventional treatments. Pheochromocytoma also causes hyper-secretion of catecholamines that cause severe hypertension. We found that an antidepressant, tianeptine, interfered with normal life cycle of pheochromocytoma cells at its clinical doses. Treatment with tianeptine caused microtubule bundling and specific degradation of cytoplasmic dynein, a retrograde microtubule motor that mediates various microtubule-dependent processes during interphase and mitosis, in the rat pheochromocytoma PC12 cells. Tianeptine also increased the levels of pro-apoptotic proteins, slowed cell cycle progression, and increased apoptosis in PC12 cells. Importantly, tianeptine treatment decreased high K(+)-stimulated secretion of norepinephrine and chromogranin A in PC12 cells and of epinephrine in the mouse pheochromocytoma MPC cells. Our study demonstrates, for the first time, that tianeptine interferes with normal life cycle of pheochromocytoma cells.

  14. Tianeptine interferes with microtubule organization and hormone secretion of pheochromocytoma cells.

    PubMed

    Makani, Vishruti; Hall, James; Qamar, Khola; Jain, Priyanka; Jang, Yonggil; Hensley, Kenneth; Park, Joshua J

    2013-12-01

    Pheochromocytoma originates from chromaffin cells in the adrenal medulla and sympathetic paraganglia. 36-53% of pheochromocytoma becomes malignant and, thereafter, resistant to conventional treatments. Pheochromocytoma also causes hyper-secretion of catecholamines that cause severe hypertension. We found that an antidepressant, tianeptine, interfered with normal life cycle of pheochromocytoma cells at its clinical doses. Treatment with tianeptine caused microtubule bundling and specific degradation of cytoplasmic dynein, a retrograde microtubule motor that mediates various microtubule-dependent processes during interphase and mitosis, in the rat pheochromocytoma PC12 cells. Tianeptine also increased the levels of pro-apoptotic proteins, slowed cell cycle progression, and increased apoptosis in PC12 cells. Importantly, tianeptine treatment decreased high K(+)-stimulated secretion of norepinephrine and chromogranin A in PC12 cells and of epinephrine in the mouse pheochromocytoma MPC cells. Our study demonstrates, for the first time, that tianeptine interferes with normal life cycle of pheochromocytoma cells. PMID:23933152

  15. Tianeptine interferes with microtubule organization and hormone secretion of pheochromocytoma cells

    PubMed Central

    Makani, Vishruti; Hall, James; Qamar, Khola; Jain, Priyanka; Jang, Yonggil; Hensley, Kenneth; Park, Joshua J.

    2013-01-01

    Pheochromocytoma originates from chromaffin cells in the adrenal medulla and sympathetic paraganglia. 36–53% of pheochromocytoma becomes malignant and, thereafter, resistant to conventional treatments. Pheochromocytoma also causes hyper-secretion of catecholamines that cause severe hypertension. We found that an antidepressant, tianeptine, interfered with normal life cycle of pheochromocytoma cells at its clinical doses. Treatment with tianeptine caused microtubule bundling and specific degradation of cytoplasmic dynein, a retrograde microtubule motor that mediates various microtubule-dependent processes during interphase and mitosis, in the rat pheochromocytoma PC12 cells. Tianeptine also increased the levels of pro-apoptotic proteins, slowed cell cycle progression, and increased apoptosis in PC12 cells. Importantly, tianeptine treatment decreased high K+-stimulated secretion of norepinephrine and chromogranin A in PC12 cells and of epinephrine in the mouse pheochromocytoma MPC cells. Our study demonstrates, for the first time, that tianeptine interferes with normal life cycle of pheochromocytoma cells. PMID:23933152

  16. Effects of exposure to male goat hair extracts on luteinizing hormone secretion and neuronal activation in seasonally anestrous ewes.

    PubMed

    Ohara, Hiromi; Mogi, Kazutaka; Ichimaru, Toru; Ohkura, Satoshi; Takeuchi, Yukari; Mori, Yuji; Okamura, Hiroaki

    2014-10-01

    In sheep and goats, exposure of seasonally anestrous females to males or their fleece/hair activates the gonadotropin-releasing hormone (GnRH) pulse generator leading to pulsatile luteinizing hormone (LH) secretion. Pheromones emitted by sexually mature males are thought to play a prominent role in this male effect. In the present study, we first aimed to clarify whether the male goat pheromone is effective in ewes. Seasonally anestrous St. Croix ewes were exposed to hair extracts derived from either intact or castrated (control) male Shiba goats. The male goat-hair extract significantly increased LH secretion compared to the control, suggesting that an interspecies action of the male pheromone occurs between sheep and goats. Using the male goat-hair extract as the pheromone source, we then aimed to clarify the neural pathway involved in the signal transduction of the male pheromone. Ewes were exposed to either the goat-hair extract or the control and sacrificed 2 hr after the exposure. Expression of c-Fos, a marker of neuronal activation, was immunohistochemically examined. The male goat-hair extract significantly increased the c-Fos expression compared to the control in regions of the vomeronasal system, such as the accessory olfactory bulb and medial amygdala, and the arcuate nucleus. The main olfactory bulb did not exhibit any significant increase in the c-Fos expression by the male goat-hair extract. This result suggests that the neural signal of the male pheromone is conveyed to the GnRH pulse generator through the activated regions in ewes.

  17. The ghrelin/obestatin balance in the physiological and pathological control of growth hormone secretion, body composition and food intake.

    PubMed

    Hassouna, R; Zizzari, P; Tolle, V

    2010-07-01

    Ghrelin and obestatin are two gastrointestinal peptides obtained by post-translational processing of a common precursor, preproghrelin. Ghrelin is an orexigenic and adipogenic peptide and a potent growth hormone secretagogue (GHS) modified by the enzyme ghrelin-O-acyl-transferase to bind and activate its receptor, the GHS-R. The ghrelin/GHS-R pathway is complex and the effects of ghrelin on GH secretion, adiposity and food intake appear to be relayed by distinct mechanisms involving different transduction signals and constitutive activity for the GH-R, different cofactors as modulators of endogenous ghrelin signalling and/or alternative ghrelin receptors. The discovery of obestatin in 2005 brought an additional level of complexity to this fascinating system. Obestatin was initially identified as an anorexigenic peptide and as the cognate ligand for GPR39, but its effect on food intake and its ability to activate GPR39 are still controversial. Although several teams failed to reproduce the anorexigenic actions of obestatin, this peptide has been shown to antagonise GH secretion and food intake induced by ghrelin and could be an interesting pharmacological tool to counteract the actions of ghrelin. Ghrelin and obestatin immunoreactivities are recovered in the blood with an ultradian pulsatility and their concentrations in plasma vary with the nutritional status of the body. It is still a matter of debate whether both hormones are regulated by independent mechanisms and whether obestatin is a physiologically relevant peptide. Nevertheless, a significant number of studies show that the ghrelin/obestatin ratio is modified in anorexia nervosa and obesity. This suggests that the ghrelin/obestatin balance could be essential to adapt the body's response to nutritional challenges. Although measuring ghrelin and obestatin in plasma is challenging because many forms of the peptides circulate, more sensitive and selective assays to detect the different preproghrelin

  18. Hypokalemia decreases testosterone production in male mice by altering luteinizing hormone secretion.

    PubMed

    Sánchez-Capelo, A; Castells, M T; Cremades, A; Peñafiel, R

    1996-09-01

    Potassium deficiency produced by feeding mice a low potassium diet caused a marked decrease in plasma and testicular testosterone concentrations and a concomitant fall in the weight of seminal vesicles and in renal ornithine decarboxylase activity. All of these parameters were rapidly restored when potassium supply was normalized. Immunocytochemical analysis of gonadotropes and plasma LH values suggested that the pulsatile liberation of LH by the pituitary was impaired in the potassium-deficient male mice. Because the synthesis of testosterone in the potassium-deficient mice was stimulated by exogenous LH, hCG, or GnRH, one can conclude that alteration of the transcellular potassium gradient could affect the regulation of the hypothalamo-hypophyseal-testicular axis by affecting the pulsatile release of GnRH. Our results showing that the stimulation of LH secretion after castration was similar in control and potassium-deficient male mice suggest that a testicular factor(s) different from testosterone could be implicated in the abnormal regulation of LH secretion in potassium-deficient mice. We conclude that plasma potassium concentration is an important factor in the regulation of gonadotropin secretion and testicular functions. PMID:8756540

  19. Lead (Pb) alters the norepinephrine-induced secretion of luteinizing hormone releasing hormone from the median eminence of adult male rats in vitro

    SciTech Connect

    Bratton, G.R.; Hiney, J.K.; Dees, W.L. )

    1994-01-01

    In the present study, the authors evaluated the in vitro effects of lead (Pb) on basal and stimulated luteinizing hormone releasing hormone (LHRH) and Prostaglandin E[sub 2] (PGE[sub 2]) secretion. Median eminences (ME) were removed from brains of adult male rats and preincubated for 15 minutes in Krebs-Ringer bicarbonate glucose buffer in an atmosphere of 95% O[sub 2]-5% CO[sub 2]. These media were discarded and all MEs were subjected to one of the following experiments. In Experiment 1, all MEs were incubated for 30 minutes in medium only. These media were collected and replaced with medium only (controls) or with medium containing Pb doses ranging from 5 to 20 [mu]M. After this 60-minute incubation, media were collected, then replaced with new medium containing 60 [mu]M norepinephrine (NE), or NE plus each dose of Pb, then incubated for a final 30-minute period. Experiment 2 was conducted as above, except PGE[sub 2] (2.8 [mu]M) replaced the NE. In both experiments, the amounts of LHRH released was measured by RIA. In experiment 3, NE was again used for the challenge; however, this time, the amount of PGE[sub 2] released was measured by RIA. Results indicate that Pb did not alter basal LHRH release, but compared with controls, significantly blocked NE-induced LHRH release in a dose-related manner. Conversely, Pb had no effect on the PGE[sub 2]-induced release of LHRH. Additionally, Pb did not alter basal PGE[sub 2] release; however, it significantly blocked the NE-induced release of PGE[sub 2]. Since NE-induced LHRH release is mediated by PGE[sub 2], these results support the hypothesis that Pb is capable of altering the hypothalamus and suggest that this effect is due, at least in part, to the diminished PGE[sub 2] synthesis/release within the ME, resulting in diminished LHRH secretion.

  20. Hormone-sensitive lipase deficiency suppresses insulin secretion from pancreatic islets of Lep{sup ob/ob} mice

    SciTech Connect

    Sekiya, Motohiro; Yahagi, Naoya; Tamura, Yoshiaki; Okazaki, Hiroaki; Igarashi, Masaki; Ohta, Keisuke; Takanashi, Mikio; Kumagai, Masayoshi; Takase, Satoru; Nishi, Makiko; Takeuchi, Yoshinori; Izumida, Yoshihiko; Kubota, Midori; Ohashi, Ken; Iizuka, Yoko; Yagyu, Hiroaki; Gotoda, Takanari; Nagai, Ryozo; Shimano, Hitoshi; Yamada, Nobuhiro; and others

    2009-09-25

    It has long been a matter of debate whether the hormone-sensitive lipase (HSL)-mediated lipolysis in pancreatic {beta}-cells can affect insulin secretion through the alteration of lipotoxicity. We generated mice lacking both leptin and HSL (Lep{sup ob/ob}/HSL{sup -/-}) and explored the role of HSL in pancreatic {beta}-cells in the setting of obesity. Lep{sup ob/ob}/HSL{sup -/-} developed elevated blood glucose levels and reduced plasma insulin levels compared with Lep{sup ob/ob}/HSL{sup +/+} in a fed state, while the deficiency of HSL did not affect glucose homeostasis in Lep{sup +/+} background. The deficiency of HSL exacerbated the accumulation of triglycerides in Lep{sup ob/ob} islets, leading to reduced glucose-stimulated insulin secretion. The deficiency of HSL also diminished the islet mass in Lep{sup ob/ob} mice due to decreased cell proliferation. In conclusion, HSL affects insulin secretary capacity especially in the setting of obesity.

  1. Effects of recombinant human insulin-like growth factor I administration on spontaneous and growth hormone (GH)-releasing hormone-stimulated GH secretion in anorexia nervosa.

    PubMed

    Gianotti, L; Pincelli, A I; Scacchi, M; Rolla, M; Bellitti, D; Arvat, E; Lanfranco, F; Torsello, A; Ghigo, E; Cavagnini, F; Müller, E E

    2000-08-01

    Exaggerated GH and reduced insulin-like growth factor I (IGF-I) levels are common features in anorexia nervosa (AN). A reduction of the negative IGF-I feedback could account, in part, for GH hypersecretion. To ascertain this, we studied the effects of recombinant human (rh)IGF-I on spontaneous and GH-releasing hormone (GHRH)-stimulated GH secretion in nine women with AN [body mass index, 14.1 +/- 0.6 kg/m2] and in weight matched controls (normal weight). Mean basal GH concentrations (mGHc) and GHRH (2.0 microg/kg, iv) stimulation were significantly higher in AN. rhIGF-I administration (20 microg/kg, sc) significantly reduced mGHc in AN (P < 0.01), but not normal weight, and inhibited peak GH response to GHRH in both groups; mGHc and peak GH, however, persisted at a significantly higher level in AN. Insulin, glucose, and IGFBP-1 basal levels were similar in both groups. rhIGF-I inhibited insulin in AN, whereas glucose remained unaffected in both groups. IGFBP-1 increased in both groups (P < 0.05), with significantly higher levels in AN. IGFBP-3 was under basal conditions at a lower level in AN (P < 0.05) and remained unaffected by rhIGF-I. This study demonstrates that a low rhIGF-I dose inhibits, but does not normalize, spontaneous and GHRH-stimulated GH secretion in AN, pointing also to the existence of a defective hypothalamic control of GH release. Moreover, the increased IGFBP-1 levels might curtail the negative IGF-I feedback in AN.

  2. Neuropeptide S receptor 1 expression in the intestine and skin--putative role in peptide hormone secretion.

    PubMed

    Sundman, L; Saarialho-Kere, U; Vendelin, J; Lindfors, K; Assadi, G; Kaukinen, K; Westerholm-Ormio, M; Savilahti, E; Mäki, M; Alenius, H; D'Amato, M; Pulkkinen, V; Kere, J; Saavalainen, P

    2010-01-01

    Neuropeptide S receptor 1 (NPSR1) was recently found to be genetically associated with inflammatory bowel disease in addition to asthma and related traits. Epithelia of several organs express NPSR1 isoforms A and B, including the intestine and the skin, and NPSR1 appears to be upregulated in inflammation. In this study, we used cell lines and tissue samples to characterize the expression of NPSR1 and its ligand neuropeptide S (NPS) in inflammation. We used polyclonal and monoclonal antibodies to investigate the expression of NPS and NPSR1 in intestinal diseases, such as celiac disease and food allergy, and in cutaneous inflammatory disorders. We found that NPSR1-A was expressed by the enteroendocrine cells of the gut. Overall, the expression pattern of NPS was similar to its receptor suggesting an autocrine mechanism. In an NPSR1-A overexpressing cell model, stimulation with NPS resulted in a dose-dependent upregulation of glycoprotein hormone, alpha polypeptide (CGA), tachykinin 1 (TAC1), neurotensin (NTS) and galanin (GAL) encoding peptide hormones secreted by enteroendocrine cells. Because NPSR1 was also expressed in macrophages, neutrophils, and intraepithelial lymphocytes, we demonstrated that stimulation with the pro-inflammatory cytokines tumour necrosis factor alpha and interferon gamma increased NPSR1 expression in the THP-1 monocytic cells. In conclusion, similar to other neuropeptides and their receptors, NPSR1 signalling might play a dual role along the gut-brain axis. The NPS/NPSR1 pathway may participate in the regulation of the peptide hormone production in enteroendocrine cells of the small intestine.

  3. Effects of prenatal treatment with antiandrogens on luteinizing hormone secretion and sex steroid concentrations in adult spotted hyenas, Crocuta crocuta.

    PubMed

    Place, Ned J; Holekamp, Kay E; Sisk, Cheryl L; Weldele, Mary L; Coscia, Elizabeth M; Drea, Christine M; Glickman, Stephen E

    2002-11-01

    Prenatal androgen treatment can alter LH secretion in female offspring, often with adverse effects on ovulatory function. However, female spotted hyenas (Crocuta crocuta), renowned for their highly masculinized genitalia, are naturally exposed to high androgen levels in utero. To determine whether LH secretion in spotted hyenas is affected by prenatal androgens, we treated pregnant hyenas with antiandrogens (flutamide and finasteride). Later, adult offspring of the antiandrogen-treated (AA) mothers underwent a GnRH challenge to identify sex differences in the LH response and to assess the effects of prenatal antiandrogen treatment. We further considered the effects of blocking prenatal androgens on plasma sex steroid concentrations. To account for potential differences in the reproductive state of females, we suppressed endogenous hormone levels with a long-acting GnRH agonist (GnRHa) and then measured plasma androgens after an hCG challenge. Plasma concentrations of LH were sexually dimorphic in spotted hyenas, with females displaying higher levels than males. Prenatal antiandrogen treatment also significantly altered the LH response to GnRH. Plasma estradiol concentration was higher in AA-females, whereas testosterone and androstenedione levels tended to be lower. This trend toward lower androgen levels disappeared after GnRHa suppression and hCG challenge. In males, prenatal antiandrogen treatment had long-lasting effects on circulating androgens: AA-males had lower T levels than control males. The sex differences and effects of prenatal antiandrogens on LH secretion suggest that the anterior pituitary gland of the female spotted hyena is partially masculinized by the high androgen levels that normally occur during development, without adverse effects on ovulatory function.

  4. Attenuation of skeletal muscle wasting with recombinant human growth hormone secreted from a tissue-engineered bioartificial muscle

    NASA Technical Reports Server (NTRS)

    Vandenburgh, H.; Del Tatto, M.; Shansky, J.; Goldstein, L.; Russell, K.; Genes, N.; Chromiak, J.; Yamada, S.

    1998-01-01

    Skeletal muscle wasting is a significant problem in elderly and debilitated patients. Growth hormone (GH) is an anabolic growth factor for skeletal muscle but is difficult to deliver in a therapeutic manner by injection owing to its in vivo instability. A novel method is presented for the sustained secretion of recombinant human GH (rhGH) from genetically modified skeletal muscle implants, which reduces host muscle wasting. Proliferating murine C2C12 skeletal myoblasts stably transduced with the rhGH gene were tissue engineered in vitro into bioartificial muscles (C2-BAMs) containing organized postmitotic myofibers secreting 3-5 microg of rhGH/day in vitro. When implanted subcutaneously into syngeneic mice, C2-BAMs delivered a sustained physiologic dose of 2.5 to 11.3 ng of rhGH per milliliter of serum. rhGH synthesized and secreted by the myofibers was in the 22-kDa monomeric form and was biologically active, based on downregulation of a GH-sensitive protein synthesized in the liver. Skeletal muscle disuse atrophy was induced in mice by hindlimb unloading, causing the fast plantaris and slow soleus muscles to atrophy by 21 to 35% ( < 0.02). This atrophy was significantly attenuated 41 to 55% (p < 0.02) in animals that received C2-BAM implants, but not in animals receiving daily injections of purified rhGH (1 mg/kg/day). These data support the concept that delivery of rhGH from BAMs may be efficacious in treating muscle-wasting disorders.

  5. In pubertal girls, naloxone fails to reverse the suppression of luteinizing hormone secretion by estradiol.

    PubMed

    Cemeroglu, A P; Kletter, G B; Guo, W; Brown, M B; Kelch, R P; Marshall, J C; Padmanabhan, V; Foster, C M

    1998-10-01

    Estradiol (E2) negative feedback on LH secretion was examined in 10 pubertal girls, testing the hypothesis that E2 suppresses LH pulse frequency and amplitude through opioid pathways. At 1000 h, a 32-h saline infusion was given, followed 1 week later by an E2 infusion at 13.8 nmol/m2 x h. During both infusions, four iv boluses of saline were given hourly beginning at 1200 h, and four naloxone iv boluses (0.1 mg/kg each) were given hourly beginning at 1200 h on the following day. Blood was obtained every 15 min for LH determination and every 60 min for E2 determination from 1200 h to the end of the infusion. E2 infusion increased the mean serum E2 concentration from 44+/-17 to 112+/-26 pmol/L (P < 0.01). The mean LH concentration between 2200-1200 h decreased from 3.19+/-0.89 to 1.99+/-0.65 IU/L (P = 0.014), and LH pulse amplitude decreased from 3.4+/-0.6 to 2.6+/-0.5 IU/L (P = 0.0076). Although there were 1.2 fewer pulses during E2 infusion compared to saline infusion, differences did not reach significance (P = 0.1; 95% confidence interval for the difference, -3.5, 1.1). Pituitary responsiveness to GnRH, assessed at the end of the infusion by administering 250 ng/kg GnRH iv, did not change during E2 infusion. The effect of naloxone blockade of opioid activity on LH secretion was determined by assessing the area under the curve (AUC) from 1200-1600 h. During saline infusion, the LH AUC was 1122+/-375 IU/L during saline boluses and 1575+/-403 IU/L during naloxone boluses (P = 0.39). When E2 was infused, the LH AUCs during saline and naloxone boluses were 865+/-249 and 866+/-250 IU/L, respectively. Thus, in pubertal girls: 1) E2 decreases the LH concentration and LH pulse amplitude; 2) the main site of negative feedback effect of E2 appears to be at the level of the hypothalamus; 3) an increase in LH secretion after naloxone administration could not be demonstrated in these girls and may depend on the maturity of the hypothalamic-pituitary-gonadal axis; and 4) opioid

  6. Bursicon functions within the Drosophila CNS to modulate wing expansion behavior, hormone secretion, and cell death.

    PubMed

    Peabody, Nathan C; Diao, Fengqiu; Luan, Haojiang; Wang, Howard; Dewey, Elizabeth M; Honegger, Hans-Willi; White, Benjamin H

    2008-12-31

    Hormones are often responsible for synchronizing somatic physiological changes with changes in behavior. Ecdysis (i.e., the shedding of the exoskeleton) in insects has served as a useful model for elucidating the molecular and cellular mechanisms of this synchronization, and has provided numerous insights into the hormonal coordination of body and behavior. An example in which the mechanisms have remained enigmatic is the neurohormone bursicon, which, after the final molt, coordinates the plasticization and tanning of the initially folded wings with behaviors that drive wing expansion. The somatic effects of the hormone are governed by bursicon that is released into the blood from neurons in the abdominal ganglion (the B(AG)), which die after wing expansion. How bursicon induces the behavioral programs required for wing expansion, however, has remained unknown. Here we show by targeted suppression of excitability that a pair of bursicon-immunoreactive neurons distinct from the B(AG) and located within the subesophageal ganglion in Drosophila (the B(SEG)) is involved in controlling wing expansion behaviors. Unlike the B(AG), the B(SEG) arborize widely in the nervous system, including within the abdominal neuromeres, suggesting that, in addition to governing behavior, they also may modulate the B(AG.) Indeed, we show that animals lacking bursicon receptor function have deficits both in the humoral release of bursicon and in posteclosion apoptosis of the B(AG). Our results reveal novel neuromodulatory functions for bursicon and support the hypothesis that the B(SEG) are essential for orchestrating both the behavioral and somatic processes underlying wing expansion.

  7. Comparison of the in vitro effects of TCDD, PCB 126 and PCB 153 on thyroid-restricted gene expression and thyroid hormone secretion by the chicken thyroid gland.

    PubMed

    Katarzyńska, Dorota; Hrabia, Anna; Kowalik, Kinga; Sechman, Andrzej

    2015-03-01

    The aim of this study was to compare the in vitro effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) and 2,2'4,4',5,5'-hexachlorobiphenyl (PCB153; non-coplanar PCB) on mRNA expression of thyroid-restricted genes, i.e. sodium iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (TG), and thyroid hormone secretion from the thyroid gland of the laying chicken. Relative expression levels of NIS, TG and TPO genes and thyroxine (T4) and triiodothyronine (T3) secretion from the thyroidal explants were quantified by the real-time qPCR and RIA methods, respectively. In comparison with the control group, TCDD and PCB 126 significantly increased mRNA expression of TPO and TG genes. TCDD did not affect NIS mRNA levels, but PCB 126 decreased its expression. No effect of PCB 153 on the expression of these genes was observed. TCDD and PCB 126 significantly decreased T4 and T3 secretion. There was no significant effect of PCB 153 on these hormone secretions. In conclusion, the results obtained show that in comparison with non-coplanar PCB 153, TCDD and coplanar PCB 126 can directly affect thyroid hormone synthesis and secretion, and in consequence, they may disrupt the endocrine function of the thyroid gland of the laying chicken.

  8. Circannual changes in progesterone secretion in intact ewes, luteinizing hormone secretion in ovariectomized estradiol-implanted ewes, and prolactin secretion in three sheep breeds anticipated to differ in seasonality of reproduction.

    PubMed

    Goff, Katherine J; Knight, James W; Pelzer, Kevin D; Akers, R Michael; Notter, David R

    2013-05-01

    Changes in progesterone secretion in intact ewes (7 or 9 per breed) and luteinizing hormone secretion in ovariectomized, estradiol-implanted ewes (9 or 10 per breed) were monitored for 12 mo in Suffolk, tropically adapted St. Croix, and OOS ewes. The OOS line is a composite population of 50% Dorset, 25% Rambouillet, and 25% Finnish Landrace breeding that was selected for 10 yr for ability to lamb in October and early November. Ewes were isolated from rams, and blood samples were collected twice weekly. Circulating prolactin concentrations were also determined from blood samples collected near the summer and winter solstice and vernal and autumnal equinox. Intact OOS ewes entered anestrus later, began the subsequent breeding season sooner, and had a shorter seasonal anestrus than Suffolk and St. Croix ewes (P ≤ 0.005). St. Croix ewes did not differ from Suffolk ewes in date of onset or cessation of breeding or duration of anestrus (P ≥ 0.06). Breed differences in duration of luteinizing hormone inhibition in ovariectomized ewes were essentially identical to those observed for duration of anestrous. Prolactin concentrations varied during the year: annual changes were larger in relatively seasonal Suffolk ewes than in tropically-derived St. Croix ewes (P<0.01), and OOS ewes were intermediate to, and tended to differ from (P<0.10), the other two breeds. We conclude that OOS ewes developed by selection for fertility in spring matings had an abbreviated seasonal anestrus that is one of the shortest ever reported for temperate breeds, and that tropical St. Croix sheep did not have a shorter seasonal anestrus than Suffolk sheep under temperate conditions and ram isolation. PMID:23528712

  9. Testosterone selectively increases serum follicle-stimulating hormonal (FSH) but not luteinizing hormone (LH) in gonadotropin-releasing hormone antagonist-treated male rats: evidence for differential regulation of LH and FSH secretion.

    PubMed

    Bhasin, S; Fielder, T J; Swerdloff, R S

    1987-08-01

    Both testosterone (T) and gonadotropin-releasing hormone (GnRH)-antagonist (GnRH-A) when given alone lower serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in intact and castrated rats. However, when graded doses of testosterone enanthate (T.E.) were given to GnRH-A-treated intact male rats, a paradoxical dose-dependent increase in serum FSH occurred; whereas serum LH remained suppressed. This surprising finding led us to ask whether the paradoxical increase in serum FSH in GnRH-A-suppressed animals was a direct stimulatory effect of T on the hypothalamic-pituitary axis or the result of a T effect on a testicular regulator of FSH. To test these hypotheses, we treated adult male castrated rats with GnRH-A and graded doses of T.E. In both intact and castrated rats, serum LH remained undetectable in GnRH-A-treated rats with or without T.E. However, addition of T.E. to GnRH-A led to a dose-dependent increase in serum FSH in castrated animals as well, thus pointing against mediation by a selective testicular regulator of FSH. These data provide evidence that pituitary LH and FSH responses may be differentially regulated under certain conditions. When the action of GnRH is blocked (such as in GnRH-A-treated animals), T directly and selectively increases pituitary FSH secretion.

  10. Ghrelin – A Pleiotropic Hormone Secreted from Endocrine X/A-Like Cells of the Stomach

    PubMed Central

    Stengel, Andreas; Taché, Yvette

    2012-01-01

    The gastric X/A-like endocrine cell receives growing attention due to its peptide products with ghrelin being the best characterized. This peptide hormone was identified a decade ago as a stimulator of food intake and to date remains the only known peripherally produced and centrally acting orexigenic hormone. In addition, subsequent studies identified numerous other functions of this peptide including the stimulation of gastrointestinal motility, the maintenance of energy homeostasis and an impact on reproduction. Moreover, ghrelin is also involved in the response to stress and assumed to play a role in coping functions and exert a modulatory action on immune pathways. Our knowledge on the regulation of ghrelin has markedly advanced during the past years by the identification of the ghrelin acylating enzyme, ghrelin-O-acyltransferase, and by the description of changes in expression, activation, and release under different metabolic as well as physically and psychically challenging conditions. However, our insight on regulatory processes of ghrelin at the cellular and subcellular levels is still very limited and warrants further investigation. PMID:22355282

  11. Melatonin modulates secretion of growth hormone and prolactin by trout pituitary glands and cells in culture.

    PubMed

    Falcón, J; Besseau, L; Fazzari, D; Attia, J; Gaildrat, P; Beauchaud, M; Boeuf, G

    2003-10-01

    In Teleost fish, development, growth, and reproduction are influenced by the daily and seasonal variations of photoperiod and temperature. Early in vivo studies indicated the pineal gland mediates the effects of these external factors, most probably through the rhythmic production of melatonin. The present investigation was aimed at determining whether melatonin acts directly on the pituitary to control GH and prolactin (PRL) secretion in rainbow trout. We show that 2-[125I]-iodomelatonin, a melatonin analog, binds selectively to membrane preparations and tissue sections from trout pituitaries. The affinity was within the range of that found for the binding to brain microsomal preparations, but the number of binding sites was 20-fold less than in the brain. In culture, melatonin inhibited pituitary cAMP accumulation induced by forskolin, the adenyl cyclase stimulator. Forskolin also induced an increase in GH release, which was reduced in the presence of picomolar concentrations of melatonin. At higher concentrations, the effects of melatonin became stimulatory. In the absence of forskolin, melatonin induced a dose-dependent increase in GH release, and a dose-dependent decrease in PRL release. Melatonin effects were abolished upon addition of luzindole, a melatonin antagonist. Our results provide the first evidence that melatonin modulates GH and PRL secretion in Teleost fish pituitary. Melatonin effects on GH have never been reported in any vertebrate before. The effects result from a direct action of melatonin on pituitary cells. The complexity of the observed responses suggests several types of melatonin receptors might be involved.

  12. Evidence for a defect in pituitary secretion of luteinizing hormone in chronic alcoholic men.

    PubMed

    Van Thiel, D H; Lester, R; Vaitukaitis, J

    1978-09-01

    To characterize the defect in the hypothalamic-pituitary-gonadal axis of alcoholic men, acute and chronic LRF responses were evaluated in 22 chronic alcoholic men with varying degrees of biochemically and histologically confirmed liver disease. In addition, acute LRF responses in 14 normal men, before and at the end of 72 h of administration of 2 ml/kg/day 95% ethanol, were evaluated. The alcoholics hd significantly reduced basal testosterone and elevated gonadotropin levels (both FSH and LH) compared to the normal volunteers (P less than 0.02). Serum concentrations of estradiol and PRL did not differ between alcoholics and normal volunteers. A 100-micrograms bolus of LRF resulted in a 3-fold increase of LH in alcoholic men as compared to a 6-fold increase of serum LH in normal volunteers. No significant difference in the LRF-induced FSH responses was observed. When the response of normal volunteers to LRF before and after ethanol administration was evaluated, basal levels of both gonadotropins were increased after alcohol administration and a reduced LRF-induced LH response was observed. Based upon these results, we conclude that: 1) the central hypothalamic-pituitary defect known to exist for LH secretion is in part due to inadequate pituitary secretion and 2) acute alcohol ingestion in normal men suppresses the LRF-induced LH but not the FSH response.

  13. [Hyponatremia in neurologic intensive care: cerebral salt wasting syndrome and inappropriate antidiuretic hormone secretion].

    PubMed

    Bracco, D; Favre, J B; Ravussin, P

    2001-02-01

    Hyponatraemia is a frequent complication in neurologically injured patients; it is a secondary cerebral injury. Hyponatraemia leads to consciousness problems, convulsions, worsening of the neurological status and thus the neurological evaluation. Hyponatraemia is secondary to free water retention (inappropriate ADH secretion) or to renal salt loss. The cerebral salt wasting syndrome (CSWS) has been described with head injury, subarachnoid haemorrhage and after several sorts of brain insults. It is characterised by an increased natriuresis and diuresis. Diagnosis is based on hyponatraemia, hypernatriuresis, increased diuresis and hypovolaemia. However, inappropriate ADH secretion and CSWS share several diagnostic criteria. The atrial natriuretic factor and the C-type natriuretic factors play a role in the development of the CSWS. The diagnostic approach and monitoring are based on the assessment of sodium and water losses. Therapy is based on correction of the circulating volume and natraemia. Speed of correction is a matter of debate: slow correction presents the risk of further neurological injury whereas rapid correction presents the risk of central pontine myelinosis.

  14. Growth hormone (hGH) secretion and turnover in three patients with Laron-type dwarfism.

    PubMed

    Keret, R; Pertzelan, A; Zeharia, A; Zadik, Z; Laron, Z

    1988-02-01

    The 24-h secretory pattern of hGH was studied by the aid of a continuous blood withdrawal pump in three Laron-type dwarfism (LTD) patients and compared with that in sex- and age-matched normal control subjects. It was found that the secretion of hGH was enhanced in the LTD patients, but in all three the diurnal secretory profile, as expressed by the number of pulses and the sleep-related maximal pulse, was preserved. In the younger LTD patients, women aged 19 and 21 years, the number of pulses was 9 and 7 (compared with 6 in the control subjects), the maximal hGH pulse amplitude was 164 and 280 ng/ml (compared with 135 ng/ml), the area under the curve (AUC) was 560 and 780 (compared with 268), and the average integrated concentration (A-IC) of hGH was 33.9 and 23.4 ng/ml (compared with 11.3). In the older LTD patient, a man aged 27 years, the hGH secretion was lower than that in the LTD women, but still higher than that in normal matched controls: the number of pulses was 4 (control 2), maximal pulse amplitude 67 ng/ml (control 19), AUC 231 (control 51), and A-IC 9.9 ng/ml (control 2.2). The decline in hGH secretion, which is characteristic of advancing age in normal subjects, seems to occur in LTD as well. Metabolic clearance rate (MCR) and production rate (PR) of hGH were measured in the 19-year-old female LTD patient. Her MCR was 73.4 ml/m2 per min, and her PR was 2,480 ng/ml compared with 158.3 and 839, respectively, in a normal subject. The exaggerated PR explains the elevation of plasma hGH in this syndrome and is probably the result of a lack of negative feedback due to insulin-like growth factor deficiency.

  15. β-Hydroxybutyric acid inhibits growth hormone-releasing hormone synthesis and secretion through the GPR109A/extracellular signal-regulated 1/2 signalling pathway in the hypothalamus.

    PubMed

    Fu, S-P; Liu, B-R; Wang, J-F; Xue, W-J; Liu, H-M; Zeng, Y-L; Huang, B-X; Li, S-N; Lv, Q-K; Wang, W; Liu, J-X

    2015-03-01

    β-Hydroxybutyric acid (BHBA) has recently been shown to regulate hormone synthesis and secretion in the hypothalamus. However, little is known about the effects of BHBA-mediated hormone regulation or the detailed mechanisms by which BHBA regulates growth hormone-releasing hormone (GHRH) synthesis and secretion. In the present study, we examined the expression of the BHBA receptor GPR109A in primary hypothalamic cell cultures. We hypothesised that BHBA regulates GHRH via GPR109A and its downstream signals. Initial in vivo studies conducted in rats demonstrated that GHRH mRNA expression in the hypothalamus was strongly inversely correlated with BHBA levels in the cerebrospinal fluid during postnatal development (r = -0.89, P < 0.01). Furthermore, i.c.v. administration of BHBA acutely decreased GHRH mRNA expression in rats. Further in vitro studies revealed a decrease in GHRH synthesis and secretion in primary hypothalamic cells after treatment with BHBA; this effect was inhibited when hypothalamic cells were pretreated with pertussis toxin (PTX). BHBA had no effect on GHRH synthesis and secretion in GT1-7 cells, which do not exhibit cell surface expression of GPR109A. Furthermore, BHBA acutely decreased the transcription of the homeobox gene for Gsh-1 in the hypothalamus in both in vivo and in vitro, and this effect was also inhibited by PTX in vitro. In primary hypothalamic cells, BHBA activated the extracellular signal-regulated kinase (ERK)1/2, p38 and c-Jun N-terminal kinase mitogen-activated protein kinase (MAPK) kinases, as shown by western blot analysis. Moreover, inhibition of ERK1/2 with U0126 attenuated the BHBA-mediated reduction in Gsh-1 expression and GHRH synthesis and secretion. These results strongly suggest that BHBA directly regulates GHRH synthesis and secretion via the GPR109A/ERK1/2 MAPK pathway, and also that Gsh-1 is essential for this function.

  16. Diurnal pattern of pulsatile luteinizing hormone and testosterone secretion in adult male rhesus monkeys (Macaca mulatta): influence of the timing of daily meal intake.

    PubMed

    Mattern, L G; Helmreich, D L; Cameron, J L

    1993-03-01

    Adult male rhesus monkeys have a diurnal pattern of reproductive hormone secretion that is characterized by significantly elevated LH and testosterone secretion in the evening hours and a nadir in secretion of these hormones in the morning. To test the hypothesis that the daily pattern of food intake may play a role in regulating the diurnal pattern of reproductive hormone secretion we performed three studies. First, to determine the relationship between the timing of the diurnal rise in LH secretion and meal consumption, blood samples were collected from 13 adult male rhesus monkeys via chronically indwelling venous catheters (samples every 15-20 min from 0800-0800 h) while monkeys were maintained on the standard feeding regimen in our colony (one meal of Purina monkey chow fed between 1100 and 1200 h). On a day of normal feeding there was a significant diurnal rhythm in mean LH concentrations with elevated levels at night (nadir: 13.41 +/- 0.82 ng/ml from 0800-1100 h; peak: 21.34 +/- 1.56 ng/ml from 2000-2300 h, P < or = 0.05). The rising phase of the diurnal rhythm in LH secretion was apparent starting in the early afternoon, shortly after the daily meal, at 1400 h (5 h before lights went off at 1900 h), and the diurnal rise in LH secretion was no longer apparent by 0500 h (several hours before the lights went on at 0700 h). Second, we examined the influence of missing the daily meal on the diurnal pattern of LH and testosterone secretion. Blood samples were collected for a 24-h period on a day of fasting from 9 monkeys. On a day of fasting there was no diurnal rise in plasma LH or testosterone concentrations; plasma concentrations of these hormones remained at the low morning levels throughout the day. Third, we examined the diurnal pattern of LH and testosterone secretion after adapting 5 monkeys (for 6-8 weeks) to a new meal time that was 6 h later in the day than the standard meal time (i.e. at 1700 h). After adaptation to this later feeding time monkeys

  17. Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) in Strongyloides stercoralis Hyperinfection

    PubMed Central

    Chowdhury, Deepshikha Nag; Dhadham, Gautamy Chitiki; Shah, Anish; Baddoura, Walid

    2014-01-01

    Strongyloides stercoralis (S. stercoralis) is a soil transmitted intestinal roundworm that has a unique ability to multiply within the human host and reinfect the human carrier by a process of autoinfection. By this property, S. stercoralis can persist as an occult infection for many decades. In situations of immunosuppression or other permissive gastrointestinal conditions, there occurs a massive increase in parasite multiplication. The parasites penetrate through the intestinal mucosa and are carried in circulation and can cause multisystem involvement. We report a case of a 76-year-old Columbian male who presented with intractable vomiting and hyponatremia who was then diagnosed to have syndrome of inappropriate antidiuretic hormone (SIADH). The patient's symptoms improved after treatment with two doses of ivermectin and his serum sodium levels returned to normal. S. stercoralis infection should be suspected in patients from endemic regions who present with gastrointestinal symptoms and unexplained hyponatremia. PMID:24741227

  18. Exaggerated thyroid stimulating hormone secretion in children exposed to the Chernobyl nuclear reactor catastrophe.

    PubMed

    Boyarskaya, O Y; Kopilova, O V

    2008-02-01

    We present results of a long-term study of the morpho-functional state of the thyroid gland and of the functional capacities of the hypothalamic-hypophyseal system, as shown by thyrotropin releasing hormone stimulation, in different groups of children who suffered from the Chernobyl accident. It was shown that the thyroid gland of the children who were evacuated from the 30-km zone was damaged most severely due to the influence of radioactive iodine (131I). Living on radionuclide-polluted territories in conditions of iodine deficiency has been an additional contributory factor in the development of thyroid gland diseases. Latent functional deficiency of the hypothalamic-hypophyseal system can be one of the reasons leading to oncopathology of the thyroid gland.

