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Sample records for adult rat leydig

  1. Effects of Estradiol and Methoxychlor on Leydig Cell Regeneration in the Adult Rat Testis

    PubMed Central

    Chen, Bingbing; Chen, Dongxin; Jiang, Zheli; Li, Jingyang; Liu, Shiwen; Dong, Yaoyao; Yao, Wenwen; Akingbemi, Benson; Ge, Renshan; Li, Xiaokun

    2014-01-01

    The objective of the present study is to determine whether methoxychlor (MXC) exposure in adulthood affects rat Leydig cell regeneration and to compare its effects with estradiol (E2). Adult 90-day-old male Sprague-Dawley rats received ethane dimethane sulfonate (EDS) to eliminate the adult Leydig cell population. Subsequently, rats were randomly assigned to four groups and gavaged with corn oil (control), 0.25 mg/kg E2 and 10 or 100 mg/kg MXC daily from days 5 to 30 post-EDS treatment. The results showed that MXC and E2 reduced serum testosterone levels on day 58 post-EDS treatment. qPCR showed Hsd17b3 mRNA levels were downregulated 7–15 fold by E2 and MXC, indicating that development of the new population of Leydig cells was arrested at the earlier stage. This observation was supported by the results of histochemical staining, which demonstrated that Leydig cells in MXC-treated testis on day 58 post-EDS treatment were mostly progenitor Leydig cells. However, Pdgfb mRNA levels were downregulated, while Lif transcript levels were increased by MXC. In contrast, E2 did not affect gene expression for these growth factors. In conclusion, our findings indicated that both MXC and E2 delayed rat Leydig cell regeneration in the EDS-treated model, presumably acting by different mechanisms. PMID:24806340

  2. Regulation of seminiferous tubule-associated stem Leydig cells in adult rat testes.

    PubMed

    Li, Xiaoheng; Wang, Zhao; Jiang, Zhenming; Guo, Jingjing; Zhang, Yuxi; Li, Chenhao; Chung, Jinyong; Folmer, Janet; Liu, June; Lian, Qingquan; Ge, Renshan; Zirkin, Barry R; Chen, Haolin

    2016-03-08

    Testicular Leydig cells are the primary source of testosterone in males. Adult Leydig cells have been shown to arise from stem cells present in the neonatal testis. Once established, adult Leydig cells turn over only slowly during adult life, but when these cells are eliminated experimentally from the adult testis, new Leydig cells rapidly reappear. As in the neonatal testis, stem cells in the adult testis are presumed to be the source of the new Leydig cells. As yet, the mechanisms involved in regulating the proliferation and differentiation of these stem cells remain unknown. We developed a unique in vitro system of cultured seminiferous tubules to assess the ability of factors from the seminiferous tubules to regulate the proliferation of the tubule-associated stem cells, and their subsequent entry into the Leydig cell lineage. The proliferation of the stem Leydig cells was stimulated by paracrine factors including Desert hedgehog (DHH), basic fibroblast growth factor (FGF2), platelet-derived growth factor (PDGF), and activin. Suppression of proliferation occurred with transforming growth factor β (TGF-β). The differentiation of the stem cells was regulated positively by DHH, lithium- induced signaling, and activin, and negatively by TGF-β, PDGFBB, and FGF2. DHH functioned as a commitment factor, inducing the transition of stem cells to the progenitor stage and thus into the Leydig cell lineage. Additionally, CD90 (Thy1) was found to be a unique stem cell surface marker that was used to obtain purified stem cells by flow cytometry.

  3. Effect of dibutyl phthalate on expression of connexin 43 and testosterone production of leydig cells in adult rats.

    PubMed

    Zhang, Jing; Jin, Shuguang; Zhao, Jinchang; Li, Huan

    2016-10-01

    To investigate the adverse effect of dibutyl phthalate (DBP) on Leydig cells and its mechanism related to gap junction, Leydig cells isolated from adult rats were treated with 0.1% dimethylsulfoxide (DMSO), 50mg/L DBP, 50mg/L DBP+10μM prostaglandin E2 (PGE2) and 40μM flutamide respectively. Radioimmunoassay, semi-quantitative RT-PCR, immunofluorescence and Western blot were applied to determine the expression of testosterone and Connexin 43 (Cx43) in Leydig cells. The expression of testosterone and Cx43 were both decreased in DBP group (P<0.05). While Cx43 was up-regulated after administered to PGE2, there was no significant change in testosterone. However, testosterone was down-regulated with a significant decrease of Cx43 in flutamide group. The results indicated that the inhibitory effect of DBP on testosterone production was not through the down-regulation of Cx43. On the contrary, the change of testosterone can influence the expression of Cx43 in Leydig cells.

  4. NGF induces adult stem Leydig cells to proliferate and differentiate during Leydig cell regeneration

    SciTech Connect

    Zhang, Lei; Wang, Huaxi; Yang, Yan; Liu, Hui; Zhang, Qihao; Xiang, Qi; Ge, Renshan; Su, Zhijian; Huang, Yadong

    2013-06-28

    Highlights: •Nerve growth factor has shown significant changes on mRNA levels during Adult Leydig cells regeneration. •We established the organ culture model of rat seminiferous tubules with ethane dimethyl sulphonate (EDS) treatment. •Nerve growth factor has shown proliferation and differentiation-promoting effects on Adult stem Leydig cells. •Nerve growth factor induces progenitor Leydig cells to proliferate and differentiate and immature Leydig cells to proliferate. -- Abstract: Nerve growth factor (NGF) has been reported to be involved in male reproductive physiology. However, few reports have described the activity of NGF during Leydig cell development. The objective of the present study was to examine the role of NGF during stem-Leydig-cell (SLC) regeneration. We investigated the effects of NGF on Leydig-cell (LC) regeneration by measuring mRNA levels in the adult rat testis after ethane dimethanesulfonate (EDS) treatment. Furthermore, we used the established organ culture model of rat seminiferous tubules to examine the regulation of NGF during SLC proliferation and differentiation using EdU staining, real-time PCR and western blotting. Progenitor Leydig cells (PLCs) and immature Leydig cells (ILCs) were also used to investigate the effects of NGF on LCs at different developmental stages. NGF mRNA levels changed significantly during Leydig-cell regeneration in vivo. In vitro, NGF significantly promoted the proliferation of stem Leydig cells and also induced steroidogenic enzyme gene expression and 3β-HSD protein expression. The data from PLCs and ILCs showed that NGF could increase Cyclin D1 and Hsd 17b3 mRNA levels in PLCs and Cyclin D1 mRNA levels in ILCs. These results indicate that NGF may play an important role during LC regeneration by regulating the proliferation and differentiation of LCs at different developmental stages, from SLCs to PLCs and from PLCs to ILCs. The discovery of this effect of NGF on Leydig cells will provide useful

  5. Steroid metabolism by purified adult rat Leydig cells in primary culture

    SciTech Connect

    Browning, J.Y.; Tcholakian, R.K.; Kessler, M.J.; Grotjan, H.E. Jr.

    1982-11-01

    To characterize Leydig cell steroidogensis, we examined the metabolism of (3H)pregnenolone (3 beta-hydroxy-5-pregnen-20-one) to androgens in the presence and absence of human chorionic gonadotropin (hCG) as a function of culture duration. Approximately 20-30% of the (3H)pregnenolone was converted to testosterone (17 beta-hydroxy-4-androsten-3-one) by purified Leydig cells at 0, 3 and 5 days (d) of culture. Androstenedione (4-androstene-3,17-dione) and dihydrotestosterone (17 beta-hydroxy-5 alpha-androstan-3-one) were also produced while on day 5 of culture, significant amounts of progesterone (4-pregnene-3,20-dione) were isolated. The delta 5 intermediates, 17-hydroxypregnenolone (3 beta, 17-dihydroxy-5-pregnen-20-one) and dehydroepiandrosterone (3 beta-hydroxy-5-androsten-17-one), accounted for less than 1% of substrate conversion, indicating a clear preference for Leydig cells to metabolize (3H)pregnenolone via the delta 4 pathway. On day 0 of culture, unidentified metabolites considered of predominately polar steroids while on day 5 of culture, the unidentified metabolites consisted of predominately nonpolar steroids. In the presence of hCG, (3H-pregnenolone metabolism did not differ from basal on day 0 or 3 of culture. HCG increased the conversion of pregnenolone to progesterone and 17-hydroxyprogesterone (17-hydroxy-4-pregnene-3,20-dione) on 5d. This suggests that Leydig cells cultured for 5d have decreased C17-20 desmolase activity or that hCG acutely stimulates 3 beta-hydroxysteroid dehydrogenase and delta 5-delta 5 isomerase activities.

  6. Regulation of development of rat stem and progenitor Leydig cells by activin.

    PubMed

    Li, L; Wang, Y; Li, X; Liu, S; Wang, G; Lin, H; Zhu, Q; Guo, J; Chen, H; Ge, H-S; Ge, R-S

    2017-01-01

    Stem Leydig cells have been demonstrated to differentiate into adult Leydig cells via intermediate stages of progenitor and immature Leydig cells. However, the exact regulatory mechanisms are unclear. We hypothesized that the development of stem or progenitor Leydig cells depends upon locally produced growth factors. Microarray analysis revealed that the expression levels of activin type I receptor (Acvr1) and activin A receptor type II-like 1 (Acvrl1) were stem > progenitor = immature = adult Leydig cells. This indicates that their ligand activin might play an important role in stem and progenitor Leydig cell proliferation and differentiation. When seminiferous tubules were incubated with 1 or 10 ng/mL activin A for 3 days, it concentration-dependently increased EdU incorporation into stem Leydig cells by up to 20-fold. When progenitor Leydig cells were incubated with 1 or 10 ng/mL activin A for 2 days, it concentration-dependently increased (3) H-thymidine incorporation into progenitor Leydig cells by up to 200%. Real-time PCR analysis showed that activin A primarily increased Pcna expression but reduced Star, Hsd3b1, and Cyp17a1 expression levels. Activin A also significantly inhibited the basal and luteinizing hormone-stimulated androgen production. In conclusion, activin A primarily stimulates the proliferation of stem and progenitor Leydig cells, but inhibits the differentiation of stem and progenitor Leydig cells into the Leydig cell lineage in rat testis.

  7. Exposure to phytoestrogens in the perinatal period affects androgen secretion by testicular Leydig cells in the adult rat.

    PubMed

    Akingbemi, Benson T; Braden, Tim D; Kemppainen, Barbara W; Hancock, Karen D; Sherrill, Jessica D; Cook, Sarah J; He, Xiaoying; Supko, Jeffrey G

    2007-09-01

    The use of soy-based products in the diet of infants has raised concerns regarding the reproductive toxicity of genistein and daidzein, the predominant isoflavones in soybeans with estrogenic activity. Time-bred Long-Evans dams were fed diets containing 0, 5, 50, 500, or 1000 ppm of soy isoflavones from gestational d 12 until weaning at d 21 postpartum. Male rats in all groups were fed soy-free diets from postnatal d 21 until 90 d of age. The mean +/- SD concentration of unconjugated (i.e. biologically active) genistein and daidzein in serum from the group of dams maintained on the diet containing the highest amount of isoflavones (1000 ppm) were 17 +/- 27 and 56 +/- 30 nM, respectively, at d 21 postpartum. The concentrations were considerably greater in male offspring (genistein: 73 +/- 46 nM; daidzein: 106 +/- 53 nM). Although steroidogenesis was decreased in individual Leydig cells, male rats from the highest exposure group (1000 ppm diet) exhibited elevated serum levels of the sex steroid hormones androsterone at 21 d (control: 15 +/- 1.5 vs.28 +/- 3.5 ng/ml; P < 0.05) and testosterone at 90 d of age (control: 7.5 +/- 1 vs.17 +/- 2 ng/ml; P < 0.05). Testosterone secretion by immature Leydig cells, isolated from 35-d-old male rats, decreased on exposure to 0.1 nm genistein in vitro (control: 175 +/- 5 vs. 117 +/- 3 ng/10(6) cells per 24 h; P < 0.05), indicative of direct phytoestrogen action. Thus, phytoestrogens have the ability to regulate Leydig cells, and additional studies to assess potential adverse effects of dietary soy-based products on reproductive tract development in neonates are warranted.

  8. Chronic hypothyroidism only marginally affects adult-type Leydig cell regeneration after EDS administration.

    PubMed

    Rijntjes, Eddy; van Kesteren-Buiting, Anita; Keijer, Jaap; Teerds, Katja J

    2010-02-01

    Chronic prenatally induced dietary hypothyroidism delays adult-type Leydig cell development, but does not block this process. Using a chemical model to induce hypothyroidism, it was suggested that development of a new population of Leydig cells was completely inhibited following the addition of the cytotoxic compound ethane-1,2-dimethyl sulphonate (EDS). In this study, we used a dietary approach to induce hypothyroidism and reinvestigated the regeneration of the Leydig cell population following EDS administration. Eighty-four day old euthyroid and chronically hypothyroid rats received an injection of EDS and were killed directly before or at regular intervals up to 77 days after EDS. In some control and hypothyroid animals, the first progenitor-type Leydig cells were observed at day 12 after EDS. At day 16, Leydig cell progenitors were present in all rats. The percentage of proliferating Leydig cells peaked in the euthyroid animals at day 21 after EDS. In the hypothyroid testis such a peak was not observed, although the percentage of proliferating regenerating Leydig cells was significantly higher from days 35 to 56 compared with the controls. This suggested that the wave of Leydig cell proliferation was delayed in the hypothyroid animals as compared with the euthyroid controls. On the day of EDS injection, the Leydig/Sertoli cell ratio was 37% lower in the hypothyroid rats compared with the controls. The Leydig/Sertoli cell ratio remained lower in the EDS-treated hypothyroid animals compared with the controls at all time points investigated. At day 77 after EDS, the Leydig cell population had returned to its pre-treatment size in both groups. Plasma testosterone production was reduced to below detectable levels immediately after EDS injection, and started to increase again on day 16, reaching pre-treatment values on day 21 in both groups. Taken together, severely reduced thyroid hormone levels did not block the regeneration of the adult-type Leydig cell population

  9. Steroidogenic Factor 1 Differentially Regulates Fetal and Adult Leydig Cell Development in Male Mice1

    PubMed Central

    Karpova, Tatiana; Ravichandiran, Kumarasamy; Insisienmay, Lovella; Rice, Daren; Agbor, Valentine; Heckert, Leslie L.