  19. Effect of acute ether stress on monoamine metabolism in median eminence and discrete hypothalamic nuclei of the rat brain and on anterior pituitary hormone secretion.

    PubMed

    Johnston, C A; Spinedi, E J; Negro-Vilar, A

    1985-07-01

    This study was designed to correlate the endocrine responses elicited by acute ether stress with the changes in metabolism of several monoamines in discrete nuclei of the rat brain. Concentrations of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine (5-HT) and also of the specific metabolites of NE, DA, and 5-HT, 3-methoxy-4-hydroxyphenylethylene glycol, 3,4-dihydroxyphenylacetic acid, and 5-hydroxyindole-3-acetic acid, respectively, were concurrently measured in microdissected nuclei using high-performance liquid chromatography with electrochemical detection. The ratio of the metabolites to their respective amines was used as an estimate of the metabolism of NE, DA, and 5-HT. Acute exposure to ether vapors induced, within 5-15 min, large increments in plasma levels of adrenocorticotropic hormone (ACTH), beta-endorphin, and prolactin (PRL), and decrements in the levels of plasma growth hormone (GH). Significant increases in NE metabolism were observed in the rostral (ANr) and caudal (ANc) divisions of the arcuate nucleus, as well as in the paraventricular (PVN) and dorsomedial nuclei, 15 min after ether stress. A significant decrease in 5-HT metabolism was observed in the PVN, supraoptic nucleus, and ANc, whereas significant increases in 5-HT metabolism were detected in the suprachiasmatic nucleus and ANr. DA metabolism selectively increased in the ANr. The present results indicate that the acute changes in ACTH, beta-endorphin, PRL, and GH release induced by ether exposure are temporally correlated with increases in NE metabolism in many hypothalamic nuclei; a selective increase in DA metabolism restricted to the ANr, and differential effects on 5-HT metabolism, probably reflecting selective activation or inhibition of different populations of 5-HT neurons.

  20. Influence of morphine during pregnancy on neuroendocrine regulation of pituitary hormone secretion.

    PubMed

    Litto, W J; Griffin, J P; Rabii, J

    1983-08-01

    The effects of exposure to morphine during pregnancy on postnatal neuroendocrine systems were investigated. Rats received morphine sulphate or 0.9% (w/v) NaCl twice daily on days 5-12 of pregnancy. A dose of 5 mg morphine sulphate/kg was administered for the first three injections while 10 mg/kg was used for each of the remaining 13. This treatment regimen led to a significant delay in the onset of vaginal opening in the female offspring. Mothers treated with morphine sulphate showed a marked attenuation of their prolactin response to the suckling stimulus, although they still released significant amounts of the hormone. Both male and female offspring of the opiate-treated dams showed a major reduction in the sensitivity of their hypothalamic-pituitary axis to gonadal steroids at 15 days of age. No significant differences were found in the acute thyrotrophin response to single injection of morphine sulphate of prepuberal male and female pups of morphine- and saline-treated dams. These data show that exposure to opiates during critical periods of prenatal development lead to long-lasting alterations in the neuroendocrine control systems of the animal. These alterations may then have significant consequences on the physiological maturation and adult behaviour of the animal.

  1. Increased steroid hormone secretion in mouse Leydig tumor cells after induction of cholesterol translocation by sphingomyelin degradation.

    PubMed

    Pörn, M I; Tenhunen, J; Slotte, J P

    1991-06-01

    The effects of sphingomyelin degradation on [3H]cholesterol transfer from the cell surface to mitochondria were examined in mouse Leydig tumor cells. These cells were used since they utilize cholesterol for steroid hormone synthesis in the mitochondria, and also possess acyl-CoA: cholesterol acyl transferase (ACAT) activity in the endoplasmic reticulum. Exposure of glutaraldehyde-fixed mouse Leydig tumor cells to sphingomyelinase (50 mU/ml, 60 min) resulted in the degradation of about 50% of cell sphingomyelin, suggesting that only half of the sphingomyelin mass in these cells was located in the exoleaflet of the plasma membrane. The partial sphingomyelin degradation resulted in the translocation of cellular unesterified [3H]cholesterol from plasma membranes (cholesterol oxidase-susceptible) to intracellular compartments (oxidase-resistant). The fraction of [3H]cholesterol that was translocated, i.e., between 20 and 50%, varied with different [3H]cholesterol-labeling methods. Cholesterol translocation induced by sphingomyelin degradation subsequently led to the stimulation of ACAT activity, suggesting that a fraction of cell surface cholesterol was transported to the endoplasmic reticulum. The sphingomyelinase-induced [3H]cholesterol flow from the cell surface to the cell interior was also in part directed to the mitochondria, as evidenced by the increased secretion of [3H]steroid hormones. In addition, the cyclic AMP-induced activation of steroidogenesis was further enhanced by the sphingomyelinase-induced cholesterol translocation. Based on the current results, it seems evident that a significant portion of the translocated [3H]cholesterol made its way from plasma membranes into the mitochondria for steroidogenesis.

  2. The impact of acute ethanol on reproductive hormone synthesis, processing, and secretion in female rats at proestrous.

    PubMed

    LaPaglia, N; Steiner, J; Kirsteins, L; Emanuele, M A; Emanuele, N

    1997-12-01

    It is the purpose of this study to investigate the effects of acute ethanol (EtOH) on the female rat hypothalamic-pituitary-gonadal (HPG) axis. The molecular and cellular mechanistic details of such effects have been studied intensively in the male rat. However, there has been relatively little in-depth study of EtOH's effects on the adult, postpubertal female rat. Adult female rats with confirmed 4- or 5-day estrous cycles were given a single injection of EtOH or saline between noon and 1:00 PM on proestrous and were killed at 4:00 PM. EtOH caused a sharp 97% reduction in luteinizing hormone (LH) serum levels (p < 0.001), compared with controls with no concomitant change in LH mRNA. EtOH also significantly reduced hypothalamic LH releasing hormone (LHRH) by 49% (p < 0.01), with no change in content of the precursor pro-LHRH compared with saline-injected controls. The ratio of LHRH to pro-LHRH was also significantly reduced by EtOH (p < 0.05), compared with control. There was no EtOH-induced change in LHRH mRNA. Compared with saline, EtOH reduced both serum estradiol by 37% (p < 0.02) and progesterone by 47% (p < 0.001). These results show that EtOH has profound disruptive effects on the female HPG axis. Our data suggests that EtOH decreases the releasable LHRH pool either by decreasing conversion of pro-LHRH to LHRH and/or by increasing local LHRH degradation. This acutely restricts the release of LH and subsequent estradiol and progesterone secretion.

  3. Regulation of gonadotropin-releasing hormone secretion: insights from GT1 immortal GnRH neurons.

    PubMed

    Martínez de la Escalera, G; Clapp, C

    2001-01-01

    The study of the mammalian GnRH system has been greatly advanced by the development of immortalized cell lines. Of particular relevance are the so-called GT1 cells. Not only do they exhibit many of the known physiologic characteristics of GnRH neurons in situ, but in approximately one decade have yielded new insights regarding the intrinsic physiology of individual cells and networks of GnRH neurons, as well as the nature of central and peripheral signals that directly modulate their function. For instance, valuable information has been generated concerning intrinsic properties of the system such as the inherent pulsatile pattern of secretion displayed by networks of GT1 cells. Concepts regarding feedback regulation and autocrine feedback of GnRH neurons have been dramatically expanded. Likewise, the nature of the receptors and of the proximal and distal signal transduction mechanisms involved in the actions of multiple afferent signals has been identified. Understanding this neuronal system allows a better comprehension of the hypothalamic-pituitary-gonadal axis and of the regulatory influences that ultimately control reproductive competence.

  4. Hormonal doping and androgenization of athletes: a secret program of the German Democratic Republic government.

    PubMed

    Franke, W W; Berendonk, B

    1997-07-01

    Several classified documents saved after the collapse of the German Democratic Republic (GDR) in 1990 describe the promotion by the government of the use of drugs, notably androgenic steroids, in high-performance sports (doping). Top-secret doctoral theses, scientific reports, progress reports of grants, proceedings from symposia of experts, and reports of physicians and scientists who served as unofficial collaborators for the Ministry for State Security ("Stasi") reveal that from 1966 on, hundreds of physicians and scientists, including top-ranking professors, performed doping research and administered prescription drugs as well as unapproved experimental drug preparations. Several thousand athletes were treated with androgens every year, including minors of each sex. Special emphasis was placed on administering androgens to women and adolescent girls because this practice proved to be particularly effective for sports performance. Damaging side effects were recorded, some of which required surgical or medical intervention. In addition, several prominent scientists and sports physicians of the GDR contributed to the development of methods of drug administration that would evade detection by international doping controls.

  5. Effect of phosphate-regulating hormones on plasma composition, cardiovascular function, and parotid salivary phosphate secretion in red kangaroos (Macropus rufus).

    PubMed

    Beal, A M

    1991-01-01

    The effects of administration of phosphate-regulating hormones on plasma composition, cardiovascular function, and secretion of phosphate and other electrolytes in parotid saliva were investigated in anesthetized red kangaroos. Plasma [PO4] was elevated by intravenous injections of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) at 5 or 12.5 nmol/12 hr for 72 hr but was unaltered by intravenous or intracarotid infusion of either salmon or porcine calcitonins at rates up to 3.2 IU min-1 for 60 min or by intracarotid infusions of the 1-34 amino acid fragments of rat, human, or bovine parathyroid hormones (PTH(1-34) at 350-460 pmol/min for 60 min. Plasma [Ca] fell during high-rate calcitonin infusion and rose during 1,25(OH)2D3 administration. PTH(1-34) infusion did not alter plasma [Ca] but did lower plasma [K] and arterial blood pressure and elevated heart rate and hematocrit. Salivary [PO4] and [Ca] and secretion rates were unaffected by the calcitonin infusions, by PTH(1-34) infusions, or by 1,25(OH)2D3 injection. Plasma and salivary concentrations of other ions were unaltered. These data provide evidence that kangaroo tissue can recognize and respond to all three types of phosphate-regulating hormones despite the peptides being foreign; however, the parotid gland of kangaroos, unlike the parotids of rats and sheep, did not respond and presumably lacks some component of the receptor-secretion couplings for these hormones. This independence of salivary PO4 secretion from hormonal regulation may be one of several adaptations which ensure relatively stable and adequate phosphate delivery to the foregut microorganisms despite an unreliable phosphorus intake in the natural diet.

  6. Casein and whey exert different effects on plasma amino acid profiles, gastrointestinal hormone secretion and appetite.

    PubMed

    Hall, W L; Millward, D J; Long, S J; Morgan, L M

    2003-02-01

    Protein, generally agreed to be the most satiating macronutrient, may differ in its effects on appetite depending on the protein source and variation in digestion and absorption. We investigated the effects of two milk protein types, casein and whey, on food intake and subjective ratings of hunger and fullness, and on postprandial metabolite and gastrointestinal hormone responses. Two studies were undertaken. The first study showed that energy intake from a buffet meal ad libitum was significantly less 90 min after a 1700 kJ liquid preload containing 48 g whey, compared with an equivalent casein preload (P<0.05). In the second study, the same whey preload led to a 28 % increase in postprandial plasma amino acid concentrations over 3 h compared with casein (incremental area under the curve (iAUC), P<0.05). Plasma cholecystokinin (CCK) was increased by 60 % (iAUC, P<0.005), glucagon-like peptide (GLP)-1 by 65 % (iAUC, P<0.05) and glucose-dependent insulinotropic polypeptide by 36 % (iAUC, P<0.01) following the whey preload compared with the casein. Gastric emptying was influenced by protein type as evidenced by differing plasma paracetamol profiles with the two preloads. Greater subjective satiety followed the whey test meal (P<0.05). These results implicate post-absorptive increases in plasma amino acids together with both CCK and GLP-1 as potential mediators of the increased satiety response to whey and emphasise the importance of considering the impact of protein type on the appetite response to a mixed meal.

  7. The effect of nalmefene on pulsatile secretion of luteinizing hormone and prolactin in men.

    PubMed

    Graves, G R; Kennedy, T G; Weick, R F; Casper, R F

    1993-10-01

    Luteinizing hormone (LH) and prolactin are released in pulses which are relatively synchronous in the luteal phase of the menstrual cycle in women. The concordance of LH and prolactin pulses in normal men has not been reported. The objectives of this study were firstly to determine whether LH and prolactin pulses are synchronous in men, and secondly to examine the effects of naloxone and a new orally active opiate antagonist, nalmefene, on LH and prolactin release in men. Three groups of normal male subjects received saline infusion (control n = 5), naloxone infusion (2 mg/h; n = 5) or nalmefene (10 mg p.o.; n = 6). Blood samples were collected every 15 min for 2 h before and 6 h after study medication for determination of LH, prolactin and testosterone by radioimmunoassay. Both naloxone and nalmefene resulted in a significant increase in LH pulse frequency and in mean serum LH and testosterone concentrations with no change in LH pulse amplitude, prolactin pulse frequency or amplitude. In controls, 61% of LH pulses were synchronous with prolactin pulses. There was a decrease in concomitance of LH and prolactin pulses with naloxone (48%) and nalmefene (24%; P < 0.025) administration. In contrast, 52% of prolactin pulses were concomitant with LH pulses in controls, while naloxone (100%) but not nalmefene (67%) resulted in a significant (P < 0.01) increase in pulse synchrony. The difference observed between naloxone and nalmefene on prolactin--LH pulse synchrony is probably due to differential opioid receptor activity at the pituitary and hypothalamic level.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8300813

  8. The Syndrome of Inappropriate Secretion of Anti-Diuretic Hormone (SIADH) and Brucellosis

    PubMed Central

    Bala, Keziban Asli; Doğan, Murat; Kaba, Sultan; Akbayram, Sinan; Aslan, Oktay; Kocaman, Selami; Bayhan, Gülsüm İclal; Üstyol, Lokman; Demir, Nihat

    2016-01-01

    Background Our study aimed to demonstrate the frequency of the syndrome of inappropriate ADH secretion (SIADH) and associated factors during the course of brucellosis in children and adolescents. Material/Methods The study included children and adolescents aged 0–18 years old diagnosed with brucellosis between 2012 and 2014. The data were collected from patient charts. The diagnosis of brucellosis was made based on titrations >1:160 in standard Wright tube agglutination tests and/or positive culture tests. SIADH diagnosis was made based on the following criteria: euvolemic hyponatremia, serum Na+ <135 mmol/L, presence of serum hypoosmolarity (serum osmolarity <275 mOsm/L), increased urinary sodium (>25 mmol/L with normal dietary salt intake), low uric acid (<2 mg/dL), absence of kidney, thyroid or adrenal disease, and any anti-diuretic use. Results The study included 160 children and adolescents with mean age of 9.58±3.95 years (range: 2–18 years) including 70 girls (43.8%) and 90 boys (56.2%). When the patients were stratified based on SIADH, it was found that SIADH was present in 35 patients (21.9%). SIADH was associated with elevated glucose (p<0.001), ALT (p<0.05), AST (p<0.05), LDH (p<0.001), CRP (p<0.001), and MPV (p<0.001); and decreased potassium (p<0.05), chloride (p<0.001), albumin (p<0.001), total protein (p<0.05), and hemoglobin (p<0.05) levels. Conclusions Our study reports on the frequency, clinical characteristics, predisposing factors, and management of SIADH that can develop in children and adolescents diagnosed with brucellosis. PMID:27590789

  9. The Syndrome of Inappropriate Secretion of Anti-Diuretic Hormone (SIADH) and Brucellosis.

    PubMed

    Bala, Keziban Aslı; Doğan, Murat; Kaba, Sultan; Akbayram, Sinan; Aslan, Oktay; Kocaman, Selami; Bayhan, Gülsüm İclal; Üstyol, Lokman; Demir, Nihat

    2016-01-01

    BACKGROUND Our study aimed to demonstrate the frequency of the syndrome of inappropriate ADH secretion (SIADH) and associated factors during the course of brucellosis in children and adolescents. MATERIAL AND METHODS The study included children and adolescents aged 0-18 years old diagnosed with brucellosis between 2012 and 2014. The data were collected from patient charts. The diagnosis of brucellosis was made based on titrations >1:160 in standard Wright tube agglutination tests and/or positive culture tests. SIADH diagnosis was made based on the following criteria: euvolemic hyponatremia, serum Na+ <135 mmol/L, presence of serum hypoosmolarity (serum osmolarity <275 mOsm/L), increased urinary sodium (>25 mmol/L with normal dietary salt intake), low uric acid (<2 mg/dL), absence of kidney, thyroid or adrenal disease, and any anti-diuretic use. RESULTS The study included 160 children and adolescents with mean age of 9.58±3.95 years (range: 2-18 years) including 70 girls (43.8%) and 90 boys (56.2%). When the patients were stratified based on SIADH, it was found that SIADH was present in 35 patients (21.9%). SIADH was associated with elevated glucose (p<0.001), ALT (p<0.05), AST (p<0.05), LDH (p<0.001), CRP (p<0.001), and MPV (p<0.001); and decreased potassium (p<0.05), chloride (p<0.001), albumin (p<0.001), total protein (p<0.05), and hemoglobin (p<0.05) levels. CONCLUSIONS Our study reports on the frequency, clinical characteristics, predisposing factors, and management of SIADH that can develop in children and adolescents diagnosed with brucellosis. PMID:27590789

  10. Vesicles and mixed micelles in hypothyroid rat bile before and after thyroid hormone treatment: evidence for a vesicle transport system for biliary cholesterol secretion.

    PubMed

    Andreini, J P; Prigge, W F; Ma, C; Gebbard, R L

    1994-08-01

    Hypothyroid rats show reduced secretion of biliary lipids, especially cholesterol. Secretion of biliary cholesterol is markedly augmented to levels above euthryroid beginning 12-24 h after administration of thyroid hormone. In the current studies, bile from hypothyroid and triiodothyronine-treated chronic bile-fistula rats was analyzed for vesicles and mixed micelles by metrizamide gradient ultracentrifugation. For euthryoid and hypothyroid animals, less than 12% of biliary cholesterol was in a vesicle gradient fraction. After treatment with triiodothyronine, biliary cholesterol increased markedly, and 50% of total cholesterol, 60% of excess cholesterol secreted, appeared in the vesicle fraction. Triiodothyronine stimulation of vesicle secretion resulted in cholesterol-rich vesicles (cholesterol:phospholipid ratio rose from less than 0.1 to 0.56), but no change in the distinct fatty acid composition of vesicle phospholipids. The microtubule inhibitor colchicine, given 12 h after triiodothyronine, prevented subsequent increase in cholesterol secretion in the form of vesicles. These studies, in a model that allows rapid changes in biliary lipid secretion, support the hypothesis that an important component of cholesterol and phospholipid secretion into bile involves microtubules and may involve a vesicle pathway.

  11. Different effects of subnormal levels of progesterone on the pulsatile and surge mode secretion of luteinizing hormone in ovariectomized goats.

    PubMed

    Kim, Seungjoon; Tanaka, Tomomi; Kamomae, Hideo

    2003-07-01

    This study tested the hypothesis that endocrinological threshold levels of progesterone that induce negative feedback effects on the pulsatile and surge modes of LH secretion are different. Our approach was to examine the effects of subnormal progesterone concentrations on LH secretion. Long-term ovariectomized Shiba goats that had received implants of silastic capsules containing estradiol were divided into three groups. The high progesterone (high P) group received a subcutaneous implant of a silastic packet (50 x 70 mm) containing progesterone, and the low progesterone (low P) group received a similar implant of a small packet (25 x 40 mm) containing progesterone. The control (non-P) group received no treatment with exogenous progesterone. Blood samples were collected daily throughout the experiment for the analysis of gonadal steroid hormone levels and at 10-min intervals for 8 h on Days 0, 3, and 7 (Day 0: just before progesterone treatment) for analysis of the pulsatile frequency of LH secretion. Then estradiol was infused into the jugular vein of all animals at a rate of 3 microg/h for 16 h on Day 8 to determine whether an LH surge was induced. Blood samples were collected every 2 h from 4 h before the start of the estradiol infusion until 48 h after the start of the infusion. In each group, the mean +/- SEM concentration after progesterone implant treatment was 3.3 +/- 0.1 ng/ml for the high P group, 1.1 +/- 0.1 ng/ml for the low P group, and <0.1 ng/ml for the non-P group, concentrations similar to the luteal levels, subluteal levels, and follicular phase levels of the normal estrous cycle, respectively. The estradiol concentration ranged from 4 to 8 pg/ml after estradiol capsule implants in all groups. The LH pulse frequency was significantly (P < 0.05) suppressed on Day 3 (6.2 +/- 0.5 pulses/8 h) and on Day 7 (2.6 +/- 0.9 pulses/8 h) relative to Day 0 (9.0 +/- 0.5 pulses/8 h) in the high P group. In both the low P and non-P groups, however, the changes

  12. Growth hormone secretion during space flight and evaluation of the physiological responses of animals held in the research animal holding facility

    NASA Technical Reports Server (NTRS)

    Fast, Thomas N.; Grindeland, Richard; Mehler, William; Oyama, Jiro

    1987-01-01

    The spaceflight of the Research Animal Holding Facility (RAHF) on the Space Laboratory 3 (SL 3) provided the opportunity to evaluate the suitability of the RAHF for housing and maintaining experimental animals during spaceflight, and to determine changes in the secretion of growth hormone during spaceflight. Using ground-based studies the following were investigated: the optimum conditions for creating gravitational force on space flight animals; neural pathways that may play a role in the space flight syndrome; and the time course of muscle atrophy due to hypodynamia and hypokenesia in hindlimb-suspended animals and the role of growth hormone in these processes.

  13. [Oxytocin and syndrome of inappropriate secretion of antidiuretic neonatal hormone. Case report of early severe hyponatremia and literature review].

    PubMed

    Aldana-Valenzuela, Carlos; Prieto-Pantoja, José Alfredo; Hernández-Acevedo, Angélica

    2010-12-01

    This is a clinical case presentation of a full term newborn infant who suffered severe hyponatremia and early seizures, associated with maternal fluid overload with electrolyte free solutions and high doses of oxytocin for labor augmentation. Although this condition has been recognized since the 1960's with isolated reports, this particular case has features that needs further investigation, not only for the unsually severe hyponatremia, but most importantly we think, for the prominent signs of fluid retention, the infant had, that suggest excessive antidiuretic activity probably due to oxytocin. These findings are consistent with syndrome of inappropriate secretion of antidiuretic hormone. Although until now there is no proof that oxytocin by itself produces this syndrome. We think the association is possible in certain clinical circumstances, such as those found in this case. We also, briefly discussed the pathophysiology of perinatal hyponatremia, the neonatal treatment of this condition and the current guidelines for the women in labor. Hyponatremia should not be considered a benign condition, since in the neonate, it may affect brain function. PMID:21961376

  14. Analysis of differential gene expression by bead-based fiber-optic array in growth-hormone-secreting pituitary adenomas.

    PubMed

    Jiang, Zhiquan; Gui, Songbo; Zhang, Yazhuo

    2010-09-01

    Growth-hormone-secreting pituitary adenomas (GHomas) account for approximately 20% of all pituitary neoplasms. However, the pathogenesis of GHomas remains to be elucidated. To explore the possible pathogenesis of GHomas, we used bead-based fiber-optic arrays to examine the gene expression in five GHomas and compared them to three healthy pituitaries. Four differentially expressed genes were chosen randomly for validation by quantitative real-time reverse transcription-polymerase chain reaction. We then performed pathway analysis on the identified differentially expressed genes using the Kyoto Encyclopedia of Genes and Genomes. Array analysis showed significant increases in the expression of 353 genes and 206 expressed sequence tags (ESTs) and decreases in 565 genes and 29 ESTs. Bioinformatic analysis showed that the genes HIGD1B, HOXB2, ANGPT2, HPGD and BTG2 may play an important role in the tumorigenesis and progression of GHomas. Pathway analysis showed that the wingless-type signaling pathway and extracellular-matrix receptor interactions may play a key role in the tumorigenesis and progression of GHomas. Our data suggested that there are numerous aberrantly expressed genes and pathways involved in the pathogenesis of GHomas. Bead-based fiber-optic arrays combined with pathway analysis of differentially expressed genes appear to be a valid method for investigating the pathogenesis of tumors. PMID:22993617

  15. Effects of STX, a novel estrogen membrane receptor agonist, on GnRH-induced luteinizing hormone secretion from cultured bovine anterior pituitary cells.

    PubMed

    Rudolf, Faidiban Oktofianus; Kadokawa, Hiroya

    2014-12-01

    STX is an agonist for a recently characterized membrane estrogen receptor whose structure has not been identified. We evaluated whether STX suppresses gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) release from bovine anterior pituitary (AP) cells. We cultured AP cells (n=12) for 3 days in steroid-free conditions, followed by increasing concentrations (0.001, 0.01, 0.1, 1 and 10 nM) of 17β-estradiol or STX for 5 min before GnRH stimulation until the end of the experiment. Estradiol (0.001 to 0.1 nM) significantly suppressed GnRH-stimulated LH secretion, whereas STX did not affect GnRH-stimulated LH secretion at any of the tested concentrations. In conclusion, STX, unlike estradiol, possesses no suppressive effect on GnRH-induced LH release from bovine AP cells.

  16. The CRH-R₁ receptor mediates luteinizing hormone, prolactin, corticosterone and progesterone secretion induced by restraint stress in estrogen-primed rats.

    PubMed

    Traslaviña, Guillermo A Ariza; Franci, Celso Rodrigues

    2011-11-01

    Acute stress has been shown to modify hypothalamus-pituitary-gonadal (HPG) axis activity. Corticotropin-releasing hormone (CRH), the principal regulator of the hypothalamus-pituitary-adrenal (HPA) axis, has been implicated as a mediator of stress-induced effects on the reproductive axis. The role of the specific CRH receptor subtypes in this response is not completely understood. In the current study, we investigated the role of the CRH-R(1) receptor on luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), progesterone (P) and corticosterone (CT) secretion in stress-induced responses under the influence of estrogen (E(2)). Estrogen-primed ovariectomized rats (estradiol cypionate, 10 μg sc) received an i.v. administration of antalarmin (0.1 or 1mg/kg), a selective CRH-R(1) antagonist, or vehicle before restraint stress for 40 min. Seven blood samples were collected from two experimental groups (one from 10:00 h to 14:00 h and the other from 10:00 h to 18:00 h). An increase of plasma LH induced by restraint acute-stress was followed by alteration of the secretion pattern in the estrogen-induced afternoon surge. In a similar manner, we observed a suppression of the afternoon surge in plasma FSH, a delay of E(2)-induced PRL secretion, and an increase in plasma P and CT. Antalarmin attenuated stress-induce LH increase, decreased CT and P secretion and blocked the stress effects on PRL secretion. These findings suggest that CRH-R(1) mediates, at least in part, the restraint stress effects on the HPA, PRL, and reproductive axes.

  17. Inhibition of proliferation, VEGF secretion of human neuroendocrine tumor cell line NCI-H727 by an antagonist of growth hormone-releasing hormone (GH-RH) in vitro.

    PubMed

    Sacewicz, Małgorzata; Lawnicka, Hanna; Siejka, Agnieszka; Stepień, Tomasz; Krupiński, Roman; Komorowski, Jan; Stepień, Henryk

    2008-09-01

    Growth hormone-releasing hormone (GH-RH) can stimulate not only growth hormone (GH) secretion by anterior pituitary gland but also proliferation of many cancer cell lines in vitro and in xenografts tumor models in vivo. Several antagonists of GH-RH have been shown to inhibit several cancer growths, but the role of GH-RH antagonists in the regulation of neuroendocrine cancers cell proliferation and tumor progression remains obscure. The aim of the study was to evaluate the influence of JV-1-36 (synthetic GH-RH antagonist) on proliferation and VEGF secretion by human neuroendocrine lung non-small cell carcinoma (NCI-H727) using cell culture model. The in vitro effect of JV-1-36 on the proliferation of NCI-H727 cells was assessed by the measurement of BrdU incorporation by colorimetric immunoassay. The presence of VEGF and membrane GH-RH receptors on the surface of H727 cells were visualized by immunocytochemistry using specific anti-GH-RH receptor antibody directed to the carboxy-terminal region. VEGF secretion to the cell cultures supernatants was assessed by ELISA methods. Immunoreactive cell membrane GH-RH receptors and VEGF-immunopositive cytoplasmatic granules were clearly confined on the surface of nearly all cancer cells. JV-1-36 at the concentration of 10(-6)-10(-10)M significantly inhibited growth of H727 cells, compared with untreated controls. In H727 cells, the antiproliferative JV-1-36 effect was associated with a dose-dependent reduction of VEGF secretion. In conclusion, our findings demonstrate the strong evidence for the antiproliferative action of GH-RH antagonist JV-1-36 for the NCI-H727 cells. In addition the suppression of VEGF secretion by H727 cells might contribute, at least in part, to the antitumor action of GH-RH antagonists.

  18. POTENTIAL ROLE OF TUBERO-INFUNDIBULAR DOPAMINERGIC NEURONS IN THE DISRUPTION OF PITUITARY HORMONE SECRETION BY ATRAZINE

    EPA Science Inventory

    Previously, we demonstrated that atrazine suppressed the ovulatory surge of luteininzing hormone and disrupted estrous cycles in the female rat. We also reported that this disruption of ovulation is likely the result of atrazine's effect on hypothalamic gonadotropin hormone rele...

  19. Purification and characterization of the glycoprotein hormone. cap alpha. -subunit-like material secreted by HeLa cells

    SciTech Connect

    Cox, G.S.; Rimerman, R.A.

    1988-08-23

    The protein secreted by HeLa cells that cross-reacts with antiserum developed against the ..cap alpha..-subunit of human chorionic gonadotropin (hCG) has been purified approximately 30,000-fold from concentrated culture medium by organic solvent fractionation followed by ion exchange, gel filtration, and lectin affinity chromatography. The final preparation had a specific activity (by RIA) of 6.8 x 10/sup 5/ ng of ..cap alpha../mg of protein and appeared homogeneous by electrophoresis on reducing/denaturing polyacrylamide gels (SDS-PAGE). Amino acid analysis indicated that HeLa-..cap alpha.. had a composition very similar to that of the urinary hCG ..cap alpha..-subunit. However, comparison of hCG-..cap alpha.. and HeLa-..cap alpha.. demonstrated that the tumor-associated subunit was not identical with its normal counterpart. The purified tumor protein had an apparent molecular weight greater than that of the urinary ..cap alpha..-subunit when analyzed by SDS-PAGE, and this difference was even greater when a partially purified preparation was examined by an immunoblot technique (Western). Isoelectric focusing of the HeLa and hCG subunits demonstrated that the tumor protein had a lower pI. Immunoprecipitation and electrophoresis of ..cap alpha..-subunit from HeLa cultures labeled with (/sup 3/H)fucose indicated that the tumor subunit was fucosylated, whereas analysis of hCG-..cap alpha.. hydrosylates by HPLC confirmed previous reports that the placental subunit does not contain fucose. The results indicate that, regardless of whether or not a single ..cap alpha..-subunit gene is being expressed in both normal and neoplastic tissues, posttranslational modifications lead to a highly altered subunit in the tumor. The differences observed may be useful in diagnosing neoplastic vs hyperplastic conditions and may lend insight into the mechanism of ectopic hormone production by tumors.

  20. Juvenile hormone biosynthesis and secretion by the female Corpora allata of the larval gypsy moth, Lymantria dispar (L. ) utilizing in vitro organ culture

    SciTech Connect

    Jones, G.L.

    1986-01-01

    Junvenile hormone synthesis and secretion in the female larval gypsy moth was investigated. In vitro culturing methods were developed including: incubating 2 pair of CC-CA gland complexes in 50 ul of osmotically balanced Grace's insect medium containing 1 uCi /sup 3/H-methyl-methionine for 6 hr. JH homologues were identified and quantified using TLC and HPLC. In vitro methods were employed to investigate trends of JH secretion in 4th and ultimate female larval instar CA. Fourth instar CA produced JH peaks of 0.15 pmole/pr/hr between days 2 and 3, but the rate declined to half by day 4. Ultimate instar larvae began secreting 0.48 pmole/pr/hr, but by day 10, had decreased JH output to negligible levels which continued until pupation. Effects upon in vitro JH secretion produced by precocene II and caffeine were examined. Feulgen staining techniques revealed an equal number of cells (30) in 4th and last instar CA. Last instar Ca were 3 times larger than 4th in volume but their actual in vitro JH secretion at peak levels was only 20% greater. In vitro methods demonstrated that JH secretory trends differ in younger versus mature larval instars. Glandular volume increased in last instars but JH secretion was only 20% greater than in 4th's when compared on the basis of volume. Precocene II elicited a negative response on in vivo JH secretion at levels 10 times less than caffeine. Caffeine was judged not to significantly alter JH secretion.

  1. Prolactin secretion after hypothalamic deafferentation in beef calves: response to haloperidol, alpha-methyl-rho-tyrosine, thyrotropin-releasing hormone and ovariectomy.

    PubMed

    Benoit, Allison M; Molina, Jose R; Lkhagvadorj, Sender; Anderson, Lloyd L

    2009-03-01

    In ruminant species photoperiod regulates prolactin (PRL) secretion. It is hypothesized that the inhibition of PRL secretion resides in dopaminergic neurons of the medial basal hypothalamus (MBH). To test this hypothesis, anterior (AHD), posterior (PHD) and complete (CHD) hypothalamic deafferentation and sham operation control (SOC) surgeries were carried out during May (long-day photoperiod) in beef heifer calves (6-8 mo old) to measure basal PRL secretion and PRL secretion as affected by intravenous secretagogues. On the day of surgery (day 0), PRL secretion reflected stress of anesthesia and surgery in all groups. Thyrotropin-releasing hormone (TRH), alpha-methyl-rho-tyrosine (alphaMrhoT), and haloperidol (HAL) was iv injected on days 11, 13 and 15, respectively. AHD, PHD, CHD, and SOC calves responded to TRH (100 microg) with an acute increase in PRL that peaked within 20 min. All heifers responded to alphaMrhoT (10 mg/kg BW) with an acute elevation in PRL within 10 min and remaining elevated for 3 h. HAL (0.1 mg/kg BW) induced an acute increase in PRL secretion in all groups, peaking within 15-30 min. Seven months later (December, short-day photoperiod) these heifers were ovariectomized. Basal plasma PRL levels were seasonally low, PRL secretion in AHD, PHD and CHD animals abruptly increased within 15 min to iv injection of 100 microg TRH to a greater amount than seen in SOC heifers. Although a biphasic effect on PRL secretion entrains under long-day and short-day photoperiods, hypothalamic deafferentation in cattle did not affect the pituitary gland's responsiveness to secretagogues.

  2. Fasting suppresses pulsatile luteinizing hormone (LH) secretion and enhances orderliness of LH release in young but not older men.

    PubMed

    Bergendahl, M; Aloi, J A; Iranmanesh, A; Mulligan, T M; Veldhuis, J D

    1998-06-01

    Pulsatile gonadotropin secretion and sex-steroid concentrations are suppressed reversibly in young fasted or malnourished human subjects. In this study, we investigated the impact of age on the dynamic neuroendocrine mechanisms underlying this stress response in healthy young (age, 28 +/- 3 yr, n = 8) vs. older (age 67 +/- 2 yr, n = 8) men with similar body mass indices (mean, 26 +/- 0.6 vs. 26 +/- 1.3 kg/m2, respectively). Serum LH concentrations were measured by immunoradiometric assay (IRMA) in blood collected at 10-min intervals over 27 h on a control (fed) day and on the third day of a 3.5-day fast (water only) assigned in randomized order. After 24 h of basal sampling, GnRH (10 micrograms i.v. bolus) was administered to test gonadotrope responsiveness. Cortisol, dehydroepiandrosterone sulfate, androstenedione, testosterone, FSH, GH, and PRL were measured in 24-h pooled serum as positive and negative control hormones. Approximate entropy was used to quantitate the orderliness of LH release over 24 h, and a multiple-parameter deconvolution method was applied to quantify pulsatile LH secretion and LH half-life. In the fed state, older men exhibited elevated mean (24-h pooled) serum FSH and cortisol concentrations compared with young controls but equivalent serum LH concentrations and reduced serum GH, free testosterone, androstenedione, and dehydroepiandrosterone sulfate concentrations. Fed older men also manifested a lower frequency and amplitude of 24-h pulsatile LH secretion, and, by approximate entropy calculations, a more disorderly pattern of basal LH release than younger individuals. Three- and one-half days of fasting evoked 40% and 47% increases in mean (24-h) serum cortisol concentrations in young and older men, respectively (P < 0.01 vs. fed, but P = not significant for percentage rise in older vs. young men). Concurrently, fasting induced a 2.1-fold fall in the 24-h endogenous LH production rate in young men (fed 36 +/- 9.7 vs. fasted 17 +/- 2.0 IU

  3. Hormone therapy in acne.

    PubMed

    Lakshmi, Chembolli

    2013-01-01

    Underlying hormone imbalances may render acne unresponsive to conventional therapy. Relevant investigations followed by initiation of hormonal therapy in combination with regular anti-acne therapy may be necessary if signs of hyperandrogenism are present. In addition to other factors, androgen-stimulated sebum production plays an important role in the pathophysiology of acne in women. Sebum production is also regulated by other hormones, including estrogens, growth hormone, insulin, insulin-like growth factor-1, glucocorticoids, adrenocorticotropic hormone, and melanocortins. Hormonal therapy may also be beneficial in female acne patients with normal serum androgen levels. An understanding of the sebaceous gland and the hormonal influences in the pathogenesis of acne would be essential for optimizing hormonal therapy. Sebocytes form the sebaceous gland. Human sebocytes express a multitude of receptors, including receptors for peptide hormones, neurotransmitters and the receptors for steroid and thyroid hormones. Various hormones and mediators acting through the sebocyte receptors play a role in the orchestration of pathogenetic lesions of acne. Thus, the goal of hormonal treatment is a reduction in sebum production. This review shall focus on hormonal influences in the elicitation of acne via the sebocyte receptors, pathways of cutaneous androgen metabolism, various clinical scenarios and syndromes associated with acne, and the available therapeutic armamentarium of hormones and drugs having hormone-like actions in the treatment of acne.

  4. Dynamics of circulating concentrations of gonadotropins and ovarian hormones throughout the menstrual cycle in the bonnet monkey: role of inhibin A in the regulation of follicle-stimulating hormone secretion.