    2015-01-01

    The nuclear receptor steroidogenic factor 1 (SF-1, AD4BP, NR5A1) is a key regulator of the endocrine axes and is essential for adrenal and gonad development. Partial rescue of Nr5a1−/− mice with an SF-1-expressing transgene caused a hypomorphic phenotype that revealed its roles in Leydig cell development. In contrast to controls, all male rescue mice (Nr5a1−/−;tg+/0) showed varying signs of androgen deficiency, including spermatogenic arrest, cryptorchidism, and poor virilization. Expression of various Leydig cell markers measured by immunohistochemistry, Western blot analysis, and RT-PCR indicated fetal and adult Leydig cell development were differentially impaired. Whereas fetal Leydig cell development was delayed in Nr5a1−/−;tg+/0 embryos, it recovered to control levels by birth. In contrast, Sult1e1, Vcam1, and Hsd3b6 transcript levels in adult rescue testes indicated complete blockage in adult Leydig cell development. In addition, between Postnatal Days 8 and 12, peritubular cells expressing PTCH1, SF-1, and CYP11A1 were observed in control testes but not in rescue testes, indicating SF-1 is needed for either survival or differentiation of adult Leydig cell progenitors. Cultured prepubertal rat peritubular cells also expressed SF-1 and PTCH1, but Cyp11a1 was expressed only after treatment with cAMP and retinoic acid. Together, data show SF-1 is needed for proper development of fetal and adult Leydig cells but with distinct primary functions; in fetal Leydig cells, it regulates differentiation, whereas in adult Leydig cells it regulates progenitor cell formation and/or survival. PMID:26269506

  10. Tungstate treatment improves Leydig cell function in streptozotocin-diabetic rats.

    PubMed

    Ballester, Joan; Domínguez, Jorge; Muñoz, M Carmen; Sensat, Meritxell; Rigau, Teresa; Guinovart, Joan J; Rodríguez-Gil, Joan E

    2005-01-01

    Oral administration of sodium tungstate to adult male streptozotocin-diabetic rats for 3 months normalized serum levels of glucose, insulin, luteinizing hormone, and follicle-stimulating hormone. These effects were accompanied by an increase in reproductive performance, which was related to a strong improvement in Leydig cell function markers, such as the recovery of the number of Leydig cells and serum testosterone levels. Moreover, this in vivo recovery was related to a concomitant increase in the cell expression of insulin receptors. Tungstate treatment did not modify Leydig cell function in healthy rats. Furthermore, the addition of tungstate or insulin to the mTLC-1 cell line from Leydig cell origin increased the phosphorylation states of MAP-kinase and glycogen synthase kinase-3. Our results indicate that tungstate treatment in diabetic rats leads to a recovery of reproductive performance by increasing the number of Leydig cells. This increase contributes to the recovery of their functionality, thereby improving the overall function of these cells. We propose that this improvement is caused by the combined effect of the tungstate-induced normalization of insulin glucose and luteinizing hormone serum levels and a direct action of the effector on Leydig cells through modulation of at least MAP-kinase and glycogen synthase kinase-3 activities.

  11. Effects of Neuroendocrine CB1 Activity on Adult Leydig Cells

    PubMed Central

    Cobellis, Gilda; Meccariello, Rosaria; Chianese, Rosanna; Chioccarelli, Teresa; Fasano, Silvia; Pierantoni, Riccardo

    2016-01-01

    Endocannabinoids control male reproduction acting at central and local level via cannabinoid receptors. The cannabinoid receptor CB1 has been characterized in the testis, in somatic and germ cells of mammalian and non-mammalian animal models, and its activity related to Leydig cell differentiation, steroidogenesis, spermiogenesis, sperm quality, and maturation. In this short review, we provide a summary of the insights concerning neuroendocrine CB1 activity in male reproduction focusing on adult Leydig cell ontogenesis and steroid biosynthesis. PMID:27375550

  12. [Leydig cell function in experimental cryptorchism and varicocele in rats].

    PubMed

    Hernández-Yánez, L; Marín-López, G; Vílchez-Martínez, J; Bishop, W

    1999-06-01

    Leydig cells were isolated from testes of normal, cryptorchid and induced- varicocele rats. These cells were counted and coincubated with and without human Chorionic Gonadotropin (hCG) during 3 hours; thereafter, steroids were measured in the incubation media. Cryptorchid animals showed the lowest number of Leydig cells, the highest Progesterone response to hCG, a slight increment of testosterone and a decrease of estradiol. On the contrary, both left and right testes from varicocele induced rats showed a higher cell number (per g of tissue), lower progesterone response, slightly higher response testosterone and lower testosterone response. These results demonstrate that these conditions of testicular hyperthermia do not affect the number and function of Leydig cells to the same degree. This may be due to differences in the testicular temperature reached with each procedure.

  13. Steroidogenic fate of the Leydig cells that repopulate the testes of young and aged Brown Norway rats after elimination of the preexisting Leydig cells.

    PubMed

    Chen, Haolin; Guo, Jingjing; Ge, Renshan; Lian, Qingquan; Papadopoulos, Vassilios; Zirkin, Barry R

    2015-12-01

    The capacity of Brown Norway rat Leydig cells to produce testosterone (T) decreases with aging. In a previous study, we reported that a new generation of Leydig cells can be restored in both young and old rat testes after a single injection of ethane dimethanesulfonate (EDS), and that the abilities of the new Leydig cells in young and old rats to produce T were equivalent. Our objective herein was to compare the steroidogenic fate of the new Leydig cells over time. Young (3 month-old) and old (18 month-old) rats were injected with EDS to eliminate the existing Leydig cells. Ten weeks after EDS, Leydig cells had been restored and T production by the new Leydig cells isolated from young and old rat testes was equivalent. Thirty weeks after EDS treatment of young rats, the ability of the new Leydig cells to produce T had not diminished from 10 weeks post-EDS. In contrast, at 30 weeks post-EDS, T production by new cells in old rat testes was reduced significantly from the 10-week level. Serum T levels at 10 and 30 weeks were consistent with Leydig cell T production. Serum LH levels did not differ in any group. Thus, although the Leydig cells restored to both young and old rats after EDS initially produced T at high, equivalent levels, the cells in the old testes did not maintain this ability. These results suggest that: 1) the cells from which new populations of Leydig cells are derived may differ depending upon the age of the rat; and/or 2) factors extrinsic to the new Leydig cells in young and old testes differ, and it is these differences that are responsible for reductions in T by the newly formed Leydig cells in the testes of old rats.

  14. Dehydroepiandrosterone inhibits cell proliferation and improves viability by regulating S phase and mitochondrial permeability in primary rat Leydig cells.

    PubMed

    Liu, Lin; Wang, Dian; Li, Longlong; Ding, Xiao; Ma, Haitian

    2016-07-01

    Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement and exhibits putative anti‑aging properties. However, the molecular basis of the actions of DHEA, particularly on the biological characteristics of target cells, remain unclear. The aim of the current study was to investigate the effects of DHEA on cell viability, cell proliferation, cell cycle and mitochondrial function in primary rat Leydig cells. Adult Leydig cells were purified by Percoll gradient centrifugation, and cell proliferation was detected using a Click-iT® EdU Assay kit and cell cycle assessment performed using flow cytometry. Mitochondrial membrane potential was detected using JC-1 staining assay. The results of the current study demonstrate that DHEA decreased cell proliferation in a dose‑dependent manner, whereas it improved cell viability in a time‑dependent and dose‑dependent manner. Flow cytometry analysis demonstrated that DHEA treatment increased the S phase cell population and decreased the G2/M cell population. Cyclin A and CDK2 mRNA levels were decreased in primary rat Leydig cells following DHEA treatment. DHEA treatment decreased the transmembrane electrical gradient in primary Leydig cells, whereas treatment significantly increased succinate dehydrogenase activity. These results indicated that DHEA inhibits primary rat Leydig cell proliferation by decreasing cyclin mRNA level, whereas it improves cells viability by modulating the permeability of the mitochondrial membrane and succinate dehydrogenase activity. These findings may demonstrate an important molecular mechanism by which DHEA activity is mediated.

  15. Covalent affinity labeling, radioautography, and immunocytochemistry localize the glucocorticoid receptor in rat testicular Leydig cells

    SciTech Connect

    Stalker, A.; Hermo, L.; Antakly, T. )

    1989-12-01

    The presence and distribution of glucocorticoid receptors in the rat testis were examined by using 2 approaches: in vivo quantitative radioautography and immunocytochemistry. Radioautographic localization was made possible through the availability of a glucocorticoid receptor affinity label, dexamethasone 21-mesylate, which binds covalently to the glucocorticoid receptor, thereby preventing dissociation of the steroid-receptor complex. Adrenalectomized adult rats were injected with a tritiated (3H) form of this steroid into the testis and the tissue was processed for light-microscope radioautography. Silver grains were observed primarily over the Leydig cells of the interstitial space and to a lesser extent, over the cellular layers which make up the seminiferous epithelium, with no one cell type showing preferential labeling. To determine the specificity of the labeling, a 25- or 50-fold excess of unlabeled dexamethasone was injected simultaneously with the same dose of (3H)-dexamethasone 21-mesylate. In these control experiments, a marked reduction in label intensity was noted over the Leydig as well as tubular cells. Endocytic macrophages of the interstitium were non-specifically labeled, indicating uptake of the ligand possibly by fluid-phase endocytosis. A quantitative analysis of the label confirmed the presence of statistically significant numbers of specific binding sites for glucocorticoids in both Leydig cells and the cellular layers of the seminiferous epithelium; 86% of the label was found over Leydig cells, and only 14% over the cells of the seminiferous epithelium. These binding data were confirmed by light-microscope immunocytochemistry using a monoclonal antibody to the glucocorticoid receptor.

  16. Chronic stress induces ageing-associated degeneration in rat Leydig cells

    PubMed Central

    Wang, Fei-Fei; Wang, Qian; Chen, Yong; Lin, Qiang; Gao, Hui-Bao; Zhang, Ping

    2012-01-01

    Several studies have suggested that stress and ageing exert inhibitory effects on rat Leydig cells. In a pattern similar to the normal process of Leydig cell ageing, stress-mediated increases in glucocorticoid levels inhibit steroidogenic enzyme expression that then results in decreased testosterone secretion. We hypothesized that chronic stress accelerates the degenerative changes associated with ageing in Leydig cells. To test this hypothesis, we established a model of chronic stress to evaluate stress-induced morphological and functional alterations in Brown Norway rat Leydig cells; additionally, intracellular lipofuscin levels, reactive oxygen species (ROS) levels and DNA damage were assessed. The results showed that chronic stress accelerated ageing-related changes: ultrastructural alterations associated with ageing, cellular lipofuscin accumulation, increased ROS levels and more extensive DNA damage were observed. Additionally, testosterone levels were decreased. This study sheds new light on the idea that chronic stress contributes to the degenerative changes associated with ageing in rat Leydig cells in vivo. PMID:22609820

  17. Effects of the Janus Kinase Inhibitor, Tofacitinib, on Testicular Leydig Cell Hyperplasia and Adenoma in Rats, and on Prolactin Signaling in Cultured Primary Rat Leydig Cells.

    PubMed

    Chapin, Robert E; Ball, Douglas J; Radi, Zaher A; Kumpf, Steven W; Koza-Taylor, Petra H; Potter, David M; Mark Vogel, W

    2017-01-01

    Tofacitinib is an oral Janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis. Tofacitinib preferentially inhibits receptor signaling through JAK3 and JAK1, relative to JAK2. In the 2-year rat carcinogenicity study, there were tofacitinib, dose-related increases in the incidences of testicular Leydig cell hyperplasia and benign adenomas in male rats, and decreased incidences of mammary tumors and duct dilatation/galactocele in female rats. Such findings in rats are typical of agents, such as dopamine agonists, which decrease prolactin (PRL) activity. Since prolactin signals through the JAK2 pathway, we hypothesized that these findings were off-target effects due to inhibition of PRL signaling via JAK2. The studies reported here were designed to investigate the interruption of PRL signaling pathways in Leydig cells. In isolated primary rat Leydig cells, PRL increased phosphorylated Signal Transducer and Activator of Transcription-5 protein, and mRNA levels for luteinizing hormone receptor. Tofacitinib, at concentrations observed in the rat carcinogenicity study, dose-dependently inhibited these effects. These observations illustrate a novel mechanism, the inhibition of prolactin signaling by which modulation of JAK activity can modulate PRL signaling pathways to induce Leydig cell tumors in rats. Since human Leydig cells lack this PRL dependence for normal function, these rodent tumors do not indicate a health risk to human patients.

  18. Drug ligand-induced activation of translocator protein (TSPO) stimulates steroid production by aged brown Norway rat Leydig cells.