    PubMed

    Suresh, P S; Medhamurthy, R

    2009-10-01

    In higher primates, increased circulating follicle-stimulating hormone (FSH) levels seen during late menstrual cycle and during menstruation has been suggested to be necessary for initiation of follicular growth, recruitment of follicles and eventually culminating in ovulation of a single follicle. With a view to establish the dynamics of circulating FSH secretion with that of inhibin A (INH A) and progesterone (P(4)) secretions during the menstrual cycle, blood was collected daily from bonnet monkeys beginning day 1 of the menstrual cycle up to 35 days. Serum INH A levels were low during early follicular phase, increased significantly coinciding with the mid cycle luteinizing hormone (LH) surge to reach maximal levels during the mid luteal phase before declining at the late luteal phase, essentially paralleling the pattern of P(4) secretion seen throughout the luteal phase. Circulating FSH levels were low during early and mid luteal phases, but progressively increased during the late luteal phase and remained high for few days after the onset of menses. In another experiment, lutectomy performed during the mid luteal phase resulted in significant decrease in INH A concentration within 2 hr (58.3+/-2 vs. 27.3+/-3 pg/mL), and a 2- to 3-fold rise in circulating FSH levels by 24 hr (0.20+/-0.02 vs. 0.53+/-0.14 ng/mL) that remained high until 48 hr postlutectomy. Systemic administration of Cetrorelix (150 microg/kg body weight), a gonadotropin releasing hormone receptor antagonist, at mid luteal phase in monkeys led to suppression of serum INH A and P(4) concentrations 24 hr post treatment, but circulating FSH levels did not change. Administration of exogenous LH, but not FSH, significantly increased INH A concentration. The results taken together suggest a tight coupling between LH and INH A secretion and that INH A is largely responsible for maintenance of low FSH concentration seen during the luteal phase.

  5. Actions of NPY, and its Y1 and Y2 receptors on pulsatile growth hormone secretion during the fed and fasted state.

    PubMed

    Huang, Lili; Tan, Hwee Y; Fogarty, Matthew J; Andrews, Zane B; Veldhuis, Johannes D; Herzog, Herbert; Steyn, Frederik J; Chen, Chen

    2014-12-01

    The hypothalamic NPY system plays an important role in regulating food intake and energy expenditure. Different biological actions of NPY are assigned to NPY receptor subtypes. Recent studies demonstrated a close relationship between food intake and growth hormone (GH) secretion; however, the mechanism through which endogenous NPY modulates GH release remains unknown. Moreover, conclusive evidence demonstrating a role for NPY and Y-receptors in regulating the endogenous pulsatile release of GH does not exist. We used genetically modified mice (germline Npy, Y1, and Y2 receptor knock-out mice) to assess pulsatile GH secretion under both fed and fasting conditions. Deletion of NPY did not impact fed GH release; however, it reversed the fasting-induced suppression of pulsatile GH secretion. The recovery of GH secretion was associated with a reduction in hypothalamic somatotropin release inhibiting factor (Srif; somatostatin) mRNA expression. Moreover, observations revealed a differential role for Y1 and Y2 receptors, wherein the postsynaptic Y1 receptor suppresses GH secretion in fasting. In contrast, the presynaptic Y2 receptor maintains normal GH output under long-term ad libitum-fed conditions. These data demonstrate an integrated neural circuit that modulates GH release relative to food intake, and provide essential information to address the differential roles of Y1 and Y2 receptors in regulating the release of GH under fed and fasting states.

  6. CaSR function in the intestine: Hormone secretion, electrolyte absorption and secretion, paracrine non-canonical Wnt signaling and colonic crypt cell proliferation.

    PubMed

    Macleod, R John

    2013-06-01

    Expression and function of the CaSR have been shown in some mammalian taste buds and basal cells of the esophagus. Signaling cascades responsible for CaSR-mediated stimulation of H(+)-K(+)-ATPase on human parietal cells have been defined. Transgenic mice and reductionistic cell culture models have shown that the CaSR promotes gastrin secretion from G cells, cholecystokinin (CCK) secretion from duodenal I cells and BMP-2 secretion from sub-epithelial myofibroblasts. In addition, the CaSR mediates a novel paracrine relationship between myofibroblasts and overlying epithelial cells in the colon. Thus, CaSR activators stimulate secretion of Wnt5a from myofibroblasts and expression of the Wnt5a receptor Ror2 in epithelial cells. CaSR-mediated Wnt5a/Ror2 engagement stimulates epithelial differentiation and reduces expression of the receptor for tumor necrosis factor (TNFR1). CaSR activators also modulate intestinal motility, inhibit Cl(-) secretion and stimulate Na(+) absorption in both the small intestine and colon. Colonic epithelia from conditional and global CaSR knockout mice exhibit increased proliferation with increased Wnt/β-catenin signaling, demonstrating that the CaSR negatively modulates colonic epithelial growth.

  7. The influence of insulin, beta-estradiol, dexamethasone and thyroid hormone on the secretion of coagulant and anticoagulant proteins by HepG2 cells.

    PubMed

    Niessen, R W; Pfaffendorf, B A; Sturk, A; Lamping, R J; Schaap, M C; Hack, C E; Peters, M

    1995-08-01

    As a basis for regulatory studies on the influence of hormones on (anti)coagulant protein production by hepatocytes, we examined the amounts of the plasma proteins antithrombin III (AT III), protein C, protein S, factor II, factor X, fibrinogen, and prealbumin produced by the hepatoma cell line HepG2, into the culture medium, in the absence and presence of insulin, beta-estradiol, dexamethasone and thyroid hormone. Without hormones these cells produced large amounts of fibrinogen (2,452 +/- 501 ng/mg cell protein), AT III (447 +/- 16 ng/mg cell protein) and factor II (464 +/- 31 ng/mg cell protein) and only small amounts of protein C (50 +/- 7 ng/mg cell protein) and factor X (55 +/- 5 ng/mg cell protein). Thyroid hormone had a slight but significant effect on the enrichment in the culture medium of the anticoagulant protein AT III (1.34-fold) but not on protein C (0.96-fold) and protein S (0.91-fold). This hormone also significantly increased the amounts of the coagulant proteins factor II (1.28-fold), factor X (1.45-fold) and fibrinogen (2.17-fold). Insulin had an overall stimulating effect on the amounts of all the proteins that were investigated. Neither dexamethasone nor beta-estradiol administration did substantially change the amounts of these proteins. We conclude that the HepG2 cell is a useful tool to study the hormonal regulation of the production of (anti)coagulant proteins. We studied the overall process of protein production, i.e., the amounts of proteins produced into the culture medium. Detailed studies have to be performed to establish the specific hormonal effects on the underlying processes, e.g., transcription, translation, cellular processing and transport, and secretion.

  8. The orderliness of the growth hormone (GH) release process and the mean mass of GH secreted per burst are highly conserved in individual men on successive days.

    PubMed

    Friend, K; Iranmanesh, A; Veldhuis, J D

    1996-10-01

    Endocrine glands signal their remote target tissues via physiologically pulsatile release of regulatory molecules. A cardinal assumption of most pathophysiological experiments is that discrete attributes of pulsatile hormone secretion are stable over successive untreated observation intervals; i.e. repeated measurements show serial within-subject reproducibility. To test this hypothesis in the GH axis, we sampled blood every 10 min for 48 h in 14 healthy men (age range, 29-77 yr; body mass index, 21-51 kg/m2). The 2 consecutive 24-h serum profiles were subjected to ultrasensitive GH chemiluminescence assay (sensitivity, 0.002 micrograms/L) with a new dose-dependent variance model to estimate within-assay precision. We then applied deconvolution analysis to estimate the number, mass, amplitude, and duration of underlying GH secretory bursts as well as simultaneously calculate the apparent GH half-life and any concurrent basal hormone secretion. Test-retest consistency was assessed by the Pearson correlation coefficient, and differences were determined by paired nonparametric (Wilcoxon) testing. Comparing successive 24-h profiles, no significant differences existed in any of the foregoing secretion or half-life measures or in a novel estimate of the relative disorderliness of hormone release, namely approximate entropy. Correlation was minimal for secretory burst amplitude and half-duration. In contrast, the calculated mean mass of GH secreted per burst was highly conserved across sessions within subjects, with an r value of 0.932 (P < 10(-6). This correlation equaled or exceeded that of mean and integrated serum GH concentrations on consecutive days (r = 0.920; P = 0.00003). The calculated daily GH production rate was also strongly reproduced (r = 0.784; P = 0.0009). Moreover, the within-subject GH half-life and GH secretory burst frequency estimates were well correlated on successive days (P = 0.034-0.004; r = 0.568-0.711). Approximate entropy values were

  9. Effect of pulse frequency and amplitude of D-Trp6-luteinizing hormone-releasing hormone on the pulsatile secretion of prolactin and LH.

    PubMed

    Rodriguez, T; Bordiu, E; Rubio, J A; Duran, A; Charro, A L

    1993-09-01

    This work analyzes the effect of the pulse amplitude and frequency of a potent LHRH analog, D-Trp6-LHRH, in a perfusion system of isolated rat pituitary cells. To this purpose, we studied the LH and PRL secretion in different conditions: basal secretion, secretion after increasing concentrations of D-Trp6-LHRL (0.001, 0.01, 0.1 and 1 nM) secretion in function of the pulses frequency (2,3, and 4 pulses per h) and amplitude (0.1, 1 and 10 nM). The principal findings were: 1. The basal LH and PRL secretions was pulsatile; 2. The stimulation of LH by the analog was not dose-dependent; 3. When more than 2 pulses per h were administered, a rapid desensitization of gonadotroph to release LH (at 20-30 min) occurred; 4. There was a loss of pulsatility of PRL secretion with an increase in the pulse frequency and amplitude of the D-Trp6-LHRH, which was produced parallelly to the desensitization of the gonadotroph to release LH. In summary, these findings suggest that a rapid loss of pulsatility of the PRL when the D-Trp6-LHRH pulse frequency and amplitude is increased might be due to the early desensitization of the gonadotroph to the analog.

  10. Pituitary gonadotrophic hormone synthesis, secretion, subunit gene expression and cell structure in normal and follicle-stimulating hormone β knockout, follicle-stimulating hormone receptor knockout, luteinising hormone receptor knockout, hypogonadal and ovariectomised female mice.

    PubMed

    Abel, M H; Widen, A; Wang, X; Huhtaniemi, I; Pakarinen, P; Kumar, T R; Christian, H C

    2014-11-01

    To investigate the relationship between gonadotroph function and ultrastructure, we have compared, in parallel in female mice, the effects of several different mutations that perturb the hypothalamic-pituitary-gonadal axis. Specifically, serum and pituitary gonadotrophin concentrations, gonadotrophin gene expression, gonadotroph structure and number were measured. Follicle-stimulating hormone β knockout (FSHβKO), follicle-stimulating hormone receptor knockout (FSHRKO), luteinising hormone receptor knockout (LuRKO), hypogonadal (hpg) and ovariectomised mice were compared with control wild-type or heterozygote female mice. Serum levels of LH were elevated in FSHβKO and FSHRKO compared to heterozygote females, reflecting the likely decreased oestrogen production in KO females, as demonstrated by the threadlike uteri and acyclicity. As expected, there was no detectable FSH in the serum or pituitary and an absence of expression of the FSHβ subunit gene in FSHβKO mice. However, there was a significant increase in expression of the FSHβ and LHβ subunit genes in FSHRKO female mice. The morphology of FSHβKO and FSHRKO gonadotrophs was not significantly different from the control, except that secretory granules in FSHRKO gonadotrophs were larger in diameter. In LuRKO and ovariectomised mice, stimulation of LHβ and FSHβ mRNA, as well as serum protein concentrations, were reflected in subcellular changes in gonadotroph morphology, including more dilated rough endoplasmic reticula and fewer, larger secretory granules. In the gonadotophin-releasing hormone deficient hpg mouse, gonadotrophin mRNA and protein levels were significantly lower than in control mice and gonadotrophs were correspondingly smaller with less abundant endoplasmic reticula and reduced numbers of secretory granules. In summary, major differences in pituitary content and serum concentrations of the gonadotrophins LH and FSH were found between control and mutant female mice. These changes were

  11. Ovariectomy during the luteal phase influences secretion of prolactin, growth hormone, and insulin-like growth factor-I in the bitch.

    PubMed

    Lee, W M; Kooistra, H S; Mol, J A; Dieleman, S J; Schaefers-Okkens, A C

    2006-07-15

    A decline in circulating progesterone concentration plays an important role in the ethiopathogenesis of pseudopregnancy in the bitch. Because growth hormone (GH) and prolactin (PRL) are essential for normal mammogenesis and the secretion of these hormones is influenced by changes in the circulating progesterone concentration, the purpose of this study was to investigate the effects of mid-luteal phase ovariectomy on the 6-h pulsatile plasma profiles of GH and PRL and the basal plasma concentrations of GH, PRL, and insulin-like growth factor-I (IGF-I) in six beagle bitches. Ovariectomy was followed by only mild or covert signs of pseudopregnancy. The sharp decrease of the plasma progesterone concentration was accompanied by decreased basal plasma concentrations of GH and IGF-I and a rise in basal plasma PRL concentration. GH and PRL were secreted in a pulsatile fashion both prior to and after ovariectomy. The mean basal plasma GH concentration was significantly higher before ovariectomy than on days 1 and 7 after ovariectomy. The mean area under the curve above the zero level (AUC(0)) for GH was significantly higher before than at 7 days after ovariectomy. The mean area under the curve above basal level (AUC(b)) and the frequency of GH pulses at 7 days after ovariectomy were significantly higher than before and 1 day after ovariectomy. Both the mean basal plasma PRL concentration and the mean AUC(0) for PRL increased after ovariectomy. In conclusion, ovariectomy of bitches in the mid-luteal phase stops progesterone-induced GH release from the mammary gland, as evidenced by the lowering of basal plasma GH levels, the recurrence of GH pulsatility, and the lowering of circulating IGF-I levels. The sudden lowering of plasma progesterone concentration is probably a primary cause of a prolonged increase in PRL secretion. These observations underscore the importance of similar, albeit less abrupt, hormonal changes in the cyclical physiological alterations in the mammary

  12. Pathophysiologic changes in IA-2/IA-2β null mice are secondary to alterations in the secretion of hormones and neurotransmitters.

    PubMed

    Cai, Tao; Notkins, Abner L

    2016-02-01

    IA-2 and IA-2β are transmembrane proteins of dense-core vesicles (DCV). The deletion of these proteins results in a reduction in the number of DCV and the secretion of hormones and neurotransmitters. As a result, this leads to a variety of pathophysiologic changes. The purpose of this review is to describe these changes, which are characterized by glucose intolerance, female infertility, behavior and learning abnormalities and alterations in the diurnal circadian rhythms of blood pressure, heart rate, spontaneous physical activity and body temperature. These findings show that the deletion of IA-2 and IA-2β results in multiple pathophysiologic changes and represents a unique in vivo model for studying the effect of hormone and neurotransmitter reduction on known and still unrecognized targets.

  13. A new human breast cancer cell line, KPL-3C, secretes parathyroid hormone-related protein and produces tumours associated with microcalcifications in nude mice.

    PubMed Central

    Kurebayashi, J.; Kurosumi, M.; Sonoo, H.

    1996-01-01

    Parathyroid hormone-related protein (PTHrP) is the main cause of humoral hypercalcaemia of malignancy (HHM). We recently established a new human breast cancer cell line, designated KPL-3C, from the malignant effusion of a breast cancer patient with HHM. Morphological, cytogenetic and immunohistochemical analyses indicated that the cell line is derived from human breast cancer. The KPL-3C cells stably secrete immunoreactive PTHrP measured by a two-site immunoradiometric assay, possess both oestrogen and progesterone receptors and are tumorigenic in female nude mice. The addition of phorbol-12-myristate-13-acetate to the medium significantly increased PTHrP secretion from the cells. In contrast, hydrocortisone, medroxyprogesterone acetate and 22-oxacalcitriol decreased PTHrP secretion in a dose-dependent manner. Unexpectedly, a number of microcalcifications were observed in the transplanted tumours. Radiographical examination indicated that the microcalcifications in the tumours are very similar to those commonly observed in human breast cancer. These findings suggest that this KPL-3C cell line may be useful for studying the regulatory mechanisms of PTHrP secretion and the mechanisms that lead to the deposition of microcalcifications in breast cancer. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 PMID:8688322

  14. Enhanced accumulation of secreted human growth hormone by transgenic tobacco cells correlates with the introduction of an N-glycosylation site.

    PubMed

    Xu, Jianfeng; Kieliszewski, Marcia

    2011-06-10

    Extracellular secretion of recombinant proteins from plant cell suspension culture will simplify the protein purification procedure and greatly reduce the production cost. Our early work indicated that presence of hydroxyproline-O-glycosylation at the C- or N-terminus of the target protein boosted the secreted yields in the culture medium. Inspired by early successes, we tested the possibility of introducing an N-glycosylation site to facilitate the secretion of human growth hormone (hGH) from cultured tobacco cells. Three N-glycosylated hGH fusion proteins, designated NAS-EK-hGH, NAS-Kex2-hGH and hGH-NAS, were expressed in tobacco BY-2 cells. Where NAS denotes the "Asn-Ala-Ser" consensus sequence for N-glycosylation; EK denotes an enterokinase cleavage site and Kex2 a sequence to be cleaved by a Golgi-localized Kex2p-like protease. Our results indicated that a single N-glycan attached either at the N-terminus or C-terminus of hGH correlated with enhanced extracellular accumulation of the transgenic proteins; the secreted yield of NAS-EK-hGH and hGH-NAS was 70-90 fold greater than the control targeted, non-glycosylated hGH. NAS-Kex2-hGH was subject to partial cleavage of the N-glycan tag at the Kex2 site in Golgi apparatus, and therefore gave lower yields than the other two constructs.

  15. A longitudinal study of growth and growth hormone secretion in children during treatment for acute lymphoblastic leukemia

    SciTech Connect

    Marky, I.; Mellander, L.; Lannering, B.; Albertsson-Wikland, K. )

    1991-01-01

    Diminished growth rate during treatment for acute lymphoblastic leukemia (ALL) is of the multifactorial etiology. Effects on GH secretion have been shown after discontinuation of treatment including prophylactic CNS irradiation. Seventeen children treated for ALL with three different CNS preventive schedules were followed longitudinally with repeated estimations of the spontaneous GH secretion during a 24-month period. No difference was found in GH secretion during this time between patients who had received no radiotherapy and those who had received 18 or 24 Gy as CNS prophylaxis. During dexamethasone treatment the GH secretion was completely suppressed, which can be a mediator for the diminished growth rate during the first 2 years of ALL treatment. We conclude that there is no clinical reason to perform GH analysis within the first 24 months of treatment for ALL.

  16. Processing of thyrotropin-releasing hormone prohormone (pro-TRH) generates a biologically active peptide, prepro-TRH-(160-169), which regulates TRH-induced thyrotropin secretion

    SciTech Connect

    Bulant, M.; Vaudry, H. ); Roussel, J.P.; Astier, H. ); Nicolas, P. )

    1990-06-01

    Rat thyrotropin-releasing hormone (TRH) prohormone contains five copies of the TRH progenitor sequence Gln-His-Pro-Gly linked together by connecting sequences whose biological activity is unknown. Both the predicted connecting peptide prepro-TRH-(160-169) (Ps4) and TRH are predominant storage forms of TRH precursor-related peptides in the hypothalamus. To determine whether Ps4 is co-released with TRH, rat median eminence slices were perfused in vitro. Infusion of depolarizing concentrations of KCl induced stimulation of release of Ps4- and TRH-like immunoreactivity. The possible effect of Ps4 on thyrotropin release was investigated in vitro using quartered anterior pituitaries. Infusion of Ps4 alone had no effect on thyrotropin secretion but potentiated TRH-induced thyrotropin release in a dose-dependent manner. In addition, the occurrence of specific binding sites for {sup 125}I-labeled Tyr-Ps4 in the distal lobe of the pituitary was demonstrated by binding analysis and autoradiographic localization. These findings indicate that these two peptides that arise from a single multifunctional precursor, the TRH prohormone, act in a coordinate manner on the same target cells to promote hormonal secretion. These data suggest that differential processing of the TRH prohormone may have the potential to modulate the biological activity of TRH.

  17. The action of synthetic secretin, cholecystokinin-octapeptide and combinations of these hormones on the secretion of the isolated perfused rat pancreas.

    PubMed

    Sommer, H; Kasper, H

    1981-12-01

    Determinations of dose-response curves for synthetic secretin and for the octapeptide of cholecystokinin (CCK-8) in the isolated perfused rat pancreas reveal that both secretin and CCK stimulate the pancreatic secretory flow and enzyme secretion. The maximal secretory flow evoked by CCK-8 (1.75 +/- 0.24 microliter/min) equals that evoked by secretin, while the protein output (57.1 +/- 6.3 microgram/min) is approximately twice as high. Stimulation by secretin combined with CCK-8 results in summation of the hydrokinetic action and potentiation of the ecbolic action of these hormones. Since the secretory parameters decrease by supramaximal stimulation, the dose-response curves are biphasic. The secretion of pancreatic enzymes correlates significantly (p less than 0.0005) with the protein output. However, the ratio of amylase, lipase and chymotrypsinogen to protein depends on the degree of pancreatic stimulation in so far as amylase secretion increases significantly (p less than 0.01) more markedly than that of both other enzymes.

  18. The action of synthetic secretin, cholecystokinin-octapeptide and combinations of these hormones on the secretion of the isolated perfused rat pancreas.

    PubMed

    Sommer, H; Kasper, H

    1981-12-01

    Determinations of dose-response curves for synthetic secretin and for the octapeptide of cholecystokinin (CCK-8) in the isolated perfused rat pancreas reveal that both secretin and CCK stimulate the pancreatic secretory flow and enzyme secretion. The maximal secretory flow evoked by CCK-8 (1.75 +/- 0.24 microliter/min) equals that evoked by secretin, while the protein output (57.1 +/- 6.3 microgram/min) is approximately twice as high. Stimulation by secretin combined with CCK-8 results in summation of the hydrokinetic action and potentiation of the ecbolic action of these hormones. Since the secretory parameters decrease by supramaximal stimulation, the dose-response curves are biphasic. The secretion of pancreatic enzymes correlates significantly (p less than 0.0005) with the protein output. However, the ratio of amylase, lipase and chymotrypsinogen to protein depends on the degree of pancreatic stimulation in so far as amylase secretion increases significantly (p less than 0.01) more markedly than that of both other enzymes. PMID:6178671

  19. Proteome analysis of male accessory gland secretions in oriental fruit flies reveals juvenile hormone-binding protein, suggesting impact on female reproduction.

    PubMed

    Wei, Dong; Li, Hui-Min; Tian, Chuan-Bei; Smagghe, Guy; Jia, Fu-Xian; Jiang, Hong-Bo; Dou, Wei; Wang, Jin-Jun

    2015-01-01

    In insects, the accessory gland proteins (Acps) secreted by male accessory glands (MAGs) account for the majority of seminal fluids proteins. Mixed with sperm, they are transferred to the female at mating and so impact reproduction. In this project, we identified 2,927 proteins in the MAG secretions of the oriental fruit fly Bactrocera dorsalis, an important agricultural pest worldwide, using LC-MS analysis, and all sequences containing open reading frames were analyzed using signalP. In total, 90 Acps were identified. About one third (26) of these 90 Acps had a specific functional description, while the other two thirds (64) had no functional description including dozens of new classes of proteins. Hence, several of these novel Acps were abundant in the MAG secretions, and we confirmed their MAG-specific expression by qPCR. Finally and interestingly, one of these novel proteins was functionally predicted as juvenile hormone-binding protein, suggesting the impact of Acps with reproductive events in the female. Our results will aid in the development of an experimental method to identify Acps in insects, and in turn this information with new Acps in B. dorsalis will pave the way of further exploration their function in reproduction and potential development as new insecticide targets.

  20. Proteome analysis of male accessory gland secretions in oriental fruit flies reveals juvenile hormone-binding protein, suggesting impact on female reproduction

    PubMed Central

    Wei, Dong; Li, Hui-Min; Tian, Chuan-Bei; Smagghe, Guy; Jia, Fu-Xian; Jiang, Hong-Bo; Dou, Wei; Wang, Jin-Jun

    2015-01-01

    In insects, the accessory gland proteins (Acps) secreted by male accessory glands (MAGs) account for the majority of seminal fluids proteins. Mixed with sperm, they are transferred to the female at mating and so impact reproduction. In this project, we identified 2,927 proteins in the MAG secretions of the oriental fruit fly Bactrocera dorsalis, an important agricultural pest worldwide, using LC-MS analysis, and all sequences containing open reading frames were analyzed using signalP. In total, 90 Acps were identified. About one third (26) of these 90 Acps had a specific functional description, while the other two thirds (64) had no functional description including dozens of new classes of proteins. Hence, several of these novel Acps were abundant in the MAG secretions, and we confirmed their MAG-specific expression by qPCR. Finally and interestingly, one of these novel proteins was functionally predicted as juvenile hormone-binding protein, suggesting the impact of Acps with reproductive events in the female. Our results will aid in the development of an experimental method to identify Acps in insects, and in turn this information with new Acps in B. dorsalis will pave the way of further exploration their function in reproduction and potential development as new insecticide targets. PMID:26582577

  1. Hormone secretion by euthyroid and hypothyroid rat ovaries during the early stages of hCG-induced ovarian cyst development.

    PubMed

    Bruot, B C

    1987-02-01

    This study was undertaken to examine ovarian steroid production during the early stages of hCG-induced ovarian cyst formation in the hypothyroid rat. Rats were placed into two groups with one group made hypothyroid by adding thiouracil to their diet. After 10 days, each group was divided into two subgroups with one subgroup receiving daily injections of hCG for 2 days and the other subgroup receiving saline. On the morning of Day 13, ovaries were removed and incubated for 2 hr. No significant difference in progesterone secretion was observed. However, ovaries from hypothyroid, hCG-treated rats secreted significantly more testosterone and estradiol than ovaries from vehicle-treated, hypothyroid rats and euthyroid, hCG-treated rats. In a second experiment, ovaries from euthyroid and hypothyroid rats treated with hCG were incubated in medium supplemented with 100 nM androstenedione and 0 or 100 ng FSH/ml. FSH failed to affect progesterone, testosterone, and estradiol secretions by ovaries from euthyroid, hCG-treated rats. In contrast, FSH significantly enhanced testosterone and estradiol secretion by ovaries from hypothyroid, hCG-treated rats. These results support the hypothesis that increased levels of testosterone and estradiol secretion have a central role in the induction of polycystic ovaries by hCG in the hypothyroid rat. PMID:3101068

  2. Influence of season and nutritional status on the direct effects of leptin, orexin-A and ghrelin on luteinizing hormone and growth hormone secretion in the ovine pituitary explant model.

    PubMed

    Kirsz, K; Szczesna, M; Dudek, K; Bartlewski, P M; Zieba, D A

    2014-07-01

    The aim of this study was to examine whether leptin (anorexigenic peptide), orexin-A, and ghrelin (orexigenic peptides) could directly (ie, independently of hypothalamic influences) affect the secretion of luteinizing hormone (LH) and growth hormone (GH) by adenohypophyseal (AP) explants obtained from normally fed or fasted (48 h) ewes during the breeding and nonbreeding seasons. In addition, a specific ovine super leptin antagonist (SLAN-3) was used to assess the interactions between leptin and ghrelin and/or orexin-A. Pituitary glands from 16 ovariectomized Polish Longwool ewes that had received estradiol-releasing subcutaneous implants were collected in the breeding (November; n = 8) and nonbreeding (May; n = 8) seasons. The AP explants were incubated for 240 min in a gas-liquid interface and treated with leptin (50 ng/mL), ghrelin (100 ng/mL), orexin-A (100 ng/mL), and SLAN-3 (500 ng/mL) with orexin-A or ghrelin. Treatments with leptin and SLAN-3 + orexin-A increased (P < 0.05) LH concentrations in the cultures of AP explants from fasted animals in the breeding season. Orexin-A increased (P < 0.05) LH secretion by AP explants from both fasted and fed animals in the breeding season. Ghrelin stimulated (P < 0.05) GH secretion by AP explants collected from fasted animals in nonbreeding season and from normally fed ewes in both seasons. Leptin decreased (P < 0.05) GH secretion by AP explants collected from fasted ewes in both seasons and from nonfasted ewes in the breeding season. However, the treatment with SLAN-3 + ghrelin resulted in greater (P < 0.05) GH concentrations compared with leptin treatment of AP explants from fasted ewes in the breeding season and from normally fed ewes in nonbreeding season. In summary, leptin, orexin-A, and ghrelin exerted direct effects on AP secretory function in an ex situ model and both the reproductive season and nutritional status of the animals impinged on the direct effects of the peptides on LH and GH release

  3. Gonadotrophin-Inhibitory Hormone in the Cichlid Fish Cichlasoma dimerus: Structure, Brain Distribution and Differential Effects on the Secretion of Gonadotrophins and Growth Hormone.

    PubMed

    Di Yorio, M P; Pérez Sirkin, D I; Delgadin, T H; Shimizu, A; Tsutsui, K; Somoza, G M; Vissio, P G

    2016-05-01

    The role of gonadotrophin-inhibitory hormone (GnIH) in the inhibition of the reproductive axis has been well-established in birds and mammals. However, its role in other vertebrates, such as the teleost fish, remains controversial. In this context, the present study aimed to evaluate whether GnIH modulates the release of gonadotrophins and growth hormone (GH) in the cichlid fish Cichlasoma dimerus. First, we partially sequenced the precursor polypeptide for GnIH and identified three putative GnIH peptides. Next, we analysed the expression of this precursor polypeptide via a polymerase chain reaction in the reproductive axis of both sexes. We found a high expression of the polypeptide in the hypothalamus and gonads of males. Immunocytochemistry allowed the observation of GnIH-immunoreactive somata in the nucleus posterioris periventricularis and the nucleus olfacto-retinalis, with no differences between the sexes. GnIH-immunoreactive fibres were present in all brain regions, with a high density in the nucleus lateralis tuberis and at both sides of the third ventricle. Finally, we performed in vitro studies on intact pituitary cultures to evaluate the effect of two doses (10(-6)  m and 10(-8)  m) of synthetic C. dimerus (cd-) LPQRFa-1 and LPQRFa-2 on the release of gonadotrophins and GH. We observed that cd-LPQRFa-1 decreased β-luteinising hormone (LH) and β-follicle-stimulating hormone (FSH) and also increased GH release to the culture medium. The release of β-FSH was increased only when it was stimulated with the higher cd-LPQRFa-2 dose. The results of the present study indicate that cd-LPQRFa-1, the cichlid fish GnIH, inhibits β-LH and β-FSH release and stimulates GH release in intact pituitary cultures of C. dimerus. The results also show that cd-LPQRF-2 could act as an β-FSH-releasing factor in this fish species. PMID:26919074

  4. Metabolic Effects of a Growth Hormone-Releasing Factor in Obese Subjects with Reduced Growth Hormone Secretion: A Randomized Controlled Trial

    PubMed Central

    Makimura, Hideo; Feldpausch, Meghan N.; Rope, Alison M.; Hemphill, Linda C.; Torriani, Martin; Lee, Hang

    2012-01-01

    Context: Obesity is associated with reduced GH secretion and increased cardiovascular disease risk. Objective: We performed this study to determine the effects of augmenting endogenous GH secretion on body composition and cardiovascular disease risk indices in obese subjects with reduced GH secretion. Design, Patients and Methods: A randomized, double-blind, placebo-controlled study was performed involving 60 abdominally obese subjects with reduced GH secretion. Subjects received tesamorelin, a GHRH1–44 analog, 2 mg once daily, or placebo for 12 months. Abdominal visceral adipose tissue (VAT) was assessed by abdominal computed tomography scan, and carotid intima-media thickness (cIMT) was assessed by ultrasound. Treatment effect was determined by longitudinal linear mixed-effects modeling. Results: VAT [−16 ± 9 vs.19 ± 9 cm2, tesamorelin vs. placebo; treatment effect (95% confidence interval): −35 (−58, −12) cm2; P = 0.003], cIMT (−0.03 ± 0.01 vs. 0.01 ± 0.01 mm; −0.04 (−0.07, −0.01) mm; P = 0.02), log C-reactive protein (−0.17 ± 0.04 vs. −0.03 ± 0.05 mg/liter; −0.15 (−0.30, −0.01) mg/liter, P = 0.04), and triglycerides (−26 ± 16 vs. 12 ± 8 mg/dl; −37 (−67, −7) mg/dl; P = 0.02) improved significantly in the tesamorelin group vs. placebo. No significant effects on abdominal sc adipose tissue (−6 ± 6 vs. 3 ± 11 cm2; −10 (−32, +13) cm2; P = 0.40) were seen. IGF-I increased (86 ± 21 vs. −6 ± 8 μg/liter; 92 (+52, +132) μg/liter; P < 0.0001). No changes in fasting, 2-h glucose, or glycated hemoglobin were seen. There were no serious adverse events or differences in adverse events between the groups. Conclusion: Among obese subjects with relative reductions in GH, tesamorelin selectively reduces VAT without significant effects on sc adipose tissue and improves triglycerides, C-reactive protein, and cIMT, without aggravating glucose. PMID:23015655

  5. Intracellular mechanism of the action of inhibin on the secretion of follicular stimulating hormone and of luteinizing hormone induced by LH-RH in vitro

    NASA Technical Reports Server (NTRS)

    Lecomte-Yerna, M. J.; Hazee-Hagelstein, M. T.; Charlet-Renard, C.; Franchimont, P.

    1982-01-01

    The FSH secretion-inhibiting action of inhibin in vitro under basal conditions and also in the presence of LH-RH is suppressed by the addition of MIX, a phosphodiesterase inhibitor. In the presence of LH-RH, inhibin reduces significantly the intracellular level of cAMP in isolated pituitary cells. In contrast, the simultaneous addition of MIX and inhibin raises the cAMP level, and this stimulation is comparable to the increase observed when MIX is added alone. These observations suggest that one mode of action of inhibin could be mediated by a reduction in cAMP within the pituitary gonadotropic cell.

  6. Using Cox cluster processes to model latent pulse location patterns in hormone concentration data.

    PubMed

    Carlson, Nichole E; Grunwald, Gary K; Johnson, Timothy D

    2016-04-01

    Many hormones, including stress hormones, are intermittently secreted as pulses. The pulsatile location process, describing times when pulses occur, is a regulator of the entire stress system. Characterizing the pulse location process is particularly difficult because the pulse locations are latent; only hormone concentration at sampled times is observed. In addition, for stress hormones the process may change both over the day and relative to common external stimuli. This potentially results in clustering in pulse locations across subjects. Current approaches to characterizing the pulse location process do not capture subject-to-subject clustering in locations. Here we show how a Bayesian Cox cluster process may be adapted as a model of the pulse location process. We show that this novel model of pulse locations is capable of detecting circadian rhythms in pulse locations, clustering of pulse locations between subjects, and identifying exogenous controllers of pulse events. We integrate our pulse location process into a model of hormone concentration, the observed data. A spatial birth-and-death Markov chain Monte Carlo algorithm is used for estimation. We exhibit the strengths of this model on simulated data and adrenocorticotropic and cortisol data collected to study the stress axis in depressed and non-depressed women. PMID:26553914

  7. Effects of ghrelin on Kisspeptin mRNA expression in the hypothalamic medial preoptic area and pulsatile luteinising hormone secretion in the female rat.

    PubMed

    Forbes, Sarah; Li, Xiao Feng; Kinsey-Jones, James; O'Byrne, Kevin

    2009-08-28

    The orexigenic gut peptide ghrelin negatively modulates the hypothalamic-pituitary-gonadal (HPG) axis. Hyperghrelinaemia results during negative energy balance, a state often associated with delayed puberty and disrupted fertility, whilst exogenous ghrelin suppresses pulsatile luteinising hormone (LH) secretion. The recent identification of kisspeptin (Kiss1) and its G protein-coupled receptor (GPR)54 (Kiss1r) as an essential component of the HPG axis controlling gonadotrophin secretion raises the possibility that kisspeptin-Kiss1r signalling may play a critical role in the transduction of ghrelin-induced suppression of LH. Ovariectomised oestrogen-replaced rats were implanted with intravenous catheters and blood samples collected for detection of LH pulses prior to and after intravenous administration of ghrelin (3nM/250 microl) or saline (250 microl) during ad libitum feeding or after overnight fasting. Quantitative RT-PCR was used to determine Kiss1 and Kiss1r mRNA levels in brain punches of the key hypothalamic sites regulating gonadotrophin secretion, the medial preoptic area (mPOA) and arcuate nucleus (ARC), collected 6h following administration of ghrelin. Ghrelin significantly lowered LH pulse frequency in fed rats, an effect significantly enhanced by food deprivation. Fasting, ghrelin or their combination down-regulated Kiss1, without affecting Kiss1r, expression in the mPOA, and affected the expression of neither in the ARC. Considering the pivotal role for kisspeptin signalling in the activation of the HPG axis, the ability of ghrelin to down-regulate Kiss1 expression in mPOA may be a contributing factor in ghrelin-related suppression of pulsatile LH secretion.

  8. Testosterone regulates the secretion of thyrotrophin-releasing hormone (TRH) and TRH precursor in the rat hypothalamic-pituitary axis.

    PubMed

    Pekary, A E; Knoble, M; Garcia, N H; Bhasin, S; Hershman, J M

    1990-05-01

    Orchidectomy has been reported to decrease concentrations of thyrotrophin (TSH) in the circulation of male rats without affecting serum levels of thyroid hormones. To understand the mechanism underlying this observation, we have measured the effect of gonadal status on the in-vitro release of TSH-releasing hormone (TRH) by male rat hypothalamic fragments. Because hormone release rates can be affected by changes in the post-translational processing of the hormonal precursors, we have also studied the corresponding changes in the concentrations of TRH and TRH-Gly, a TRH precursor peptide in hypothalamus and pituitary, by radioimmunoassay. We observed a significant decline in the in-vitro release of TRH from incubated hypothalami 1 week after castration, which was quantitatively reversed by testosterone replacement. Concentrations of TRH and TRH-Gly in the posterior pituitary, on the other hand, which derive from neurones of hypothalamic origin, increased significantly with castration and were returned to the normal range by testosterone replacement. We conclude that the primary effect of testosterone is the stimulation of hypothalamic TRH release, resulting in the depletion of TRH and TRH precursors from TRH-containing neurones which project into the median eminence and posterior pituitary.

  9. [The effect of recombinant somatotropin hormone on the secretion of ovarian hormones in sexually mature swine in vivo and in vitro].

    PubMed

    Nitray, J; Sirotkin, A V; Poltársky, J; Bulla, J

    1993-01-01

    The development of recombinant somatotropic hormone (STH) creates a prerequisite for a wide application of exogenous stimulation of meat and milk performance of cows and pigs. Reproduction effect and its mechanism is till now restricted by a lack of complex information though there are several studies of principal character and basic effects of STH on reproduction process are also known. The result of some experimental studies, quoted in scientific literature, was a hypothesis that STH effect is accompanied by increased production of so-called insulin-like growth factors. Moreover, it is known that these factors have a steroidogenic effect. A hypothesis of STH action, just by means of insulin-like growth factors, was expressed on the basis of the above mentioned fact. Our study was aimed at the analysis of the effect of recombinant porcine somatotropic hormone (rpSTH, Research and Development, Pittman-Moore, Inc.; Terre Haute, Indiana, the U.S.A., LG-COMP-1776/93) on the dynamics of progesterone, cAMP, cGMP concentrations in the blood plasma of sexually mature gilts with surgically introduced permanent canula in v. jugularis. Gilts of early and medium follicular stages of the oestrous cycle (found laparoscopically) without any developmental or any other anomalies in reproductive organs. Blood samples were collected each 15 minutes in the period of 30 minutes before and 150 minutes after rpSTH application (5 mg per gilt). The control of gilts was administered 0.9% NaCl solution under the same conditions. Blood plasma samples collected and processed were stored not earlier than after radioimmunoassay of substances. A part of the study was to analyze different rpSTH doses (1-100,000 ng/ml) on granulosis cells on gilts' ovaries obtained after slaughtering of sexually mature gilts without any visible changes in the reproductive system. Granulosis cells were separated after aspiration of follicles of the size 2 to 5 mm without marked paleness, after thrice resuspending

  10. Experiment K-6-22. Growth hormone regulation, synthesis and secretion in microgravity. Part 1: Somatotroph physiology. Part 2: Immunohistochemical analysis of hypothalamic hormones. Part 3: Plasma analysis

    NASA Technical Reports Server (NTRS)

    Grindeland, R.; Vale, W.; Hymer, W.; Sawchenko, P.; Vasques, M.; Krasnov, I.; Kaplanski, A.; Victorov, I.