    PubMed

    Chung, J Y; Chen, H; Midzak, A; Burnett, A L; Papadopoulos, V; Zirkin, B R

    2013-06-01

    Translocator protein (TSPO; 18 kDA) is a high-affinity cholesterol-binding protein that is integrally involved in cholesterol transfer from intracellular stores into mitochondria, the rate-determining step in steroid formation. Previous studies have shown that TSPO drug ligands are able to activate steroid production by MA-10 mouse Leydig tumor cells and by mitochondria isolated from steroidogenic cells. We hypothesized herein that the direct, pharmacological activation of TSPO might induce aged Leydig cells, which are characterized by reduced T production, to produce significantly higher levels of T both in vitro and in vivo. To test this, we first examined the in vitro effects of the TSPO selective and structurally distinct drug ligands N,N-dihexyl-2-(4-fluorophenyl)indole-3-acetamide (FGIN-1-27) and benzodiazepine 4'-chlorodiazepam (Ro5-4864) on steroidogenesis by Leydig cells isolated from aged (21-24 months old) and young adult (3-6 months old) Brown Norway rats. The ligands stimulated Leydig cell T production significantly, and equivalently, in cells of both ages, an effect that was significantly inhibited by the specific TSPO inhibitor 5-androsten-3,17,19-triol (19-Atriol). Additionally, we examined the in vivo effects of administering FGIN-1-27 to young and aged rats. In both cases, serum T levels increased significantly, consistent with the in vitro results. Indeed, serum T levels in aged rats administered FGIN-1-27 were equivalent to T levels in the serum of control young rats. Taken together, these results indicate that although there are reduced amounts of TSPO in aged Leydig cells, its direct activation is able to increase T production. We suggest that this approach might serve as a therapeutic means to increase steroid levels in vivo in cases of primary hypogonadism.

  19. MODULATION OF RAT LEYDIG CELL STEROIDOGENIC FUNCTION BY DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Modulation of rat Leydig cell steroidogenic function by di(2-ethylhexyl)phthalate.

    Akingbemi BT, Youker RT, Sottas CM, Ge R, Katz E, Klinefelter GR, Zirkin BR, Hardy MP.

    Center for Biomedical Research, Population Council, New York, New York 10021, USA. benson@popcbr...

  20. Effects of luteinizing hormone and androgen on the development of rat progenitor Leydig cells in vitro and in vivo

    PubMed Central

    Guo, Jing-Jing; Ma, Xue; Wang, Claire QF; Ge, Yu-Fei; Lian, Qing-Quan; Hardy, Dianne O; Zhang, Yu-Fei; Dong, Qiang; Xu, Yun-Fei; Ge, Ren-Shan

    2013-01-01

    Progenitor Leydig cells are derived from stem cells. The proliferation and differentiation of progenitor Leydig cells significantly contributes to Leydig cell number during puberty. However, the regulation of these processes remains unclear. The objective of the present study was to determine whether luteinizing hormone (LH) or androgen contributes to the proliferation and differentiation of progenitor Leydig cells. Fourteen-day-old male Sprague–Dawley rats were treated for 7 days with NalGlu, which is a gonadotropin-releasing hormone antagonist, to reduce the secretion of LH in the pituitary and thus, androgen in the testis. Rats were co-administered with LH or 7α-methyl-nortestosterone (MENT), which is an androgen resistant to metabolism by 5α-reductase 1 in progenitor Leydig cells, and the subsequent effects of LH or androgen were measured. 3H-Thymidine was also intravenously injected into rats to study thymidine incorporation in progenitor Leydig cells. Progenitor Leydig cells were examined. NalGlu administration reduced progenitor Leydig cell proliferation by 83%. In addition, LH or MENT treatment restored Leydig cell proliferative capacity to 73% or 50% of control, respectively. The messenger RNA levels of proliferation-related genes were measured using real-time PCR. The expression levels of Igf1, Lifr, Pdgfra, Bcl2, Ccnd3 and Pcna were upregulated by MENT, and those of Pdgfra, Ccnd3 and Pcna were upregulated by LH. Both LH and MENT stimulated the differentiation of progenitor Leydig cells in vitro. We concluded that both LH and MENT were involved in regulating the development of progenitor Leydig cells. PMID:23792342

  1. Effects of luteinizing hormone and androgen on the development of rat progenitor Leydig cells in vitro and in vivo.

    PubMed

    Guo, Jing-Jing; Ma, Xue; Wang, Claire Q F; Ge, Yu-Fei; Lian, Qing-Quan; Hardy, Dianne O; Zhang, Yu-Fei; Dong, Qiang; Xu, Yun-Fei; Ge, Ren-Shan

    2013-09-01

    Progenitor Leydig cells are derived from stem cells. The proliferation and differentiation of progenitor Leydig cells significantly contributes to Leydig cell number during puberty. However, the regulation of these processes remains unclear. The objective of the present study was to determine whether luteinizing hormone (LH) or androgen contributes to the proliferation and differentiation of progenitor Leydig cells. Fourteen-day-old male Sprague-Dawley rats were treated for 7 days with NalGlu, which is a gonadotropin-releasing hormone antagonist, to reduce the secretion of LH in the pituitary and thus, androgen in the testis. Rats were co-administered with LH or 7α-methyl-nortestosterone (MENT), which is an androgen resistant to metabolism by 5α-reductase 1 in progenitor Leydig cells, and the subsequent effects of LH or androgen were measured. (3)H-Thymidine was also intravenously injected into rats to study thymidine incorporation in progenitor Leydig cells. Progenitor Leydig cells were examined. NalGlu administration reduced progenitor Leydig cell proliferation by 83%. In addition, LH or MENT treatment restored Leydig cell proliferative capacity to 73% or 50% of control, respectively. The messenger RNA levels of proliferation-related genes were measured using real-time PCR. The expression levels of Igf1, Lifr, Pdgfra, Bcl2, Ccnd3 and Pcna were upregulated by MENT, and those of Pdgfra, Ccnd3 and Pcna were upregulated by LH. Both LH and MENT stimulated the differentiation of progenitor Leydig cells in vitro. We concluded that both LH and MENT were involved in regulating the development of progenitor Leydig cells.

  2. Fetal programming of adult Leydig cell function by androgenic effects on stem/progenitor cells.

    PubMed

    Kilcoyne, Karen R; Smith, Lee B; Atanassova, Nina; Macpherson, Sheila; McKinnell, Chris; van den Driesche, Sander; Jobling, Matthew S; Chambers, Thomas J G; De Gendt, Karel; Verhoeven, Guido; O'Hara, Laura; Platts, Sophie; Renato de Franca, Luiz; Lara, Nathália L M; Anderson, Richard A; Sharpe, Richard M

    2014-05-06

    Fetal growth plays a role in programming of adult cardiometabolic disorders, which in men, are associated with lowered testosterone levels. Fetal growth and fetal androgen exposure can also predetermine testosterone levels in men, although how is unknown, because the adult Leydig cells (ALCs) that produce testosterone do not differentiate until puberty. To explain this conundrum, we hypothesized that stem cells for ALCs must be present in the fetal testis and might be susceptible to programming by fetal androgen exposure during masculinization. To address this hypothesis, we used ALC ablation/regeneration to identify that, in rats, ALCs derive from stem/progenitor cells that express chicken ovalbumin upstream promoter transcription factor II. These stem cells are abundant in the fetal testis of humans and rodents, and lineage tracing in mice shows that they develop into ALCs. The stem cells also express androgen receptors (ARs). Reduction in fetal androgen action through AR KO in mice or dibutyl phthalate (DBP) -induced reduction in intratesticular testosterone in rats reduced ALC stem cell number by ∼40% at birth to adulthood and induced compensated ALC failure (low/normal testosterone and elevated luteinizing hormone). In DBP-exposed males, this failure was probably explained by reduced testicular steroidogenic acute regulatory protein expression, which is associated with increased histone methylation (H3K27me3) in the proximal promoter. Accordingly, ALCs and ALC stem cells immunoexpressed increased H3K27me3, a change that was also evident in ALC stem cells in fetal testes. These studies highlight how a key component of male reproductive development can fundamentally reprogram adult hormone production (through an epigenetic change), which might affect lifetime disease risk.

  3. A role of KIT receptor signaling for proliferation and differentiation of rat stem Leydig cells in vitro.

    PubMed

    Liu, Shiwen; Chen, Xiaomin; Wang, Yiyan; Li, Linxi; Wang, Guimin; Li, Xiaoheng; Chen, Haolin; Guo, Jingjing; Lin, Han; Lian, Qing-Quan; Ge, Ren-Shan

    2017-03-15

    In the testis, KIT ligand (KITL, also called stem cell factor) is expressed by Sertoli cells and its receptor (c-kit, KIT) is expressed by spermatogonia and Leydig cells. Although KITL-KIT signaling is critical for the spermatogenesis, its roles in Leydig cell development during puberty are not clear. In the present study, we investigated effects of KITL on stem Leydig cell proliferation and differentiation. Using an in vitro culture system of seminiferous tubules from Leydig cell-depleted testis, we found that KITL increased the proliferation activity of putative stem Leydig cells at higher concentration (10 and 100 ng/ml). Low concentration (1 ng/ml) of KITL significantly induced the differentiation of stem Leydig cells via increasing the expression level of steroidogenic acute regulatory protein (Star). In contrast, higher concentration (100 ng/ml) of KITL inhibited the differentiation of stem Leydig cells via inhibiting the steroidogenic enzyme (Cyp11a1, Cyp17a1, and Hsd17b3) expression levels. We cultured rat progenitor Leydig cells with KITL for 48 h and did not find any influence of KITL on the proliferation and androgen production of these cells. In conclusion, KITL is a growth factor that regulates the development of the stem Leydig cell.

  4. Sertoli Cells Maintain Leydig Cell Number and Peritubular Myoid Cell Activity in the Adult Mouse Testis

    PubMed Central

    Monteiro, Ana; Milne, Laura; Cruickshanks, Lyndsey; Jeffrey, Nathan; Guillou, Florian; Freeman, Tom C.; Mitchell, Rod T.; Smith, Lee B.

    2014-01-01

    The Sertoli cells are critical regulators of testis differentiation and development. In the adult, however, their known function is restricted largely to maintenance of spermatogenesis. To determine whether the Sertoli cells regulate other aspects of adult testis biology we have used a novel transgenic mouse model in which Amh-Cre induces expression of the receptor for Diphtheria toxin (iDTR) specifically within Sertoli cells. This causes controlled, cell-specific and acute ablation of the Sertoli cell population in the adult animal following Diphtheria toxin injection. Results show that Sertoli cell ablation leads to rapid loss of all germ cell populations. In addition, adult Leydig cell numbers decline by 75% with the remaining cells concentrated around the rete and in the sub-capsular region. In the absence of Sertoli cells, peritubular myoid cell activity is reduced but the cells retain an ability to exclude immune cells from the seminiferous tubules. These data demonstrate that, in addition to support of spermatogenesis, Sertoli cells are required in the adult testis both for retention of the normal adult Leydig cell population and for support of normal peritubular myoid cell function. This has implications for our understanding of male reproductive disorders and wider androgen-related conditions affecting male health. PMID:25144714

  5. Annexin V-induced rat Leydig cell proliferation involves Ect2 via RhoA/ROCK signaling pathway.

    PubMed

    Jing, Jun; Chen, Li; Fu, Hai-Yan; Fan, Kai; Yao, Qi; Ge, Yi-Feng; Lu, Jin-Chun; Yao, Bing

    2015-03-24

    This study investigated the effect of annexin V on the proliferation of primary rat Leydig cells and the potential mechanism. Our results showed that annexin V promoted rat Leydig cell proliferation and cell cycle progression in a dose- and time-dependent manner. Increased level of annexin V also enhanced Ect2 protein expression. However, siRNA knockdown of Ect2 attenuated annexin V-induced proliferation of rat Leydig cells. Taken together, these data suggest that increased level of annexin V induced rat Leydig cell proliferation and cell cycle progression via Ect2. Since RhoA activity was increased following Ect2 activation, we further investigated whether Ect2 was involved in annexin V-induced proliferation via the RhoA/ROCK pathway, and the results showed that annexin V increased RhoA activity too, and this effect was abolished by the knockdown of Ect2. Moreover, inhibition of the RhoA/ROCK pathway by a ROCK inhibitor, Y27632, also attenuated annexin V-induced proliferation and cell cycle progression. We thus conclude that Ect2 is involved in annexin V-induced rat Leydig cell proliferation through the RhoA/ROCK pathway.

  6. Annexin V-induced rat Leydig cell proliferation involves Ect2 via RhoA/ROCK signaling pathway

    PubMed Central

    Jing, Jun; Chen, Li; Fu, Hai-Yan; Fan, Kai; Yao, Qi; Ge, Yi-Feng; Lu, Jin-Chun; Yao, Bing

    2015-01-01

    This study investigated the effect of annexin V on the proliferation of primary rat Leydig cells and the potential mechanism. Our results showed that annexin V promoted rat Leydig cell proliferation and cell cycle progression in a dose- and time-dependent manner. Increased level of annexin V also enhanced Ect2 protein expression. However, siRNA knockdown of Ect2 attenuated annexin V-induced proliferation of rat Leydig cells. Taken together, these data suggest that increased level of annexin V induced rat Leydig cell proliferation and cell cycle progression via Ect2. Since RhoA activity was increased following Ect2 activation, we further investigated whether Ect2 was involved in annexin V-induced proliferation via the RhoA/ROCK pathway, and the results showed that annexin V increased RhoA activity too, and this effect was abolished by the knockdown of Ect2. Moreover, inhibition of the RhoA/ROCK pathway by a ROCK inhibitor, Y27632, also attenuated annexin V-induced proliferation and cell cycle progression. We thus conclude that Ect2 is involved in annexin V-induced rat Leydig cell proliferation through the RhoA/ROCK pathway. PMID:25807302

  7. AB250. Annexin V-induced rat Leydig cell proliferation involves Ect2 via RhoA/ROCK signaling pathway

    PubMed Central

    Yao, Bin

    2016-01-01

    Background This study investigated the effect of annexin V on the proliferation of primary rat Leydig cells and the potential mechanism. Methods The primary rat Leydig cells were cultured in vitro and treated with 1 nmol/L annexin 5 and with siRNA–Ect2 transfection. The cell proliferation rate was measured by MTT assay. Phase distribution of cell cycle was analyzed by flow cytometry. The expression of Ect2 in protein level were detected by western blotting. RhoA activity was measured by Rho activation assay kit. Results Our results showed that annexin V promoted rat Leydig cell proliferation and cell cycle progression in a dose- and time-dependent manner. Increased level of annexin V also enhanced Ect2 protein expression. However, siRNA knockdown of Ect2 attenuated annexin V-induced proliferation of rat Leydig cells. Taken together, these data suggest that increased level of annexin V induced rat Leydig cell proliferation and cell cycle progression via Ect2. Since RhoA activity was increased following Ect2 activation, we further investigated whether Ect2 was involved in annexin V-induced proliferation via the RhoA/ROCK pathway, and the results showed that annexin V increased RhoA activity too, and this effect was abolished by the knockdown of Ect2. Moreover, inhibition of the RhoA/ROCK pathway by a ROCK inhibitor, Y27632, also attenuated annexin V-induced proliferation and cell cycle progression. Conclusions We thus conclude that Ect2 is involved in annexin V-induced rat Leydig cell proliferation through the RhoA/ROCK pathway.

  8. Goliath, a ring-H2 mitochondrial protein, regulated by luteinizing hormone/human chorionic gonadotropin in rat leydig cells.

    PubMed

    Guais, A; Solhonne, B; Melaine, N; Guellaen, G; Bulle, F

    2004-01-01

    We have cloned the rat homologue of the ring-H2 protein Goliath involved in Drosophila development. The rat Goliath mRNA (1.85 kb) was translated as a major ubiquitous protein species of 28-kDa and three larger isoforms (50, 46, and 36 kDa) expressed mainly in liver, lung, stomach, heart, and thymus and barely detectable in other tissues (kidney, skeletal muscle, brain, testis, intestine, and spleen). By immunohistochemistry on rat testis sections, we localized the protein in interstitial tissue and seminiferous tubules. In tubules, Goliath was expressed mainly in postmeiotic germ cells and to a much lesser extent in Sertoli cells. In the interstitium, Goliath was exclusively present in Leydig cells. Using a series of immunolabeling, cellular fractionation, and electron microscopy experiments, we established that Goliath is present in mitochondria of the R2C Leydig cell line. Using short-term hypophysectomized animals, we showed that Goliath is regulated by LH/hCG in Leydig cells but not in germ cells. This regulation in Leydig cells concerned only the 50-kDa isoform. This report is the first description of a differential regulation of the Goliath protein between germ cells and Leydig cells.

  9. Effect of ETBE on reproductive steroids in male rats and rat Leydig cell cultures.

    PubMed

    de Peyster, Ann; Stanard, Bradley; Westover, Christian

    2009-10-08

    These experiments were conducted to follow up on a report of testis seminiferous tubular degeneration in Fischer 344 rats treated with high doses of ethyl t-butyl ether (ETBE). Also, high doses of a related compound, methyl t-butyl ether (MTBE), had been shown to reduce circulating testosterone (T) in rats. Isolated rat Leydig cells were used to compare hCG-stimulated T production following exposure to ETBE, MTBE, and their common main metabolite, TBA. In addition, male Fischer 344 rats were gavaged daily with 600 mg/kg, 1200 mg/kg or 1800 mg/kg ETBE in corn oil (n=12) for 14 days, the 1200 mg/kg dose chosen for comparison with a prior 14-day MTBE gavage experiment. In cell culture experiments, TBA was more potent than either ETBE or MTBE, both of which caused similar inhibition of T production at equimolar concentrations. In the in vivo study, no significant plasma T reduction was seen 1h after the final 1200 mg/kg ETBE dose, whereas 1200 mg/kg MTBE had significantly lowered T when administered similarly to Sprague-Dawley rats. Some rats treated with 1800 mg/kg ETBE had noticeably lower T levels, and the group average T level was 66% of corn oil vehicle control (p>0.05) with high variability also evident in ETBE-treated rats. 17beta-Estradiol had been increased by 1200 mg/kg MTBE, and was elevated in the 1200 and 1800 mg/kg ETBE dose groups (p<0.05), both groups also experiencing significantly reduced body weight gain. None of these effects were seen with 600 mg/kg/day ETBE. No definitive evidence of androgen insufficiency was seen in accessory organ weights, and no testicular pathology was observed after 14 days in a small subset of 1800 mg/kg ETBE-treated animals. Like MTBE, ETBE appears to be capable of altering reproductive steroid levels in peripheral blood sampled 1h after treatment, but only with extremely high doses that inhibit body weight gain and may produce mortality.

  10. Aging and luteinizing hormone effects on reactive oxygen species production and DNA damage in rat Leydig cells.

    PubMed

    Beattie, Matthew C; Chen, Haolin; Fan, Jinjiang; Papadopoulos, Vassilios; Miller, Paul; Zirkin, Barry R

    2013-04-01

    We observed previously that after long-term suppression of luteinizing hormone (LH) and thus of Leydig cell steroidogenesis, restimulation of the Leydig cells by LH resulted in significantly higher testosterone production than by age-matched cells from control rats. These studies suggest that stimulation over time may elicit harmful effects on the steroidogenic machinery, perhaps through alteration of the intracellular oxidant-to-antioxidant balance. Herein we compared the effects of LH stimulation on stress response genes, formation of intracellular reactive oxygen species (ROS), and ROS-induced damage to ROS-susceptible macromolecules (DNA) in young and in aged cells. Microarray analysis indicated that LH stimulation resulted in significant increases in expression of genes associated with stress response and antiapoptotic pathways. Short-term LH treatment of primary Leydig cells isolated from young rats resulted in transiently increased ROS levels compared to controls. Aged Leydig cells also showed increased ROS soon after LH stimulation. However, in contrast to the young cells, ROS production peaked later and the time to recovery was increased. In both young and aged cells, treatment with LH resulted in increased levels of DNA damage but significantly more so in the aged cells. DNA damage levels in response to LH and the levels of intracellular ROS were highly correlated. Taken together, these results indicate that LH stimulation causes increased ROS production by young and aged Leydig cells and that while DNA damage occurs in cells of both ages, there is greater damage in the aged cells.

  11. A METABOLITE OF METHOXYCHLOR,2,2-BIS(P-HYDOXYPHENYL)-1,1,1- TRICHLOROETHANE REDUCES TESTOSTERONE BIOSYNTHESIS IN RAT LEYDIG CELLS THROUGH SUPPRESSION OF STEADY-STATE MESSENGER RIBONUCLEIC ACID LEVELS OF THE CHOLESTEROL SIDE-CHAIN CLEAVAGE ENZYME

    EPA Science Inventory

    Postnatal development of Leydig cells involves transformation through three stages: progenitor, immature, and adult Leydig cells. The process of differentiation is accompanied by a progressive increase in the capacity of Leydig cells to produce testosterone (T). T promotes the ma...

  12. Inhibition of 3beta- and 17beta-hydroxysteroid dehydrogenase activities in rat Leydig cells by perfluorooctane acid.

    PubMed

    Zhao, Binghai; Chu, Yanhui; Hardy, Dianne O; Li, Xiao-kun; Ge, Ren-Shan

    2010-01-01

    Perfluorooctane acid (PFOA) is classified as a persistent organic pollutant and as an endocrine disruptor. The mechanism by which PFOA causes reduced testosterone production in males is not known. We tested our hypothesis that PFOA interferes with Leydig cell steroidogenic enzymes by measuring its effect on 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydrogenase 3 (17beta-HSD3) activities in rat testis microsomes and Leydig cells. The IC(50)s of PFOA and mode of inhibition were assayed. PFOA inhibited microsomal 3beta-HSD with an IC(50) of 53.2+/-25.9 microM and 17beta-HSD3 with an IC(50) 17.7+/-6.8 microM. PFOA inhibited intact Leydig cell 3beta-HSD with an IC(50) of 146.1+/-0.9 microM and 17beta-HSD3 with an IC(50) of 194.8+/-1.0 microM. The inhibitions of 3beta-HSD and 17beta-HSD3 by PFOA were competitive for the substrates. In conclusion, PFOA inhibits 3beta-HSD and 17beta-HSD3 in rat Leydig cells.

  13. Effect of an acute exposure of rat testes to gamma rays on germ cells and on Sertoli and Leydig cell functions.

    PubMed

    Pinon-Lataillade, G; Viguier-Martinez, M C; Touzalin, A M; Maas, J; Jégou, B

    1991-01-01

    Germ cells and Sertoli and Leydig cell functions were studied from 7 to 180 days after an acute exposure of 2-month-old rat testes to 9 Gy of gamma rays. Body weight, testis and epididymal weights were recorded. Sertoli cell parameters (androgen-binding protein, ABP, in caput epididymis and plasma follicle stimulating hormone, FSH) and Leydig cell parameters (plasma luteinizing hormone, LH, testosterone and prostate and seminal vesicle weights) were determined together with the number of germ cells and Sertoli cells. Irradiation did not affect body weight but significantly reduced testicular and epididymal weights from day 7 and day 15 post-irradiation respectively. The cells killed by irradiation were mainly spermatogonia and preleptotene spermatocytes engaged in replicating their DNA at the time of exposure, but all spermatocytes seemed damaged as they gave abnormal descendent cells. By day 34, only elongated spermatids remained in a few tubules and thereafter very little regeneration of the seminiferous epithelium occurred, except for one rat which showed a better regeneration. Levels of ABP decreased by day 15 when the germ cell depletion had reached the pachytene spermatocytes, whereas FSH and LH levels rose when the number of elongated spermatids decreased. Levels of testosterone and the weight of the seminal vesicles did not change; occasionally, the prostate weight was slightly reduced. These results support our hypothesis that pachytene spermatocytes and elongated spermatids are involved in influencing some aspects of Sertoli cell function in the adult rat.

  14. HBCDD-induced sustained reduction in mitochondrial membrane potential, ATP and steroidogenesis in peripubertal rat Leydig cells

    SciTech Connect

    Fa, Svetlana; Pogrmic-Majkic, Kristina; Samardzija, Dragana; Hrubik, Jelena; Glisic, Branka; Kovacevic, Radmila; Andric, Nebojsa

    2015-01-01

    Hexabromocyclododecane (HBCDD), a brominated flame retardant added to various consumer products, is a ubiquitous environmental contaminant. We have previously shown that 6-hour exposure to HBCDD disturbs basal and human chorionic gonadotropin (hCG)-induced steroidogenesis in rat Leydig cells. Reduction in mitochondrial membrane potential (ΔΨm) and cAMP production was also observed. Here, we further expanded research on the effect of HBCDD on Leydig cells by using a prolonged exposure scenario. Cells were incubated in the presence of HBCDD during 24 h and then treated with HBCDD + hCG for additional 2 h. Results showed that HBCDD caused a sustained reduction in ATP level after 24 h of exposure, which persisted after additional 2-hour treatment with HBCDD + hCG. cAMP and androgen accumulations measured after 2 h of HBCDD + hCG treatment were also inhibited. Real-time PCR analysis showed significant inhibition in the expression of genes for steroidogenic enzymes, luteinizing hormone receptor, regulatory and transport proteins, and several transcription factors under both treatment conditions. Western blot analysis revealed a decreased level of 30 kDa steroidogenic acute regulatory protein (StAR) after HBCDD + hCG treatment. In addition, HBCDD decreased the conversion of 22-OH cholesterol to pregnenolone and androstenedione to testosterone, indicating loss of the activity of cytochrome P450C11A1 (CYP11A1) and 17β-hydroxysteroid dehydrogenase (HSD17β). Cell survival was not affected, as confirmed by cytotoxicity and trypan blue tests or DNA fragmentation analysis. In summary, our data showed that HBCDD inhibits ATP supply, most likely through a decrease in ΔΨm, and targets multiple sites in the steroidogenic pathway in Leydig cells. - Highlights: • HBCDD causes a sustained reduction in ΔΨm and ATP level in Leydig cells. • Prolonged HBCDD exposure decreases hCG-supported steroidogenesis in Leydig cells. • HBCDD targets StAR, HSD17β and CYP11A1 in Leydig

  15. Effects of in Utero Exposure to Dicyclohexyl Phthalate on Rat Fetal Leydig Cells

    PubMed Central

    Li, Xiaoheng; Chen, Xiaomin; Hu, Guoxin; Li, Linxi; Su, Huina; Wang, Yiyan; Chen, Dongxin; Zhu, Qiqi; Li, Chao; Li, Junwei; Wang, Mingcang; Lian, Qingquan; Ge, Ren-Shan

    2016-01-01

    Dicyclohexyl phthalate (DCHP) is one of the phthalate plasticizers. The objective of the present study was to investigate the effects of DCHP on fetal Leydig cell distribution and function as well as testis development. Female pregnant Sprague Dawley dams orally received vehicle (corn oil, control) or DCHP (10, 100, and 500 mg/kg/day) from gestational day (GD) 12 to GD 21. At GD 21.5, testicular testosterone production, fetal Leydig cell number and distribution, testicular gene and protein expression levels were examined. DCHP administration produced a dose-dependent increase of the incidence of multinucleated gonocytes at ≥100 mg/kg. DCHP dose-dependently increased abnormal fetal Leydig cell aggregation and decreased fetal Leydig cell size, cytoplasmic size, and nuclear size at ≥10 mg/kg. DCHP reduced the expression levels of steroidogenesis-related genes (including Star, Hsd3b1, and Hsd17b3) and testis-descent related gene Insl3 as well as protein levels of 3β-hydroxysteroid dehydrogenase 1 (HSD3B1) and insulin-like 3 (INSL3) at ≥10 mg/kg. DCHP significantly inhibited testicular testosterone levels at ≥100 mg/kg. The results indicate that in utero exposure to DCHP affects the expression levels of fetal Leydig cell steroidogenic genes and results in the occurrence of multinucleated gonocytes and Leydig cell aggregation. PMID:26907321

  16. Feeding hydroalcoholic extract powder of Lepidium meyenii (maca) increases serum testosterone concentration and enhances steroidogenic ability of Leydig cells in male rats.