    1990-01-01

    The objectives of the 1887 mission were: (1) to determine if the results of the SL-3 pituitary gland experiment (1) were repeatable; and (2) to determine what effect a longer mission would have on the rat pituitary gland growth hormone (GH) system. In the 1887 experiment two issues were considered especially important. First, it was recognized that cells prepared from individual rat pituitary glands should be considered separately so that the data from the 5 glands could be analyzed in a statistically meaningful way. Second, results of the SL-3 flight involving the hollow fiber implant and HPLC GH-variant experiments suggested that the biological activity of the hormone had been negatively affected by flight. The results of the 1887 experiment documented the wisdom of addressing both issues in the protocol. Thus, the reduction in secretory capacity of flight cells during subsequent extended cell culture on Earth was documented statistically, and thereby established the validity of the SL-3 result. The results of both flight experiments thus support the contention that there is a secretory lesion in pituitary GH cells of flight animals. The primary objective of both missions was a clear definition of the effect of spaceflight on the GH cell system. There can no longer be any reasonable doubt that this system is affected in microgravity. One explanation for the reason(s) underlying the better known effects of spaceflight on organisms, viz. changes in bone, muscle and immune systems may very well rest with such changes in bGH. In spite of the fact that rats in the Cosmos 1887 flight were on Earth for two days after flight, the data show that the GH system had still not recovered from the effects of flight. Many questions remain. One of the more important concerns the GRF responsiveness of somatotrophs after flight. This will be tested in an upcoming experiment.

  11. Dynamic evaluation of growth hormone (GH) and prolactin (hPRL) secretion in active acromegaly with high and low GH output.

    PubMed

    Tolis, G; Kovacs, L; Friesen, H; Martin, J B

    1975-02-01

    Ten patients with active acromegaly were studied. In 9 plasma GH levels failed to suppress after glucose (OGTT), in 8 an increase in serum GH occurred after thyrotropin releasing hormone (TRH). After L-Dopa, 4 patients showed no change in serum GH, 3 exhibited a decrease and in 3 an increase in serum hGH occurred. With a combined insulin (ITT) and arginine (ATT) test, 2 patients exhibited an increase in hGH, and in 6 no change occurred. Fasting serum GH concentration was less than 11 ng/ml in 5 patients. Basal prolactin (hPRL) levels were normal in all patients including two with galactorrhea. L-Dopa suppressed and TRH stimulated hPRL secretion in all, but the responses which were seen were subnormal. Hydrocortisone infusion in two acromegalics did not affect the prolactin induced increase after TRH but blunted the GH increase after TRH.

  12. Prompt efficacy of tolvaptan in treating hyponatremia of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) closely associated with rupture of a gastric artery aneurysm.

    PubMed

    Yamashita, Takeshi; Yoshida, Masashi; Yamada, Hodaka; Asano, Tomoko; Aoki, Atsushi; Ikoma, Aki; Kusaka, Ikuyo; Kakei, Masafumi; Ishikawa, San-e

    2014-01-01

    A 78-year-old man with abdominal pain was diagnosed with a rupture of a gastric artery aneurysm. The serum Na level promptly decreased from 135 to 110 mmol/L within several days. Brain magnetic resonance angiography revealed severe vasoconstriction of the cerebral basilar artery and anterior cerebral artery. There was neither dehydration nor edema. The plasma arginine vasopressin level was 3.3 pg/mL, despite hypoosmolality. These findings indicated a diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) derived from severe vasoconstriction of the cerebral arteries. The administration of 7.5 mg of tolvaptan rapidly increased the serum Na level from 123 to 138 mmol/L within the first 24 hours, thereafter continuously maintaining a normal level. Treatment with tolvaptan corrected the patient's dilutional hyponatremia.

  13. The postweaning rise of tonic luteinizing hormone secretion in anestrous cows is not prevented by chronic milking or the physical presence of the calf.

    PubMed

    Williams, G L; Koziorowski, M; Osborn, R G; Kirsch, J D; Slanger, W D

    1987-06-01

    The objective of the following study was to examine the ability of frequent milking, the physical presence of the calf, and their combination to prevent a postweaning rise in tonic luteinizing hormone (LH) secretion, estrus, and ovulation. Thirty Hereford cows were allowed to suckle their calves ad libitum until 17-21 days post partum and confirmed as anestrus. They were then assigned alternately by order of calving to 1 of 5 treatment groups: (1) Suckled (S) ad libitum; (2) Nonsuckled (NS)--calf removed for 102 h; (3) Nonsuckled--calf present (NSC)--calf remained with cow, but muzzled to prevent suckling for 102 h; (4) Nonsuckled--milked 8 times a day (NSM)--calf removed for 102 h and cow hand-milked for 10 min every 2 h from 0700 to 2100 h; (5) Nonsuckled--calf present--milked 8 times a day (NSMC)--combination of 3 and 4. Luteinizing hormone secretion patterns, estrous activity, and ovulation were monitored throughout the experiment. Prior to treatment (Day 0), mean pulse frequency (pulses/6 h), mean concentrations (ng/ml), and median concentrations (ng/ml) of LH did not differ (p greater than 0.45) between groups, and were 0.7 +/- 0.15, 2.8 +/- 0.14, and 2.6 +/- 0.11, respectively. Marked rises (p less than 0.01--p less than 0.03) in LH pulse frequency were observed in all groups except S between 48 and 54 h after onset of treatment. Mean and median concentrations of LH were lower (p less than 0.02) in S cows than in all other groups at 48-54 h.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Estradiol regulation of luteinizing hormone secretion in heifers of two breed types that reach puberty at different ages.

    PubMed

    Rodrigues, H D; Kinder, J E; Fitzpatrick, L A

    2002-03-01

    The working hypothesis was that 17 beta-estradiol (E(2)) negative feedback on the hypothalamic-pituitary axis in regulation of LH secretion decreases during peripuberty in heifers of 2 different genotypes. We investigated whether Bos indicus heifers had a period postpuberty, as compared with prepuberty, of greater E(2) inhibition of LH secretion at a time when heifers of this genotype have been reported to have a period of anestrus. Prepubertal heifers 9 mo of age of 2 genotypes (B. indicus and B. taurus) were assigned to 3 groups (6 animals/group) to either remain intact (control), be ovariectomized, or be ovariectomized and implanted with E(2). Variables evaluated from 10 to 28 mo of age were circulating concentrations of progesterone (P(4)), presence of corpora lutea, and pulsatile pattern of LH release. Results confirmed that B. taurus heifers attained puberty at younger ages (P < 0.001) and at lower live weights (P = 0.015) than did B. indicus heifers (507 +/- 37 days of age vs. 678 +/- 7 days of age; 259 +/- 14 kg vs. 312 +/- 11 kg; respectively). There was cessation of E(2) inhibition of LH pulses coincident with the onset of puberty in heifers of both breed types but at a much younger age in B. taurus heifers. There was no evidence of enhanced negative feedback of E(2) on LH secretion subsequent to puberty in B. indicus heifers nor was there cessation of estrous cycles in control heifers of either breed type after puberty.

  15. Molecular cloning and characterization of two forms of trout growth hormone cDNA: expression and secretion of tGH-II by Escherichia coli.

    PubMed

    Rentier-Delrue, F; Swennen, D; Mercier, L; Lion, M; Benrubi, O; Martial, J A

    1989-03-01

    We constructed a cDNA library using mRNA isolated from rainbow trout pituitaries. Two types of cDNA clones encoding growth hormone (GH) were isolated and their complete nucleotide sequences determined. Twenty seven nucleotide substitutions in the coding region and 108 in the noncoding region distinguish the cDNAs of trout GH-I and II. Both cDNAs encode polypeptides of 210 amino acids, including a putative signal peptide of 22 amino acids, which differ by 12 residues. In both trout and salmon, GH-I mRNA is predominant, which suggests that the variation in the amount of secreted GH originates from a transcriptional event. Moreover, comparison of rainbow trout and chum salmon GH reveals that, in both cases, the predominant GH-I has mutated less than its GH-II counterpart. Mature tGH-II was expressed in Escherichia coli using the pIN-III-ompA-Hind secretion vector. PMID:2647438

  16. Effects of age and reproductive experience on the distribution of prolactin and growth hormone secreting cells in the anterior pituitary of a passerine.

    PubMed

    Christensen, Debora; Vleck, Carol M

    2015-10-01

    Plasma prolactin (PRL) is released from lactotrophs in the anterior pituitary. As plasma PRL levels rise during incubation in domestic fowl, the number of lactotrophs (PRL-immunoreactive, PRL-IR cells) increases while the number of growth hormone secreting cells, somatotrophs (GH-IR cells), declines. We measured plasma PRL levels using radioimmunoassay (RIA) and examined the distribution of lactotrophs and somatotrophs in the anterior pituitary of breeding and nonbreeding zebra finches of known ages with and without prior breeding experience using fluorescent immunohistochemistry (IHC). Plasma PRL levels were higher in breeding than in nonbreeding birds, regardless of age, sex, or previous breeding history. PRL-IR cells were localized primarily, but not exclusively, to the cephalic aspect of the anterior pituitary (AP) and along the ventral margin. Birds with prior reproductive experience had more PRL-IR cells than birds with no prior reproductive experience and breeders had slightly higher PRL-IR cell counts than did nonbreeders, but there was no correlation between the number of PRL-IR cells and plasma PRL levels. GH-IR cells were concentrated in the caudal aspect of the AP with some cells in the cephalic lobe, but numbers did not differ between any of the groups studied. An increase in PRL-IR cells corresponded with an increase in GH-IR cells. An increase in lactotroph number with reproductive experience in zebra finches may facilitate future reproductive events by allowing for more robust PRL secretion and increased reproductive success.

  17. Prazosin blocks the glutamatergic effects of N-methyl-D-aspartic acid on lordosis behavior and luteinizing hormone secretion in the estrogen-primed female rat.

    PubMed

    Landa, A I; Cabrera, R J; Gargiulo, P A

    2006-03-01

    We have observed that intracerebroventricular (icv) injection of selective N-methyl-D-aspartic acid (NMDA)-type glutamatergic receptor antagonists inhibits lordosis in ovariectomized (OVX), estrogen-primed rats receiving progesterone or luteinizing hormone-releasing hormone (LHRH). When NMDA was injected into OVX estrogen-primed rats, it induced a significant increase in lordosis. The interaction between LHRH and glutamate was previously explored by us and another groups. The noradrenergic systems have a functional role in the regulation of LHRH release. The purpose of the present study was to explore the interaction between glutamatergic and noradrenergic transmission. The action of prazosin, an alpha1- and alpha2b-noradrenergic antagonist, was studied here by injecting it icv (1.75 and 3.5 microg/6 microL) prior to NMDA administration (1 microg/2 microL) in OVX estrogen-primed Sprague-Dawley rats (240-270 g). Rats manually restrained were injected over a period of 2 min, and tested 1.5 h later. The enhancing effect induced by NMDA on the lordosis/mount ratio at high doses (67.06 +/- 3.28, N = 28) when compared to saline controls (6 and 2 microL, 16.59 +/- 3.20, N = 27) was abolished by prazosin administration (17.04 +/- 5.52, N = 17, and 9.33 +/- 3.21, N = 20, P < 0.001 for both doses). Plasma LH levels decreased significantly only with the higher dose of prazosin (1.99 +/- 0.24 ng/mL, N = 18, compared to saline-NMDA effect, 5.96 +/- 2.01 ng/mL, N = 13, P < 0.05). Behavioral effects seem to be more sensitive to the alpha-blockade than hormonal effects. These findings strongly suggest that the facilitatory effects of NMDA on both lordosis and LH secretion in this model are mediated by alpha-noradrenergic transmission.

  18. [Maintenance of the relation between the pulsed secretion of hormones and the internal sleep structure in human African trypanosomiasis].

    PubMed

    Brandenberger, G; Buguet, A; Spiegel, K; Stanghellini, A; Mouanga, G; Bogui, P; Montmayeur, A; Dumas, M

    1994-01-01

    In order to determine whether sleep disturbances would affect the hormonal patterns and the normal relationships between hormone pulses and sleep stages, the 24-hour profiles of cortisol, prolactin and plasma renin activity (PRA) were analysed in 6 sleeping sickness patients studied at Brazzaville and in 5 healthy African controls studied in Abidjan. Polysomnographic recordings were done continuously and blood was taken every 10 minutes throughout the 24-hour period. Plasma was analyzed for cortisol, prolactin and PRA. The circadian rhythm of cortisol, considered as an example of an endogenous rhythm was attenuated in all the patients but one, but as in normal subjects, slow wave sleep (SWS) remained associated with the declining phases of the secretory episodes. Prolactin and PRA profiles, which are strongly influenced by the sleep-wake cycle did not show the increase normally associated with long sleep periods and reflected the spreading of sleep and wakefulness throughout the 24-hour period. However, rapid-eye movement (REM) sleep began in sleeping sickness patients, as in normal subjects, during the descending phases of prolactin pulses. In both groups, PRA reflected the sleep stage distribution with non rapid-eye movement (NREM) sleep occurring during the ascending phases and REM sleep during the descending phases of the oscillations. However, in sleeping sickness patients, the marked sleep fragmentation often did not allow sufficient time for PRA to increase significantly, as observed with regular NREM-REM sleep cycles. These results demonstrate that, together with the disruption of the sleep-wake cycle, there are profound differences in the temporal organization of the 24 hour hormone profiles in human African trypanosomiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. An investigation into pituitary gonadotrophic hormone synthesis, secretion, subunit gene expression and cell structure in normal and mutant male mice.

    PubMed

    Abel, M H; Charlton, H M; Huhtaniemi, I; Pakarinen, P; Kumar, T R; Christian, H C

    2013-10-01

    To investigate brain-pituitary-gonadal inter-relationships, we have compared the effects of mutations that perturb the hypothalamic-pituitary-gonadal axis in male mice. Specifically, serum and pituitary gonadotrophin concentrations, gonadotrophin gene expression, and gonadotroph structure and number were measured. Follicle-stimulating hormone (FSH)β knockout (FSHβKO), FSH receptor knockout (FSHRKO), luteinising hormone (LH) receptor knockout (LuRKO), hypogonadal (hpg), testicular feminised (tfm) and gonadectomised mice were compared with control wild-type mice or heterozygotes. Serum levels of LH were similar in FSHβKO, FSHRKO and heterozygote males despite decreased androgen production in KO males. As expected, there was no detectable FSH in the serum or pituitary and an absence of expression of the FSHβ subunit gene in FSHβKO mice. However, there was a significant increase in expression of the common α and LHβ subunit genes in FSHRKO males. The morphology of FSHβKO and FSHRKO gonadotrophs was not significantly different from controls, except that the subpopulation of granules consisting of an electron-dense core and electron-lucent 'halo' was not observed in FSHβKO gonadotrophs and the granules were smaller in diameter. In the gonadotrophin-releasing hormone deficient hpg mouse, gonadotrophin mRNA and hormone levels were significantly lower compared to control mice and gonadotrophs were correspondingly smaller, with less abundant endoplasmic reticulum and reduced secretory granules. In LuRKO, tfm and gonadectomised mice, hyperstimulation of LHβ and FSHβ mRNA and serum protein concentrations was reflected by subcellular changes in gonadotroph morphology, including more dilated rough endoplasmic reticulum and more secretory granules distributed adjacent to the plasma membrane. In summary, major differences in pituitary content and serum concentrations of the gonadotrophins LH and FSH have been found between normal and mutant male mice. These changes are

  20. The differential effects of exposure to tobacco smoke on the secretion of luteinizing hormone and prolactin in the proestrous rat.

    PubMed

    McLean, B K; Rubel, A; Nikitovitch-Winer, M B

    1977-06-01

    The acute effects of tobacco smoke inhalation on the spontaneous proestrous rise in serum luteinizing hormone and prolactin have been investigated in the female Wistar rat. It was found that the surge of LH normally seen throughout the afternoon of proestrus was delayed by inhalation of tobacco smoke and that the delay was dose-related to the nicotine content of the cigarettes used in the experiment. In the case of prolactin neither the timing nor the magnitude of the surge was altered when compared with controls. These results suggest that under certain well-defined conditions inhalation of tobacco smoke of known nicotine content is capable of exerting profound influences on the hypothalamic-pituitary-gonadal axis.

  1. Gut hormone secretion, gastric emptying, and glycemic responses to erythritol and xylitol in lean and obese subjects.

    PubMed

    Wölnerhanssen, Bettina K; Cajacob, Lucian; Keller, Nino; Doody, Alison; Rehfeld, Jens F; Drewe, Juergen; Peterli, Ralph; Beglinger, Christoph; Meyer-Gerspach, Anne Christin

    2016-06-01

    With the increasing prevalence of obesity and a possible association with increasing sucrose consumption, nonnutritive sweeteners are gaining popularity. Given that some studies indicate that artificial sweeteners might have adverse effects, alternative solutions are sought. Xylitol and erythritol have been known for a long time and their beneficial effects on caries prevention and potential health benefits in diabetic patients have been demonstrated in several studies. Glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) are released from the gut in response to food intake, promote satiation, reduce gastric emptying (GE), and modulate glucose homeostasis. Although glucose ingestion stimulates sweet taste receptors in the gut and leads to incretin and gastrointestinal hormone release, the effects of xylitol and erythritol have not been well studied. Ten lean and 10 obese volunteers were given 75 g of glucose, 50 g of xylitol, or 75 g of erythritol in 300 ml of water or placebo (water) by a nasogastric tube. We examined plasma glucose, insulin, active GLP-1, CCK, and GE with a [(13)C]sodium acetate breath test and assessed subjective feelings of satiation. Xylitol and erythritol led to a marked increase in CCK and GLP-1, whereas insulin and plasma glucose were not (erythritol) or only slightly (xylitol) affected. Both xylitol and erythritol induced a significant retardation in GE. Subjective feelings of appetite were not significantly different after carbohydrate intake compared with placebo. In conclusion, acute ingestion of erythritol and xylitol stimulates gut hormone release and slows down gastric emptying, whereas there is no or only little effect on insulin release. PMID:27117004

  2. Curcumin (Diferuloylmethane) Inhibits Cell Proliferation, Induces Apoptosis, and Decreases Hormone Levels and Secretion in Pituitary Tumor Cells

    PubMed Central

    Miller, Matthew; Chen, Shenglin; Woodliff, Jeffrey; Kansra, Sanjay

    2008-01-01

    Prolactinomas are the most prevalent functional pituitary adenomas. Dopamine D2 receptor (D2R) agonists, such as bromocriptine are the first line of therapy; however, drug intolerance/resistance to D2R agonists exists. Apart from D2R agonists, there is no established medical therapy for prolactinomas; therefore, identifying novel therapeutics is warranted. Curcumin, a commonly used food additive in South Asian cooking, inhibits proliferation of several tumor cell lines; however, its effect on pituitary tumor cell proliferation has not been determined. Our objectives were to: 1) determine whether curcumin inhibits proliferation of pituitary tumor cell lines; 2) identify the signaling intermediaries that mediate the effect of curcumin; 3) examine whether curcumin inhibited pituitary hormone production and release; and 4) examine whether curcumin could enhance the growth-inhibitory effect of bromocriptine. Using rat lactotroph cell lines, GH3 and MMQ cells, we report that curcumin had a robust dose and time-dependent inhibitory effect on GH3 and MMQ cell proliferation. Inhibitory effects of curcumin persisted, even on removal of curcumin, and curcumin also blocked colony formation ability of pituitary tumor cells. The growth-inhibitory effect of curcumin was accompanied by decreased expression of cyclin D3 and ser 780 phosphorylation of retinoblastoma protein. In addition, curcumin also induced apoptosis in both GH3 and MMQ cells. Furthermore, curcumin suppresses intracellular levels and release of both prolactin and GH. Finally, we show that low concentrations of curcumin enhanced the growth-inhibitory effect of bromocriptine on MMQ cell proliferation. Taken together we demonstrate that curcumin inhibits pituitary tumor cell proliferation, induces apoptosis, and decreases hormone production and release, and thus, we propose developing curcumin as a novel therapeutic tool in the management of prolactinomas. PMID:18450960

  3. Curcumin (diferuloylmethane) inhibits cell proliferation, induces apoptosis, and decreases hormone levels and secretion in pituitary tumor cells.

    PubMed

    Miller, Matthew; Chen, Shenglin; Woodliff, Jeffrey; Kansra, Sanjay

    2008-08-01

    Prolactinomas are the most prevalent functional pituitary adenomas. Dopamine D2 receptor (D2R) agonists, such as bromocriptine are the first line of therapy; however, drug intolerance/resistance to D2R agonists exists. Apart from D2R agonists, there is no established medical therapy for prolactinomas; therefore, identifying novel therapeutics is warranted. Curcumin, a commonly used food additive in South Asian cooking, inhibits proliferation of several tumor cell lines; however, its effect on pituitary tumor cell proliferation has not been determined. Our objectives were to: 1) determine whether curcumin inhibits proliferation of pituitary tumor cell lines; 2) identify the signaling intermediaries that mediate the effect of curcumin; 3) examine whether curcumin inhibited pituitary hormone production and release; and 4) examine whether curcumin could enhance the growth-inhibitory effect of bromocriptine. Using rat lactotroph cell lines, GH3 and MMQ cells, we report that curcumin had a robust dose and time-dependent inhibitory effect on GH3 and MMQ cell proliferation. Inhibitory effects of curcumin persisted, even on removal of curcumin, and curcumin also blocked colony formation ability of pituitary tumor cells. The growth-inhibitory effect of curcumin was accompanied by decreased expression of cyclin D3 and ser 780 phosphorylation of retinoblastoma protein. In addition, curcumin also induced apoptosis in both GH3 and MMQ cells. Furthermore, curcumin suppresses intracellular levels and release of both prolactin and GH. Finally, we show that low concentrations of curcumin enhanced the growth-inhibitory effect of bromocriptine on MMQ cell proliferation. Taken together we demonstrate that curcumin inhibits pituitary tumor cell proliferation, induces apoptosis, and decreases hormone production and release, and thus, we propose developing curcumin as a novel therapeutic tool in the management of prolactinomas.

  4. Gut hormone secretion, gastric emptying, and glycemic responses to erythritol and xylitol in lean and obese subjects.

    PubMed

    Wölnerhanssen, Bettina K; Cajacob, Lucian; Keller, Nino; Doody, Alison; Rehfeld, Jens F; Drewe, Juergen; Peterli, Ralph; Beglinger, Christoph; Meyer-Gerspach, Anne Christin

    2016-06-01

    With the increasing prevalence of obesity and a possible association with increasing sucrose consumption, nonnutritive sweeteners are gaining popularity. Given that some studies indicate that artificial sweeteners might have adverse effects, alternative solutions are sought. Xylitol and erythritol have been known for a long time and their beneficial effects on caries prevention and potential health benefits in diabetic patients have been demonstrated in several studies. Glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) are released from the gut in response to food intake, promote satiation, reduce gastric emptying (GE), and modulate glucose homeostasis. Although glucose ingestion stimulates sweet taste receptors in the gut and leads to incretin and gastrointestinal hormone release, the effects of xylitol and erythritol have not been well studied. Ten lean and 10 obese volunteers were given 75 g of glucose, 50 g of xylitol, or 75 g of erythritol in 300 ml of water or placebo (water) by a nasogastric tube. We examined plasma glucose, insulin, active GLP-1, CCK, and GE with a [(13)C]sodium acetate breath test and assessed subjective feelings of satiation. Xylitol and erythritol led to a marked increase in CCK and GLP-1, whereas insulin and plasma glucose were not (erythritol) or only slightly (xylitol) affected. Both xylitol and erythritol induced a significant retardation in GE. Subjective feelings of appetite were not significantly different after carbohydrate intake compared with placebo. In conclusion, acute ingestion of erythritol and xylitol stimulates gut hormone release and slows down gastric emptying, whereas there is no or only little effect on insulin release.

  5. Effects of adrenocorticotropic hormone and flunixin meglumine on pregnancy retention in beef cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pregnancy loss in beef cattle after d 28 of gestation is variable, but has been reported to be as high as 14% and has been related to transportation or handling stress. The objective of this study was to determine effects of ACTH administration on mimicking a stress response and whether this respon...

  6. A rare cause of Cushing's syndrome: an ACTH-secreting phaeochromocytoma

    PubMed Central

    Folkestad, Lars; Andersen, Marianne Skovsager; Nielsen, Anne Lerberg; Glintborg, Dorte

    2014-01-01

    Excess glucocorticoid levels cause Cushing's syndrome (CS) and may be due to pituitary, adrenal or ectopic tumours. Adrenocorticotropic hormone (ACTH) levels are useful in identifying adrenal tumours. In rare cases, ACTH-producing phaeochromocytomas are the cause of CS. We present two cases of ACTH-secreting phaeochromocytoma as the underlying cause of CS. In both cases, female patients presented with the classical clinical signs of CS and an adrenal mass. High ACTH levels raised the suspicion of an ACTH-secreting phaeochromocytoma. The diagnosis was confirmed by urinary catecholamine levels and positive fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) CT (Case 1) and fluorodeoxyglucose PET-CT (Case 2). Both patients were treated with an α-blocker prior to surgical intervention. The two cases underline the importance of thorough diagnostic workup in patients with CS. An ACTH-secreting phaeochromocytoma should be checked for in patients with an adrenal mass and elevated ACTH levels. PMID:25297883

  7. Cerebrospinal fluid immunoreactive corticotropin-releasing hormone and adrenocorticotropin secretion in Cushing's disease and major depression: potential clinical implications.

    PubMed

    Kling, M A; Roy, A; Doran, A R; Calabrese, J R; Rubinow, D R; Whitfield, H J; May, C; Post, R M; Chrousos, G P; Gold, P W

    1991-02-01

    To explore whether possible differences in central nervous system neuromodulators contribute to the differential presentation of affective symptomatology in Cushing's disease and major depression, we examined the levels of immunoreactive CRH and ACTH in the cerebrospinal fluid (CSF) of 11 patients with Cushing's disease, a patient with ectopic ACTH secretion, 34 patients with major depression, and 60 healthy subjects. We elected to measure these peptides not only because both are classically involved in pituitary-adrenal regulation, but also because their primarily arousal-producing and anorexigenic behavioral effects in experimental animals suggest that they may play a role in the symptom complex of depressive syndromes. We also explored whether the CSF levels of these peptides were more helpful in determining the often difficult differential diagnosis between major depression and Cushing's disease than the plasma ACTH response to ovine CRH, a currently used but somewhat insensitive laboratory means of distinguishing these disorders. CSF levels of immunoreactive CRH and ACTH were significantly lower in Cushing's disease patients [21.9 +/- 2.7 and 15.4 +/- 1.8 pg/mL, (mean +/- SEM), respectively] compared to patients with major depression [38.4 +/- 2.3 pg/mL (P less than 0.01) and 24.5 +/- 1.6 pg/mL (P less than 0.01), respectively] and controls [38.4 +/- 1.6 pg/mL (P less than 0.001) and 26.3 +/- 1.1 pg/mL (P less than 0.001), respectively]. The coexistence of high plasma ACTH and low CSF ACTH in Cushing's disease yielded a CSF/plasma ACTH ratio consistently less than that in depressed patients, with only 2 of 31 subjects comprising both groups showing values that overlapped. In contrast, 9 of the combined patients showed ACTH responses to ovine CRH that overlapped. These data suggest that differences in centrally directed CRH secretion may account for the differential presentation of the dysphoric syndromes seen in major depression and Cushing's disease. Hence

  8. Effect of anordiol on ovarian hormone secretion, ovulation, and uterine and vaginal responses in the immature rat.

    PubMed

    Lu, Y C; Chatterton, R T

    1994-06-01

    The purpose of this investigation was to determine the estrogenic and antiestrogenic activities of the potential contraceptive agent anordiol in the immature rat. A dose of 2.45 mumol of anordiol (AD), estradiol (E2), clomiphene citrate (CC), tamoxifen (TA), or the vehicle alone was administered to rats on the 25th and 29th days of age. Serum hormones were measured between 16:00 and 17:00 on days 30, 31, and 32; organ weights were determined on day 32. Anordiol and estradiol treatments significantly increased ovarian and uterine weight and serum LH concentrations, but CC and TA had no effect on these parameters. Vaginal cornification occurred before day 32 in all rats receiving anordiol or estradiol and in 3/5 and 4/5 rats receiving CC and TA, respectively, but not in control rats. Based on serum progesterone levels, ovulation was induced only in rats receiving anordiol or estradiol. All of the compounds tested significantly increased serum testosterone above levels in control animals, but both AD and E2 induced ovulation without a further increase in serum testosterone. We conclude that in the immature rat anordiol produces estrogenic responses in the vagina, uterus and in the hypothalamic-pituitary-ovarian axis, whereas TA and CC are estrogenic only on the vaginal and uterine epithelium.

  9. Seasonal differences in the secretion of luteinising hormone and prolactin in response to N-methyl-DL-aspartate in starlings (Sturnus vulgaris).

    PubMed

    Dawson, A

    2005-02-01

    In birds, unlike mammals, seasonal changes in reproductive function are associated with marked changes in the amount of gonadotrophin-releasing hormone (GnRH) stored in the hypothalamus. Prolonged exposure to long photoperiods leads to photorefractoriness after the breeding season. Photorefractory birds have low hypothalamic concentrations of chicken GnRH-I (cGnRH-I). Exposure to short photoperiods results in renewed cGnRH-I synthesis and increased hypothalamic stores. Birds are then photosensitive and subsequent exposure to an increase in photoperiod results in increased cGnRH-I secretion and gonadal maturation. However, it is unclear whether the reverse is true at the time of gonadal regression during long photoperiods (i.e. that a decrease in GnRH-I synthesis precedes regression). Hypothalamic stores of cGnRH-I, and possibly therefore of releasable GnRH-I, decrease after regression. Single injections of the glutamate agonist N-methyl-DL-aspartate (NMA) were used as a probe to assess releasable stores of cGnRH-I in male starlings at four physiologically different reproductive stages. Treatment induced the greatest increase in luteinising hormone (LH) in photosensitive birds in January, and a slight increase in sexually mature birds in April. There was a slight but significant increase in June, immediately after testicular regression, but no increase in fully photorefractory birds in September. These data confirm that photorefractoriness is associated with a lack of releasable cGnRH-I, but that decreased synthesis of cGnRH-I is not the proximate cause of regression. There was an increase in prolactin in response to NMA at all times. The magnitude of the response was proportional to pre-treatment concentrations, with the greatest response in June. It is suggested that high circulating prolactin may fine-tune the timing of gonadal regression in advance of the inhibition of cGnRH-I synthesis. PMID:15796761

  10. Development of tolerance to the effects of morphine on luteinizing hormone secretion as a function of castration in the male rat.

    PubMed

    Cicero, T J; Meyer, E R; Schmoeker, P F

    1982-12-01

    The effects of morphine on the secretion of luteinizing hormone (LH) were examined in male rats at intervals after castration. We found that morphine was extremely effective in suppressing serum LH levels in animals that had been castrated for periods of less than 7 days, but was considerably less potent in long-term castrates (13 + days). For example, the dose of morphine producing the half-maximal suppression of serum LH levels in 3-day castrates was 1.5 mg/kg, whereas in 31-day castrates the ED50 was 13.8 mg/kg. This insensitivity to morphine satisfied the two pharmacological criteria for tolerance: a parallel shift to the right in the morphine dose-response curve and a reduced effect of the drug at the same brain concentration. Hence, castration appeared to render male rats, never exposed to opiates, tolerant to the effects of morphine. Corresponding to the development of tolerance to morphine, 31-day castrates were also less responsive to the LH-depressing effects of testosterone than were 3-day castrates or sham-operated controls. In marked contrast to these results, castration did not significantly affect naloxone-induced increases in serum LH levels. The tolerance observed to morphine in the long-term castrated rat was selective to LH secretion because long- and short-term castrates and sham-operated controls were equally responsive to the antinociceptive effects of morphine (in fact, at a dose of 8 mg/kg long-term castrates were more sensitive to morphine than short-term castrates or sham-operated controls) and there was no apparent shift in the LD50. The mechanisms underlying the development of tolerance to morphine in castrated male rats are not clear at the present time. PMID:7143239

  11. Growth hormone-secreting macroadenoma of the pituitary gland successfully treated with the radiolabeled somatostatin analog (90)Y-DOTATATE: case report.

    PubMed

    Waligórska-Stachura, Joanna; Gut, Paweł; Sawicka-Gutaj, Nadia; Liebert, Włodzimierz; Gryczyńska, Maria; Baszko-Błaszyk, Daria; Blanco-Gangoo, Al Ricardo; Ruchała, Marek

    2016-08-01

    Pituitary tumors causing acromegaly are usually macroadenomas at the time of diagnosis, and they can grow aggressively, infiltrating surrounding tissues. Difficulty in achieving complete tumor removal at surgery can lead toward a strong tendency for recurrence, making it necessary to consider a means of treatment other than those currently used such as somatostatin analogs (SSAs), growth hormone (GH) receptor antagonist, surgical removal, and radiotherapy. The purpose of this paper is to describe a patient diagnosed with an aggressive, giant GH-secreting tumor refractory to medical therapy but ultimately treated with the radiolabeled somatostatin analog (90)Y-DOTATATE. A 26-year-old male with an invasive macroadenoma of the pituitary gland (5.6 × 2.5 × 3.6 cm) and biochemically confirmed acromegaly underwent 2 partial tumor resections: the first used the transsphenoidal approach and the second used the transcranial method. The patient received SSAs pre- and postoperatively. Because of the progression in pituitary tumor size, he underwent classic irradiation of the tumor (50 Gy). One and a half years later, the patient presented with clinically and biochemically active disease, and the tumor size was still 52 mm in diameter (height). Two neurosurgeons disqualified him from further surgical procedures. After confirming the presence of somatostatin receptors in the pituitary tumor by using (68)Ga-DOTATATE PET/CT, we treated the patient 4 times with an SSA bound with (90)Y-DOTATATE. After this treatment, the patient attained partial biochemical remission and a reduction in the tumor mass for the first time. Treatment with an SSA bound with (90)Y-DOTATATE may be a promising option for some aggressive GH-secreting pituitary adenomas when other methods have failed. PMID:26636388

  12. Secretion of anti-Müllerian hormone in the Florida manatee Trichechus manatus latirostris, with implications for assessing conservation status

    USGS Publications Warehouse

    Wilson, Rhian C.; Reynolds, John E.; Wetzel, Dana L.; Schwierzke-Wade, Leslie; Bonde, Robert K.; Breuel, Kevin F.; Roudebush, William E.

    2011-01-01

    Environmental and anthropogenic stressors can affect wildlife populations in a number of ways. For marine mammals (e.g. the Florida manatee Trichechus manatus latirostris), certain stressors or conservation risk factors have been identified, but sublethal effects have been very difficult to assess using traditional methods. The development of 'biomarkers' allows us to correlate effects, such as impaired reproduction, with possible causes. A recently developed biomarker (anti-Müllerian hormone, AMH) provides an enzyme-linked immunosorbent assay of gonadal function. The study objective was to determine AMH levels in wild manatees. In total, 28 male and 17 female manatee serum samples were assayed. Animal demographics included collection date, body weight (kg) and total length (cm). In certain cases, age of individuals was also known. AMH levels ranged from 160 to 2451.85 ng ml-1 (mean = 844.65 ng ml-1) in males and 0.00 to 0.38 ng ml-1 (mean = 0.10 ng ml-1) in females. Linear regression analyses revealed a significant relationship between male AMH levels and body weight (R2 = 0.452; p 2 = 0.338; p < 0.001). Due to the small sample size, regression analyses for female AMH and body weight and length were not significant. This represents the first report of AMH detection in a marine mammal. AMH levels in male manatees are the highest of any species observed to date, whereas levels in females are within reported ranges. Further studies will promote improved conservation decision by assessing AMH levels in the manatee as a function of various stressors including, but not limited to, nutritional status, serious injuries (e.g. watercraft collisions), exposure to biotoxins or contaminants, or disease.

  13. Role of endogenous opiates in the expression of negative feedback actions of androgen and estrogen on pulsatile properties of luteinizing hormone secretion in man.

    PubMed

    Veldhuis, J D; Rogol, A D; Samojlik, E; Ertel, N H

    1984-07-01

    We have tested the participation of endogenous opiate pathways in the negative feedback actions of gonadal steroids on pulsatile properties of luteinizing (LH) hormone release in normal men. To this end, sex steroid hormones were infused intravenously at dosages that under steady state conditions selectively suppressed either the frequency or the amplitude of the pulsatile LH signal. The properties of pulsatile LH secretion were assessed quantitatively by computerized analysis of LH series derived from serial blood sampling over 12 h of observation. When the pure (nonaromatizable) androgen, 5-alpha-dihydrotestosterone, was infused continuously for 108 h at the blood production rate of testosterone, we were able to achieve selective inhibition of LH pulse frequency akin to that observed in experimental animals after low-dosage androgen replacement. Under these conditions, serum concentrations of testosterone and estradiol-17 beta did not change significantly, but serum 5 alpha-dihydrotestosterone concentrations increased approximately two- to threefold, with a corresponding increase in levels of its major metabolite, 5 alpha-androstan-3 alpha, 17 beta-diol. In separate experiments, the infusion of estradiol-17 beta at its blood production rate over a 4.5-d interval selectively suppressed LH pulse amplitude without influencing LH pulse frequency. Estrogen infusion increased serum estradiol-17 beta levels approximately twofold without significantly altering blood androgen concentrations. We then used these schedules of selective androgen or estrogen infusion to investigate the participation of endogenous opiates in the individual inhibitory feedback actions of pure androgen or estrogen on pulsatile LH release by administering a potent and specific opiate-receptor antagonist, naltrexone, during the infusions. Our observations indicate that, despite the continuous infusion of a dosage of 5 alpha-dihydrotestosterone that significantly suppresses LH pulse frequency, co

  14. Sexual differentiation of the mechanism controlling pulsatile secretion of luteinizing hormone contributes to sexual differences in the timing of puberty in sheep.