    PubMed

    Ohta, Y; Yoshida, K; Kamiya, S; Kawate, N; Takahashi, M; Inaba, T; Hatoya, S; Morii, H; Takahashi, K; Ito, M; Ogawa, H; Tamada, H

    2016-04-01

    Although Lepidium meyenii (maca), a plant growing in Peru's central Andes, has been traditionally used for enhancing fertility and reproductive performance in domestic animals and human beings, effects of maca on reproductive organs are still unclear. This study examined whether feeding the hydroalcoholic extract powder of maca for 6 weeks affects weight of the reproductive organs, serum concentrations of testosterone and luteinising hormone (LH), number and cytoplasmic area of immunohistochemically stained Leydig cells, and steroidogenesis of cultured Leydig cells in 8-week-old male rats. Feeding the extract powder increased weight of seminal vesicles, serum testosterone level and cytoplasmic area of Leydig cells when compared with controls. Weight of prostate gland, serum LH concentration and number of Leydig cells were not affected by the maca treatment. The testosterone production by Leydig cells significantly increased when cultured with 22R-hydroxycholesterol or pregnenolone and tended to increase when cultured with hCG by feeding the extract powder. The results show that feeding the hydroalcoholic extract powder of maca for 6 weeks increases serum testosterone concentration associated with seminal vesicle stimulation in male rats, and this increase in testosterone level may be related to the enhanced ability of testosterone production by Leydig cells especially in the metabolic process following cholesterol.

  17. Inter-relationship between testicular dysgenesis and Leydig cell function in the masculinization programming window in the rat.

    PubMed

    van den Driesche, Sander; Kolovos, Petros; Platts, Sophie; Drake, Amanda J; Sharpe, Richard M

    2012-01-01

    The testicular dysgenesis syndrome (TDS) hypothesis proposes that maldevelopment of the testis, irrespective of cause, leads to malfunction of the somatic (Leydig, Sertoli) cells and consequent downstream TDS disorders. Studies in rats exposed in utero to di(n-butyl) phthalate (DBP) have strongly supported the TDS concept, but so far no direct evidence has been produced that links dysgenesis per se to somatic cell dysfunction, in particular to androgen production/action during the 'masculinization programming window' (MPW; e15.5-e18.5). Normal reproductive tract development and anogenital distance (AGD) are programmed within the MPW, and TDS disorders arise because of deficiencies in this programming. However, DBP-induced focal testicular dysgenesis (Leydig cell aggregation, ectopic Sertoli cells, malformed seminiferous cords) is not evident until after the MPW. Therefore, we used AGD as a read-out of androgen exposure in the MPW, and investigated if this measure was related to objectively quantified dysgenesis (Leydig cell aggregation) at e21.5 in male fetuses exposed to vehicle, DBP (500 or 750 mg/kg/day) or the synthetic glucocorticoid dexamethasone (Dex; alone or plus DBP-500) from e15.5-e18.5 (MPW), e13.5-e20.5 or e19.5-e20.5 (late window). Dysgenesis was found only in animals exposed to DBP during the MPW, and was negatively correlated (R² = -0.5) with AGD at e21.5 and at postnatal day 8, irrespective of treatment period. Dysgenesis was also negatively correlated (R² = -0.5) with intratesticular testosterone (ITT) at e21.5, but only when treatments in short windows (MPW, late window) were excluded; the same was true for correlation between AGD and ITT. We conclude that AGD, reflecting Leydig cell function solely within the MPW, is strongly related to focal dysgenesis. Our results point to this occurring because of a common early mechanism, targeted by DBP that determines both dysgenesis and early (during the MPW) fetal Leydig cell dysfunction. The

  18. Long-term feeding of hydroalcoholic extract powder of Lepidium meyenii (maca) enhances the steroidogenic ability of Leydig cells to alleviate its decline with ageing in male rats.

    PubMed

    Yoshida, K; Ohta, Y; Kawate, N; Takahashi, M; Inaba, T; Hatoya, S; Morii, H; Takahashi, K; Ito, M; Tamada, H

    2017-03-10

    This study examined whether feeding hydroalcoholic extract of Lepidium meyenii (maca) to 8-week-old (sexually maturing) or 18-week-old (mature) male rats for more than a half year affects serum testosterone concentration and testosterone production by Leydig cells cultured with hCG, 22R-hydroxycholesterol or pregnenolone. Testosterone concentration was determined in the serum samples obtained before and 6, 12, 18 and 24 weeks after the feeding, and it was significantly increased only at the 6 weeks in the group fed with the maca extract to maturing rats when it was compared with controls. Testosterone production by Leydig cells significantly increased when cultured with hCG by feeding the maca extract to maturing rats for 27 weeks (35 weeks of age) and when cultured with 22R-hydroxycholesterol by feeding it to mature rats for 30 weeks (48 weeks of age). Overall testosterone production by cultured Leydig cells decreased to about a half from 35 to 48 weeks of age. These results suggest that feeding the maca extract for a long time to male rats may enhance the steroidogenic ability of Leydig cells to alleviate its decline with ageing, whereas it may cause only a transient increase in blood testosterone concentration in sexually maturing male rats.

  19. [The ultrastructure of Leydig cells under the influence of drinking mineral water and electromagnetic radiation under the stress conditions in the rats].

    PubMed

    Geniatulina, M S; Korolev, Yu N; Nikulina, L A

    2016-01-01

    The objective of the present study was elucidate the peculiar features of low-intensity electromagnetic radiation (LI EMR) and mineral water (MW) on the ultrastructure of rat Leydig cells under conditions of immobilization stress. The experiments were carried out on outbred male rats with the use of electron microscopy. It has been demonstrated that the prophylactic consumption of drinking sulfate-containing mineral water and the application low-intensity electromagnetic radiation (with the flow power density of 1 mcW/cm2 and frequency around 1,000 Hz) or the combination of these two modalities under conditions of immobilization stress reduced the degree of ultrastructural derangement in the rat Leydig cells and stimulated the development of regenerative processes. In the cases of the single-factor impact, drinking mineral water exerted more pronounced action than low-intensity electromagnetic radiation on mitochondrial regeneration. In case of the simultaneous application of the two factors their protective action on the Leydig cells was much more conspicuous than that of either of them applied alone. It is concluded that drinking sulfate-containing mineral water in combination with the application of low-intensity electromagnetic radiation enhances resistance of the rat Leydig cells to stress.

  20. Cimetidine-induced Leydig cell apoptosis and reduced EG-VEGF (PK-1) immunoexpression in rats: Evidence for the testicular vasculature atrophy.

    PubMed

    Beltrame, Flávia L; Cerri, Paulo S; Sasso-Cerri, Estela

    2015-11-01

    The antiulcer drug cimetidine has shown to cause changes in the testicular microvasculature of adult rats. Since Leydig cells (LCs) produce the pro-angiogenic factor, EG-VEGF (endocrine gland-derived vascular endothelial growth factor), also known as prokineticin 1 (PK-1), this study examined the effect that cimetidine might have on LCs in testes with damaged vasculature. Rats received intraperitoneal injections of 100mg/kg of cimetidine (cimetidine group) or saline vehicle (control group) for 50 days. Serum testosterone levels were measured by chemiluminescence immunoassay and testicular sections were subjected to TUNEL and immunohistochemical reactions for caspase-3, 17β-HSD6, CD163 (ED2 macrophage), PK-1 and androgen receptor (AR). LCs in the cimetidine group showed TUNEL and caspase-3 positive labeling and apoptotic ultrastructural features. Moreover, the presence of 17β-HSD6-positive inclusions inside macrophages and the reduced number of LCs, AR immunoreactivity and serum testosterone levels correlated with a decrease in either the number of PK-1-immunostained LCs or PK-1 immunoreactivity. Although it is not clear which cell type is the primary target of cimetidine in the testicular interstitial compartment, these findings support a direct link between cimetidine-induced testicular vascular atrophy and LCs damage.

  1. Effect of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) hull extracts on testosterone release from rat Leydig cells.

    PubMed

    Hsia, Shih-Min; Tseng, Yi-Wen; Wang, Shyi-Wu; Kuo, Yueh-Hsiung; Huang, Din-Wen; Wang, Paulus S; Chiang, Wenchang

    2009-05-01

    Adlay has been used as a traditional Chinese medicine for the treatment of many diseases. However, few studies have reported the effects of adlay seeds on the endocrine system. In the present study, the effects of methanol extracts of adlay hull (AHM) on testosterone synthesis were studied. Rat Leydig cells were incubated with different reagents including human chorionic gonadotropin, 8-bromo-adenosine-3',5'-cyclic monophosphate, forskolin, A23187, progesterone and androstenedione in the presence or absence of AHM. The rat anterior pituitary (AP) gland was treated with gonadotropin-releasing hormone (GnRH) in vitro in the presence or absence of AHM, and the concentrations of luteinizing hormone (LH) in the media were measured. AHM decreased testosterone release via the inhibition of (1) the PKA and PKC signal transduction pathways, (2) 17beta-HSD enzyme activity in rat Leydig cells, and (3) in vitro GnRH-induced LH secretion.

  2. Immunohistochemical analysis of androgen effects on androgen receptor expression in developing Leydig and Sertoli cells.

    PubMed

    Shan, L X; Bardin, C W; Hardy, M P

    1997-03-01

    Leydig and Sertoli cells are both targets of androgen action in the testis. Androgen exerts contrasting effects on the two cell types partially inhibiting steroidogenesis in adult Leydig cell and stimulating adult Sertoli cell functions required to support spermatogenesis. The developmental changes in the messenger RNA (mRNA) levels of androgen receptor (AR) also differ between Leydig and Sertoli cells, with Leydig cell AR mRNA being highest on day 35 postpartum, whereas Sertoli cell AR mRNA levels are highest on day 90. The purpose of the present study was to determine if the concentrations of AR in Leydig and Sertoli cells are differentially regulated during development using quantitative immunostaining. AR protein levels were measured in rat testes after hormonal treatments at three developmental stages: on days 21, 35, and 90 postpartum. At each age, five groups of animals were treated for 4 days with: 1) vehicle; 2) LHRH antagonist (NalGlu, 0.3 mg/kg BW.day) to suppress endogenous levels of androgen that accompany inhibition of LH and FSH secretion; 3) NalGlu + LH (0.2 mg/kg BW.day); 4) NalGlu + testosterone (T, at 7.5 mg/kg BW.day); and 5) NalGlu + MENT (a potent synthetic androgen, 7 alpha-methyl-19-nortestosterone, 0.7 mg/kg BW.day). AR protein was visualized by immunohistochemistry and measured by computer-assisted image analysis in Leydig and Sertoli cells using frozen sections of tests. After NalGlu treatment, AR levels in Leydig cells declined sharply to 42% and 31% of vehicle control (P < 0.01) in the 21 and 35 days postpartum age groups, respectively, but in 90-day-old rats there was no change. AR levels were partially maintained by exogenous LH, and completely maintained by exogenous androgen treatments in Leydig cells from 21- and 35-day-old rats, whereas in Leydig cells from 90-day-old rats, AR levels were unaffected in all treatment groups. In contrast, after NalGlu treatment, the AR concentration in Sertoli cells from 90-day-old rats were reduced

  3. Gonadotropin stimulation of cyclic adenosine monophosphate and testosterone production without detectable high-affinity binding sites in purified Leydig cells from rat testis

    SciTech Connect

    Browne, E.S.; Bhalla, V.K. )

    1991-02-01

    Rat testicular interstitial cells were separated by three different gradient-density procedures and, with each, two biochemically and morphologically distinct cell fractions were isolated. The lighter density cells in fraction-I bound iodine 125-labeled human chorionic gonadotropin (hCG) with high-affinity (apparent equilibrium dissociation constant, Kd, approximately 10{sup {minus} 10} M) without producing either cyclic adenosine monophosphate or testosterone in response to hormone action. The heavier-density cells displayed morphologic features typical of Leydig cells and produced cyclic adenosine monophosphate and testosterone in the presence of hCG without detectable {sup 125}I-labeled hCG high-affinity binding. These cell fractions were further characterized by studies using deglycosylated hCG, a known antagonist to hCG action. Cell concentration-dependent studies with purified Leydig cells revealed that maximal testosterone production was achieved when lower cell concentrations (0.5 x 10(6) cells/250 microliters) were used for in vitro hCG stimulation assays. Under these conditions, the {sup 125}I-labeled hCG binding was barely detectable (2.24 fmol; 2,698 sites/cell). Furthermore, these studies revealed that the hCG-specific binding in Leydig cells is overestimated by the classic method for nonspecific binding correction using excess unlabeled hormone. An alternate method is presented.

  4. Different processing of LH/hCG receptors in cultured rat luteal cells and murine Leydig tumor cells (MLTC-1)

    SciTech Connect

    Kellokumpu, S.

    1987-02-01

    The metabolic fate of LH/hCG receptors after exposure to human chorionic gonadotropin (hCG) was examined in cultured rat luteal cells and murine Leydig tumor cells (MLTC-1). Kinetic studies performed after pulse-labelling of the cells with (/sup 125/I)hCG indicated that the bound hormone was lost much more rapidly from the tumor cells than from the luteal cells. The tumor cells were also found to internalize and degrade the hormone more effectively than the luteal cells. Chemical cross-linking and analyses by SDS-PAGE of this material revealed that both cell types also released, in addition to intact hCG, two previously characterized receptor fragment-(/sup 125/I)hCG complexes (M/sub r/ 96,000 and 74,000) into the medium, although their amount was negligible in MLTC-1 cells. Possibly due to rapid discharge of the ligand from its receptor, no similar complexes could be detected inside the MLTC-1 cells, suggesting that they were released directly from the cell surface. However, the M/sub r/ 74,000 complex was observed inside MLTC-1 cells if chloroquine, a lysosomotropic agent, was present during the incubations. This suggests that the internalized receptor also becomes degraded, at least when complexed to hCG. The results thus provide evidence that there exist two different mechanisms for proteolytic processing of LH/hCG receptors in these target cells. In tumor cells, the degradation seems to occur almost exclusively intracellularly, whereas in luteal cells a substantial portion of the receptors is also degraded at the cell surface.

  5. Decreased cyclin A2 and increased cyclin G1 levels coincide with loss of proliferative capacity in rat Leydig cells during pubertal development.

    PubMed

    Ge, R S; Hardy, M P

    1997-09-01

    Postnatal development of Leydig cells can be divided into three distinct stages of differentiation: initially they exist as mesenchymal-like progenitors (PLC) by day 21; subsequently, as immature Leydig cells (ILC) by day 35, they acquire steroidogenic organelle structure and enzyme activities but metabolize most of the testosterone they produce; finally, as adult Leydig cells (ALC) by day 90 they actively produce testosterone. The aims of the present study were to determine whether changes in proliferative capacity are associated with progressive differentiation of Leydig cells, and if the proliferative capacity of Leydig cells is controlled by known hormonal regulators of testosterone biosynthesis: LH, insulin-like growth factor I (IGF-I), androgen, and estradiol (E2). Isolated PLC, ILC, and ALC were cultured in DMEM/F-12 for 24 h followed by an additional 24 h in the presence of LH (1 ng/ml), IGF-I (70 ng/ml), 7alpha-methyl-19-nortestosterone (MENT, 50 nM), a synthetic androgen that is not metabolized by 5alpha-reductase, or E2 (50 nM). Proliferative capacity was measured by assaying [3H]thymidine incorporation and labeling index (LI). Messenger RNA (mRNA) and protein levels for cyclin A2 and G1, which are putative intracellular regulators of Leydig cell proliferation and differentiation, were measured by RT-PCR and immunoblotting, respectively. Thymidine incorporation was highest in PLC (9.24 +/- 0.21 cpm/10(3) cell, mean +/- SE), intermediate in ILC (1.74 +/- 0.07) and lowest in ALC (0.24 +/- 0.03). Similarly, LI was highest in PLC (13.42 +/- 0.30%, mean +/- SE), intermediate in ILC (1.95 +/- 0.08%), and undetectable in ALC. Cyclin A2 mRNA levels, normalized to ribosomal protein S16 (RPS16), were highest in PLC (2.76 +/- 0.21, mean +/- SE), intermediate in ILC (1.79 +/- 0.14), and lowest in ALC (0.40 +/- 0.06). In contrast, cyclin G1 mRNA levels were highest in ALC (1.32 +/- 0.16), intermediate in ILC (0.47 +/- 0.07), and lowest in PLC (0.12 +/- 0.02). The

  6. Statin Drugs Markedly Inhibit Testosterone Production by Rat Leydig Cells In Vitro: Implications for Men

    EPA Science Inventory

    Statin drugs lower blood cholesterol by inhibiting hepatic 3-hydroxy-3-methylglutaryl-Coenzyme-A reductase. During drug development it was shown that statins inhibit production of cholesterol in the testis. We evaluated testosterone production in vitro, using highly purified rat ...

  7. PURIFICATION OF RAT LEYDIG CELLS: INCREASED YIELDS AFTER UNIT-GRAVITY SEDIMENTATION OF COLLAGENASE-DISPERSED INTERSTITIAL CELLS

    EPA Science Inventory

    Abstract

    Procedures for purification of Leydig cells have facilitated studies of their regulatory biology. A multistep procedure, that includes a filtration with nylon mesh (100 micron pore size) to separate interstitial cells from the seminiferous tubules, combining centr...

  8. Autocrine androgen action is essential for Leydig cell maturation and function, and protects against late-onset Leydig cell apoptosis in both mice and men.

    PubMed

    O'Hara, Laura; McInnes, Kerry; Simitsidellis, Ioannis; Morgan, Stephanie; Atanassova, Nina; Slowikowska-Hilczer, Jolanta; Kula, Krzysztof; Szarras-Czapnik, Maria; Milne, Laura; Mitchell, Rod T; Smith, Lee B

    2015-03-01

    Leydig cell number and function decline as men age, and low testosterone is associated with all "Western" cardio-metabolic disorders. However, whether perturbed androgen action within the adult Leydig cell lineage predisposes individuals to this late-onset degeneration remains unknown. To address this, we generated a novel mouse model in which androgen receptor (AR) is ablated from ∼75% of adult Leydig stem cell/cell progenitors, from fetal life onward (Leydig cell AR knockout mice), permitting interrogation of the specific roles of autocrine Leydig cell AR signaling through comparison to adjacent AR-retaining Leydig cells, testes from littermate controls, and to human testes, including from patients with complete androgen insensitivity syndrome (CAIS). This revealed that autocrine AR signaling is dispensable for the attainment of final Leydig cell number but is essential for Leydig cell maturation and regulation of steroidogenic enzymes in adulthood. Furthermore, these studies reveal that autocrine AR signaling in Leydig cells protects against late-onset degeneration of the seminiferous epithelium in mice and inhibits Leydig cell apoptosis in both adult mice and patients with CAIS, possibly via opposing aberrant estrogen signaling. We conclude that autocrine androgen action within Leydig cells is essential for the lifelong support of spermatogenesis and the development and lifelong health of Leydig cells.

  9. High-fat diet aggravates 2,2',4,4'-tetrabromodiphenyl ether-inhibited testosterone production via DAX-1 in Leydig cells in rats.

    PubMed

    Zhang, Zhan; Yu, Yongquan; Xu, Hengsen; Wang, Chao; Ji, Minghui; Gu, Jun; Yang, Lu; Zhu, Jiansheng; Dong, Huibin; Wang, Shou-Lin

    2017-03-12

    Growing evidence has revealed that a high-fat diet (HFD) could lead to disorders of glycolipid metabolism and insulin-resistant states, and HFDs have been associated with the inhibition of testicular steroidogenesis. Our previous study demonstrated that 2,2',4,4'-tetrabromodiphenyl ether (BDE47) could increase the risk of diabetes in humans and reduce testosterone production in rats. However, whether the HFD affects BDE47-inhibited testosterone production by elevating insulin levels and inducing related pathways remains unknown. In male rats treated with BDE47 by gavage for 12 weeks, the HFD significantly increased the BDE47 content of the liver and testis and increased the weight of the adipose tissue; increased macrovesicular steatosis in the liver and the levels of triglycerides, fasting glucose and insulin; further aggravated the disruption of the seminiferous epithelium; and lowered the level of testosterone, resulting in fewer sperm in the epididymis. Of note, the HFD enhanced BDE47-induced DAX-1 expression and decreased the expression levels of StAR and 3β-HSD in the testicular interstitial compartments in rats. In isolated primary Leydig cells from rats, BDE47 or insulin increased DAX-1 expression, decreased the expression of StAR and 3β-HSD, and reduced testosterone production, which was nearly reversed by knocking down DAX-1. These results indicated that the HFD aggravates BDE47-inhibited testosterone production through hyperinsulinemia, and the accumulation of testicular BDE47 that induces the up-regulation of DAX-1 and the subsequent down-regulation of steroidogenic proteins, i.e., StAR and 3β-HSD, in Leydig cells.

  10. Aging has the opposite effect on cAMP and cGMP circadian variations in rat Leydig cells.

    PubMed

    Baburski, Aleksandar Z; Sokanovic, Srdjan J; Andric, Silvana A; Kostic, Tatjana S

    2016-12-03

    The Leydig cell physiology displays a circadian rhythm driven by a complex interaction of the reproductive axis hormones and circadian system. The final output of this regulatory process is circadian pattern of steroidogenic genes expression and testosterone production. Aging gradually decreases robustness of rhythmic testosterone secretion without change in pattern of LH secretion. Here, we analyzed effect of aging on circadian variation of cAMP and cGMP signaling in Leydig cells. Results showed opposite effect of aging on cAMP and cGMP daily variation. Reduced amplitude of cAMP circadian oscillation was probably associated with changed expression of genes involved in cAMP production (increased circadian pattern of Adcy7, Adcy9, Adcy10 and decreased Adcy3); cAMP degradation (increased Pde4a, decreased Pde8b, canceled rhythm of Pde4d, completely reversed circadian pattern of Pde7b and Pde8a); and circadian expression of protein kinase A subunits (Prkac/PRKAC and Prkar2a). Aging stimulates expression of genes responsible for cGMP production (Nos2, Gucy1a3 and Gucy1b3/GUCYB3) and degradation (Pde5a, Pde6a and Pde6h) but the overall net effect is elevation of cGMP circadian oscillations in Leydig cells. In addition, the expression of cGMP-dependent kinase, Prkg1/PRKG1 is up-regulated. It seems that aging potentiate cGMP- and reduce cAMP-signaling in Leydig cells. Since both signaling pathways affect testosterone production and clockwork in the cells, further insights into these signaling pathways will help to unravel disorders linked to the circadian timing system, aging and reproduction.

  11. Binding and internalization in vivo of (/sup 125/I)hCG in Leydig cells of the rat

    SciTech Connect

    Hermo, L.; Lalli, M.

    1988-01-01

    The present study was performed to demonstrate the binding, mode of uptake, pathway and fate of iodinated human chorionic gonadotropin ((/sup 125/I)hCG) by Leydig cells in vivo using electron microscope radioautography. Following a single injection of (/sup 125/I)hCG into the interstitial space of the testis, the animals were fixed by perfusion with glutaraldehyde at 20 minutes, 1, 3, 6 and 24 hours. The electron microscope radioautographs demonstrated a prominent and qualitatively similar binding of the labeled hCG on the microvillar processes of the Leydig cells at 20 minutes, 1, 3, and 6 hours. The specificity of the (/sup 125/I)hCG binding was determined by injecting a 100-fold excess of unlabeled hormone concurrently with the labeled hormone. Under these conditions, the surface, including the microvillar processes of Leydig cells, was virtually unlabeled, indicating that the binding was specific and receptor-mediated. In animals injected with labeled hCG and sacrificed 20 minutes later, silver grains were also seen overlying the limiting membrane of large, uncoated surface invaginations and large subsurface vacuoles with an electron-lucent content referred to as endosomes. A radioautographic reaction was also seen within multivesicular bodies with a pale stained matrix. At 1 hour, silver grains appeared over dense multivesicular bodies and occasionally over secondary lysosomes, in addition to the structures mentioned above, while at 3 and 6 hours, an increasing number of secondary lysosomes became labeled. At 24 hours, binding of (/sup 125/I)hCG to the microvillar processes of Leydig cells persisted but was diminished, although a few endosomes, multivesicular bodies and secondary lysosomes still showed a radioautographic reaction. No membranous tubules that were seen in close proximity to, or in continuity with, endosomes and multivesicular bodies were observed to be labeled at any time interval.

  12. Apoptosis Process in Mouse Leydig Cells during Postnatal Development

    NASA Astrophysics Data System (ADS)

    Salles Faria, Maria José; Simões, Zilá Paulino; Luz; Orive Lunardi, Laurelucia; Hartfelder, Klaus

    2003-02-01

    The development of Leydig cells in mammals has been widely described as a biphasic pattern with two temporally mature Leydig cell populations, fetal stage followed by the adult generation beginning at puberty. In the present study, mouse Leydig cells were examined for apoptosis during postnatal testis development using electron microscopy and in situ DNA fragmentation by terminal deoxynucleotidyl transferase staining (TdT). Both the morphological study and the DNA fragmentation analysis showed that cellular death by apoptosis did not occur in Leydig cells during the neonatal, prepubertal, puberty, and adult periods. From these results, we suggest that the remaining fetal Leydig cells in the neonatal testis are associated with the involution or degeneration processes. In contrast, in the prepubertal and puberty stages, fragmentation of apoptotic DNA was detected in germ cells present in some seminiferous tubules.

  13. Age and markers of Leydig cell function, but not of Sertoli cell function predict the success of sperm retrieval in adolescents and adults with Klinefelter's syndrome.