    PubMed

    Claypool, L E; Foster, D L

    1990-02-01

    Sexual differences in the regulation of tonic luteinizing hormone (LH) secretion were examined in immature female and male sheep (eight each, including six pairs of female/male twins). After gonadectomy of lambs at 2 weeks of age, Silastic capsules filled with estradiol, a primary central feedback steroid in both females and males, were implanted every 3 weeks for 3 days, and then removed, so that the pattern of LH secretion could be repeatedly determined in the same individuals both with and without steroid feedback. Implanted capsules yielded circulating steroid levels of 2-5 pg/ml. Circulating LH concentrations were determined by radioimmunoassay in blood samples collected at 12-min intervals for 4 h immediately before estradiol was implanted, and again, immediately before it was removed 3 days later. In male lambs, a decrease in responsiveness of the hypothalamic-pituitary axis to inhibition by estradiol began at 8-11 weeks, as evidenced by the progressive increase in mean LH concentrations and frequency of LH pulses. This correlated temporally with the onset of spermatogenesis in intact male controls (n = 8). In females, a similar decrease in responsiveness did not occur until 26-29 weeks of age, corresponding to the onset of ovulatory cycles in intact female controls (n = 6). In the absence of estradiol implants, LH pulse frequencies were higher in male lambs than in female lambs between 5 and 35 weeks of age. There was no further increase in LH pulse frequency in the absence of the gonads in either sex during the pubertal period. These findings suggest that the mechanism regulating tonic LH secretion in developing lambs is sexually differentiated in its responsiveness to inhibition by estradiol. This differentiation also occurs at a more fundamental steroid-independent level, but any causal relationship between the higher steroid-independent LH pulse frequency and the lower responsiveness to estradiol negative feedback in males is not evident. We hypothesize

  15. T-2 toxin regulates steroid hormone secretion of rat ovarian granulosa cells through cAMP-PKA pathway.

    PubMed

    Wu, Jing; Tu, Di; Yuan, Li-Yun; Yi, Jin-e; Tian, Yanan

    2015-02-01

    T-2 toxin is a secondary metabolite produced by Fusarium genus and is a common contaminant in food and feedstuffs of cereal origin. In porcine granulosa cells(GC), T-2 toxin has been shown to inhibit the steroidogenesis; however, the mechanism has not been well understood. Gonadotropin-stimulated steroidogenesis is regulated by the cAMP-PKA pathway. In this study, we investigated potential mechanisms for T-2 toxin-induced reproductive toxicity focusing on the critical steps of the cAMP-PKA pathway affected by T-2 toxin. We first analyzed the effects of T-2 toxin on progesterone and estrogen production in rat granulosa cells. For this purpose the granulosa cells were cultured for 48 h in 10% fetal bovine serum-containing medium followed by 24h in serum-free medium containing FSH (10 ng/ml) and androstenedione (3 ng/ml), both are required for normal steroidogenesis. Treatment of these cells with T-2 toxin dose-dependently inhibited the growth of cells and the steroid hormone production. Cellular cyclic AMP levels were dose-dependently inhibited by T-2 toxin (0, 1, 10 and 100 nM, 24 h). Furthermore, we found that although the induction of progesterone by 8-Br-cAMP (a FSH mimetic) and 22R-HC (substrate for progesterone) could both be inhibited by T-2 toxin treatment, the T-2-imposed inhibitory effects could be reversed by increasing doses of 22R-HC, while increasing 8-Br-cAMP had no effects, suggesting that T2 toxin targeted at distinct mechanisms. cAMP-stimulated steroidogenic acute regulatory protein (StAR) is a rate limiting protein in progesterone synthesis. Exposure to T2 toxin caused significant suppression of StAR expression as determined by Western blotting and semi-quantitative RT-PCR suggesting StAR is a sensitive target for T-2 toxin. Taken together, our results strongly suggest that T2 toxin inhibits steroidogenesis by suppressing cAMP-PKA pathway and StAR is a target for T-2-toxin. The antisteroidogenesis effects were observable at low T-2 dose (1 ng

  16. Ambient temperature effects on photo induced gonadal cycles and hormonal secretion patterns in Great Tits from three different breeding latitudes.

    PubMed

    Silverin, Bengt; Wingfield, John; Stokkan, Karl-Arne; Massa, Renato; Järvinen, Antero; Andersson, Nils-Ake; Lambrechts, Marcel; Sorace, Alberto; Blomqvist, Donald

    2008-06-01

    The present study determines how populations of Great Tits (Parus major) breeding in southern, mid and northern European latitudes have adjusted their reproductive endocrinology to differences in the ambient temperature during the gonadal cycle. A study based on long-term breeding data, using the Colwell predictability model, showed that the start of the breeding season has a high predictability ( approximately 0.8-0.9) at all latitudes, and that the environmental information factor (I(e)) progressively decreased from mid Italy (I(e)>4) to northern Finland (I(e)<1). The results indicate that integration of supplementary information, such as ambient temperature, with photoperiodic initial predictive information (day length), becomes progressively more important in maintaining the predictability of the breeding season with decreasing latitude. This hypothesis was verified by exposing photosensitive Great Tits from northern Norway, southern Sweden and northern Italy to sub-maximal photo-stimulatory day lengths (13L:11D) under two different ambient temperature regimes (+4 degrees C and +20 degrees C). Changes in testicular size, plasma levels of LH and testosterone were measured. The main results were: (1) Initial testicular growth rate, as well as LH secretion, was affected by temperature in the Italian, but not in birds from the two Scandinavian populations. (2) Maximum testicular size, maximum LH and testosterone levels were maintained for a progressively shorter period of time with increasing latitude, regardless of whether the birds were kept on a low or a high ambient temperature. (3) In birds from all latitudes, the development of photorefractoriness, as indicated by testicular regression and a decrease in plasma levels of LH and testosterone, started much earlier (with the exception for LH Great Tits from northern Scandinavia) when kept on +20 degrees C than when kept on +4 degrees C. The prolonging effects of a low temperature was more pronounced in

  17. Hypothesis: Musculin is a hormone secreted by skeletal muscle, the body's largest endocrine organ. Evidence for actions on the endocrine pancreas to restrain the beta-cell mass and to inhibit insulin secretion and on the hypothalamus to co-ordinate the neuroendocrine and appetite responses to exercise.

    PubMed

    Engler, Dennis

    2007-01-01

    Recent studies indicate that skeletal muscle may act as an endocrine organ by secreting interleukin-6 (IL-6) into the systemic circulation. From an analysis of the actions of IL-6 and of additional literature, we postulate that skeletal muscle also secretes an unidentified hormone, which we have named Musculin (Latin: musculus = muscle), which acts on the pancreatic beta-cell to restrain the size of the (beta-cell mass and to tonically inhibit insulin secretion and biosynthesis. It is suggested that the amount of Musculin secreted is determined by, and is positively correlated with, the prevailing insulin sensitivity of skeletal muscle, thereby accounting for the hyperinsulinemia that occurs in insulin resistant disorders such as type 2 diabetes mellitus, obesity, and the polycystic ovary syndrome. In addition, it is postulated that Musculin acts on the hypothalamus (arcuate nucleus, dorsomedial hypothalamic nucleus) to co-ordinate the neuroendocrine and appetite responses to exercise. However, the possibilities that Musculin may act on additional central nervous system sites and that an additional hormone(s) may be responsible for these actions are not excluded. It is suggested that a search be made for Musculin, since analogues of such a substance may be of therapeutic benefit in the treatment of the current global diabetes and obesity epidemic.

  18. Diurnal secretion of ghrelin, growth hormone, insulin binding proteins, and prolactin in normal weight and overweight subjects with and without the night eating syndrome.

    PubMed

    Birketvedt, Grethe S; Geliebter, Allan; Kristiansen, Ingrid; Firgenschau, Yngve; Goll, Rasmus; Florholmen, Jon R

    2012-12-01

    The regulatory peptide ghrelin has been proposed to help mediate both hunger and sleep. The neuroendocrine circadian patterns in the night eating syndrome (NES) have been distinguished by an attenuated nocturnal rise in the plasma concentrations of melatonin and leptin and a greater increase in the concentrations of cortisol. In this study we wanted to test the hypothesis that night eaters have disturbances in the circadian levels of ghrelin, growth hormone (GH) and associated regulatory peptides. In 12 female night eaters (6 normal weight and 6 overweight), and 25 healthy controls (12 normal weight and 13 overweight), blood was sampled over a 24-hour period. Four meals were served from 8 AM to 8 PM, and blood samples were drawn every second hour for determination of plasma ghrelin concentrations and GH by radioimmunoassay (RIA). Analysis of serum GH, IGF-1, IGFBP-3 and prolactin were performed by ELISA. In healthy normal weight subjects there was a slight but non significant nocturnal increase of ghrelin, whereas a more or less flat curve was observed for healthy overweight, NES normal weight and NES overweight patients. The RMANOVA analysis showed a significant independent lowering effect of overweight on the grand mean of ghrelin. No direct effects on NES normal weight and overweight subjects were found, but a near-significant interaction was found between healthy overweight and overweight NES subjects. There were independent significant lowering effects of overweight and NES on the serum GH levels. During the time course no changes in the serum levels of IGF-1 or IGFB-3 were observed. Independent significant lowering effects of overweight and NES on the levels of IGF-1 were detected, whereas a near significant reduction in the global levels of IGFBP-3 was observed in both NES groups. Finally, significant nocturnal changes were observed for serum levels of prolactin in all four subgroups. Grand mean levels tended to be higher in NES subjects whereas the opposite

  19. Modeling mechanisms of cell secretion.

    PubMed

    Tsaneva-Atanasova, Krasimira; Osinga, Hinke M; Tabak, Joël; Pedersen, Morten Gram

    2010-12-01

    Secretion is a fundamental cellular process involving the regulated release of intracellular products from cells. Physiological functions such as neurotransmission, or the release of hormones and digestive enzymes, are all governed by cell secretion. Anomalies in the processes involved in secretion contribute to the development and progression of diseases such as diabetes and other hormonal disorders. To unravel the mechanisms that govern such diseases, it is essential to understand how hormones, growth factors and neurotransmitters are synthesized and processed, and how their signals are recognized, amplified and transmitted by intracellular signaling pathways in the target cells. Here, we discuss diverse aspects of the detailed mechanisms involved in secretion based on mathematical models. The models range from stochastic ones describing the trafficking of secretory vesicles to deterministic ones investigating the regulation of cellular processes that underlie hormonal secretion. In all cases, the models are closely related to experimental results and suggest theoretical predictions for the secretion mechanisms.

  20. The NK3 Receptor Antagonist ESN364 Interrupts Pulsatile LH Secretion and Moderates Levels of Ovarian Hormones Throughout the Menstrual Cycle.

    PubMed

    Fraser, Graeme L; Hoveyda, Hamid R; Clarke, Iain J; Ramaswamy, Suresh; Plant, Tony M; Rose, Claudia; Millar, Robert P

    2015-11-01

    Women's health disorders such as uterine fibroids and endometriosis are currently treated by GnRH modulators that effectively suppress the hypothalamic-pituitary-gonadal axis. The neurokinin-3 receptor (NK3R) is an alternative target with an important role in the modulation of this axis. In this report, we demonstrate that systemic administration of an NK3R antagonist (ESN364) prolongs the LH interpulse interval in ovarectomized ewes and significantly lowers plasma LH and FSH concentrations in castrated nonhuman primates (Macaca fascicularis). Moreover, daily oral dosing of ESN364 throughout the menstrual cycle in M fascicularis lowered plasma estradiol levels in a dose-dependent manner, although nadir levels of estradiol were maintained well above menopausal levels. Nevertheless, estradiol levels during the follicular phase were sufficiently inhibited at all doses to preclude the triggering of ovulation as evidenced by the absence of the LH surge and failure of a subsequent luteal phase rise in plasma progesterone concentrations, consistent with the absence of normal cycle changes in the uterus. Apart from the point at surge, FSH levels were not altered over the course of the menstrual cycle. These effects of ESN364 were reversible upon cessation of drug treatment. Together these data support the proposed role of neurokinin B-NK3R signaling in the control of pulsatile GnRH secretion. Furthermore, in contrast to GnRH antagonists, NK3R antagonists induce a partial suppression of estradiol and thereby offer a viable therapeutic approach to the treatment of ovarian sex hormone disorders with a mitigated risk of menopausal-like adverse events in response to long-term drug exposure.

  1. The NK3 Receptor Antagonist ESN364 Interrupts Pulsatile LH Secretion and Moderates Levels of Ovarian Hormones Throughout the Menstrual Cycle.

    PubMed

    Fraser, Graeme L; Hoveyda, Hamid R; Clarke, Iain J; Ramaswamy, Suresh; Plant, Tony M; Rose, Claudia; Millar, Robert P

    2015-11-01

    Women's health disorders such as uterine fibroids and endometriosis are currently treated by GnRH modulators that effectively suppress the hypothalamic-pituitary-gonadal axis. The neurokinin-3 receptor (NK3R) is an alternative target with an important role in the modulation of this axis. In this report, we demonstrate that systemic administration of an NK3R antagonist (ESN364) prolongs the LH interpulse interval in ovarectomized ewes and significantly lowers plasma LH and FSH concentrations in castrated nonhuman primates (Macaca fascicularis). Moreover, daily oral dosing of ESN364 throughout the menstrual cycle in M fascicularis lowered plasma estradiol levels in a dose-dependent manner, although nadir levels of estradiol were maintained well above menopausal levels. Nevertheless, estradiol levels during the follicular phase were sufficiently inhibited at all doses to preclude the triggering of ovulation as evidenced by the absence of the LH surge and failure of a subsequent luteal phase rise in plasma progesterone concentrations, consistent with the absence of normal cycle changes in the uterus. Apart from the point at surge, FSH levels were not altered over the course of the menstrual cycle. These effects of ESN364 were reversible upon cessation of drug treatment. Together these data support the proposed role of neurokinin B-NK3R signaling in the control of pulsatile GnRH secretion. Furthermore, in contrast to GnRH antagonists, NK3R antagonists induce a partial suppression of estradiol and thereby offer a viable therapeutic approach to the treatment of ovarian sex hormone disorders with a mitigated risk of menopausal-like adverse events in response to long-term drug exposure. PMID:26305889

  2. Augmented Growth Hormone Secretion and Stat3 Phosphorylation in an Aryl Hydrocarbon Receptor Interacting Protein (AIP)-Disrupted Somatotroph Cell Line

    PubMed Central

    Hamaguchi, Yuriko; Kawanami, Takako; Nomiyama, Takashi; Yanase, Toshihiko

    2016-01-01

    Aryl hydrocarbon receptor interacting protein (AIP) is thought to be a tumor suppressor gene, as indicated by a mutational analysis of pituitary somatotroph adenomas. However, the physiological significance of AIP inactivation in somatotroph cells remains unclear. Using CRISPR/Cas9, we identified a GH3 cell clone (termed GH3-FTY) in which Aip was genetically disrupted, and subsequently investigated its character with respect to growth hormone (Gh) synthesis and proliferation. Compared with GH3, GH3-FTY cells showed remarkably increased Gh production and a slight increase in cell proliferation. Gh-induced Stat3 phosphorylation is known to be a mechanism of Gh oversecretion in GH3. Interestingly, phosphorylated-Stat3 expression in GH3-FTY cells was increased more compared with GH3 cells, suggesting a stronger drive for this mechanism in GH3-FTY. The phenotypes of GH3-FTY concerning Gh overproduction, cell proliferation, and increased Stat3 phosphorylation were significantly reversed by the exogenous expression of Aip. GH3-FTY cells were less sensitive to somatostatin than GH3 cells in the suppression of cell proliferation, which might be associated with the reduced expression of somatostatin receptor type 2. GH3-FTY xenografts in BALB/c nude mice (GH3-FTY mice) formed more mitotic somatotroph tumors than GH3 xenografts (GH3 mice), as also evidenced by increased Ki67 scores. GH3-FTY mice were also much larger and had significantly higher plasma Gh levels than GH3 mice. Furthermore, GH3-FTY mice showed relative insulin resistance compared with GH3 mice. In conclusion, we established a somatotroph cell line, GH3-FTY, which possessed prominent Gh secretion and mitotic features associated with the disruption of Aip. PMID:27706259

  3. Long-term results of hypofractionated stereotactic radiotherapy with CyberKnife for growth hormone-secreting pituitary adenoma: evaluation by the Cortina consensus.

    PubMed

    Iwata, Hiromitsu; Sato, Kengo; Nomura, Ryutaro; Tabei, Yusuke; Suzuki, Ichiro; Yokota, Naoki; Inoue, Mitsuhiro; Ohta, Seiji; Yamada, Shozo; Shibamoto, Yuta

    2016-06-01

    The aim of the present study was to evaluate the safety and feasibility of hypofractionated stereotactic radiotherapy (SRT) with CyberKnife for growth hormone-secreting pituitary adenoma (GH-PA). Fifty-two patients with GH-PA were treated with hypofractionated SRT between September 2001 and October 2012. Eight patients had clinically silent GH-PA and 44 were symptomatic. Only 1 patient was inoperable. The other patients had recurrent or postoperative residual tumors on MRI. All patients had received pharmacotherapy prior to SRT with a somatostatin analog, dopamine agonist, and/or GH receptor antagonist. The marginal doses were 17.4-26.8 Gy for the 3-fraction schedule and 20.0-32.0 Gy for the 5-fraction schedule. Endocrinological remission was assessed by the Cortina consensus criteria 2010 (random GH <1 ng/ml or nadir GH after an oral glucose tolerance test <0.4 ng/ml and normalization of age- and sex-adjusted insulin-like growth factor-1). The median follow-up period was 60 months (range 27-137). The 5-year overall survival, local control, and disease-free survival rates were 100, 100, and 96 %, respectively. Nine patients (5 clinically silent and 4 symptomatic patients) satisfied the Cortina criteria without receiving further pharmacotherapy, whereas the remaining 43 patients did not. No post-SRT grade 2 or higher visual disorder occurred. Symptomatic post-SRT hypopituitarism was observed in 1 patient. CyberKnife hypofractionated SRT is safe and effective when judged by imaging findings for GH-PA. However, it may be difficult to satisfy the Cortina consensus criteria in most symptomatic patients with SRT alone. Further investigations of optimal treatments are warranted. PMID:26961771

  4. 2,3,7,8-Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor and alters sex steroid hormone secretion without affecting growth of mouse antral follicles in vitro

    SciTech Connect

    Karman, Bethany N. Basavarajappa, Mallikarjuna S. Craig, Zelieann R. Flaws, Jodi A.

    2012-05-15

    The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1–100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, androstenedione, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 μM) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3–4 fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles. -- Highlights: ►TCDD disrupts sex steroid hormone levels, but not growth of antral follicles. ►Pregnenolone co-treatment by-passes TCDD-induced steroid hormone disruption. ►TCDD affects steroid hormone levels through an AHR pathway in antral follicles.

  5. Modulation of ovine fetal adrenocorticotropin secretion by androstenedione and 17beta-estradiol.

    PubMed

    Saoud, C J; Wood, C E

    1997-04-01

    Parturition in sheep is initiated by increases in activity of the fetal hypothalamic-pituitary-adrenal axis. We have previously reported that cortisol negative feedback efficacy is decreased at the end of gestation. The present study was designed to test the hypothesis that increasing plasma estrogen and/or androgen concentrations in the fetus might increase plasma adrenocorticotropic hormone (ACTH) concentration, either by stimulating ACTH secretion or by altering the negative feedback effect of cortisol on ACTH. Fetal sheep were chronically catheterized and treated with no steroid (control), 17beta-estradiol, or androstenedione (each approximately 0.24 mg/day). After catheterization and implantation of steroid pellet, fetuses were subjected to two short (10 min) periods of sodium nitroprusside-induced hypotension with or without pretreatment with intravenous infusion of hydrocortisone sodium succinate (0.5 microg/min) to test fetal ACTH responsiveness to stress and cortisol negative feedback efficacy. Estradiol treatment significantly increased basal plasma ACTH and cortisol concentrations relative to control fetuses but did not interfere with the inhibition of ACTH secretion by cortisol. Fetal plasma ACTH responses to hypotension were significantly suppressed approximately 60% in both control and estradiol-treated groups. Androstenedione treatment significantly increased basal fetal plasma ACTH and decreased basal fetal plasma cortisol concentration. Androstenedione did not alter stimulated levels of fetal ACTH but did block the inhibition of stimulated ACTH by cortisol. We conclude that increased fetal cortisol and ACTH secretion at the end of gestation may be due to the combined effects of the gonadal steroids in that estradiol increases basal plasma ACTH secretion while androstenedione reduces cortisol negative feedback efficacy.

  6. Continuous Positive Airway Pressure Increases Pulsatile Growth Hormone Secretion and Circulating Insulin-like Growth Factor-1 in a Time-Dependent Manner in Men With Obstructive Sleep Apnea: A Randomized Sham-Controlled Study

    PubMed Central

    Hoyos, Camilla M.; Killick, Roo; Keenan, Daniel M.; Baxter, Robert C.; Veldhuis, Johannes D.; Liu, Peter Y.

    2014-01-01

    Study Objectives: To assess the time-dependent effect of continuous positive airway pressure (CPAP), on insulin-like growth factor-1 (IGF-1), IGF binding proteins (IGFBPs) and pulsatile growth hormone (GH) secretion. Design: A randomized, double-blind, sham-controlled, parallel group study. Participants: Sixty-five middle-aged men with moderate to severe obstructive sleep apnea. Intervention: Active (n = 34) or sham (n = 31) CPAP for 12 weeks, followed by 12 weeks of active CPAP (n = 65). Measurements and Results: Fasting morning IGF-1, IGFBP-3, and IGFBP-1 blood levels at 0, 6, 12, and 24 weeks. Overnight GH secretion was calculated by mathematical deconvolution of serial GH measurements from serum samples collected every 10 min (22:00-06:00) during simultaneous polysomnography in a subset of 18 men (active n = 11, sham n = 7) at week 12. Active, compared with sham, CPAP increased IGF-1 at 12 weeks (P = 0.006), but not at 6 weeks (P = 0.44). Changes in IGFBP-3 and IGFBP-1 were not different between groups at 6 or 12 weeks (all P ≥ 0.15). At week 24, there was a further increase in IGF-1 and a decrease in IGFBP-1 in the pooled group (P = 0.0001 and 0.046, respectively). In the subset, total (P = 0.001) and pulsatile (P = 0.002) GH secretion, mean GH concentration (P = 0.002), mass of GH secreted per pulse (P = 0.01) and pulse frequency (P = 0.04) were all higher after 12 weeks of CPAP compared with sham. Basal secretion, interpulse regularity, and GH regularity were not different between groups (all P > 0.11). Conclusions: Twelve weeks, but not 6 weeks, of CPAP increases IGF-1, with a further increase after 24 weeks. Total and pulsatile GH secretion, secretory burst mass and pulse frequency are also increased by 12 weeks. CPAP improves specific elements of the GH/IGF-1 axis in a time-dependent manner. Clinical Trials Registration: Australia New Zealand Clinical Trials Network, www.anzctr.org.au, number ACTRN12608000301369. Citation: Hoyos CM; Killick R; Keenan DM

  7. A comparative study of the effects of ranitidine and cimetidine on carbohydrate tolerance, growth hormone secretion and the hypothalamic-pituitary-gonadal axis in man.

    PubMed

    Scobie, I N; Saunders, J; Barnes, G D; Hoad, J; Wheeler, M J; Lowry, C; Sonksen, P H; Amphlett, G; Riley, A J

    1986-01-01

    The effect of chronic oral administration of cimetidine (1 g per day) and ranitidine (300 mg per day) on plasma levels of prolactin (PRL), testosterone, dihydrotestosterone (DHT), luteinizing hormone (LH), follicle stimulating hormone (FSH), sex hormone binding globulin (SHBG) and human growth hormone was compared in 2 groups of male patients who presented with dyspeptic symptoms. Eight were treated with ranitidine and 9 with cimetidine for 4 weeks. The glucose and insulin response to a 100 g oral glucose load was also assessed. Cimetidine treatment resulted in a significant increase in plasma testosterone levels which was not found in the ranitidine group. No significant change occurred in PRL, LH, FSH, SHBG, DHT and growth hormone. There was no evidence of a significant alteration in carbohydrate metabolism.

  8. Hormone-induced intercellular signal transfer dissociates cyclic AMP- dependent protein kinase

    PubMed Central

    1984-01-01

    We used co-cultures of porcine ovarian granulosa cells and mouse adrenocortical tumor cells (Y-1) to examine the kinetics of contact- dependent intercellular signal transfer and to assess the molecular mechanisms employed by this process. Exposure to follicle-stimulating hormone (FSH) caused cAMP-dependent protein kinase dissociation in granulosa cells and, with time, in Y-1 cells if, and only if, they contacted a responding granulosa cell. Y-1 cells close to a granulosa cell but not touching it failed to respond similarly. In reciprocal experiments, co-cultures were stimulated with adrenocorticotropic hormone (ACTH). Y-1 cells dissociated protein kinase as did granulosa cells in contact with Y-1 cells; however, granulosa cells that were not in contact with Y-1 cells failed to respond to the hormone. Fluorogenic steroids were secreted by Y-1 cells cultured alone and stimulated with ACTH, but were not secreted by cultures exposed to FSH. Neither hormone caused fluorogenic steroid production by granulosa cells. On the other hand these steroids were secreted in co-cultures stimulated with ACTH and to a lesser degree in co-cultures exposed to FSH. Autoradiography revealed that I125-FSH bound only to granulosa cells, never to Y-1 cells, even if they were in contact with an ovarian cell. The possibility of cell fusion was tested by experiments in which Y-1 cell membranes were labeled with cationized ferritin. These cells were then placed in co-culture with ovarian granulosa cells that had previously been allowed to ingest latex spheres. At regions of gap junctions between Y-1 and granulosa cells ferritin remained attached to the adrenal cell membrane and was never observed to migrate to the granulosa cell membrane. From these data, we conclude that hormone specific stimulation of one cell type leads to protein kinase dissociation in heterotypic partners only if they contact a hormone responsive cell. This signal transfer is bidirectional, exhibits temporal kinetics and

  9. Was sind hormone?

    NASA Astrophysics Data System (ADS)

    Karlson, P.

    1982-01-01

    Historically, the meaning of the term hormone has changed during the last decades. Morphological studies of secreting cells lead Feyrter to the concept of paracrine action of some hormones. While endocrine regulators are blood-borne, paracrine messengers reach their target cells through the diffusion in the intracellular space. Though it is rather difficult to draw a line between true hormones and hormone-like substances, valid definitions for endocrine and paracrine regulatory systems can be given. The term ‘hormonal control’ should be restricted to endocrine systems. For effectors acting by paracrine mechanisms, the term paramone is proposed in this article.

  10. A model of human sleep-related growth hormone secretion in dogs: effects of 3, 6, and 12 hours of forced wakefulness on plasma growth hormone, cortisol, and sleep stages.

    PubMed

    Takahashi, Y; Ebihara, S; Nakamura, Y; Takahashi, K

    1981-07-01

    Twenty-four canine GH (cGH) and cortisol secretion patterns associated with sleep stages were studied in 10 male adult dogs. Plasma samples were obtained at 30- or 15-min intervals via an indwelling catheter. Under baseline conditions, all dogs showed irregular polyphasic sleep, and the episodic cGH secretion had no apparent relationship with sleep or the light-dark cycle. Five dogs were subjected to regular sleep-wake cycles; 3, 6, and 12 h of forced wakefulness (FW) were repeated at 3-, 6-, and 12-h intervals (recovery sleep periods), respectively. Peak cGH secretion (mean +/- SD, 6.4 ng/ml +/- 2.4) occurred soon after recovery sleep onset in 25 of 40 total recovery periods. The incidence of sleep-onset cGH peaks and cGH secretion during the first hour of recovery sleep significantly increased with the length of the preceding FW, but were not affected by the time of day. Delta wave sleep increased during this hour, suggesting a possible correlation with the sleep-onset cGH peak. During the first 3 h of recovery after 6 and 12 h of FW, cGH secretion was significantly enhanced, but cortisol was not. Considering the characteristics of human sleep-related GH secretion, we suggest that this peak cGH secretion represents a model of human GH secretion. Possibly, a close association of cGH secretion with sleep is concealed under the baseline condition and uncovered by inducing longer sleep-wake cycles in dogs. No circadian cortisol variation was detected under the baseline or the experimental conditions. PMID:7238408

  11. Nur77 gene expression levels were involved in different ACTH-secretion autonomy between Cushing's disease and subclinical Cushing's disease.

    PubMed

    Tabuchi, Yukiko; Kitamura, Tetsuhiro; Fukuhara, Atsunori; Mukai, Kosuke; Onodera, Toshiharu; Miyata, Yugo; Hamasaki, Toshimitsu; Oshino, Satoru; Saitoh, Youichi; Morii, Eiichi; Otsuki, Michio; Shimomura, Iichiro

    2016-06-30

    Cushing's disease (CD) and subclinical Cushing's disease (subCD) are both diseases caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. However, ACTH autonomy in subCD is weaker than in CD and there are no Cushingoid features in subCD. The differences of molecular mechanisms in ACTH autonomy between CD and subCD have not yet been reported. Therefore, we aimed to investigate the differences in molecular mechanisms of ACTH-secretion autonomy between CD and subCD. The study included 23 patients [7 CD, 6 subCD, and 10 non-functioning pituitary tumors (NFTs)] who underwent transsphenoidal surgery at the Osaka University Hospital between December 2009 and October 2013. Using quantitative real-time PCR, various ACTH-related gene expressions in tumor tissues from CD, subCD, and NFT were measured such as pro-opiomelanocortin (POMC), POMC transcription factor (Tpit, Pitx1, NeuroD1, and Nur77), POMC peptide processing enzymes (prohormone convertase: PC1/3 and PC2), and ACTH secretion-related factors (corticotropin-releasing hormone receptor 1: CRHR1 and glucocorticoid receptor α: GRα). Only Nur77 mRNA levels were significantly higher in CD than in subCD. Furthermore, we stained 6 CD and 6 subCD with anti-Nur77 antibody. All tumor samples from CD had Nur77 protein positive cells. On the other hand, Nur77 protein was expressed in only one tumor sample from subCD. This sample showed high expression of Nur77 mRNA. Nur77 is an important to regulate POMC transcription and negative-feedback by glucocorticoids. Nur77 gene expression levels might involve different autonomy of ACTH production between CD and subCD. PMID:27025408

  12. Nur77 gene expression levels were involved in different ACTH-secretion autonomy between Cushing's disease and subclinical Cushing's disease.

    PubMed

    Tabuchi, Yukiko; Kitamura, Tetsuhiro; Fukuhara, Atsunori; Mukai, Kosuke; Onodera, Toshiharu; Miyata, Yugo; Hamasaki, Toshimitsu; Oshino, Satoru; Saitoh, Youichi; Morii, Eiichi; Otsuki, Michio; Shimomura, Iichiro

    2016-06-30

    Cushing's disease (CD) and subclinical Cushing's disease (subCD) are both diseases caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. However, ACTH autonomy in subCD is weaker than in CD and there are no Cushingoid features in subCD. The differences of molecular mechanisms in ACTH autonomy between CD and subCD have not yet been reported. Therefore, we aimed to investigate the differences in molecular mechanisms of ACTH-secretion autonomy between CD and subCD. The study included 23 patients [7 CD, 6 subCD, and 10 non-functioning pituitary tumors (NFTs)] who underwent transsphenoidal surgery at the Osaka University Hospital between December 2009 and October 2013. Using quantitative real-time PCR, various ACTH-related gene expressions in tumor tissues from CD, subCD, and NFT were measured such as pro-opiomelanocortin (POMC), POMC transcription factor (Tpit, Pitx1, NeuroD1, and Nur77), POMC peptide processing enzymes (prohormone convertase: PC1/3 and PC2), and ACTH secretion-related factors (corticotropin-releasing hormone receptor 1: CRHR1 and glucocorticoid receptor α: GRα). Only Nur77 mRNA levels were significantly higher in CD than in subCD. Furthermore, we stained 6 CD and 6 subCD with anti-Nur77 antibody. All tumor samples from CD had Nur77 protein positive cells. On the other hand, Nur77 protein was expressed in only one tumor sample from subCD. This sample showed high expression of Nur77 mRNA. Nur77 is an important to regulate POMC transcription and negative-feedback by glucocorticoids. Nur77 gene expression levels might involve different autonomy of ACTH production between CD and subCD.

  13. Growth hormone (GH) secretory dynamics in a case of acromegalic gigantism associated with hyperprolactinemia: nonpulsatile secretion of GH may induce elevated insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 levels.

    PubMed

    Yoshida, T; Shimatsu, A; Sakane, N; Hizuka, N; Horikawa, R; Tanaka, T

    1996-01-01

    We describe a case of pituitary gigantism with low levels of growth hormone (GH), elevated insulin-like growth factor-I (IGF-I), and IGF-binding protein-3 (IGF-BP-3). The patient had characteristic clinical features of gigantism and acromegaly. The basal serum GH levels ranged from 1.2-1.9 micrograms/L, which were considered to be within normal limits. Serum GH response to either insulin-induced hypoglycemia or GH-releasing hormone was blunted. Frequent blood samplings during daytime and at night showed nonpulsatile GH secretion. Serum prolactin, IGF-I and IGF-binding protein-3 levels were elevated. After unsuccessful surgery, bromocryptine treatment normalized serum prolactin without affecting serum GH and IGF-I levels. Combined administration of octreotide and bromocryptine reduced serum GH and IGF-I levels. GH bioactivity as measured by Nb2 cell proliferation assay was within reference range. In the present case, nonpulsatile GH secretion and enhanced tissue sensitivity to GH may induce hypersecretion of IGF-I and IGF-BP-3 and cause clinical acromegalic gigantism. PMID:8550769

  14. Growth hormone.

    PubMed

    Bidlingmaier, Martin; Strasburger, Christian J

    2010-01-01

    Human growth hormone (hGH) is a proteohormone secreted by the pituitary gland. It acts through binding to the hGH receptor, inducing either direct effects or initiating the production of insulin-like growth-factor I (IGF-I), the most important mediator of hGH effects. Growth hormone is primarily known to promote longitudinal growth in children and adolescents, but has also various important metabolic functions throughout adult life. Effects of hGH on the adult organism are well established from studies with recombinant growth hormone (rhGH) therapy in growth hormone deficient subjects. In this particular group of patients, replacement of hGH leads to increased lipolysis and lean body mass, decreased fat mass, improvements in VO(2max), and maximal power output. Although extrapolation from these findings to the situation in well trained healthy subjects is impossible, and controlled studies in healthy subjects are scarce, abuse of hGH seems to be popular among athletes trying to enhance physical performance. Detection of the application of rhGH is difficult, especially because the amino acid sequence of rhGH is identical to the major 22,000 Da isoform of hGH normally secreted by the pituitary. Furthermore, some physiological properties of hGH secretion also hindered the development of a doping test: secreted in a pulsatile manner, it has a very short half-life in circulation, which leads to highly variable serum levels. Concentration alone therefore cannot prove the exogenous administration of hGH.Two approaches have independently been developed for the detection of hGH doping: The so-called "marker approach" investigates changes in hGH-dependent parameters like IGF-I or components of bone and collagen metabolism, which are increased after hGH injection. In contrast, the so-called "isoform approach" directly analyses the spectrum of molecular isoforms in circulation: the pituitary gland secretes a spectrum of homo- and heterodimers and - multimers of a variable

  15. Luteinizing hormone secretion and corticotropin-releasing factor gene expression in the paraventricular nucleus of rhesus monkeys following cortisol synthesis inhibition.

    PubMed

    Van Vugt, D A; Piercy, J; Farley, A E; Reid, R L; Rivest, S

    1997-06-01

    Corticotropin-releasing Factor (CRF) is an important inhibitory neuromodulator of GnRH/LH secretion, and mediates in part the inhibitory effects of stress on the hypothalamic-pituitary-gonadal axis. The purpose of the present study was to further investigate CRF's role in regulating LH secretion in primates. This was accomplished by examining LH secretion in ovariectomized rhesus monkeys (n = 7) following cortisol synthesis inhibition with metyrapone. Infusion of metyrapone (5 mg/kg per h) for 4 h decreased cortisol levels to less than 20% of controls while increasing ACTH approximately 10-fold. LH concentrations were not affected by this acute activation of the hypothalamic-corticotroph axis. In a second experiment, metyrapone was infused for 10 h before collecting serial blood samples every 15 min for 6 h. Although this protocol produced a sustained increase in ACTH, no apparent effect on pulsatile LH secretion compared with saline controls was observed. Mean LH (+/- SEM) levels calculated for consecutive 2-h increments were 87.6 +/- 9.2 (0-2 h) 82.1 +/- 5.5 (2-4 h), and 80.7 +/- 4.8 (4-6 h) ng/ml in saline pretreated animals compared with 83.6 +/- 4.9, 79.8 +/- 5.8, and 72.5 +/- 6.2 ng/ml, respectively, in metyrapone pretreated monkeys. The same regimen of metyrapone infusion increased CRF messenger RNA levels in the paraventricular nucleus by approximately 33% (P < 0.0002). In a final experiment designed to examine the potential synergy between CRF and cortisol, the LH response to insulin-induced hypoglycemia was contrasted in saline and metyrapone pretreated monkeys. LH concentrations were reduced to approximately 40% of basal levels following insulin in both metyrapone and saline pretreated monkeys. Therefore, even though inhibition of cortisol synthesis leads to an increase in CRF messenger RNA in the paraventricular nucleus and a robust increase in ACTH secretion in rhesus monkeys, presumably due in part to increased neuroendocrine CRF secretion, LH

  16. The sensitivity of growth hormone and prolactin secretion to the somatostatin analogue SMS 201-995 in patients with prolactinomas and acromegaly.

    PubMed

    Lamberts, S W; Zweens, M; Klijn, J G; van Vroonhoven, C C; Stefanko, S Z; Del Pozo, E

    1986-08-01

    The somatostatin analogue SMS 201-995 has recently been shown to be effective in suppressing GH secretion in most acromegalic patients. In the present study it was investigated whether PRL release in prolactinoma and acromegalic patients might also be sensitive to SMS 201-995 and whether co-secretion of PRL in acromegaly plays a role in determining the sensitivity of GH secretion to SMS 201-995. The s.c. administration of 50 micrograms SMS 201-995 did not affect high plasma PRL levels in four microprolactinoma patients. Therapy of one of these patients for 3 d with 50 micrograms three times a day also did not affect PRL levels. The single administration of 50 micrograms SMS 201-995 in 22 acromegalic patients lowered plasma GH levels for 2-6 h to less than 5 micrograms/l in 14 patients and to less than 50% of control values in 16 patients. In 18 of these 22 patients the immunohistochemical picture of the pituitary tumour was known. Eleven patients had pure GH-containing tumours and in seven patients there were mixed GH/PRL-containing tumours. In two of these latter patients there was evidence for GH and PRL being secreted by the same tumour cells. The sensitivity of GH secretion to SMS 201-995 did not differ between the patients with pure GH or mixed GH/PRL-containing adenomas. Plasma PRL levels were not affected by SMS 201-995 in the patients with pure GH-secreting tumours, but were significantly suppressed in four of the seven patients with mixed GH/PRL containing tumours. Chronic treatment for 16 weeks of one patient with a mixed GH/PRL-containing tumour with SMS 201-995 (100 micrograms three times a day) resulted in normalization of both the increased GH and PRL levels. It is concluded that SMS 201-995 does not affect tumorous PRL secretion in patients with pure prolactinomas. In acromegalic patients with mixed GH/PRL-containing tumours PRL secretion in some patients is sensitive to SMS 201-995, making these patients good candidates for chronic treatment with

  17. [Incretin hormones].

    PubMed

    Cáp, J

    2011-04-01

    Incretin hormones are peptides that are secreted from endocrine cell of gastrointestinal tract after nutrient ingestion and stimulate insulin secretion. Glucosodependent Insulinotropic Peptide--GIP is released from K-cells of duodenum and proximal jejunum, recently GIP synthesis has been proved in pancreatic alpha cells. Besides the incretin effect causes GIP increased lipogenesis and decreased lipolysis in fat tissue, increased bone formation and decreased resorption and has protective and proliferative effect on CNS neurons. Both GIP agonists (to treat diabetes) and antagonist (to treat obesity) are being studied. Another incretin hormone is derived in intestinal I-cells by posttranslational processing of proglucagon--glucagon-like peptides 1 and 2 (GLP-1 and GLP-2). GLP-1 stimulates insuline production and inhibits glucagon secretion, exerts proliferative and antiapoptotic effect on beta-cells. Via receptors on vagal nerve and central mechanisms decreases food intake and decreases body weight. By deceleration of gastric emptying it attenuates increases in meal-associated blood glucose levels. It exerts cardioprotective effects. GLP-1 receptors have been proved in liver recently but decreased liver glucose production and increased glucose uptake by liver and muscle are mediated indirectly by altering insulin and glucagons levels. GLP-2 stimulates enterocytes proliferation, up-regulates intestinal nutrient transport, improves intestinal barrier function, and inhibits gastric and intestinal motility. GLP-2 also reduces bone resorption. PMID:21612069

  18. Hormonal effects on Tetrahymena: change in case of combined treatment.

    PubMed

    Csaba, G; Lajkó, Eszter; Pállinger, Eva

    2010-12-01

    In order to approach their natural conditions, populations of Tetrahymena were kept in Losina-Losinky's salt solution for 1 h, than in the tryptone+yeast medium. During this time they were treated with histamine, serotonin or insulin, or with the combinations of these hormones. Effect of the combined treatments on the production of serotonin (5HT), or adrenocorticotropic hormone (ACTH) or triiodothyronine (T₃) by the cells was compared to the effect of single-hormone treatments. Significant differences were seen between the results obtained following the single or combined treatments. There was no summation of the effects, however an elevation or diminution of the hormone production was observed after the combined treatment, as compared with the untreated controls or with the use of one of the hormones in the samples. The experiments demonstrate that there is a hormonal regulation between the Tetrahymena cells and the hormones influence each other's effect. PMID:21183424

  19. Effects of KiSS-1 peptide, the natural ligand of GPR54, on follicle-stimulating hormone secretion in the rat.

    PubMed

    Navarro, V M; Castellano, J M; Fernández-Fernández, R; Tovar, S; Roa, J; Mayen, A; Barreiro, M L; Casanueva, F F; Aguilar, E; Dieguez, C; Pinilla, L; Tena-Sempere, M

    2005-04-01

    KiSS-1 was originally identified as a metastasis suppressor gene encoding an array of structurally related peptides, namely kisspeptins, which acting through the G protein-coupled receptor GPR54 are able to inhibit tumor progression. Unexpectedly, a reproductive facet of this newly discovered system has recently arisen, and characterization of the role of the KiSS-1/GPR54 system in the neuroendocrine control of gonadotropin secretion has been initiated. However, such studies have been so far mostly restricted to LH, and very little is known about the actual contribution of this system in the regulation of FSH release. To address this issue, the effects of KiSS-1 peptide on FSH secretion were monitored in vivo and in vitro under different experimental conditions. Intracerebroventricular administration of KiSS-1 peptide significantly stimulated FSH secretion in prepubertal and adult rats. Yet, dose-response analyses in vivo demonstrated an ED(50) value for the FSH-releasing effects of KiSS-1 of 400 pmol, i.e. approximately 100-fold higher than that of LH. In addition, systemic (ip and iv) injection of KiSS-1 significantly stimulated FSH secretion in vivo. However, KiSS-1 failed to elicit basal FSH release directly at the pituitary level, although it moderately enhanced GnRH-stimulated FSH secretion in vitro. Finally, mechanistic studies revealed that the ability of KiSS-1 to elicit FSH secretion was abolished by the blockade of endogenous GnRH actions, but it was persistently observed in different models of leptin insufficiency and after blockade of endogenous excitatory amino acid and nitric oxide pathways, i.e. relevant signals in the neuroendocrine control of gonadotropin secretion. In summary, our results extend previous recent observations on the role of KiSS-1 in the control of LH secretion and provide solid evidence for a stimulatory effect of KiSS-1 on FSH release, acting at central level. Overall, it is proposed that the KiSS-1/GPR54 system is a novel

  20. Glucoreceptors located in different areas mediate the hypoglycemia-induced release of growth hormone, prolactin, and adrenocorticotropin in man.

    PubMed

    Vigas, M; Tatár, P; Jurcovicová, J; Jezová, D

    1990-03-01

    In young male volunteers, the changes in growth hormone (GH), prolactin (PRL), and adrenocorticotropic hormone (ACTH) release in response to insulin injection combined with the infusion of saline, glucose, and fructose were evaluated. Glucose infusion in a dose which prevented insulin hypoglycemia completely abolished endocrine responses. Infusion of fructose, which is known not to cross the blood-brain barrier (BBB), did not influence the GH release during hypoglycemia; however, it inhibited PRL secretion. The ACTH response was slightly attenuated and delayed, while the hypoglycemia-induced rise in cortisol levels was not modified by fructose infusion. These data indicate that the glucoreceptors mediating the signals for a complete counterregulatory neuroendocrine response are not located in a single brain structure. Stimuli for GH release are produced in areas of the central nervous system protected by the BBB, while those for PRL release are presumably present in structures not protected by the BBB. Glucoreceptors triggering ACTH release are located both inside and outside the BBB. PMID:2157998

  1. Gonadotropin-releasing hormone II receptor (GnRHR-II) knockdown reduces testis size and decreases testosterone secretion during pubertal development in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The second mammalian isoform of gonadotropin-releasing hormone (GnRH-II) functions quite differently from the classical form (GnRH-I) as it is a poor stimulator of gonadotropin release. Unlike most species, a functional GnRHR-II has been identified in swine. Our laboratory detected GnRHR-IIs on Leyd...

  2. Inhibition of luteinizing hormone secretion by localized administration of estrogen, but not dihydrotestosterone, is enhanced in the ventromedial hypothalamus during feed restriction in the young wether.

    PubMed

    McManus, Christina J; Goodman, Robert L; Llanza, Nancy V; Valent, Miroslav; Dobbins, Adam B; Connors, John M; Hileman, Stanley M

    2005-10-01

    The ability of steroids to inhibit LH secretion is enhanced during undernutrition. To identify potential hypothalamic sites at which this enhancement may occur, we examined LH secretion in feed-restricted or fed young wethers treated with locally administered metabolites of testosterone. In experiment 1, microimplants containing crystalline estradiol-17beta (E) or cholesterol were administered via chronic guide tubes directed to the preoptic area (POA) or ventromedial hypothalamus (VMH) in fed or feed-restricted wethers. E treatment in the VMH decreased LH pulse frequency, pulse amplitude, and mean LH concentration in feed-restricted, but not fed, wethers. E may act in the POA to suppress LH under feed restriction, but definite conclusions cannot be drawn because of steroid-independent effects of feed restriction on LH pulse frequency. In experiment 2, the effect of dihydrotestosterone (DHT) in the VMH was determined. DHT administration to the VMH did not alter LH secretion in either feed-restricted or fed wethers. Thus the VMH is one site wherein E negative feedback is enhanced during feed restriction in the wether. In contrast, we found no evidence for enhanced responsiveness to androgen negative feedback within the VMH of feed-restricted wethers. We suggest that increased sensitivity within the VMH to E, but not to DHT, is important for suppressing LH secretion in undernourished male sheep.

  3. Replacement therapy with DHEA plus corticosteroids in patients with chronic inflammatory diseases--substitutes of adrenal and sex hormones.

    PubMed

    Straub, R H; Schölmerich, J; Zietz, B

    2000-01-01

    A dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis was found in animal models of chronic inflammatory diseases, and the defect was located in more central portions of the HPA axis. This defect of neuroendocrine regulatory mechanisms contributes to the onset of the model disease. Since these first observations in animal models were made, evidence has accumulated that the possible defect in the HPA axis in humans is more distal to the hypothalamus or pituitary gland: In chronic inflammatory diseases, such as rheumatoid arthritis, an alteration of the HPA stress response results in inappropriately low cortisol secretion in relation to adrenocorticotropic hormone (ACTH) secretion. Furthermore, it has recently been shown that the serum levels of another adrenal hormone, dehydroepiandrosterone (DHEA), were significantly lower after ACTH stimulation in patients with rheumatoid arthritis without prior corticosteroids than in healthy controls. These studies clearly indicate that chronic inflammation alters, particularly, the adrenal response. However, at this point, the reason for the specific alteration of adrenal function in relation to pituitary function remains to be determined. Since one of the down-regulated adrenal hormones, DHEA, is an inhibitor of cytokines due to an inhibition of nuclear factor-kappa B (NF-kappa B) activation, low levels of this hormone may be deleterious in chronic inflammatory diseases. We have recently demonstrated that DHEA is a potent inhibitor of IL-6, which confirmed an earlier study in mice. Since IL-6 is an important factor for B lymphocyte differentiation, the missing down-regulation of this cytokine, and others such as TNF, may be a significant risk factor in rheumatic diseases. Since in these patients, administration of prednisolone or the chronic inflammatory process itself alters adrenal function, endogenous adrenal hormones in relation to proinflammatory cytokines change. Furthermore, these mechanisms may also lead to

  4. Diabetes-related changes in brain beta adrenoreceptors in rats as assessed by quantitative autoradiography: relationship to hypothalamic norepinephrine metabolism and pituitary-gonadal hormone secretion.

    PubMed

    Bitar, M S; DeSouza, E B

    1990-09-01

    Streptozotocin (STZ)-induced diabetes produced significant and selective alterations in brain beta adrenoreceptor subtypes, norepinephrine (NE) metabolism and pituitary-testicular hormone in male rats. The densities of beta-1 but not beta-2 adrenoreceptors were increased in hypothalamus (anterior and lateral nuclei), thalamus (ventral posterior nucleus) and amygdala (basolateral nucleus) of the STZ diabetic rats. In contrast, a decrease in the rate of metabolism of NE (estimated by the concentration of the NE metabolite, 3-methoxy-4-hydroxyphenylglycol) was observed in these STZ-treated animals. Serum concentrations of luteinizing hormone and testosterone were lower in the STZ diabetic rats. Pretreatment of rats with nicotinamide prevented the induction of hyperglycemia, upregulation of brain beta-1 adrenoreceptors, decreases in NE metabolism and reduction in serum levels of luteinizing hormone and testosterone seen in STZ-treated rats. These data suggest that derangements in the hypothalamic-pituitary-testicular axis seen in uncontrolled diabetes may be secondary to decreases in NE metabolism and compensatory upregulation of beta-1 adrenoreceptors in brain.

  5. Hormone levels

    MedlinePlus

    Blood or urine tests can determine the levels of various hormones in the body. This includes reproductive hormones, thyroid hormones, adrenal hormones, pituitary hormones, and many others. For more information, see: ...

  6. Down-regulation of hypothalamic kisspeptin and its receptor, Kiss1r, mRNA expression is associated with stress-induced suppression of luteinising hormone secretion in the female rat.

    PubMed

    Kinsey-Jones, J S; Li, X F; Knox, A M I; Wilkinson, E S; Zhu, X L; Chaudhary, A A; Milligan, S R; Lightman, S L; O'Byrne, K T

    2009-01-01

    Identification of kisspeptin (Kiss1) and its G protein-coupled receptor 54 (Kiss1r) as an essential component of the hypothalamic-pituitary-gonadal (HPG) axis controlling gonadotrophin secretion raises the possibility that kisspeptin-Kiss1r signalling may play a critical role in the transduction of stress-induced suppression of reproduction. We examined the effects of: (i) three different stressors, known to suppress pulsatile luteinising hormone (LH) secretion; (ii) corticotrophin-releasing factor (CRF); and (iii) corticosterone on Kiss1 and Kiss1r expression in key hypothalamic sites regulating gonadotrophin secretion: the medial preoptic area (mPOA) and arcuate nucleus (ARC). Ovariectomised oestrogen-replaced rats were implanted with i.v., subcutaneous or i.c.v. cannulae. Blood samples were collected at 5-min intervals for 5-6 h for detection of LH. Quantitative reverse transcriptase-polymerase chain reaction was used to determine Kiss1 and Kiss1r mRNA levels in brain punches of the mPOA and ARC collected 6 h after restraint, insulin-induced hypoglycaemia or lipopolysaccharide stress, or after i.c.v. administration of CRF, or acute or chronic subcutaneous administration of corticosterone. We observed down-regulation of at least one component of the kisspeptin-Kiss1r signalling system by each of the stress paradigms within the mPOA and ARC. CRF decreased Kiss1 and Kiss1r expression in both the mPOA and ARC. Both acute and chronic stress levels of corticosterone resulted in a concomitant decrease in Kiss1 and an increase in kiss1r mRNA expression in the mPOA and ARC. This differential regulation of Kiss1 and Kiss1r might account for the lack of effect corticosterone has on pulsatile LH secretion. Considering the pivotal role for kisspeptin-Kiss1r signalling in the control of the HPG axis, these results suggest that the reduced Kiss1-Kiss1r expression may be a contributing factor in stress-related suppression of LH secretion.

  7. Neuroendocrine and reproductive consequences of overexpression of growth hormone in transgenic mice.

    PubMed

    Bartke, A; Cecim, M; Tang, K; Steger, R W; Chandrashekar, V; Turyn, D

    1994-09-01

    Availability of recombinant growth hormone (GH) and development of long-acting formulations of this material will undoubtedly lead to widespread use of GH in animal industry and in medicine. GH can act, directly or indirectly, on multiple targets, but its influence on the reproductive system and on the hormonal control of reproduction is poorly understood. Overexpression of GH genes in transgenic animals provides a unique opportunity to study the effects of long-term GH excess. Transgenic mice overexpressing bovine, ovine, or rat GH (hormones with actions closely resembling, if not identical to, those of endogenous [mouse] GH), exhibit enhancement of growth, increased adult body size, and reduced life-span as well as a number of endocrine and reproductive abnormalities. Ectopic overexpression of bovine GH (bGH) driven by metallothionein or phosphoenolpyruvate carboxykinase promoters is associated with altered activity of hypothalamic neurons which produce somatostatin, loss of adenohypophyseal GH releasing hormone (GHRH) receptors, and suppression of endogenous (mouse) GH release. Elevation of plasma levels of GH (primarily bGH) and insulin-like growth factor (IGF-I) in these transgenic mice leads to increases in the number of hepatic GH and prolactin (PRL) receptors, in the serum levels of GH-binding protein (GHBP), in the percent of GHBP complexed with GH, and in the circulating insulin levels. In addition, plasma adrenocorticotropic hormone (ACTH) and corticosterone levels are elevated. Plasma levels of luteinizing hormone (LH), as well as its synthesis and release, are not consistently affected, but follicle-stimulating hormone (FSH) levels are suppressed, apparently due to pre- and post-translational effects. Pituitary lactotrophs exhibit characteristics of chronic enhancement of secretory activity, and plasma PRL levels are elevated. Prolactin responses to mating or to pharmacological blockade of dopamine synthesis are abnormal. Reproductive life span and

  8. Impact of the Leu7Pro polymorphism of preproNPY on diurnal NPY and hormone secretion in type 2 diabetes.

    PubMed

    Jaakkola, U; Koulu, M; Karvonen, M K; Seppälä, H; Pesonen, U; Vahlberg, T; Kallio, J

    2007-05-01

    Neuropeptide Y (NPY) is a sympathetic neurotransmitter that plays a role in e.g. circulation, hormone release and angiogenesis. Earlier studies have shown that the Leucine 7 to Proline 7 (Leu7Pro) polymorphism of preproNPY is associated with increased risk for vascular complications in type 2 diabetes. The mechanism for this maybe altered transmitter and hormone levels or altered cardiovascular functions, which have been observed in healthy subjects having the Leu7Pro polymorphism. The current study was undertaken to explore if the Leu7Pro polymorphism has an impact on these functions in subjects with type 2 diabetes. Diurnal measurements were performed for Finnish Caucasian type 2 diabetes patients of two preproNPY genotypes (matched by sex, age, BMI, duration of diabetes and HbA1c) in resting position to prevent sympathetic stimulation. Standard meals were offered during the 24-hour study period. Nine subjects with the Leu7Pro polymorphism and ten subjects without this polymorphism were studied. Plasma concentrations of NPY, glucose, insulin, cortisol, prolactin and leptin were measured by taking blood samples at 20 time points (from 8 a.m. to 8 a.m.). Heart rate and blood pressure were measured at the same time points. The results show that NPY concentrations were similar in both preproNPY genotypes. Glucose, insulin, cortisol and leptin concentrations as well as heart rate and blood pressure were also similar. However, a significant difference between genotypes was found in the association of NPY concentrations with cortisol concentrations (p for difference=0.002). Also a statistically significant negative association of plasma NPY levels with plasma glucose levels was found in both genotypes. Since no impact of preproNPY genotype on mean NPY or hormone levels were detected in subjects with type 2 diabetes, the mechanisms for the increased risk for diabetic complications in the subjects with the Leu7Pro polymorphism need to be further explored.

  9. Morvan's syndrome with anti contactin associated protein like 2 – voltage gated potassium channel antibody presenting with syndrome of inappropriate antidiuretic hormone secretion

    PubMed Central

    Sharma, Anjani Kumar; Kaur, Manminder; Paul, Madhuparna

    2016-01-01

    Morvan's syndrome is a rare autoimmune disorder characterized by triad of peripheral nerve hyperexcitability, autonomic dysfunction, and central nervous system symptoms. Antibodies against contactin-associated protein-like 2 (CASPR2), a subtype of voltage-gated potassium channel (VGKC) complex, are found in a significant proportion of patients with Morvan's syndrome and are thought to play a key role in peripheral as well as central clinical manifestations. We report a patient of Morvan's syndrome with positive CASPR2–anti-VGKC antibody having syndrome of inappropriate antidiuretic hormone as a cause of persistent hyponatremia.

  10. Morvan's syndrome with anti contactin associated protein like 2 – voltage gated potassium channel antibody presenting with syndrome of inappropriate antidiuretic hormone secretion

    PubMed Central

    Sharma, Anjani Kumar; Kaur, Manminder; Paul, Madhuparna

    2016-01-01

    Morvan's syndrome is a rare autoimmune disorder characterized by triad of peripheral nerve hyperexcitability, autonomic dysfunction, and central nervous system symptoms. Antibodies against contactin-associated protein-like 2 (CASPR2), a subtype of voltage-gated potassium channel (VGKC) complex, are found in a significant proportion of patients with Morvan's syndrome and are thought to play a key role in peripheral as well as central clinical manifestations. We report a patient of Morvan's syndrome with positive CASPR2–anti-VGKC antibody having syndrome of inappropriate antidiuretic hormone as a cause of persistent hyponatremia. PMID:27695240

  11. The secretion of parathyroid hormone-related protein in the saliva of sheep and its effects on the salivary clearance of phosphate, calcium, magnesium, potassium and sodium ions.

    PubMed

    Dua, K; Abbas, S K; Care, A D

    1995-07-01

    Parathyroid hormone-related protein (PTHrP(1-34)) was infused into five sheep, each fitted with a large rumen cannula. After infusion, significant increases were observed in the total and ionized calcium concentrations in plasma but not in saliva. In contrast, significant decreases in the plasma concentrations of phosphate and potassium and corresponding increases in their salivary concentrations and clearance rates were observed. The salivary concentration of endogenous PTH1P(1-34) was significantly greater than that in plasma sampled simultaneously, but during the infusion of PTHrP(1-34) both plasma and salivary concentrations of PTHrP(1-34) increased.

  12. Lack of sensorial innervation in the newborn female rats affects the activity of hypothalamic monoaminergic system and steroid hormone secretion during puberty.

    PubMed

    Quiróz, Ubaldo; Morales-Ledesma, Leticia; Morán, Carolina; Trujillo, Angélica; Domínguez, Roberto

    2014-06-01

    There is evidence that sensory innervation plays a role regulating ovarian functions, including fertility.Since sensory denervation by means of capsaicin in newborn female rats results in a lower response togonadotropins, the present study analyzed the effects that sensory denervation by means of capsaicin in neonatal rats has on the concentration of monoamines in the anterior(AH) and medium (MH) hypothalamus, and on steroid hormone levels in serum. Groups of newborn female rats were injected subcutaneously with capsaicin and killed at 10, 20, and 30 days of age and on the first vaginal estrous.The concentrations of noradrenaline, dopamine, serotonin(5-HT), and their metabolites in the AH and MH were measured using HPLC, and the levels of estradiol (E),progesterone (P), testosterone (T), FSH, and luteinizing hormone using radioimmunoanalysis. The results show thatat 20 days of age, capsaicin-treated rats have lowernoradrenergic and serotonergic activities in the AH, and that the dopaminergic activity was lower in the MH. These results suggest that the sensorial system connections within the monoaminergic systems of the AH and MH are different.Capsaicin-treated animals had lower T, E, and P levels than in the control group, suggesting that the lower activity in the AH monoaminergic system and lower hormonesecretion could be explained by the blockade of information mediated by the sensory innervation (probably substance P), mainly between the ovary and the AH.

  13. Whey proteins have beneficial effects on intestinal enteroendocrine cells stimulating cell growth and increasing the production and secretion of incretin hormones.

    PubMed

    Gillespie, Anna L; Calderwood, Danielle; Hobson, Laura; Green, Brian D

    2015-12-15

    Whey protein has been indicated to curb diet-induced obesity, glucose intolerance and delay the onset of type 2 diabetes mellitus. Here the effects of intact crude whey, intact individual whey proteins and beta-lactoglobulin hydrolysates on an enteroendocrine (EE) cell model were examined. STC-1 pGIP/neo cells were incubated with several concentrations of yogurt whey (YW), cheese whey (CW), beta-lactoglobulin (BLG), alpha-lactalbumin (ALA) and bovine serum albumin (BSA). The findings demonstrate that BLG stimulates EE cell proliferation, and also GLP-1 secretion (an effect which is lost following hydrolysis with chymotrypsin or trypsin). ALA is a highly potent GLP-1 secretagogue which also increases the intracellular levels of GLP-1. Conversely, whey proteins and hydrolysates had little impact on GIP secretion. This appears to be the first investigation of the effects of the three major proteins of YW and CW on EE cells. The anti-diabetic potential of whey proteins should be further investigated.

  14. Human growth hormone.

    PubMed

    Strobl, J S; Thomas, M J

    1994-03-01

    The study of human growth hormone is a little more than 100 years old. Growth hormone, first identified for its dramatic effect on longitudinal growth, is now known to exert generalized effects on protein, lipid, and carbohydrate metabolism. Additional roles for growth hormone in human physiology are likely to be discovered in the areas of sleep research and reproduction. Furthermore, there is some indication that growth hormone also may be involved in the regulation of immune function, mental well-being, and the aging process. Recombinant DNA technology has provided an abundant and safe, albeit expensive, supply of human growth hormone for human use, but the pharmacological properties of growth hormone are poor. Most growth hormone-deficient individuals exhibit a secretory defect rather than a primary defect in growth hormone production, however, and advances in our understanding of the neuroendocrine regulation of growth hormone secretion have established the basis for the use of drugs to stimulate release of endogenously synthesized growth hormone. This promises to be an important area for future drug development. PMID:8190748

  15. PI3K signalling in GnRH actions on dispersed goldfish pituitary cells: relationship with PKC-mediated LH and GH release and regulation of long-term effects on secretion and total cellular hormone availability.

    PubMed

    Pemberton, Joshua G; Orr, Michael E; Stafford, James L; Chang, John P

    2014-09-01

    Goldfish pituitary cells are exposed to two GnRHs, salmon (s)GnRH and chicken (c)GnRH-II. Phosphoinositide 3-kinase (PI3K) and protein kinase C (PKC) both participate in acute sGnRH- and cGnRH-II-stimulated LH and GH release. Using goldfish pituitary cells, we examined the relationship between PI3K and PKC in acute LH and GH secretion, and PI3K involvement in chronic hormone release and total LH and GH availability. The PI3K inhibitor LY294002 did not affect PKC agonists-induced LH or GH release, and PKC agonists did not alter PI3K p85 phosphorylation, suggesting PKC activation is not upstream of PI3K in acute hormone release. In 2, 6, 12 and 24h treatments, LY294002 did not affect LH release but stimulated total LH availability at 6h. sGnRH stimulatory actions on LH release and total availability at 12 and 24h, and cGnRH-II effects on these parameters at 6h were inhibited by LY294002. LY294002 enhanced basal GH release at 2 and 6h, but reduced total GH at 12 and 24h. Increased GH release was seen following 6, 12 and 24h of sGnRH, and 2, 6 and 24h of cGnRH-II treatment but total GH availability was only elevated by 24h cGnRH-II treatment. Whereas LY294002 inhibited GH release responses to sGnRH at 12h and cGnRH-II at 6h, it attenuated cGnRH-II-elicited, but not sGnRH-induced, effects on total GH. These results indicate that PI3K differentially modulates long-term basal and GnRH-stimulated hormone release, and total hormone availability, in a time-, cell-type-, and GnRH isoform-selective manner.

  16. The relationship between luteinizing hormone and estradiol secretion in female precocious puberty: evaluation by sensitive gonadotropin assays and the leuprolide stimulation test.

    PubMed

    Garibaldi, L R; Aceto, T; Weber, C; Pang, S

    1993-04-01

    We used the GnRH agonist (GnRHa) stimulation test (20 micrograms/kg leuprolide sc, followed by 24-h serial sampling) to investigate the relationship between gonadotropin and estradiol (E2) secretion in the early phase of female central precocious puberty (CPP). Girls with CPP and moderately increased (early pubertal) peak E2 concentrations after GnRHa stimulation (136 +/- 11 pmol/L; range, 92-176; group B; n = 7) were compared to girls with CPP and higher (midpubertal) peak E2 responses to GnRHa (mean +/- SE, 590 +/- 63 pmol/L; range, 235-1189; group C; n = 19) and to a group of subjects with no breast development and a prepubertal hypothalamic-pituitary-gonadal axis (peak E2 response to GnRHa, 39 +/- 7 pM/L; range, 18-62; group A; n = 6). Compared to group A subjects, patients in group B had similar (P > 0.2) peak GnRHa-stimulated LH concentrations (B, 4.8 +/- 1 IU/L; A, 2.3 +/- 0.5 IU/L) and peak nocturnal LH (B, 0.81 +/- 0.2; A, 0.25 +/- 0 IU/L), but higher peak GnRHa-stimulated FSH concentrations (B, 26 +/- 7; A, 11 +/- 2 IU/L; P < 0.05) and mean nocturnal FSH (B, 4.2 +/- 1; A, 1.1 +/- 0.3 IU/L; P < 0.05) concentrations. Compared to group B, group C patients had higher (P < 0.001) GnRHa-stimulated peak LH (67 +/- 19 IU/L) and higher (P < 0.05) peak nocturnal LH (9.7 +/- 2.9 IU/L) concentrations, but similar GnRHa-stimulated peak FSH (27 +/- 3 IU/L) and mean nocturnal FSH (3.8 +/- 0.5 IU/L) levels. Group C patients with a ratio of peak GnRHa-stimulated LH to FSH concentrations below or above 1, respectively, had similar peak E2 responses to GnRHa (516 +/- 80 vs. 644 +/- 92 pM/L; P > 0.1). Stepwise regression analysis indicated that the peak LH response to GnRHa (r = 0.76; P < 0.001), but none of the FSH secretory parameters (P > 0.10), affected the E2 response to GnRHa. These data suggest that girls with CPP in the early phase of activation of the hypothalamic-pituitary-gonadal axis are capable of clinically relevant E2 production, which may occur in the face of

  17. Dose-dependent effects of a soluble dietary fibre (pectin) on food intake, adiposity, gut hypertrophy and gut satiety hormone secretion in rats.

    PubMed

    Adam, Clare L; Williams, Patricia A; Garden, Karen E; Thomson, Lynn M; Ross, Alexander W

    2015-01-01

    Soluble fermentable dietary fibre elicits gut adaptations, increases satiety and potentially offers a natural sustainable means of body weight regulation. Here we aimed to quantify physiological responses to graded intakes of a specific dietary fibre (pectin) in an animal model. Four isocaloric semi-purified diets containing 0, 3.3%, 6.7% or 10% w/w apple pectin were offered ad libitum for 8 or 28 days to young adult male rats (n = 8/group). Measurements were made of voluntary food intake, body weight, initial and final body composition by magnetic resonance imaging, final gut regional weights and histology, and final plasma satiety hormone concentrations. In both 8- and 28-day cohorts, dietary pectin inclusion rate was negatively correlated with food intake, body weight gain and the change in body fat mass, with no effect on lean mass gain. In both cohorts, pectin had no effect on stomach weight but pectin inclusion rate was positively correlated with weights and lengths of small intestine and caecum, jejunum villus height and crypt depth, ileum crypt depth, and plasma total glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) concentrations, and at 8 days was correlated with weight and length of colon and with caecal mucosal depth. Therefore, the gut's morphological and endocrine adaptations were dose-dependent, occurred within 8 days and were largely sustained for 28 days during continued dietary intervention. Increasing amounts of the soluble fermentable fibre pectin in the diet proportionately decreased food intake, body weight gain and body fat content, associated with proportionately increased satiety hormones GLP-1 and PYY and intestinal hypertrophy, supporting a role for soluble dietary fibre-induced satiety in healthy body weight regulation. PMID:25602757

  18. Suckling and salsolinol attenuate responsiveness of the hypothalamic-pituitary-adrenal axis to stress: focus on catecholamines, corticotrophin-releasing hormone, adrenocorticotrophic hormone, cortisol and prolactin secretion in lactating sheep.

    PubMed

    Hasiec, M; Tomaszewska-Zaremba, D; Misztal, T

    2014-12-01

    In mammals, the responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis to stress is reduced during lactation and this mainly results from suckling by the offspring. The suckling stimulus causes a release of the hypothalamic 1-metyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (salsolinol) (a derivative of dopamine), one of the prolactin-releasing factors. To investigate the involvement of salsolinol in the mechanism suppressing stress-induced HPA axis activity, we conducted a series of experiments on lactating sheep, in which they were treated with two kinds of isolation stress (isolation from the flock with lamb present or absent), combined with suckling and/or i.c.v infusion of salsolinol and 1-methyl-3,4-dihydro-isoqinoline (1-MeDIQ; an antagonistic analogue of salsolinol). Additionally, a push-pull perfusion of the infundibular nucleus/median eminence (IN/ME) and blood sample collection with 10-min intervals were performed during the experiments. Concentrations of perfusate corticotrophin-releasing hormone (CRH) and catecholamines (noradrenaline, dopamine and salsolinol), as well as concentrations of plasma adenocorticotrophic hormone (ACTH), cortisol and prolactin, were assayed. A significant increase in perfusate noradrenaline, plasma ACTH and cortisol occurred in response to both kinds of isolation stress. Suckling and salsolinol reduced the stress-induced increase in plasma ACTH and cortisol concentrations. Salsolinol also significantly reduced the stress-induced noradrenaline and dopamine release within the IN/ME. Treatment with 1-MeDIQ under the stress conditions significantly diminished the salsolinol concentration and increased CRH and cortisol concentrations. Stress and salsolinol did not increase the plasma prolactin concentration, in contrast to the suckling stimulus. In conclusion, salsolinol released in nursing sheep may have a suppressing effect on stress-induced HPA axis activity and peripheral prolactin does not appear to participate in

  19. Gibberellin secreting rhizobacterium, Pseudomonas putida H-2-3 modulates the hormonal and stress physiology of soybean to improve the plant growth under saline and drought conditions.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Khan, Abdul Latif; Kim, Min-Ji; Park, Jae-Man; Kim, Bo-Ra; Shin, Dong-Hyun; Lee, In-Jung

    2014-11-01

    The physiological changes in tolerant soybean plants under salt and drought stress conditions with Pseudomonas putida H-2-3 were investigated. A bacterial isolate H-2-3 was isolated from soil and identified as Pseudomonas putida H-2-3 by 16S rDNA sequences. The treatment of P. putida H-2-3 significantly increased the length, fresh and dry weight of shoot and chlorophyll content in gibberellins (GAs) deficient mutant Waito-c rice seedlings over the control, it might be the presence of GA1, GA4, GA9 and GA20. The soybean plant growth was retarded in salt (120 mM sodium chloride) and drought (15% polyethylene glycol) stress conditions at 10 days treatments, while P. putida H-2-3 effectively enhanced the shoot length and fresh weight of plants suffered at salt and drought stress. The chlorophyll content was lower in abiotic stress conditions and bacterial inoculant P. putida H-2-3 mitigated the stress effects by an evidence of higher quantity of chlorophyll content in plants exposed to salt and drought. The stress hormonal analysis revealed that individual treatment of P. putida H-2-3, salt and drought significantly enhanced the abscisic acid and salicylic acid content than their control. P. putida H-2-3 applied to salt and drought stressed plants showed a lower level of abscisic acid and salicylic acid and a higher level of jasmonic acid content. Under stress condition induced by salt and drought in plants expressed higher level of total polyphenol, superoxide dismutase and radical scavenging activity and no significant changes in flavonoids. The bio-inoculant, P. putida H-2-3 modulated those antioxidants by declining superoxide dismutase, flavonoids and radical scavenging activity. P. putida H-2-3 induced tolerance against abiotic stress was confirmed by a reduction of Na content in abiotic stressed plants. The results suggest that P. putida H-2-3 application reprograms the chlorophyll, stress hormones and antioxidants expression in abiotic stress affected

  20. Plasma ghrelin and growth hormone regulation in response to metabolic state in hybrid striped bass: effects of feeding, ghrelin and insulin-like growth factor-I on in vivo and in vitro GH secretion.

    PubMed

    Picha, Matthew E; Strom, Christina N; Riley, Larry G; Walker, Alicia A; Won, Eugene T; Johnstone, William M; Borski, Russell J

    2009-05-01

    The regulation of growth hormone (GH) secretion by ghrelin during variable metabolic states is poorly understood. We examined plasma GH and ghrelin in hybrid striped bass (HSB) undergoing seasonally-based feeding and temperature manipulations. Fasting for 21 days (d) at 24 degrees C resulted in catabolism and up-regulation of plasma GH and ghrelin relative to fed controls. Continued fasting during cold-banking (14 degrees C, 90 d) resulted in a further 43-fold increase in ghrelin while GH remained elevated. A subsequent 19 day refeeding period at 24 degrees C elicited hyperphagic and compensatory growth responses, accompanied by declines in ghrelin and GH. We then tested the role of ghrelin in stimulating GH release in vivo and in vitro. Intraperitoneal injections of ghrelin resulted in dose-dependent increases in plasma GH after 6 hours (h). Ghrelin also increased GH release from HSB pituitaries during 6h incubations. Lastly, we assessed how metabolic state, ghrelin and insulin-like growth factor-I (IGF-I) affect in vitro pituitary GH release. Spontaneous GH release was 5.2-fold higher from pituitaries of fasted compared with fed animals. Ghrelin was equally effective in stimulating GH release from pituitaries of fed and starved animals, while it was ineffective in enhancing GH release from pituitaries of starved (21 d) then refed (4d) HSB. Incubation with IGF-I inhibited GH release regardless of metabolic state. These studies are the first to show that seasonally-based periods of feed deprivation and low temperature yield sustained increases in GH secretion that are likely mediated, at least partially, through elevated ghrelin, reduced IGF-I negative feedback and fasting-induced spontaneous GH release.

  1. Hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH): therapeutic decision-making in real-life cases

    PubMed Central

    Laville, Maurice; Burst, Volker; Peri, Alessandro; Verbalis, Joseph G.

    2013-01-01

    Despite being the most common electrolyte disturbance encountered in clinical practice, the diagnosis and treatment of hyponatremia (defined as a serum sodium concentration <135 mmol/L) remains far from optimal. This is extremely troubling because not only is hyponatremia associated with increased morbidity, length of hospital stay and hospital resource use, but it has also been shown to be associated with increased mortality. The reasons for this poor management may partly lie in the heterogeneous nature of the disorder; hyponatremia presents with a variety of possible etiologies, differing symptomology and fluid volume status, thereby making its diagnosis potentially complex. In addition, a general lack of awareness of the clinical impact of the disorder, a fear of adverse outcomes through overcorrection of sodium levels, and a lack of effective targeted treatments until recent years, may all have contributed to a reticence to actively treat cases of hyponatremia. There is therefore a clear unmet need to further educate physicians on the pathophysiology, diagnosis and management of this important condition. Through the use of a variety of real-world cases of patients with hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone—a condition that accounts for approximately one-third of all cases of hyponatremia—this supplement aims to provide a comprehensive overview of the challenges faced in diagnosing and managing hyponatremia. These cases will also help to illustrate how some of the limitations of traditional therapies may be overcome with the use of vasopressin receptor antagonists. PMID:26069838

  2. Distribution of galanin receptor-2 immunoreactive neurones in the ovine hypothalamus: no evidence for involvement in the control of gonadotrophin-releasing hormone secretion.

    PubMed

    Chambers, G; Whitelaw, C M; Robinson, J E; Evans, N P

    2007-12-01

    Galanin is a small neuropeptide that mediates its effects via three receptor isoforms: galanin receptor-1, galanin receptor-2 and galanin receptor-3 (Gal-R1, Gal-R2 and Gal-R3). Galanin is thought to be an important intermediate in signalling in the hypothalamic-pituitary-gonadal axis and has been widely detected in the ovine hypothalamus. The expression of galanin and Gal-R1 has been reported to fluctuate during the reproductive cycle. Although the distribution of Gal-R1 has been determined in the ovine hypothalamus, the distribution of Gal-R2 was hitherto unknown. Using immunohistological and immunofluorescence techniques, we have mapped the distribution of Gal-R2 in the ovine hypothalamus, collected during the follicular phase of the oestrous cycle and examined colocalisation of Gal-R2 with oestrogen receptor alpha (ERalpha) and gonadotrophin-releasing hormone (GnRH). Gal-R2 was expressed in several regions of the hypothalamus (supraoptic nucleus, paraventricular nucleus, ventromedial nucleus, arcuate nucleus) but not as widely expressed as Gal-R1. Areas of Gal-R2 expression overlapped with those reported for Gal-R1. We observed that, in certain defined regions of the hypothalamus, up to 50% of neurones that express Gal-R2 also express ERalpha. No neurones coexpressed Gal-R2 and GnRH. Thus, we conclude that, in follicular phase animals, this receptor plays little or no role in direct intermediary signal transmission in GnRH-mediated control of the reproductive cycle.

  3. Assessing the presence of abnormal regulation of cortisol secretion by membrane hormone receptors: in vivo and in vitro studies in patients with functioning and non-functioning adrenal adenoma.

    PubMed

    Dall'Asta, C; Ballarè, E; Mantovani, G; Ambrosi, B; Spada, A; Barbetta, L; Colombo, P; Travaglini, P; Loli, P; Beck-Peccoz, P

    2004-08-01

    Regulation of cortisol secretion by aberrant hormone receptors may play a role in the pathogenesis of ACTH-independent Cushing's syndrome. In this study, the topic was evaluated by combining in vivo and in vitro approaches. Cortisol responses to various stimuli (standard meal, GnRH + TRH, cisapride, vasopressin, glucagon) were assessed in 6 patients with clinical or subclinical adrenal Cushing's syndrome, and non-functioning adrenal adenoma in two cases. Abnormal responses were observed in three patients with Cushing's syndrome; one patient showed a gastric inhibitory polypeptide (GIP)-dependent cortisol rise after meal, together with responses after GnRH and cisapride; the second patient showed an LH-dependent cortisol response to GnRH, and in the third cortisol rose after cisapride. The pattern of receptor expression performed by RT-PCR showed that while GIP-R was only expressed in tumor from the responsive patient, 5-hydroxytryptamine type 4 receptor and LH-R were also present in normal adrenal tissues and tissues from non-responsive patients. Interestingly, an activating mutation of Gsalpha gene was identified in one of these tumors. Therefore, cortisol responses to agents operating via Gs protein coupled receptors (in one case associated with Gsalpha mutation) were found in Cushing's patients, while these responses were absent in the others. The finding of receptor expression in normal and non-responsive tumors suggests that different mechanisms are probably involved in inducing in vivo cortisol responses. PMID:15326569

  4. Influence of low protein diets on gene expression of digestive enzymes and hormone secretion in the gastrointestinal tract of young weaned piglets*

    PubMed Central

    Tian, Zhi-mei; Ma, Xian-yong; Yang, Xue-fen; Fan, Qiu-li; Xiong, Yun-xia; Qiu, Yue-qin; Wang, Li; Wen, Xiao-lu; Jiang, Zong-yong

    2016-01-01

    To investigate dietary protein level effects on digestive mechanisms, weaned piglets were fed for 45 d with diets containing 20%, 17%, or 14% crude protein (CP) supplemented to meet requirements for essential amino acids. This article describes the influence of dietary protein on gastrointestinal hormones and expression of an array of digestive enzymes in the gastrointestinal tract and pancreas. Results indicated that there were no significant differences in expression of enzymes involved in carbohydrate digestion, except for maltase in the duodenum. In the jejunum, amylase expression in pigs fed 20% CP was much higher than that in pigs fed other diets (P<0.05) and maltase expression in those fed 17% CP was higher than that in other treatments (P<0.05). Although there were no remarkable differences in expression of aminopeptidase in the small intestine or carboxypeptidase in the pancreas (P>0.05), there was a trend towards higher expression of various proteases in pigs fed 17% CP. The duodenal expression of enteropeptidase in diets with 14% and 17% CP was significantly higher than that with 20% CP (P<0.05), but treatment differences did not existed in jejunum (P>0.05). The expression of GPR93 as a nutrient-responsive G protein-coupled receptor in 14% and 17% CP diets was significantly higher than that in 20% CP diet in the small intestine (P<0.05). The expressions of genes for pancreatic enzymes, lipase and elastase, were significantly higher in pigs fed diets with low CP, while similar trends occurred for carboxypeptidase, chymotrypsin and amylase. Conversely, the gastric expressions of pepsinogen A and progastricsin were lower with the 17% CP diet. Differences between treatments were found in the gastric antral contents of cholecystokinin and somatostatin: both increased in pigs fed 17% CP, accompanied by decreased content of motilin, which was also seen in plasma concentrations. These patterns were not reflected in duodenal contents. In general, 17% dietary CP

  5. Specific involvement of gonadal hormones in the functional maturation of growth hormone releasing hormone (GHRH) neurons.