    PubMed

    Rohayem, J; Fricke, R; Czeloth, K; Mallidis, C; Wistuba, J; Krallmann, C; Zitzmann, M; Kliesch, S

    2015-09-01

    Microsurgical testicular sperm extraction (mTESE), combined with intracytoplasmic sperm injection (ICSI) represents a chance for azoospermic men with Klinefelter's syndrome (KS) to father children. The objective of this study was to identify predictive factors for the success of mTESE from adolescents and adults with KS. The clinical data of 50 late pubertal adolescents (13-19 years) and 85 adult patients (20-61 years) with non-mosaic KS, who underwent mTESE, were analysed with respect to factors, potentially predictive of active spermatogenesis; specifically a history of cryptorchidism, age, testicular volumes, serum levels of LH, FSH, testosterone (T) and estradiol at the time of surgery. Inhibin B, AMH and INSL3 were additionally analysed in the adolescents. A younger age and a near-compensated Leydig cell function were associated with higher success of sperm retrieval via mTESE: In adolescents ≥15-19 years, spermatozoa were retrieved in 45%, compared to 31% in adults; in adolescents aged 13-14 years, spermatozoa were collected in only 10%. Adolescents with an LH ≤17.5 U/L, along with a T level ≥7.5 nmol/L had the best success rate (54%), which fell to 44% with higher LH, whereas those with low T (<7.5 nmol/L), irrespective of LH had no sperm retrieval. In adults with T levels above and LH below these thresholds, the success rate was 51%, falling to 19%, if LH was higher. When T was lower than threshold, the rate was 17%. No association between testicular volumes, serum levels of FSH, Inhibin B, AMH, estradiol and mTESE success was found. A history of cryptorchidism was associated with lower retrieval rates. A window of opportunity for an approximate 50% chance to retrieve spermatozoa via mTESE exists for young, late pubertal KS patients between age 15 and young adulthood, when Leydig cell function is at its best. In these cases, referral to a centre of expertise should be considered.

  14. Autocrine androgen action is essential for Leydig cell maturation and function, and protects against late-onset Leydig cell apoptosis in both mice and men

    PubMed Central

    O’Hara, Laura; McInnes, Kerry; Simitsidellis, Ioannis; Morgan, Stephanie; Atanassova, Nina; Slowikowska-Hilczer, Jolanta; Kula, Krzysztof; Szarras-Czapnik, Maria; Milne, Laura; Mitchell, Rod T.; Smith, Lee B.

    2015-01-01

    Leydig cell number and function decline as men age, and low testosterone is associated with all “Western” cardio-metabolic disorders. However, whether perturbed androgen action within the adult Leydig cell lineage predisposes individuals to this late-onset degeneration remains unknown. To address this, we generated a novel mouse model in which androgen receptor (AR) is ablated from ∼75% of adult Leydig stem cell/cell progenitors, from fetal life onward (Leydig cell AR knockout mice), permitting interrogation of the specific roles of autocrine Leydig cell AR signaling through comparison to adjacent AR-retaining Leydig cells, testes from littermate controls, and to human testes, including from patients with complete androgen insensitivity syndrome (CAIS). This revealed that autocrine AR signaling is dispensable for the attainment of final Leydig cell number but is essential for Leydig cell maturation and regulation of steroidogenic enzymes in adulthood. Furthermore, these studies reveal that autocrine AR signaling in Leydig cells protects against late-onset degeneration of the seminiferous epithelium in mice and inhibits Leydig cell apoptosis in both adult mice and patients with CAIS, possibly via opposing aberrant estrogen signaling. We conclude that autocrine androgen action within Leydig cells is essential for the lifelong support of spermatogenesis and the development and lifelong health of Leydig cells.—O’Hara, L., McInnes, K., Simitsidellis, I., Morgan, S., Atanassova, N., Slowikowska-Hilczer, J., Kula, K., Szarras-Czapnik, M., Milne, L., Mitchell, R. T., Smith, L. B. Autocrine androgen action is essential for Leydig cell maturation and function, and protects against late-onset Leydig cell apoptosis in both mice and men. PMID:25404712

  15. Circadian rhythm of the Leydig cells endocrine function is attenuated during aging.

    PubMed

    Baburski, Aleksandar Z; Sokanovic, Srdjan J; Bjelic, Maja M; Radovic, Sava M; Andric, Silvana A; Kostic, Tatjana S

    2016-01-01

    Although age-related hypofunction of Leydig cells is well illustrated across species, its circadian nature has not been analyzed. Here we describe changes in circadian behavior in Leydig cells isolated from adult (3-month) and aged (18- and 24-month) rats. The results showed reduced circadian pattern of testosterone secretion in both groups of aged rats despite unchanged LH circadian secretion. Although arrhythmic, the expression of Insl3, another secretory product of Leydig cells, was decreased in both groups. Intracellular cAMP and most important steroidogenic genes (Star, Cyp11a1 and Cyp17a1), together with positive steroidogenic regulator (Nur77), showed preserved circadian rhythm in aging although rhythm robustness and expression level were attenuated in both aged groups. Aging compromised cholesterol mobilization and uptake by Leydig cells: the oscillatory transcription pattern of genes encoding HDL-receptor (Scarb1), hormone sensitive lipase (Lipe, enzyme that converts cholesterol esters from lipid droplets into free cholesterol) and protein responsible for forming the cholesterol esters (Soat2) were flattened in 24-month group. The majority of examined clock genes displayed circadian behavior in expression but only a few of them (Bmal1, Per1, Per2, Per3 and Rev-Erba) were reduced in 24-month-old group. Furthermore, aging reduced oscillatory expression pattern of Sirt1 and Nampt, genes encoding key enzymes that connect cellular metabolism and circadian network. Altogether circadian amplitude of Leydig cell's endocrine function decreased during aging. The results suggest that clock genes are more resistant to aging than genes involved in steroidogenesis supporting the hypothesis about peripheral clock involvement in rhythm maintenance during aging.

  16. Sertoli-Leydig cell tumor

    MedlinePlus

    Sertoli-stromal cell tumor; Arrhenoblastoma; Androblastoma; Ovarian cancer - Sertoli-Leydig cell tumor ... The Sertoli cells are normally located in the male reproductive glands (the testes). They feed sperm cells. The Leydig cells, also ...

  17. [The role of gonadotropins, cyclic AMP, 22-R-OH-cholesterol and cofactors in regulating endocrine functions of the Leydig cells in rats. III. Mechanisms responsible for "desensitization" of the Leydig cells of rats caused by high doses of hCG].

    PubMed

    Grochowski, D; Szamatowicz, M

    1989-05-01

    Two groups of rats (a control group and the group examined) were administered intraperitoneally supraphysiological doses of hCG in order to induce a "down regulation" effect on the level of receptors LH and to achieve the desensibilization of Leydig cells. The authors tried to find out at which stage of sequence of changes from receptor stimulation to hormone production there appears a state of cellular resistance to further stimulation. Sections of the nucleus were incubated with various substances influencing steridogenesis (LH, hCG, dbcAMP, 22-R-OH-cholesterol, NAD + NADP + G-6-P + G-6-PDH). An index of the influence of the above substances on the synthesis of androgens were amounts of pregnenolon as the first and testosterone as the final stage of hormonal changes marked radioimmunologically in nucleus homogenates and incubating media. It was shown that the resistance of Leydig cells to further stimulation in the group of animals that were given high doses of hCG is the result of enzymatic blocks in testosterone synthesis. The first block is "late" block of 17 alpha-hydroxylase and 17-20 desmolase, disturbing transforming of 21-carbon steriods into 19-carbon androgens. When the dose of hCG increases, there appears the second block, the so called "early" block, disturbing mitochondrial synthesis of pregnenolon. It was found that exogenic cofactors are in a position, at least partially, to restore the activity of blocked enzymes.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Steroidogenesis in amlodipine treated purified Leydig cells

    SciTech Connect

    Latif, Rabia; Lodhi, Ghulam Mustafa; Hameed, Waqas; Aslam, Muhammad

    2012-01-01

    Drugs have been shown to adversely affect male fertility and recently anti-hypertensive drugs were added to the list. The anti-fertility effects of amlodipine, a calcium channel blocker, are well-illustrated in in vivo experiments but lack an in vitro proof. The present study was designed to experimentally elucidate the effects of amlodipine on Leydig cell steroidogenesis and intracellular calcium in vitro. Leydig cells of Sprague–Dawley rats were isolated and purified by Percoll. Cells were incubated for 3 h with/without amlodipine in the presence/absence of LH, dbcAMP, Pregnenolone and 25-Hydroxycholesterol. Cytosolic calcium was measured in purified Leydig cells by fluorometric technique. The results showed significantly reduced (P < 0.05) steroidogenesis and intracellular calcium in amlodipine exposed rats. The site of amlodipine induced steroidogenic inhibition seems to be prior to the formation of Pregnenolone at the level of StAR protein. -- Highlights: ► Inhibition of steroidogenesis in isolated and purified Leydig cells by amlodipine. ► Site of inhibition was before Pregnenolone formation, at the level of StAR protein. ► Inhibition of LH stimulated rise in cytosolic calcium by amlodipine.

  19. Leydig cell tumor

    MedlinePlus

    ... the cells in the testicles that release the male hormone, testosterone . ... seem to be linked to undescended testes . Leydig cell tumors make up a very small number of all testicular tumors. They are most often found in men between 30 and 60 years of age. This ...

  20. The Ultrastructural Changes of the Sertoli and Leydig Cells Following Streptozotocin Induced Diabetes

    PubMed Central

    Kianifard, Davoud; Sadrkhanlou, Rajab Ali; Hasanzadeh, Shapour

    2012-01-01

    Objective(s) This investigation was conducted to evaluate the effects of diabetes on the structure and function of testicular tissue. Materials and Methods Diabetes was induced in male adult rats by a single intraperitoneal injection of streptozotocin. Body and testicular weight, hormonal analyses, histological and ultrastructural analyses were measured. Results The body and testicular weights were dropped significantly (P< 0.05) in diabetic rats in comparison with control rats. On the other hand, in diabetic rats, the blood glucose level increased significantly (P< 0.05). The blood plasma levels of testosterone, 17-β estradiol, progesterone, FSH and LH were reduced in diabetic rats. Histomorphological studies were revealed reduction in diameter of seminiferous tubules and germinal epithelium height, edema in interstitial tissue, germ cell depletion, decrease in cellular population and activity with disruption of spermatogenesis in diabetic rats. Ultrastructural study showed the mitochondrial change and reduction of smooth endoplasmic reticulum in Sertoli and presence of lipid droplets in Leydig cells of diabetic rat’s testes. Conclusion The results of the present study confirmed that, the ultrastructural changes of Sertoli and Leydig cells, brought about by streptozotocin induced diabetes, because of the alterations in pituitary gonadotropins, and these changes influence the normal spermatogenesis in rats. PMID:23493249

  1. Leydig Cell Hyperplasia Revealed by Gynecomastia

    PubMed Central

    Tazi, Mohamed Fadl; Mellas, Soufiane; El Fassi, Mohamed Jamal; Farih, Moulay Hassan

    2008-01-01

    Leydig cell tumors are rare and represent 1% to 3% of all tumors of the testis. Leydig cell tumors affect males at any age, but there are 2 peak periods of incidence: between 5 and 10 years and between 25 and 35 years. Their main clinical presentation is a testicular mass associated with endocrinal manifestations that are variable according to age and appearance of the tumor. Our patient, a 17-year-old adolescent, presented with an isolated and painless hypertrophy of the right mammary gland. Clinical examination found gynecomastia and no testicular mass. Hormonal levels and tumor markers were normal. Testicular sonography showed an ovular and homogeneous right intratesticular mass 6 mm in diameter. We treated the patient with an inguinal right orchidectomy. The anatomopathological study found a nodule of Leydig cell hyperplasia. The patient recovered without recurrence at 8-month follow-up. The patient opted for mammoplasty 2 months after his orchidectomy rather than wait for the spontaneous gradual regression of his gynecomastia, which requires at least 1 year. Leydig cell hyperplasia manifests in the adult by signs of hypogonadism, most frequently gynecomastia. Although many teams prefer total orchidectomy because of the diagnostic difficulty associated with malignant forms, simple subcapsular orchidectomy should become the first-line treatment, provided it be subsequently followed by close surveillance, as it preserves maximum fertility, and these tumors usually resolve favorably. PMID:18660859

  2. Leydig cell hyperplasia revealed by gynecomastia.

    PubMed

    Tazi, Mohamed Fadl; Mellas, Soufiane; El Fassi, Mohamed Jamal; Farih, Moulay Hassan

    2008-01-01

    Leydig cell tumors are rare and represent 1% to 3% of all tumors of the testis. Leydig cell tumors affect males at any age, but there are 2 peak periods of incidence: between 5 and 10 years and between 25 and 35 years. Their main clinical presentation is a testicular mass associated with endocrinal manifestations that are variable according to age and appearance of the tumor. Our patient, a 17-year-old adolescent, presented with an isolated and painless hypertrophy of the right mammary gland. Clinical examination found gynecomastia and no testicular mass. Hormonal levels and tumor markers were normal. Testicular sonography showed an ovular and homogeneous right intratesticular mass 6 mm in diameter. We treated the patient with an inguinal right orchidectomy. The anatomopathological study found a nodule of Leydig cell hyperplasia. The patient recovered without recurrence at 8-month follow-up. The patient opted for mammoplasty 2 months after his orchidectomy rather than wait for the spontaneous gradual regression of his gynecomastia, which requires at least 1 year. Leydig cell hyperplasia manifests in the adult by signs of hypogonadism, most frequently gynecomastia. Although many teams prefer total orchidectomy because of the diagnostic difficulty associated with malignant forms, simple subcapsular orchidectomy should become the first-line treatment, provided it be subsequently followed by close surveillance, as it preserves maximum fertility, and these tumors usually resolve favorably.