    PubMed

    Gouty-Colomer, Laurie-Anne; Méry, Pierre-François; Storme, Emilie; Gavois, Elodie; Robinson, Iain C; Guérineau, Nathalie C; Mollard, Patrice; Desarménien, Michel G

    2010-12-01

    Growth hormone (GH) is the key hormone involved in the regulation of growth and metabolism, two functions that are highly modulated during infancy. GH secretion, controlled mainly by GH releasing hormone (GHRH), has a characteristic pattern during postnatal development that results in peaks of blood concentration at birth and puberty. A detailed knowledge of the electrophysiology of the GHRH neurons is necessary to understand the mechanisms regulating postnatal GH secretion. Here, we describe the unique postnatal development of the electrophysiological properties of GHRH neurons and their regulation by gonadal hormones. Using GHRH-eGFP mice, we demonstrate that already at birth, GHRH neurons receive numerous synaptic inputs and fire large and fast action potentials (APs), consistent with effective GH secretion. Concomitant with the GH secretion peak occurring at puberty, these neurons display modifications of synaptic input properties, decrease in AP duration, and increase in a transient voltage-dependant potassium current. Furthermore, the modulation of both the AP duration and voltage-dependent potassium current are specifically controlled by gonadal hormones because gonadectomy prevented the maturation of these active properties and hormonal treatment restored it. Thus, GHRH neurons undergo specific developmental modulations of their electrical properties over the first six postnatal weeks, in accordance with hormonal demand. Our results highlight the importance of the interaction between the somatotrope and gonadotrope axes during the establishment of adapted neuroendocrine functions.

  6. Role of ACTH and Other Hormones in the Regulation of Aldosterone Production in Primary Aldosteronism.

    PubMed

    El Ghorayeb, Nada; Bourdeau, Isabelle; Lacroix, André

    2016-01-01

    The major physiological regulators of aldosterone production from the adrenal zona glomerulosa are potassium and angiotensin II; other acute regulators include adrenocorticotropic hormone (ACTH) and serotonin. Their interactions with G-protein coupled hormone receptors activate cAMP/PKA pathway thereby regulating intracellular calcium flux and CYP11B2 transcription, which is the specific steroidogenic enzyme of aldosterone synthesis. In primary aldosteronism (PA), the increased production of aldosterone and resultant relative hypervolemia inhibits the renin and angiotensin system; aldosterone secretion is mostly independent from the suppressed renin-angiotensin system, but is not autonomous, as it is regulated by a diversity of other ligands of various eutopic or ectopic receptors, in addition to activation of calcium flux resulting from mutations of various ion channels. Among the abnormalities in various hormone receptors, an overexpression of the melanocortin type 2 receptor (MC2R) could be responsible for aldosterone hypersecretion in aldosteronomas. An exaggerated increase in plasma aldosterone concentration (PAC) is found in patients with PA secondary either to unilateral aldosteronomas or bilateral adrenal hyperplasia (BAH) following acute ACTH administration compared to normal individuals. A diurnal increase in PAC in early morning and its suppression by dexamethasone confirms the increased role of endogenous ACTH as an important aldosterone secretagogue in PA. Screening using a combination of dexamethasone and fludrocortisone test reveals a higher prevalence of PA in hypertensive populations compared to the aldosterone to renin ratio. The variable level of MC2R overexpression in each aldosteronomas or in the adjacent zona glomerulosa hyperplasia may explain the inconsistent results of adrenal vein sampling between basal levels and post ACTH administration in the determination of source of aldosterone excess. In the rare cases of glucocorticoid remediable

  7. Role of ACTH and Other Hormones in the Regulation of Aldosterone Production in Primary Aldosteronism

    PubMed Central

    El Ghorayeb, Nada; Bourdeau, Isabelle; Lacroix, André

    2016-01-01

    The major physiological regulators of aldosterone production from the adrenal zona glomerulosa are potassium and angiotensin II; other acute regulators include adrenocorticotropic hormone (ACTH) and serotonin. Their interactions with G-protein coupled hormone receptors activate cAMP/PKA pathway thereby regulating intracellular calcium flux and CYP11B2 transcription, which is the specific steroidogenic enzyme of aldosterone synthesis. In primary aldosteronism (PA), the increased production of aldosterone and resultant relative hypervolemia inhibits the renin and angiotensin system; aldosterone secretion is mostly independent from the suppressed renin–angiotensin system, but is not autonomous, as it is regulated by a diversity of other ligands of various eutopic or ectopic receptors, in addition to activation of calcium flux resulting from mutations of various ion channels. Among the abnormalities in various hormone receptors, an overexpression of the melanocortin type 2 receptor (MC2R) could be responsible for aldosterone hypersecretion in aldosteronomas. An exaggerated increase in plasma aldosterone concentration (PAC) is found in patients with PA secondary either to unilateral aldosteronomas or bilateral adrenal hyperplasia (BAH) following acute ACTH administration compared to normal individuals. A diurnal increase in PAC in early morning and its suppression by dexamethasone confirms the increased role of endogenous ACTH as an important aldosterone secretagogue in PA. Screening using a combination of dexamethasone and fludrocortisone test reveals a higher prevalence of PA in hypertensive populations compared to the aldosterone to renin ratio. The variable level of MC2R overexpression in each aldosteronomas or in the adjacent zona glomerulosa hyperplasia may explain the inconsistent results of adrenal vein sampling between basal levels and post ACTH administration in the determination of source of aldosterone excess. In the rare cases of glucocorticoid remediable

  8. Growth hormone neurosecretory dysfunction.

    PubMed

    Bercu, B B; Diamond, F B

    1986-08-01

    The basis for understanding clinical disorders in the neuroregulation of GH secretion is derived from the complexity of the CNS-hypothalamic-pituitary axis. Studies in animals and humans demonstrate an anatomic, physiological and pharmacological evidence for neurosecretory control over GH secretion including neurohormones (GRH, somatostatin), neurotransmitters (dopaminergic, adrenergic, cholinergic, serotonergic, histaminergic, GABAergic), and neuropeptides (gut hormones, opioids, CRH, TRH, etc). The observation of a defect in the neuroregulatory control of GH secretion in CNS-irradiated humans and animals led to the hypothesis of a disorder in neurosecretion, GHND, as a cause for short stature. We speculate that in this heterogeneous group of children a disruption in the neurotransmitter-neurohormonal functional pathway could modify secretion ultimately expressed as poor growth velocity and short stature.

  9. MEK1/2 differentially participates in GnRH actions on goldfish LH and GH secretion and hormone protein availability: acute and long-term effects, in vitro.

    PubMed

    Pemberton, Joshua G; Orr, Michael E; Booth, Morgan; Chang, John P

    2013-10-01

    Two endogenous gonadotropin-releasing hormones (GnRHs), sGnRH and cGnRH-II, stimulate LH and GH release via protein kinase C (PKC) signaling in goldfish. In this study, extracellular signal-regulated kinase kinase 1 and 2 (MEK1/2) involvement in acute and prolonged GnRH effects on goldfish gonadotrope and somatotrope functions, as well as potential interactions with PKC in the control of LH and GH release from goldfish pituitary cells was investigated. MEK1/2 inhibitors U0126 and PD098059 significantly decreased sGnRH but not cGnRH-II-stimulated GH release from perifused goldfish pituitary cells and U0126 significantly reduced the GH, but not the LH, release responses to synthetic PKC activators. In long-term static incubations (up to 24h) with goldfish pituitary cells, U0126 generally did not affect basal LH release but attenuated sGnRH- and cGnRH-II-induced LH release, as well as the time-dependent effects of sGnRH and/or cGnRH-II to elevate total LH availability (sum of release and cell content). sGnRH and cGnRH-II reduced cellular GH content and/or total GH availability at 2, 6, and 12h while static incubation with U0126 alone generally increased basal GH release but reduced cellular GH content and/or the total amount of GH available. U0126 also selectively reduced the sGnRH-induced GH release responses at 6 and 24h but paradoxically inhibited cGnRH-II-stimulated GH secretion while enhancing sGnRH-elicited GH release at 2h. Taken together, this study reveals the complexity of GnRH-stimulated MEK1/2 signaling and adds to our understanding of cell-type- and GnRH-isoform-selective signal transduction in the regulation of pituitary cell hormone release and production.

  10. [Laboratory diagnosis of growth hormone].

    PubMed

    Macchia, V; Mariano, A

    1993-09-01

    The role of Clinical Pathology Laboratory in normal and altered growth hormone secretion is discussed. In particular, it is reported that the normal GH secretion can be studied by serum and urine GH determinations whereas the diagnosis of GH deficiency rests upon the demonstration of an inadequate rise serum GH after provocative stimuli and serum measurement of somatomedins (IGF-I) by radioimmunoassay method. As it concerns increase GH secretion the diagnosis is clinically made (acromegaly and gigantism) and the laboratory has only the role to confirm it by the assessment of basal and stimulated GH secretion. PMID:7910655

  11. Stimulation of incretin secreting cells.

    PubMed

    Pais, Ramona; Gribble, Fiona M; Reimann, Frank

    2016-02-01

    The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon like peptide-1 (GLP-1) are secreted from enteroendocrine cells in the gut and regulate physiological and homeostatic functions related to glucose control, metabolism and food intake. This review provides a systematic summary of the molecular mechanisms underlying secretion from incretin cells, and an understanding of how they sense and interact with lumen and vascular factors and the enteric nervous system through transporters and G-protein coupled receptors (GPCRs) present on their surface to ultimately culminate in hormone release. Some of the molecules described below such as sodium coupled glucose transporter 1 (SGLT1), G-protein coupled receptor (GPR) 119 and GPR40 are targets of novel therapeutics designed to enhance endogenous gut hormone release. Synthetic ligands at these receptors aimed at treating obesity and type 2 diabetes are currently under investigation. PMID:26885360

  12. Stimulation of incretin secreting cells

    PubMed Central

    Pais, Ramona; Gribble, Fiona M.; Reimann, Frank

    2016-01-01

    The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon like peptide-1 (GLP-1) are secreted from enteroendocrine cells in the gut and regulate physiological and homeostatic functions related to glucose control, metabolism and food intake. This review provides a systematic summary of the molecular mechanisms underlying secretion from incretin cells, and an understanding of how they sense and interact with lumen and vascular factors and the enteric nervous system through transporters and G-protein coupled receptors (GPCRs) present on their surface to ultimately culminate in hormone release. Some of the molecules described below such as sodium coupled glucose transporter 1 (SGLT1), G-protein coupled receptor (GPR) 119 and GPR40 are targets of novel therapeutics designed to enhance endogenous gut hormone release. Synthetic ligands at these receptors aimed at treating obesity and type 2 diabetes are currently under investigation. PMID:26885360

  13. CT and MR imaging of the adrenal glands in cortisol-secreting tumors.

    PubMed

    Lumachi, Franco; Marchesi, Paolo; Miotto, Diego; Motta, Raffaella

    2011-09-01

    Cushing's syndrome (CS), first described by the neurosurgeon Harvey Cushing in the 1930s, is the result of chronic glucocorticoid excess. In patients with adreno-corticotropic hormone (ACTH)-dependent CS, bilateral hyperplasia of the adrenal cortex occurs, while in those with ACTH-independent primary CS, either adrenocortical tumors or primary adrenal hyperplasia can be observed. Cortisol-secreting adrenocortical tumors are more frequently adenomas, while adrenal carcinoma accounts for only 5% of cases. Unfortunately, no reliable endocrinological tests are available and no specific tumor markers exist to differentiate between benign and malignant adrenal tumors, so both computed tomography (CT) and magnetic resonance (MR) imaging studies are currently required to localize and define adrenal lesions. Additional information to conventional imaging can be obtained using ¹⁸F-fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET)/CT, while percutaneous image-guided fine-needle aspiration cytology (FNAC) in some cases has shown a high accuracy in detecting malignancy and in confirming adrenal metastases. New PET tracers with selective affinity for the adrenal tissue are still under evaluation. Multidetector CT scan, with the combination of unenhanced and dynamic scans, represents the single most accurate modality for the detection and the characterization of adrenal adenomas. In these lesions, chemical-shift MR imaging produces a typical loss of signal intensity on out-of-phase breath-hold gradient-echo images in lipid-rich adenomas. For these lesions there is no difference between CT and MR imaging, while MR chemical shift imaging is very helpful in identifying the additional small group of adenomas where intracellular lipid content is minimal. PMID:21868539

  14. SnapShot: Hormones of the gastrointestinal tract.

    PubMed

    Coate, Katie C; Kliewer, Steven A; Mangelsdorf, David J

    2014-12-01

    Specialized endocrine cells secrete a variety of peptide hormones all along the gastrointestinal (GI) tract, making it one of the largest endocrine organs in the body. Nutrients and developmental and neural cues trigger the secretion of gastrointestinal (GI) hormones from specialized endocrine cells along the GI tract. These hormones act in target tissues to facilitate digestion and regulate energy homeostasis. This SnapShot summarizes the production and functions of GI hormones.

  15. The parathyroid hormone-related protein is secreted during the osteogenic differentiation of human dental follicle cells and inhibits the alkaline phosphatase activity and the expression of DLX3.

    PubMed

    Klingelhöffer, C; Reck, A; Ettl, T; Morsczeck, C

    2016-08-01

    The dental follicle is involved in tooth eruption and it expresses a great amount of the parathyroid hormone-related protein (PTHrP). PTHrP as an extracellular protein is required for a multitude of different regulations of enchondral bone development and differentiation of bone precursor cells and of the development of craniofacial tissues. The dental follicle contains also precursor cells (DFCs) of the periodontium. Isolated DFCs differentiate into periodontal ligament cells, alveolar osteoblast and cementoblasts. However, the role of PTHrP during the human periodontal development remains elusive. Our study evaluated the influence of PTHrP on the osteogenic differentiation of DFCs under in vitro conditions for the first time. The PTHrP protein was highly secreted after 4days of the induction of the osteogenic differentiation of DFCs with dexamethasone (2160.5pg/ml±345.7SD. in osteogenic differentiation medium vs. 315.7pg/ml±156.2SD. in standard cell culture medium; Student's t Test: p<0.05 (n=3)). We showed that the supplementation of the osteogenic differentiation medium with PTHrP inhibited the alkaline phosphatase activity and the expression of the transcription factor DLX3, but the depletion of PTHrP did not support the differentiation of DFCs. Previous studies have shown that Indian Hedgehog (IHH) induces PTHrP and that PTHrP, in turn, inhibits IHH via a negative feedback loop. We showed that SUFU (Suppressor Of Fused Homolog) was not regulated during the osteogenic differentiation in DFCs. So, neither the hedgehog signaling pathway induced PTHrP nor PTHrP suppressed the hedgehog signaling pathway during the osteogenic differentiation in DFCs. In conclusion, our results suggest that PTHrP regulates independently of the hedgehog signaling pathway the osteogenic differentiated in DFCs. PMID:27368119

  16. Growth sensitivity in the epiphyseal growth plate, liver and muscle of SD rats is significantly enhanced by treatment with a fermented soybean product (cheonggukjang) through stimulation of growth hormone secretion.

    PubMed

    Hwang, In Sik; Kim, Ji Eun; Lee, Young Ju; Kwak, Mun Hwa; Lee, Hong Gu; Kim, Hye Sung; Lee, Hee Seob; Hwang, Dae Youn

    2014-01-01

    Cheonggukjang (CKJ), a fermented soybean product, has been reported to have beneficial effects on various chronic diseases, including cardiovascular disease, cancer and immune diseases. To investigate whether CKJ induces growth sensitivity in mammals, alterations of key parameters related to their growth were analyzed. Sprague‑Dawley (SD) rats were treated with a high concentration of CKJ (H‑CKJ) or a low concentration of CKJ (L‑CKJ) for 10 days, and compared with vehicle-treated rats. The CKJ contained a high concentration of total flavonoids, phenolic compounds, daidzein and genistein, compared with the non-fermented soybean product. Body weight was higher in the H‑CKJ‑treated group compared with that in the vehicle‑ and L‑CKJ‑treated groups, whereas the weights of three organs (the brain, liver and kidney) were higher in the L‑CKJ‑treated group compared with the remaining two groups. However, no significant differences in femur length and weight were detected between the CKJ‑ and vehicle‑treated groups. The thickness of the epiphyseal growth plate in proximal femoral epiphysis was broadest in the H‑CKJ‑treated group compared with the vehicle- and L‑CKJ‑treated groups. Furthermore, the level of growth hormone (GH) was highest in the serum of the L‑CKJ‑treated group, although that of the H‑CKJ‑treated group was lower compared with that in the L‑CKJ group. Moreover, the expression levels of the GH receptor increased in the liver tissue, but not in the muscle tissue, of the L‑CKJ‑ and H‑CKJ‑treated groups. In the downstream signaling pathway of the GH receptor, the phosphorylation levels of Akt and Erk were differentially regulated between the liver and muscle. These results suggest that CKJ extract may enhance the sensitivity of the femur, liver and muscle epiphyseal growth plate in SD rats, through the upregulation of GH secretion.

  17. [Paraneoplastic hormonal syndromes].

    PubMed

    Forga, L; Anda, E; Martínez de Esteban, J P

    2005-01-01

    We can define paraneoplastic syndromes as a combination of effects occurring far from the original location of the tumour and independently from the local repercussion of its metastases. Paraneoplastic hormonal syndromes depend on the secretion of hormonal peptides or their precursors, cytokines and, more rarely, thyroidal hormones and Vitamin D, which act in an endocrine, paracrine or autocrine way. Sometimes, paraneoplastic syndromes can be more serious than the consequences of the primary tumour itself and can precede, develop in parallel, or follow the manifestations of this tumour. It is important to recognise a paraneoplastic hormonal syndrome for several reasons, amongst which we would draw attention to three: 1) It can lead to the diagnosis of a previously undetected, underlying malign or benign neoplasia; 2) It can dominate the clinical picture and thus lead to errors with respect to the origin and type of primary tumour; and 3) It can follow the clinical course of the underlying tumour and thus be useful for monitoring its evolution. The molecular mechanisms responsible for the development of these syndromes are not well-known, but it is believed that they might be inherent to the mutations responsible for the primary tumour or depend on epigenetic factors such as methylation. In this review, we consider the following paraneoplastic hormonal syndromes: malign hypercalcaemia, hyponatraemia (inappropiate secretion of the antidiuretic hormone), ectopic Cushing's syndrome, ectopic acromegaly, hypoglycaemia due to tumours different from those of the islet cells and paraneoplastic gynaecomastia; we make a brief final reference to other hormones (calcitonin, somatostatin, and VIP). PMID:16155618

  18. Hormones in pregnancy

    PubMed Central

    Kumar, Pratap; Magon, Navneet

    2012-01-01

    The endocrinology of human pregnancy involves endocrine and metabolic changes that result from physiological alterations at the boundary between mother and fetus. Progesterone and oestrogen have a great role along with other hormones. The controversies of use of progestogen and others are discussed in this chapter. Progesterone has been shown to stimulate the secretion of Th2 and reduces the secretion of Th1 cytokines which maintains pregnancy. Supportive care in early pregnancy is associated with a significant beneficial effect on pregnancy outcome. Prophylactic hormonal supplementation can be recommended for all assisted reproduction techniques cycles. Preterm labor can be prevented by the use of progestogen. The route of administration plays an important role in the drug's safety and efficacy profile in different trimesters of pregnancy. Thyroid disorders have a great impact on pregnancy outcome and needs to be monitored and treated accordingly. Method of locating review: Pubmed, scopus PMID:23661874

  19. Syndrome of inappropriate antidiuretic hormone secretion

    MedlinePlus

    ... in an area of the brain called the hypothalamus . It is then released by the pituitary gland ... asthma Rare causes include: A disease of the hypothalamus or pituitary Cancer, such as lung, small intestine, ...

  20. Growth Hormone-Releasing Hormone in Diabetes

    PubMed Central

    Fridlyand, Leonid E.; Tamarina, Natalia A.; Schally, Andrew V.; Philipson, Louis H.

    2016-01-01

    Growth hormone-releasing hormone (GHRH) is produced by the hypothalamus and stimulates growth hormone synthesis and release in the anterior pituitary gland. In addition, GHRH is an important regulator of cellular functions in many cells and organs. Expression of GHRH G-Protein Coupled Receptor (GHRHR) has been demonstrated in different peripheral tissues and cell types, including pancreatic islets. Among the peripheral activities, recent studies demonstrate a novel ability of GHRH analogs to increase and preserve insulin secretion by beta-cells in isolated pancreatic islets, which makes them potentially useful for diabetes treatment. This review considers the role of GHRHR in the beta-cell and addresses the unique engineered GHRH agonists and antagonists for treatment of type 2 diabetes mellitus. We discuss the similarity of signaling pathways activated by GHRHR in pituitary somatotrophs and in pancreatic beta-cells and possible ways as to how the GHRHR pathway can interact with glucose and other secretagogues to stimulate insulin secretion. We also consider the hypothesis that novel GHRHR agonists can improve glucose metabolism in Type 2 diabetes by preserving the function and survival of pancreatic beta-cells. Wound healing and cardioprotective action with new GHRH agonists suggest that they may prove useful in ameliorating certain diabetic complications. These findings highlight the future potential therapeutic effectiveness of modulators of GHRHR activity for the development of new therapeutic approaches in diabetes and its complications. PMID:27777568

  1. Insulin signaling pathways in lepidopteran ecdysone secretion

    PubMed Central

    Smith, Wendy A.; Lamattina, Anthony; Collins, McKensie

    2014-01-01

    Molting and metamorphosis are stimulated by the secretion of ecdysteroid hormones from the prothoracic glands. Insulin-like hormones have been found to enhance prothoracic gland activity, providing a mechanism to link molting to nutritional state. In silk moths (Bombyx mori), the prothoracic glands are directly stimulated by insulin and the insulin-like hormone bombyxin. Further, in Bombyx, the neuropeptide prothoracicotropic hormone (PTTH) appears to act at least in part through the insulin-signaling pathway. In the prothoracic glands of Manduca sexta, while insulin stimulates the phosphorylation of the insulin receptor and Akt, neither insulin nor bombyxin II stimulate ecdysone secretion. Involvement of the insulin-signaling pathway in Manduca prothoracic glands was explored using two inhibitors of phosphatidylinositol-3-kinase (PI3K), LY294002 and wortmannin. PI3K inhibitors block the phosphorylation of Akt and 4EBP but have no effect on ecdysone secretion, or on the phosphorylation of the MAPkinase, ERK. Inhibitors that block phosphorylation of ERK, including the MEK inhibitor U0126, and high doses of the RSK inhibitor SL0101, effectively inhibit ecdysone secretion. The results highlight differences between the two lepidopteran insects most commonly used to directly study ecdysteroid secretion. In Bombyx, the PTTH and insulin-signaling pathways intersect; both insulin and PTTH enhance the phosphorylation of Akt and stimulate ecdysteroid secretion, and inhibition of PI3K reduces ecdysteroid secretion. By contrast, in Manduca, the action of PTTH is distinct from insulin. The results highlight species differences in the roles of translational regulators such as 4EBP, and members of the MAPkinase pathway such as ERK and RSK, in the regulation of insect ecdysone secretion, and in the impact of nutritionally-sensitive hormones such as insulin in the control of ecdysone secretion and molting. PMID:24550835

  2. Luteinizing hormone (LH)-releasing hormone agonist reduces serum adrenal androgen levels in prostate cancer patients: implications for the effect of LH on the adrenal glands.

    PubMed

    Nishii, Masahiro; Nomura, Masashi; Sekine, Yoshitaka; Koike, Hidekazu; Matsui, Hiroshi; Shibata, Yasuhiro; Ito, Kazuto; Oyama, Tetsunari; Suzuki, Kazuhiro

    2012-01-01

    Recently, adrenal androgens have been targeted as key hormones for the development of castration-resistant prostate cancer therapeutics. Although circulating adrenal androgens originate mainly from the adrenal glands, the testes also supply about 10%. Although widely used in androgen deprivation medical castration therapy, the effect of luteinizing hormone-releasing hormone (LH-RH) agonist on adrenal androgens has not been fully studied. In this study, changes in testicular and adrenal androgen levels were measured and compared to adrenocorticotropic hormone levels. To assess the possible role of LH in the adrenal glands, immunohistochemical studies of the LH receptor in normal adrenal glands were performed. Forty-seven patients with localized or locally progressive prostate cancer were treated with LH-RH agonist with radiotherapy. Six months after initiation of treatment, testosterone, dihydrotestosterone, and estradiol levels were decreased by 90%-95%, and dehydroepiandrosterone-sulfate, dehydroepiandrosterone, and androstenedione levels were significantly decreased by 26%-40%. The suppressive effect of LH-RH agonist at 12 months was maintained. Adrenocorticotropic hormone levels showed an increasing trend at 6 months and a significant increase at 12 months. LH receptors were positively stained in the cortex cells of the reticular layer of the adrenal glands. The long-term LH-RH agonist treatment reduced adrenal-originated adrenal androgens. LH receptors in the adrenal cortex cells of the reticular layer might account for the underlying mechanism of reduced adrenal androgens.

  3. Sympathetic regulation of estradiol secretion from the ovary.

    PubMed

    Uchida, Sae

    2015-01-01

    It is well known that hormone secretion from endocrine glands is regulated by hierarchical feedback mechanisms. However, although Cannon revealed in the 1920s that sympathoadrenal medullary function increased during emergency situations, no studies on the autonomic nervous regulation of hormone secretion have been undertaken for many years. In the past 40 years, the autonomic nervous regulation of insulin secretion from the pancreas, gastrin secretion from the stomach, glucocorticoid secretion from the adrenal cortex, etc., has been demonstrated. Estradiol secretion from the ovary is strongly controlled by the hypothalamic-pituitary-ovarian axis, and its possible regulation by autonomic nerves has been largely unnoticed. Some histological studies have revealed rich adrenergic sympathetic innervation in the ovary. Recently, it has been demonstrated that the activation of the sympathetic nerves to the ovary directly reduces estradiol secretion from the ovary. This article reviews physiological and morphological studies, primarily in rats, on the sympathetic regulation of estradiol secretion from the ovary.

  4. Growth Hormone Response after Administration of L-dopa, Clonidine, and Growth Hormone Releasing Hormone in Children with Down Syndrome.

    ERIC Educational Resources Information Center

    Pueschel, Seigfried M.

    1993-01-01

    This study of eight growth-retarded children with Down's syndrome (aged 1 to 6.5 years) found that administration of growth hormone was more effective than either L-dopa or clonidine. Results suggest that children with Down's syndrome have both anatomical and biochemical hypothalamic derangements resulting in decreased growth hormone secretion and…

  5. Growth hormone in musculoskeletal pain states.

    PubMed

    Bennett, Robert

    2004-08-01

    Growth hormone is essential for normal linear growth and the attainment of an adult mature height. It also plays an important role in cartilage growth and the attainment of normal bone mass. There is only one rheumatic disorder, namely acromegaly, in which abnormalities of growth hormone production play a major etiologic role. However, there is increasing appreciation that suboptimal growth hormone secretion, leading to a state of adult growth hormone deficiency, may occur in the setting of chronic inflammatory disease, chronic corticosteroid use, and fibromyalgia. Therefore, the evaluation and effective management of growth hormone oversecretion and undersecretion is relevant to practicing rheumatologists. PMID:15251074

  6. Does aerobic exercise affect the hypothalamic-pituitary-adrenal hormonal response in patients with fibromyalgia syndrome?

    PubMed Central

    Genc, Aysun; Tur, Birkan Sonel; Aytur, Yesim Kurtais; Oztuna, Derya; Erdogan, Murat Faik

    2015-01-01

    [Purpose] The hypothalamic-pituitary-adrenal (HPA) axis in the etiopathogenesis of fibromyalgia is not clear. This study aimed to analyze the effects of a 6-week aerobic exercise program on the HPA axis in patients with fibromyalgia and to investigate the effects of this program on the disease symptoms, patients’ fitness, disability, and quality of life. [Subjects and Methods] Fifty fibromyalgia patients were randomized to Group 1 (stretching and flexibility exercises at home for 6 weeks) and Group 2 (aerobic exercise three times a week and the same at-home exercises as Group 1 for 6 weeks). Serum levels of cortisol, adrenocorticotropic hormone, insulin-like growth factor-1, and growth hormone were analyzed at baseline and at the end of, and 1 hr after an exercise stress test. [Results] Group 2 showed better improvement in morning stiffness duration and pain. Growth hormone levels significantly increased after intervention and cortisol levels significantly decreased at time-time interaction in both groups. No significant differences in adrenocorticotropic hormone and insulin-like growth factor-1 were found. [Conclusion] The results of this study seem to support the hypothesis that there is a dysregulation of the HPA axis in patients with FM, and that a six-week exercise program can influence symptoms and affect the HPA axis hormones. PMID:26311959

  7. No Postoperative Adrenal Insufficiency in a Patient with Unilateral Cortisol-Secreting Adenomas Treated with Mifepristone Before Surgery

    PubMed Central

    Saroka, Rachel M.; Kane, Michael P.; Robinson, Lawrence; Busch, Robert S.

    2016-01-01

    BACKGROUND Glucocorticoid replacement is commonly required to treat secondary adrenal insufficiency after surgical resection of unilateral cortisol-secreting adrenocortical adenomas. Here, we describe a patient with unilateral cortisol-secreting adenomas in which the preoperative use of mifepristone therapy was associated with recovery of the hypothalamic–pituitary–adrenal (HPA) axis, eliminating the need for postoperative glucocorticoid replacement. CASE PRESENTATION A 66-year-old Caucasian man with type 2 diabetes mellitus, hyperlipidemia, hypertension, and obesity was hospitalized for Fournier’s gangrene and methicillin-resistant Staphylococcus aureus sepsis. Abdominal computed tomography scan revealed three left adrenal adenomas measuring 1.4, 2.1, and 1.2 cm and an atrophic right adrenal gland. Twenty-four-hour urinary free cortisol level was elevated (237 µg/24 hours, reference range 0–50 µg/24 hours). Hormonal evaluation after resolution of the infection showed an abnormal 8 mg overnight dexamethasone suppression test (cortisol postdexamethasone 14.5 µg/dL), suppressed adrenocorticotropic hormone (ACTH; <5 pg/mL, reference range 7.2–63.3 pg/mL), and low-normal dehydroepiandrosterone sulfate (50.5 µg/dL, male reference range 30.9–295.6 µg/dL). Because of his poor medical condition and uncontrolled diabetes, his Cushing’s syndrome was treated with medical therapy before surgery. Mifepristone therapy was started and, within five months, his diabetes was controlled and insulin discontinued. The previously suppressed ACTH increased to above normal range accompanied by an increase in dehydroepiandrosterone sulfate levels, indicating recovery of the HPA axis and atrophic contralateral adrenal gland. The patient received one precautionary intraoperative dose of hydrocortisone and none thereafter. Two days postoperatively, ACTH (843 pg/mL) and cortisol levels (44.8 µg/dL) were significantly elevated, reflecting an appropriate HPA axis response to

  8. Plant peptide hormone signalling.

    PubMed

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions.

  9. Reproductive hormones and bone.

    PubMed

    Nicks, Kristy M; Fowler, Tristan W; Gaddy, Dana

    2010-06-01

    Hypothalamic gonadotropin-releasing hormone (GnRH) stimulates secretion of pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which directly regulate ovarian function. Pituitary FSH can modulate osteoclast development, and thereby influence bone turnover. Pituitary oxytocin and prolactin effects on the skeleton are not merely limited to pregnancy and lactation; oxytocin stimulates osteoblastogenesis and bone formation, whereas prolactin exerts skeletal effects in an age-dependent manner. Cyclic levels of inhibins and estrogen suppress FSH and LH, respectively, and also suppress bone turnover via their suppressive effects on osteoblast and osteoclast differentiation. However, continuous exposure to inhibins or estrogen/androgens is anabolic for the skeleton in intact animals and protects against gonadectomy-induced bone loss. Alterations of one hormone in the hypothalamic-pituitary-gonadal (HPG) axis influence other bone-active hormones in the entire feedback loop in the axis. Thus, we propose that the action of the HPG axis should be extended to include its combined effects on the skeleton, thus creating the HPG skeletal (HPGS) axis.

  10. Plant peptide hormone signalling.

    PubMed

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions. PMID:26374891

  11. Thyroid hormone resistance.

    PubMed

    Olateju, Tolulope O; Vanderpump, Mark P J

    2006-11-01

    Resistance to thyroid hormone (RTH) is a rare autosomal dominant inherited syndrome of reduced end-organ responsiveness to thyroid hormone. Patients with RTH have elevated serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations and normal or slightly elevated serum thyroid stimulating hormone (TSH) level. Despite a variable clinical presentation, the common characteristic clinical features are goitre but an absence of the usual symptoms and metabolic consequences of thyroid hormone excess. Patients with RTH can be classified on clinical grounds alone into either generalized resistance (GRTH), pituitary resistance (PRTH) or combined. Mutations in the thyroid hormone receptor (TR) beta gene are responsible for RTH and 122 different mutations have now been identified belonging to 300 families. With the exception of one family found to have complete deletion of the TRbeta gene, all others have been demonstrated to have minor alterations at the DNA level. The differential diagnosis includes a TSH-secreting pituitary adenoma and the presence of endogenous antibodies directed against thyroxine (T4) and triiodothyronine (T3). Failure to differentiate RTH from primary thyrotoxicosis has resulted in the inappropriate treatment of nearly one-third of patients. Although occasionally desirable, no specific treatment is available for RTH; however, the diagnosis allows appropriate genetic counselling. PMID:17132274

  12. Bile Formation and Secretion

    PubMed Central

    Boyer, James L.

    2014-01-01

    Bile is a unique and vital aqueous secretion of the liver that is formed by the hepatocyte and modified down stream by absorptive and secretory properties of the bile duct epithelium. Approximately 5% of bile consists of organic and inorganic solutes of considerable complexity. The bile-secretory unit consists of a canalicular network which is formed by the apical membrane of adjacent hepatocytes and sealed by tight junctions. The bile canaliculi (~1 μm in diameter) conduct the flow of bile countercurrent to the direction of portal blood flow and connect with the canal of Hering and bile ducts which progressively increase in diameter and complexity prior to the entry of bile into the gallbladder, common bile duct, and intestine. Canalicular bile secretion is determined by both bile salt-dependent and independent transport systems which are localized at the apical membrane of the hepatocyte and largely consist of a series of adenosine triphosphate-binding cassette transport proteins that function as export pumps for bile salts and other organic solutes. These transporters create osmotic gradients within the bile canalicular lumen that provide the driving force for movement of fluid into the lumen via aquaporins. Species vary with respect to the relative amounts of bile salt-dependent and independent canalicular flow and cholangiocyte secretion which is highly regulated by hormones, second messengers, and signal transduction pathways. Most determinants of bile secretion are now characterized at the molecular level in animal models and in man. Genetic mutations serve to illuminate many of their functions. PMID:23897680

  13. Motilin stimulates pepsinogen secretion in Suncus murinus.

    PubMed

    Goswami, Chayon; Tanaka, Toru; Jogahara, Takamichi; Sakai, Takafumi; Sakata, Ichiro

    2015-07-01

    Motilin and ghrelin are gastrointestinal hormones that stimulate the migrating motor complex (MMC) of gastrointestinal motility during the fasting state. In this study, we examined the effect of motilin and ghrelin on pepsinogen secretion in anesthetized suncus (house musk shrew, Suncus murinus), a ghrelin- and motilin-producing mammal. By using a gastric lumen-perfusion system, we found that the intravenous administration of carbachol and motilin stimulated pepsinogen secretion, the latter in a dose-dependent manner, whereas ghrelin had no effect. We then investigated the pathways of motilin-induced pepsinogen secretion using acetylcholine receptor antagonists. Treatment with atropine, a muscarinic acetylcholine receptor antagonist, completely inhibited both carbachol and motilin-induced pepsinogen secretion. Motilin-induced pepsinogen secretion was observed in the vagotomized suncus. This is the first report demonstrating that motilin stimulates pepsinogen secretion, and suggest that this effect occurs through a cholinergic pathway in suncus. PMID:25957475

  14. Hormone supply of the organism in prolonged emotional stress

    NASA Technical Reports Server (NTRS)

    Amiragova, M. G.; Stulnikov, B. V.; Svirskaya, R. I.

    1980-01-01

    The effect of prolonged emotional stress of varying genesis on the hormonal function of the pancreas, thyroid gland, and adrenal cortex was studied. The amount of the hormonal secretion was found to depend on the type of adaptation activity and its duration. High secretion of the hormones observed outside the adaptation activity was examined as an index of the phase transition of defense reactions to the phase of overstress.

  15. Differential Activation in Amygdala and Plasma Noradrenaline during Colorectal Distention by Administration of Corticotropin-Releasing Hormone between Healthy Individuals and Patients with Irritable Bowel Syndrome

    PubMed Central

    Tanaka, Yukari; Kanazawa, Motoyori; Kano, Michiko; Morishita, Joe; Hamaguchi, Toyohiro; Van Oudenhove, Lukas; Ly, Huynh Giao; Dupont, Patrick; Tack, Jan; Yamaguchi, Takuhiro; Yanai, Kazuhiko; Tashiro, Manabu; Fukudo, Shin

    2016-01-01

    Irritable bowel syndrome (IBS) often comorbids mood and anxiety disorders. Corticotropin-releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis, but it is not clear how CRH agonists change human brain responses to interoceptive stimuli. We tested the hypothesis that brain activation in response to colorectal distention is enhanced after CRH injection in IBS patients compared to healthy controls. Brain H215O- positron emission tomography (PET) was performed in 16 male IBS patients and 16 age-matched male controls during baseline, no distention, mild and intense distention of the colorectum using barostat bag inflation. Either CRH (2 μg/kg) or saline (1:1) was then injected intravenously and the same distention protocol was repeated. Plasma adrenocorticotropic hormone (ACTH), serum cortisol and plasma noradrenaline levels were measured at each stimulation. At baseline, CRH without colorectal distention induced more activation in the right amygdala in IBS patients than in controls. During intense distention after CRH injection, controls showed significantly greater activation than IBS patients in the right amygdala. Plasma ACTH and serum cortisol secretion showed a significant interaction between drug (CRH, saline) and distention. Plasma noradrenaline at baseline significantly increased after CRH injection compared to before injection in IBS. Further, plasma noradrenaline showed a significant group (IBS, controls) by drug by distention interaction. Exogenous CRH differentially sensitizes brain regions of the emotional-arousal circuitry within the visceral pain matrix to colorectal distention and synergetic activation of noradrenergic function in IBS patients and healthy individuals. PMID:27448273

  16. Differential Activation in Amygdala and Plasma Noradrenaline during Colorectal Distention by Administration of Corticotropin-Releasing Hormone between Healthy Individuals and Patients with Irritable Bowel Syndrome.

    PubMed

    Tanaka, Yukari; Kanazawa, Motoyori; Kano, Michiko; Morishita, Joe; Hamaguchi, Toyohiro; Van Oudenhove, Lukas; Ly, Huynh Giao; Dupont, Patrick; Tack, Jan; Yamaguchi, Takuhiro; Yanai, Kazuhiko; Tashiro, Manabu; Fukudo, Shin

    2016-01-01

    Irritable bowel syndrome (IBS) often comorbids mood and anxiety disorders. Corticotropin-releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis, but it is not clear how CRH agonists change human brain responses to interoceptive stimuli. We tested the hypothesis that brain activation in response to colorectal distention is enhanced after CRH injection in IBS patients compared to healthy controls. Brain H215O- positron emission tomography (PET) was performed in 16 male IBS patients and 16 age-matched male controls during baseline, no distention, mild and intense distention of the colorectum using barostat bag inflation. Either CRH (2 μg/kg) or saline (1:1) was then injected intravenously and the same distention protocol was repeated. Plasma adrenocorticotropic hormone (ACTH), serum cortisol and plasma noradrenaline levels were measured at each stimulation. At baseline, CRH without colorectal distention induced more activation in the right amygdala in IBS patients than in controls. During intense distention after CRH injection, controls showed significantly greater activation than IBS patients in the right amygdala. Plasma ACTH and serum cortisol secretion showed a significant interaction between drug (CRH, saline) and distention. Plasma noradrenaline at baseline significantly increased after CRH injection compared to before injection in IBS. Further, plasma noradrenaline showed a significant group (IBS, controls) by drug by distention interaction. Exogenous CRH differentially sensitizes brain regions of the emotional-arousal circuitry within the visceral pain matrix to colorectal distention and synergetic activation of noradrenergic function in IBS patients and healthy individuals. PMID:27448273

  17. Third Transmembrane Domain of the Adrenocorticotropic Receptor Is Critical for Ligand Selectivity and Potency

    PubMed Central

    Yang, Yingkui; Mishra, Vinod; Crasto, Chiquito J.; Chen, Min; Dimmitt, Reed; Harmon, Carroll M.

    2015-01-01

    The ACTH receptor, known as the melanocortin-2 receptor (MC2R), plays an important role in regulating and maintaining adrenocortical function. MC2R is a subtype of the melanocortin receptor (MCR) family and has unique characteristics among MCRs. Endogenous ACTH is the only endogenous agonist for MC2R, whereas the melanocortin peptides α-, β-, and γ-melanocyte-stimulating hormone and ACTH are full agonists for all other MCRs. In this study, we examined the molecular basis of MC2R responsible for ligand selectivity using ACTH analogs and MC2R mutagenesis. Our results indicate that substitution of Phe7 with d-Phe or d-naphthylalanine (d-Nal(2′)) in ACTH(1–24) caused a significant decrease in ligand binding affinity and potency. Substitution of Phe7 with d-Nal(2′) in ACTH(1–24) did not switch the ligand from agonist to antagonist at MC2R, which was observed in MC3R and MC4R. Substitution of Phe7 with d-Phe7 in ACTH(1–17) resulted in the loss of ligand binding and activity. Molecular analysis of MC2R indicated that only mutation of the third transmembrane domain of MC2R resulted in a decrease in d-Phe ACTH binding affinity and potency. Our results suggest that Phe7 in ACTH plays an important role in ligand selectivity and that the third transmembrane domain of MC2R is crucial for ACTH selectivity and potency. PMID:25605722

  18. Parathyroid Hormone, Calcitonin, and Vitamin D

    NASA Technical Reports Server (NTRS)

    Potts, J. T.

    1972-01-01

    Analyses of secretion of parathyroid hormone during tests of stimulation and suppression of hormone-secretory activity using infusions of EDTA and calcium, respectively, have established that, in contrast to previous views, secretion of the hormone is not autonomous in many patients that have adenomatous hyperparathyroidism, but is responsive to changes in blood-calcium concentration. These findings have led to a new understanding of the pathophysiology of hormone production in hyperparathy-roidism. A related application of the diagnostic use of the radioimmunoassay is the preoperative localization of parathyroid tumors and the distinction between adenomas and chief-cell hyperplasia. Work involving catheterization and radioimmunoassay of blood samples obtained from the subclavin and innominate veins and the venae cavae, led to localization in a high percentage of patients. However, this procedure has been adopted recently to detect hormone concentration in the small veins directly draining the parathyroid glands.

  19. Cell secretion and membrane fusion.

    PubMed

    Jena, Bhanu P

    2005-07-01

    Secretion occurs in all cells of multicellular organisms and involves the delivery of secretory products packaged in membrane-bound vesicles to the cell exterior. Specialized cells for neurotransmission, enzyme secretion or hormone release utilize a highly regulated secretory process. Secretory vesicles are transported to specific sites at the plasma membrane, where they dock and fuse to release their contents. Similar to other cellular processes, cell secretion is found to be highly regulated and a precisely orchestrated event. It has been demonstrated that membrane-bound secretory vesicles dock and fuse at porosomes, which are specialized supramolecular structures at the cell plasma membrane. Swelling of secretory vesicles results in a build-up of pressure, allowing expulsion of intravesicular contents. The extent of secretory vesicle swelling dictates the amount of intravesicular contents expelled during secretion. The discovery of the porosome, its isolation, its structure and dynamics at nm resolution and in real time, its biochemical composition and functional reconstitution into artificial lipid membrane, have been determined. The molecular mechanism of secretory vesicle fusion at the base of porosomes, and vesicle swelling, has also been resolved. These findings reveal the molecular mechanism of cell secretion.

  20. Network Identification of Hormonal Regulation

    PubMed Central

    Vis, Daniel J.; Westerhuis, Johan A.; Hoefsloot, Huub C. J.; Roelfsema, Ferdinand; van der Greef, Jan

    2014-01-01

    Relations among hormone serum concentrations are complex and depend on various factors, including gender, age, body mass index, diurnal rhythms and secretion stochastics. Therefore, endocrine deviations from healthy homeostasis are not easily detected or understood. A generic method is presented for detecting regulatory relations between hormones. This is demonstrated with a cohort of obese women, who underwent blood sampling at 10 minute intervals for 24-hours. The cohort was treated with bromocriptine in an attempt to clarify how hormone relations change by treatment. The detected regulatory relations are summarized in a network graph and treatment-induced changes in the relations are determined. The proposed method identifies many relations, including well-known ones. Ultimately, the method provides ways to improve the description and understanding of normal hormonal relations and deviations caused by disease or treatment. PMID:24852517

  1. Glucagon secretion from pancreatic α-cells

    PubMed Central

    Briant, Linford; Salehi, Albert; Vergari, Elisa; Zhang, Quan; Rorsman, Patrik

    2016-01-01

    Type 2 diabetes involves a ménage à trois of impaired glucose regulation of pancreatic hormone release: in addition to impaired glucose-induced insulin secretion, the release of the hyperglycaemic hormone glucagon becomes dysregulated; these last-mentioned defects exacerbate the metabolic consequences of hypoinsulinaemia and are compounded further by hypersecretion of somatostatin (which inhibits both insulin and glucagon secretion). Glucagon secretion has been proposed to be regulated by either intrinsic or paracrine mechanisms, but their relative significance and the conditions under which they operate are debated. Importantly, the paracrine and intrinsic modes of regulation are not mutually exclusive; they could operate in parallel to control glucagon secretion. Here we have applied mathematical modelling of α-cell electrical activity as a novel means of dissecting the processes that underlie metabolic regulation of glucagon secretion. Our analyses indicate that basal hypersecretion of somatostatin and/or increased activity of somatostatin receptors may explain the loss of adequate counter-regulation under hypoglycaemic conditions, as well as the physiologically inappropriate stimulation of glucagon secretion during hyperglycaemia seen in diabetic patients. We therefore advocate studying the interaction of the paracrine and intrinsic mechanisms; unifying these processes may give a more complete picture of the regulation of glucagon secretion from α-cells than studying the individual parts. PMID:27044683

  2. Ectopic acromegaly due to growth hormone releasing hormone.

    PubMed

    Ghazi, Ali A; Amirbaigloo, Alireza; Dezfooli, Azizollah Abbasi; Saadat, Navid; Ghazi, Siavash; Pourafkari, Marina; Tirgari, Farrokh; Dhall, Dheepti; Bannykh, Serguei; Melmed, Shlomo; Cooper, Odelia

    2013-04-01

    Acromegaly secondary to extra-pituitary tumors secreting growth hormone releasing hormone (GHRH) is rarely encountered. We review the literature on ectopic acromegaly and present the index report of ectopic acromegaly secondary to GHRH secretion from a mediastinal paraganglioma. Clinical and pathological manifestations and therapeutic management of 99 patients with ectopic acromegaly are reviewed. Acromegaly secondary to ectopic GHRH secretion is usually caused by a neuroendocrine tumor in the lung and pancreas. We report an additional cause of ectopic acromegaly from a mediastinal paraganglioma. Diagnostic criteria of ectopic GHRH syndrome include biochemical and pathologic tumoral confirmation of GHRH secretion and expression. Management of ectopic acromegaly consists of surgical resection of the primary tumor and biochemical normalization, with possible adjuvant use of somatostatin analogs. The review demonstrates that there are several tumor types, including paragangliomas which may secrete GHRH, leading to acromegaly. Clinical and laboratory manifestations of the syndrome and challenges in diagnosis and management of these rarely encountered patients require early diagnosis and appropriate treatment to prevent long-term morbidity and mortality with ectopic acromegaly. PMID:22983831

  3. Effects of phenylalaninol on centrally induced gastric acid secretion.

    PubMed

    Hashizume, H; Miyamae, T; Morikawa, T; Hagiwara, M

    1992-11-01

    The effects of phenylalaninol (D-isomer) on gastric acid secretion and gastric ulcer were studied in rats. The compound reduced the gastric acid secretion stimulated by intracisternal thyrotropin releasing hormone and intravenous 2-deoxy-D-glucose, but not that stimulated by subcutaneous carbachol or histamine. Phenylalaninol prevented stress- and indomethacin-induced gastric ulcers. We conclude that phenylalaninol inhibits ulcer formation mainly by central inhibition of gastric acid secretion. PMID:1477931

  4. Studies into secretions of Tetrahymena: enzymes secreted into inorganic medium.

    PubMed

    Kovács, P; Karsa, J; Csaba, G

    1992-01-01

    The peptides secreted by Tetrahymena cells into inorganic medium were chromatographed. Six fractions showing a marked enzyme-like activity were examined for influence on certain physiological parameters of Tetrahymena. The enzymatically active fractions increased the phagocytic activity of Tetrahymena and decreased its binding capacity for lectins and hormone (insulin), but enhanced insulin imprinting at primary interaction. It remains to be clarified whether these effects were due to the enzymatic or other components of the fractions investigated, or to lack of the compensatory influence of the fractions not studied.

  5. Growth Hormone

    MedlinePlus

    ... the dose of glucose. Growth hormone stimulates the production of insulin-like growth factor-1 (IGF-1) . ... regular intervals for years afterward to monitor GH production and to detect tumor recurrence. Other blood tests ...

  6. Hormone Therapy

    MedlinePlus

    ... based lubricants include petroleum jelly, baby oil, or mineral oil. Oil-based types should not be used ... caused by low levels of these hormones. Hysterectomy: Removal of the uterus. Menopause: The time in a ...

  7. Infanticide secrets

    PubMed Central

    Barr, Jennieffer A.; Beck, Cheryl T.

    2008-01-01

    ABSTRACT OBJECTIVE To explore thoughts of infanticide that did not lead to the act among mothers with postpartum depression. DESIGN A phenomenologic hermeneutic study in which women were invited to share their experiences of having thoughts of infanticide. SETTING Community setting in a large metropolitan city, Brisbane, Australia. PARTICIPANTS Fifteen women who had been diagnosed as clinically depressed with postpartum onset whose babies were 12 months of age or younger. METHOD Audiotaped, in-depth interviews were transcribed verbatim. Thematic analysis commenced immediately after the first interview, and data collection continued until saturation was achieved. A questioning approach that reflected hermeneutics was facilitated by use of journals by the researchers. MAIN FINDINGS Six themes emerged from the data: imagined acts of infanticide, the experience of horror, distorted sense of responsibility, consuming negativity, keeping secrets, and managing the crisis. CONCLUSION Women who experienced nonpsychotic depression preferred not to disclose their thoughts of infanticide to health professionals, including trusted general practitioners or psychiatrists. These women were more likely to mention their suicidal thoughts than their infanticidal thoughts in order to obtain health care. General practitioners and other health professionals should directly ask about whether a woman has been experiencing thoughts of harming herself or her baby, regardless of the reason why she has presented. PMID:19074717

  8. Angiotensin II in the brain and pituitary: contrasting roles in the regulation of adenohypophyseal secretion.

    PubMed

    Ganong, W F

    1989-01-01

    Angiotensin II (AII) is present in gonadotropes in rats, and there are AII receptors on lactotropes and corticotropes. AII may be a paracrine mediator that stimulates the secretion of prolactin and adrenocorticotropin (ACTH) at the level of the pituitary, but additional research is needed to define its exact role. Angiotensinogen may also reach the gonadotropes via a paracrine route. On the other hand, there is considerable evidence that brain AII stimulates the secretion of luteinizing hormone (LH) by increasing the secretion of LH-releasing hormone, and that this effect is due to AII-mediated release of norepinephrine from noradrenergic nerve terminals in the preoptic region of the hypothalamus. In addition, brain AII inhibits the secretion of prolactin, probably by increasing the release of dopamine into the portal hypophyseal vessels. Circulating AII stimulates the secretion of a third anterior pituitary hormone, ACTH, by acting on one or more of the circumventricular organs to increase the secretion of corticotropin-releasing hormone.

  9. Extracts from Epilobium sp. herbs, their components and gut microbiota metabolites of Epilobium ellagitannins, urolithins, inhibit hormone-dependent prostate cancer cells-(LNCaP) proliferation and PSA secretion.

    PubMed

    Stolarczyk, Magdalena; Piwowarski, Jakub P; Granica, Sebastian; Stefańska, Joanna; Naruszewicz, Marek; Kiss, Anna K

    2013-12-01

    Extracts from Epilobium sp. herbs have been traditionally used in the treatment of prostate-associated ailments. Our studies demonstrated that the extracts from Epilobium angustifolium, Epilobium parviflorum and Epilobium hirsutum herbs are potent prostate cancer cells (LNCaP) proliferation inhibitors with IC50 values around 35 µg/ml. The tested extracts reduced prostate specific antigen (PSA) secretion (from 325.6 ± 25.3 ng/ml to ~90 ng/ml) and inhibited arginase activity (from 65.2 ± 1.1 mUnits of urea/mg of protein to ~40 mUnits of urea/mg protein). Selected constituents of extracts (oenothein B, quercetin-3-O-glucuronide, myricetin-3-O-rhamnoside) were proven to be active in relation to LNCaP cells. However, oenothein B was the strongest inhibitor of cells proliferation (IC50  = 7.8 ± 0.8 μM), PSA secretion (IC50  = 21.9 ± 3.2 μM) and arginase activity (IC50 = 19.2 ± 2.0 μM). Additionally, ellagitannins from E. hirustum extract were proven to be transformed by human gut microbiota into urolithins. Urolithin C showed the strongest activity in the inhibition of cell proliferation (IC50  = 35.2 ± 3.7 μM), PSA secretion (reduced PSA secretion to the level of 100.7 ± 31.0 ng/ml) and arginase activity (reduced to the level of 27.9 ± 3.3 mUnits of urea/mg of protein). Results of the work offer an explanation of the activity of Epilobium extracts and support the use of Epilobium preparations in the treatment of prostate diseases. PMID:23436427

  10. Extracts from Epilobium sp. herbs, their components and gut microbiota metabolites of Epilobium ellagitannins, urolithins, inhibit hormone-dependent prostate cancer cells-(LNCaP) proliferation and PSA secretion.

    PubMed

    Stolarczyk, Magdalena; Piwowarski, Jakub P; Granica, Sebastian; Stefańska, Joanna; Naruszewicz, Marek; Kiss, Anna K

    2013-12-01

    Extracts from Epilobium sp. herbs have been traditionally used in the treatment of prostate-associated ailments. Our studies demonstrated that the extracts from Epilobium angustifolium, Epilobium parviflorum and Epilobium hirsutum herbs are potent prostate cancer cells (LNCaP) proliferation inhibitors with IC50 values around 35 µg/ml. The tested extracts reduced prostate specific antigen (PSA) secretion (from 325.6 ± 25.3 ng/ml to ~90 ng/ml) and inhibited arginase activity (from 65.2 ± 1.1 mUnits of urea/mg of protein to ~40 mUnits of urea/mg protein). Selected constituents of extracts (oenothein B, quercetin-3-O-glucuronide, myricetin-3-O-rhamnoside) were proven to be active in relation to LNCaP cells. However, oenothein B was the strongest inhibitor of cells proliferation (IC50  = 7.8 ± 0.8 μM), PSA secretion (IC50  = 21.9 ± 3.2 μM) and arginase activity (IC50 = 19.2 ± 2.0 μM). Additionally, ellagitannins from E. hirustum extract were proven to be transformed by human gut microbiota into urolithins. Urolithin C showed the strongest activity in the inhibition of cell proliferation (IC50  = 35.2 ± 3.7 μM), PSA secretion (reduced PSA secretion to the level of 100.7 ± 31.0 ng/ml) and arginase activity (reduced to the level of 27.9 ± 3.3 mUnits of urea/mg of protein). Results of the work offer an explanation of the activity of Epilobium extracts and support the use of Epilobium preparations in the treatment of prostate diseases.

  11. Sex steroids and growth hormone interactions.

    PubMed

    Fernández-Pérez, Leandro; de Mirecki-Garrido, Mercedes; Guerra, Borja; Díaz, Mario; Díaz-Chico, Juan Carlos

    2016-04-01

    GH and sex hormones are critical regulators of body growth and composition, somatic development, intermediate metabolism, and sexual dimorphism. Deficiencies in GH- or sex hormone-dependent signaling and the influence of sex hormones on GH biology may have a dramatic impact on liver physiology during somatic development and in adulthood. Effects of sex hormones on the liver may be direct, through hepatic receptors, or indirect by modulating endocrine, metabolic, and gender-differentiated functions of GH. Sex hormones can modulate GH actions by acting centrally, regulating pituitary GH secretion, and peripherally, by modulating GH signaling pathways. The endocrine and/or metabolic consequences of long-term exposure to sex hormone-related compounds and their influence on the GH-liver axis are largely unknown. A better understanding of these interactions in physiological and pathological states will contribute to preserve health and to improve clinical management of patients with growth, developmental, and metabolic disorders.

  12. Hormonal responses of metoclopramide-treated subjects experiencing nausea or emesis during parabolic flight

    NASA Technical Reports Server (NTRS)

    Kohl, Randall L.

    1987-01-01

    The concentrations of adrenocorticotropic hormone (ACTH), vasopressin (AVP), epinephrine (EPI), and norepinephrine (NE) in 22 subjects administered 10 to 20 mg of metoclopramide prior to parabolic flight are measured. The effect of metoclopramide on motion sickness is examined. It is observed that metoclopramide is ineffective in the modulation of motion sickness due to stressful linear and angular acceleration and orbital flight, and it does not affect serum hormones prior to parabolic flight. It is detected that the serum level of AVP declines following emesis induced by parabolic flight and stressful angular acceleration; the serum levels of ACTH and EPI are elevated by parabolic flight and stressful angular acceleration; and serum NE is significantly elevated immediately following emesis. The possible roles of these hormones in the etiology of space motion sickness are discussed.

  13. Effects of anesthesia with isoflurane on plasma concentrations of adrenocorticotropic hormone in samples obtained from the cavernous sinus and jugular vein of horses.

    PubMed

    Carmalt, James L; Duke-Novakovski, Tanya; Schott, Harold C; van der Kolk, Johannes H

    2016-07-01

    OBJECTIVE To determine effects of anesthesia on plasma concentrations and pulsatility of ACTH in samples obtained from the cavernous sinus and jugular vein of horses. ANIMALS 6 clinically normal adult horses. PROCEDURES Catheters were placed in a jugular vein and into the cavernous sinus via a superficial facial vein. The following morning (day 1), cavernous sinus blood samples were collected every 5 minutes for 1 hour (collection of first sample = time 0) and jugular venous blood samples were collected at 0, 30, and 60 minutes. On day 2, horses were sedated with xylazine hydrochloride and anesthesia was induced with propofol mixed with ketamine hydrochloride. Horses were positioned in dorsal recumbency. Anesthesia was maintained with isoflurane in oxygen and a continuous rate infusion of butorphanol tartrate. One hour after anesthesia was induced, the blood sample protocol was repeated. Plasma ACTH concentrations were quantified by use of a commercially available sandwich assay. Generalized estimating equations that controlled for horse and an expressly automated deconvolution algorithm were used to determine effects of anesthesia on plasma ACTH concentrations and pulsatility, respectively. RESULTS Anesthesia significantly reduced the plasma ACTH concentration in blood samples collected from the cavernous sinus. CONCLUSIONS AND CLINICAL RELEVANCE Mean plasma ACTH concentrations in samples collected from the cavernous sinus of anesthetized horses were reduced. Determining the success of partial ablation of the pituitary gland in situ for treatment of pituitary pars intermedia dysfunction may require that effects of anesthesia be included in interpretation of plasma ACTH concentrations in cavernous sinus blood. PMID:27347826

  14. QUANTITATIVE STUDIES OF PROSTATIC SECRETION

    PubMed Central

    Huggins, Charles; Clark, Philip Johnson

    1940-01-01

    Cystic hyperplasia of the prostate occurs spontaneously in senile dogs only when they possess physiologically effective amounts of androgenic hormone. The cysts are closely grouped and radially arranged in a conical manner with the base of the cone at the periphery of the gland. Flattened and columnar epithelium, varying from about 5 to 25µ are seen in each cyst. The cysts communicate with the urethra by way of ducts. Both normal and cystic prostates undergo marked atrophy when the testes are removed, the chief difference 3 months after orchiectomy being the persistence of slightly dilated clefts and spaces at the site of the former cysts in the senile state. In the castrate dog whose prostate gland is being reconstructed as result of the influence of daily injections of androgen, certain doses of estrogen prevent increase of secretion and still larger doses greatly depress the output of the gland. In dogs so treated by daily injections of testosterone propionate, 10 mg., the amount of secretion is maintained from day to day at a level by daily injections of stilbestrol, 0.4 to 0.6 mg. and greatly depressed by doses of 1 to 1.5 mg. When the larger amounts of estrogen are used, together with androgen, squamous metaplasia occurs in the posterior lobe of the prostate while the epithelium of the acini decreases in height to cuboidal or low columnar form; these histological signs of activity of both androgen and estrogen on the prostate show that inhibition of the male hormone by stilbestrol is incomplete at these ratios. In dogs with either normal or cystic prostate glands, the prostate decreases in size when estrogen is injected in amounts to depress prostatic secretion profoundly. The gland is maintained in an atrophic state and overdosage avoided by controlled periodic injections of stilbestrol until secretion is reduced to the minimum, followed by free intervals, the estrogen being again administered when secretion measurably increases. The shrinkage is related to

  15. Long-term outcomes of surgery and radiotherapy for secreting and non-secreting pituitary adenoma

    PubMed Central

    Kim, Mi Young; Kim, Jin Hee; Oh, Young Kee; Kim, El

    2016-01-01

    Purpose: To investigate treatment outcome and long term complication after surgery and radiotherapy (RT) for pituitary adenoma. Materials and Methods: From 1990 to 2009, 73 patients with surgery and RT for pituitary adenoma were analyzed in this study. Median age was 51 years (range, 25 to 71 years). Median tumor size was 3 cm (range, 1 to 5 cm) with suprasellar (n = 21), cavernous sinus extension (n = 14) or both (n = 5). Hormone secreting tumor was diagnosed in 29 patients; 16 patients with prolactin, 12 patients with growth hormone, and 1 patient with adrenocorticotrophic hormone. Impairment of visual acuity or visual field was presented in 33 patients at first diagnosis. Most patients (n = 64) received RT as postoperative adjuvant setting. Median RT dose was 45 Gy (range, 45 to 59.4 Gy). Results: Median follow-up duration was 8 years (range, 3 to 22 years). In secreting tumors, hormone normalization rate was 55% (16 of 29 patients). For 25 patients with evaluable visual field and visual acuity test, 21 patients (84%) showed improvement of visual disturbance after treatment. The 10-year tumor control rate for non-secreting and secreting adenoma was 100% and 58%, respectively (p < 0.001). Progression free survival rate at 10 years was 98%. Only 1 patient experienced endocrinological recurrence. Following surgery, 60% (n = 44) suffered from pituitary function deficit. Late complication associated with RT was only 1 patient, who developed cataract. Conclusion: Surgery and RT are very effective and safe in hormonal and tumor growth control for secreting and non-secreting pituitary adenoma. PMID:27306775

  16. Dexamethasone suppresses gonadotropin-releasing hormone (GnRH) secretion and has direct pituitary effects in male rats: differential regulation of GnRH receptor and gonadotropin responses to GnRH.

    PubMed

    Rosen, H; Jameel, M L; Barkan, A L

    1988-06-01

    Endogenous or exogenous glucocorticoid excess leads to the development of hypogonadotropic hypogonadism, but the site(s) and mechanisms of glucocorticoid action are uncertain. We studied the effects of various doses of dexamethasone (Dex) on the hypothalamic-pituitary-gonadal axis in intact and castrate testosterone-replaced (cast + T) male rats and attempted to determine possible sites of Dex effects. A dose-dependent suppression of basal gonadotropin secretion was induced by 5 days of Dex treatment (20, 100, 500, or 2,500 micrograms/kg.day), and the highest dose completely abolished the postcastration rise in pituitary GnRH receptor number (GnRH-R) and serum gonadotropin levels. Administration of exogenous GnRH (0.02-200 micrograms/day over 2 days) resulted in a dose-dependent induction in GnRH-R in both intact and cast + T rats, but the effect was significantly (P less than 0.01) augmented in Dex-treated animals. In contrast, acute LH and FSH responses to GnRH (10, 25, 50, 100, or 250 ng, iv) were significantly blunted in Dex-treated rats. The data suggest that 1) Dex suppresses hypothalamic GnRH secretion, thereby preventing the postcastration rises in GnRH-R and gonadotropins; 2) at the pituitary level, Dex dissociates GnRH-R and gonadotropin responses to GnRH, augmenting GnRH-R induction by GnRH and suppressing gonadotropin responses to GnRH at a postreceptor site; and 3) the model of Dex-treated rats may be useful to study differential GnRH regulation of GnRH-R and gonadotropin secretion.

  17. Cell secretion: current structural and biochemical insights.

    PubMed

    Trikha, Saurabh; Lee, Elizabeth C; Jeremic, Aleksandar M

    2010-10-12

    Essential physiological functions in eukaryotic cells, such as release of hormones and digestive enzymes, neurotransmission, and intercellular signaling, are all achieved by cell secretion. In regulated (calcium-dependent) secretion, membrane-bound secretory vesicles dock and transiently fuse with specialized, permanent, plasma membrane structures, called porosomes or fusion pores. Porosomes are supramolecular, cup-shaped lipoprotein structures at the cell plasma membrane that mediate and control the release of vesicle cargo to the outside of the cell. The sizes of porosomes range from 150 nm in diameter in acinar cells of the exocrine pancreas to 12 nm in neurons. In recent years, significant progress has been made in our understanding of the porosome and the cellular activities required for cell secretion, such as membrane fusion and swelling of secretory vesicles. The discovery of the porosome complex and the molecular mechanism of cell secretion are summarized in this article.

  18. Insulin and Glucagon Secretion In Vitro

    NASA Technical Reports Server (NTRS)

    Rajan, Arun S.

    1998-01-01

    Long-duration space flight is associated with many physiological abnormalities in astronauts. In particular, altered regulation of the hormones insulin and glucagon may contribute to metabolic disturbances such as increased blood sugar levels, which if persistently elevated result in toxic effects. These changes are also observed in the highly prevalent disease diabetes, which affects 16 million Americans and consumes over $100 billion in annual healthcare costs. By mimicking the microgravity environment of space in the research laboratory using a NASA-developed bioreactor, one can study the physiology of insulin and glucagon secretion and determine if there are alterations in these cellular processes. The original specific objectives of the project included: (1) growing ('cell culture') of pancreatic islet beta and alpha cells that secrete insulin and glucagon respectively, in the NASA bioreactor; (2) examination of the effects of microgravity on insulin and glucagon secretion; and (3) study of molecular mechanisms of insulin and glucagon secretion if altered by microgravity.

  19. Gallbladder adenocarcinoma and paraneoplastic parathyroid hormone mediated hypercalcemia

    PubMed Central

    Yogarajah, Meera; Sivasambu, Bhradeev; Shiferaw-Deribe, Zewge

    2016-01-01

    Parathyroid hormone mediated hypercalcemia is not always exclusively primary hyperparathyroidism and rarely could be due to ectopic parathyroid hormone secretion from tumor cells. We present a case of 86-year-old female with metastatic gall bladder adenocarcinoma diagnosed eight months back who presented with generalized fatigue and poor oral intake and was found to be hypercalcemic with elevated parathyroid hormone levels. Imaging with technetium 99 m sestamibi scintigraphy with dual phase, subtraction thyroid scan (dual isotope scintigraphy), magnetic resonance imaging and ultrasonography did not demonstrate any parathyroid lesion in normal or ectopic sites. We believe that the tumor cells were the source of ectopic parathyroid hormone secretion as we had excluded all the other possibilities with extensive combined imaging thereby increasing the sensitivity of our testing. We report the first case of metastatic gall bladder adenocarcinoma with paraneoplastic ectopic parathyroid hormone secretion. PMID:27081650

  20. Gallbladder adenocarcinoma and paraneoplastic parathyroid hormone mediated hypercalcemia.

    PubMed

    Yogarajah, Meera; Sivasambu, Bhradeev; Shiferaw-Deribe, Zewge

    2016-04-10

    Parathyroid hormone mediated hypercalcemia is not always exclusively primary hyperparathyroidism and rarely could be due to ectopic parathyroid hormone secretion from tumor cells. We present a case of 86-year-old female with metastatic gall bladder adenocarcinoma diagnosed eight months back who presented with generalized fatigue and poor oral intake and was found to be hypercalcemic with elevated parathyroid hormone levels. Imaging with technetium 99 m sestamibi scintigraphy with dual phase, subtraction thyroid scan (dual isotope scintigraphy), magnetic resonance imaging and ultrasonography did not demonstrate any parathyroid lesion in normal or ectopic sites. We believe that the tumor cells were the source of ectopic parathyroid hormone secretion as we had excluded all the other possibilities with extensive combined imaging thereby increasing the sensitivity of our testing. We report the first case of metastatic gall bladder adenocarcinoma with paraneoplastic ectopic parathyroid hormone secretion. PMID:27081650

  1. [Neuropharmacological regulation of pituitary hormones. Role of acetylcholine, gamma-aminobutyric acid, histamine and endorphins (author's transl)].

    PubMed

    Martin-du Pan, R; Gomez, F

    1981-01-01

    The secretion of pituitary hormones is controlled by hypothalamic hormones which are synthetized by neurosecreting cells whose activity is modulated by different neurotransmitters as dopamine and serotonin. Centrally acting drugs interfere with the activity of these neurotransmitters. Thus they may influence the secretion of pituitary hormones. Acetylcholine, gamma-aminobutyric acid, histamine and endorphins seem also to influence the pituitary secretion. The endocrine effects of drugs (opiates, antiparkinson, antiepileptic, and antihistaminic agents) acting on these neurotransmitters is reviewed.

  2. The Radioimmunoassay of Fluid and Electrolyte Hormones

    NASA Technical Reports Server (NTRS)

    Keil, Lanny C.

    1985-01-01

    The subject of the paper will be the assay of fluid/electrolyte hormones. ADH (antidiuretic hormone also referred to as vasopressin) reduces fluid loss by increasing water reabsorption by the kidney. The stimuli for its release from the pituitary are loss of blood, dehydration, or increased salt intake. Angiotensin II is the next hormone of interest. It is "generated" from a blood protein by the release of renin from the kidney. One of its functions is to stimulate the secretion of aldosterone from the adrenal gland. Release of renin is also stimulated by volume and sodium loss.

  3. Hormone impostors

    SciTech Connect

    Colborn, T.; Dumanoski, D.; Myers, J.P.

    1997-01-01

    This article discusses the accumulating evidence that some synthetic chemicals disrupt hormones in one way or another. Some mimic estrogen and others interfere with other parts of the body`s control or endocrine system such as testosterone and thyroid metabolism. Included are PCBs, dioxins, furans, atrazine, DDT. Several short sidebars highlight areas where there are or have been particular problems.

  4. Control of prolactin secretion in mammals.

    PubMed

    Clemens, J A; Shaar, C J

    1980-06-01

    Evidence describing the neuroendocrine regulation of prolactin secretion in mammals is reviewed, with focus on catecholamines, serotonin, and polypeptides. Dopamine may be a physiological prolactin inhibiting factor (PIF), while norepinephrine and possibly epinephrine regulate prolactin release at the level of the hypothalamus. Serotonin may participate in the regulation of prolactin secretion by stimulating the release of prolactin releasing factor (PRF). The identity of PRF is not known, but two polypeptides--thyrotropin releasing hormone and vasoactive intestinal polypeptide--can act directly on the adenohypophysis to stimulate prolactin release.

  5. Pancreatic enzyme secretion during intravenous fat infusion.

    PubMed

    Burns, G P; Stein, T A

    1987-01-01

    The nutritional support of patients with pancreatic and high gastrointestinal fistulas and severe pancreatitis frequently involves intravenous fat infusion. There are conflicting reports on the effect of intravenous fat on pancreatic exocrine secretion. In 10 dogs with chronic pancreatic fistulas, pancreatic juice was collected during secretin (n = 10) or secretin + cholecystokinin (n = 4) stimulation, with and without intravenous fat infusion (5 g/hr). The hormonal-stimulated secretion of lipase, amylase, trypsin, total protein, bicarbonate, and water was unchanged during fat infusion. This study supports the use of intravenous fat as a nutritional source when it is desirable to avoid stimulation of the pancreas.

  6. Noncholinergic control of adrenal catecholamine secretion.

    PubMed Central

    Livett, B G; Marley, P D

    1993-01-01

    It has been known for over 70 years that adrenal catecholamine secretion can be modulated or elicited by noncholinergic neurotransmitters and hormones. However, our understanding of the cellular mechanisms by which these agents produce their effects and the physiological conditions under which they act are not well characterised. Here we briefly review the mechanisms by which one such agent (the neuropeptide substance P) modulates the cholinergic secretory response of adrenal chromaffin cells, and another agent (angiotensin II) elicits catecholamine secretion independently of the cholinergic innervation. PMID:7507911

  7. Adrenal Function Testing Following Hormone Therapy for Infantile Spasms: Case Series and Review of Literature

    PubMed Central

    Mytinger, John R.; Bowden, Sasigarn A.

    2015-01-01

    Prednisolone and adrenocorticotropic hormone (ACTH) are “hormone” therapies for infantile spasms. There is limited data on the occurrence of decreased adrenal reserve or signs of clinical adrenal insufficiency after hormone therapy. This is a retrospective medical record review of patients referred to our Infantile Spasms Program. Our standardized infantile spasms management guideline began in September 2012 and initially included a post-hormone laboratory assessment of adrenal function. Medical records were assessed for hormone treatments, adrenal function testing, and signs of adrenal insufficiency. Forty-two patients who received one or both hormone therapies met inclusion criteria. A post-hormone laboratory assessment of adrenal function was done in 14 patients. Of these 14 patients, 2 had an abnormal laboratory assessment of adrenal function, both by adrenal stimulation testing – one after ACTH and one after prednisolone. One patient received hydrocortisone replacement and the other received stress dose hydrocortisone as needed; neither patient developed signs of adrenal insufficiency. Another patient treated with both types of hormone therapy in tandem, who did not have a post-hormone laboratory assessment, developed signs of mild adrenal insufficiency and required replacement hydrocortisone. Our study suggests that adrenal suppression can occur after modern hormone therapy regimens. We found two patients with abnormal adrenal function testing after hormone therapy and another patient with signs adrenal insufficiency. Given the seriousness of adrenal crisis, caregiver education on the signs of adrenal insufficiency is critical. Greater vigilance may be indicated in patients receiving both types of hormone therapy in tandem. Although a routine post-hormone laboratory assessment of adrenal function may not be feasible in all patients, replacement or stress dose hydrocortisone is necessary for all patients with suspected adrenal insufficiency. PMID

  8. Types of hormone therapy

    MedlinePlus

    ... types of hormone therapy; Hormone replacement therapy - types; Menopause - types of hormone therapy; HT - types; Menopausal hormone ... Menopause symptoms include: Hot flashes Night sweats Sleep problems Vaginal dryness Anxiety Moodiness Less interest in sex ...

  9. Gastrointestinal hormone research - with a Scandinavian annotation.

    PubMed

    Rehfeld, Jens F

    2015-06-01

    Gastrointestinal hormones are peptides released from neuroendocrine cells in the digestive tract. More than 30 hormone genes are currently known to be expressed in the gut, which makes it the largest hormone-producing organ in the body. Modern biology makes it feasible to conceive the hormones under five headings: The structural homology groups a majority of the hormones into nine families, each of which is assumed to originate from one ancestral gene. The individual hormone gene often has multiple phenotypes due to alternative splicing, tandem organization or differentiated posttranslational maturation of the prohormone. By a combination of these mechanisms, more than 100 different hormonally active peptides are released from the gut. Gut hormone genes are also widely expressed outside the gut, some only in extraintestinal endocrine cells and cerebral or peripheral neurons but others also in other cell types. The extraintestinal cells may release different bioactive fragments of the same prohormone due to cell-specific processing pathways. Moreover, endocrine cells, neurons, cancer cells and, for instance, spermatozoa secrete gut peptides in different ways, so the same peptide may act as a blood-borne hormone, a neurotransmitter, a local growth factor or a fertility factor. The targets of gastrointestinal hormones are specific G-protein-coupled receptors that are expressed in the cell membranes also outside the digestive tract. Thus, gut hormones not only regulate digestive functions, but also constitute regulatory systems operating in the whole organism. This overview of gut hormone biology is supplemented with an annotation on some Scandinavian contributions to gastrointestinal hormone research.

  10. Interactions of growth hormone secretagogues and growth hormone-releasing hormone/somatostatin.

    PubMed

    Tannenbaum, G S; Bowers, C Y

    2001-02-01

    The class of novel synthetic compounds termed growth hormone secretagogues (GHSs) act in the hypothalamus through, as yet, unknown pathways. We performed physiologic and histochemical studies to further understand how the GHS system interacts with the well-established somatostatin (SRIF)/growth hormone-releasing hormone (GHRH) neuroendocrine system for regulating pulsatile GH secretion. Comparison of the GH-