  3. Exposure to constant light during testis development increases daily sperm production in adult Wistar rats.

    PubMed

    Rocha, D C; Debeljuk, L; França, L R

    1999-06-01

    Testis histometry and daily sperm production (DSP) were evaluated in adult (160-day-old) Wistar rats exposed to constant light for the first 25 days after birth, and compared with control animals which were exposed to a 12 h-light-12 h-dark light regimen. Significantly greater (P < 0.05) numbers of Sertoli cell nucleoli and round spermatids per cross-section of seminiferous tubule were found in animals exposed to constant light. In addition, epididymis weight, DSP per testis and per gram of testis, as well as Leydig cell compartment volume, were significantly increased in treated animals. Although there was a clear trend toward an increased Sertoli cell population per testis in animals exposed to constant light, this difference was not statistically significant (P < 0.05). The number of round spermatids as expressed per Sertoli cell was the same in both groups. Surprisingly, the diameter and volume of round spermatid nucleus at stages I and VII of the cycle of seminiferous epithelium were significantly lower (P < 0.05) in treated animals. In conclusion, constant illumination during neonatal testis development increased sperm production and Leydig cell compartment volume in adult rats probably through a mechanism involving elevated follicle stimulating hormone and luteinizing hormone during the prepubertal period. To our knowledge, this is the first study showing that altering the light regimen can affect sperm production in non-seasonal breeders.

  4. Genetics Home Reference: Leydig cell hypoplasia

    MedlinePlus

    ... Home Health Conditions Leydig cell hypoplasia Leydig cell hypoplasia Enable Javascript to view the expand/collapse boxes. ... PDF Open All Close All Description Leydig cell hypoplasia is a condition that affects male sexual development. ...

  5. Cyclic GMP signaling in rat urinary bladder, prostate, and epididymis: tissue-specific changes with aging and in response to Leydig cell depletion.

    PubMed

    Müller, Dieter; Mukhopadhyay, Amal K; Davidoff, Michail S; Middendorff, Ralf

    2011-08-01

    Aging of the male reproductive system leads to changes in endocrine signaling and is frequently associated with the emergence of prostate hyperplasia and bladder dysfunctions. Recent reports highlight prostate and bladder as promising targets for therapeutic interventions with inhibitors of the cyclic GMP (cGMP)-degrading phosphodiesterase 5 (PDE5). However, the cGMP signaling system in these organs is as yet poorly characterized, and the possibility of age-related alterations has not been addressed. This study investigates key proteins of cGMP pathways in bladder, prostate, and epididymis of young (3 months) and old (23-24 months) Wistar rats. Local differences in the abundance of PDE5, soluble guanylyl cyclase (sGC) and particulate guanylyl cyclases (GC-A, GC-B), endothelial nitric oxide synthase, and cGMP-dependent protein kinase I (PRKG1 (cGKI)) revealed pronounced tissue-specific peculiarities. Although cGMP-generating enzymes were not affected by age in all organs, we recognized age-related decreases of PDE5 expression in bladder and a selective diminishment of membrane-associated PRKG1 in epididymis. In disagreement with published data, all cGMP pathway proteins including PDE5 are poorly expressed in prostate. However, prostatic PRKG1 expression increases with aging. Androgen withdrawal during temporary Leydig cell elimination induced a massive (>12-fold) upregulation of PRKG1 in prostate but not in other (penis and epididymis) androgen-dependent organs. These findings identify PRKG1 as a key androgen-sensitive signaling protein in prostate of possible importance for growth regulation. The elucidated effects may have significance for age-associated pathologies in the male lower-urinary tract.

  6. The functional development of Leydig cells in a marsupial.

    PubMed

    Butler, Christopher M; Shaw, Geoff; Clark, Joan; Renfree, Marilyn B

    2008-01-01

    Leydig cells are the major source of androgen in the male mammal. We describe here for the first time the development of the Leydig cell in a macropodid marsupial, the tammar wallaby, Macropus eugenii. Leydig cells are first recognized morphologically 2 days after birth with the appearance of lipid droplets in the cytoplasm of certain interstitial cells. Lipid content closely matches the steroid content of the developing testis and marks the maturation of the steroid synthesis pathway in the tammar testis. Morphologically mature Leydig cells, marked by distinct mitochondria with tubular cristae and an extensive anastomosing network of smooth endoplasmic reticulum, are developed by day 10 after birth - the time of peak testosterone content in perinatal tammar testes. The volume percentage of each cell type in the testis does not change over time so the growth of each cellular component keeps pace with growth of the whole testis. There was no morphological or quantitative evidence of a change from one population of Leydig cells to another in the tammar testis as has been reported in several other species including the rat, mouse and human. Maturation of the testis is also marked by the development of tight junctions between the cell membranes of adjacent Sertoli cells. These appear around day 30 after birth and coincide with the onset of mitotic arrest in male germ cells. Overall, the development of the Leydig cell in the tammar wallaby follows a similar pattern to that seen in other mammals, although the start of Leydig cell differentiation is, like many other organ systems in marsupials, post natal, not fetal and there appears to be only a single population of Leydig cells.

  7. Endocrine disruptors and Leydig cell function.

    PubMed

    Svechnikov, K; Izzo, G; Landreh, L; Weisser, J; Söder, O

    2010-01-01

    During the past decades, a large body of information concerning the effects of endocrine disrupting compounds (EDCs) on animals and humans has been accumulated. EDCs are of synthetic or natural origin and certain groups are known to disrupt the action of androgens and to impair the development of the male reproductive tract and external genitalia. The present overview describes the effects of the different classes of EDCs, such as pesticides, phthalates, dioxins, and phytoestrogens, including newly synthesized resveratrol analogs on steroidogenesis in Leydig cells. The potential impact of these compounds on androgen production by Leydig cells during fetal development and in the adult age is discussed. In addition, the possible role of EDCs in connection with the increasing frequency of abnormalities in reproductive development in animals and humans is discussed.

  8. Apoptosome activation, an important molecular instigator in 6-mercaptopurine induced Leydig cell death

    PubMed Central

    Morgan, Jessica A.; Lynch, John; Panetta, John C.; Wang, Yao; Frase, Sharon; Bao, Ju; Zheng, Jie; Opferman, Joseph T.; Janke, Laura; Green, Daniel M.; Chemaitilly, Wassim; Schuetz, John D.

    2015-01-01

    Leydig cells are crucial to the production of testosterone in males. It is unknown if the cancer chemotherapeutic drug, 6-mercaptopurine (6 MP), produces Leydig cell failure among adult survivors of childhood acute lymphoblastic leukemia. Moreover, it is not known whether Leydig cell failure is due to either a loss of cells or an impairment in their function. Herein, we show, in a subset of childhood cancer survivors, that Leydig cell failure is related to the dose of 6 MP. This was extended, in a murine model, to demonstrate that 6 MP exposure induced caspase 3 activation, and the loss of Leydig cells was independent of Bak and Bax activation. The death of these non-proliferating cells was triggered by 6 MP metabolism, requiring formation of both cytosolic reactive oxygen species and thiopurine nucleotide triphosphates. The thiopurine nucleotide triphosphates (with physiological amounts of dATP) uniquely activated the apoptosome. An ABC transporter (Abcc4/Mrp4) reduced the amount of thiopurines, thereby providing protection for Leydig cells. The studies reported here demonstrate that the apoptosome is uniquely activated by thiopurine nucleotides and suggest that 6 MP induced Leydig cell death is likely a cause of Leydig cell failure in some survivors of childhood cancer. PMID:26576726

  9. 4-Nitrophenol induces Leydig cells hyperplasia, which may contribute to the differential modulation of the androgen receptor and estrogen receptor-α and -β expression in male rat testes.

    PubMed

    Zhang, Yonghui; Piao, Yuanguo; Li, Yansen; Song, Meiyan; Tang, Pingli; Li, Chunmei

    2013-11-25

    4-Nitrophenol (PNP) is generally regarded as an environmental endocrine disruptor capable of estrogenic and anti-androgenic activities. To investigate PNP-induced reproductive effects, immature male rats were injected subcutaneously with PNP (0.1, 1, 10mg/kg body weight or vehicle) daily for 4 weeks. We assessed reproductive tract alterations, sex hormone balance in the serum and estrogen receptor (ER)-α, -β and androgen receptor (AR) expression in testes. Although no significant difference was observed in body weight or testes weights of PNP-treated rats compared with the controls, the serum concentrations of testosterone in the 10mg/kg PNP-treated group were significantly elevated. This effect was accompanied by Leydig cells hyperplasia in the testes. Conversely, there was a significant decrease in estradiol concentration and aromatase expression in the testes of the 10mg/kg PNP-treated group. Furthermore, we observed a significant increase in ERα expression in the testes of the 10mg/kg PNP-treated group compared with the control group. Conversely, ERβ expression displayed a significant reduction. Moreover, AR expression was significantly increased in the 10mg/kg PNP-treated group compared with the control group. The existence of AR, ER-α and -β in the testes suggests that estradiol and testosterone directly affect germ cells and that differential modulation of AR, ER-α and -β in the testis may be involved in the direct effects of PNP or either the indirect effects of PNP-induced disruption of the estradiol-to-testosterone balance or the Leydig cells hyperplasia. Thus, the measurement of many endpoints is necessary for good risk assessment.

  10. Expression of cubilin in mouse testes and Leydig cells.

    PubMed

    Oh, Y S; Seo, J T; Ahn, H S; Gye, M C

    2016-04-01

    Cubilin (cubn) is a receptor for vitamins and various protein ligands. Cubn lacks a transmembrane domain but anchors to apical membranes by forming complexes with Amnionless or Megalin. In an effort to better understand the uptake of nutrients in testis, we analysed cubn expression in the developing mice testes. In testes, cubn mRNA increased from birth to adulthood. In the inter-stitium and isolated seminiferous tubules, neonatal increase in cubn mRNA until 14 days post-partum (pp) was followed by a marked increase at puberty (28 days pp). Cubn was found in the gonocytes, spermatogonia, spermatocytes and spermatids in the developing testes. In adult testes, strong Cubn immunoreactivity was found in the elongating spermatids, suggesting the role of Cubn in endocytosis during early spermiogenesis. In Sertoli cells and peritubular cells, Cubn immunoreactivity was weak throughout the testis development. In the inter-stitium, Cubn immunoreactivity was found in foetal Leydig cells, was weak to negligible in the stem cells and progenitor Leydig cells and was strong in immature and adult Leydig cells, demonstrating a positive association between Cubn and steroidogenic activity of Leydig cells. Collectively, these results suggest that Cubn may participate in the endocytotic uptake of nutrients in germ cells and somatic cells, supporting the spermatogenesis and steroidogenesis in mouse testes.

  11. Pachytene spermatocytes regulate the secretion of Sertoli cell protein(s) which stimulate Leydig cell steroidogenesis.

    PubMed

    Onoda, M; Djakiew, D; Papadopoulos, V

    1991-05-01

    The influence of germ cells (pachytene spermatocytes and round spermatids) on the secretion by Sertoli cells of the proteinaceous factor(s) which stimulates Leydig cell steroid biosynthesis was investigated. Sertoli cells from immature rats were cultured on plastic dishes or on Millipore filters impregnated with reconstituted basement membrane in bicameral chambers. Immature rat Sertoli cell secreted proteins (rSCSP; MW greater than 10,000), from conventional cultures, stimulated 4- to 5-fold steroid biosynthesis in normal rat and MA-10 mouse tumor Leydig cells, respectively. MA-10 cells were then used as a bioassay system for most studies, although purified rat Leydig cells were used in some cases to further confirm results obtained with MA-10 cells. rSCSP collected from both the apical and basal compartment of the chambers were examined for their ability to stimulate Leydig cell steroidogenesis. The Leydig cell stimulatory activity from Sertoli cells was found to be secreted in a polarized manner, with 80% of the total bioactivity found in the basal rSCSP. Addition of pachytene spermatocyte proteins (PSP) in the apical compartment of the chambers inhibited, in a time- and concentration-dependent manner, the basally directed Sertoli cell secretion of the Leydig cell stimulatory protein(s) by 85%. Similar results were obtained when freshly isolated pachytene spermatocytes were directly added on top of Sertoli cell epithelial sheets in the apical compartment of the chambers. In contrast, round spermatid proteins (RSP) did not exhibit a comparable effect to that of PSP in regulating the Sertoli cell secretion of the Leydig cell stimulatory activity. These results demonstrate that the Sertoli cell secreted protein(s) which stimulates Leydig cell steroid biosynthesis is secreted in a basally polarized direction, and its secretion is specifically modulated by pachytene spermatocytes.

  12. Leydig cell aging and hypogonadism.

    PubMed

    Beattie, M C; Adekola, L; Papadopoulos, V; Chen, H; Zirkin, B R

    2015-08-01

    Leydig cell testosterone (T) production is reduced with age, resulting in reduced serum T levels (hypogonadism). A number of cellular changes have been identified in the steroidogenic pathway of aged Leydig cells that are associated with reduced T formation, including reductions in luteinizing hormone (LH)-stimulated cAMP production, the cholesterol transport proteins steroidogenic acute regulatory (STAR) protein and translocator protein (TSPO), and downstream steroidogenic enzymes of the mitochondria and smooth endoplasmic reticulum. Many of the changes in steroid formation that characterize aged Leydig cells can be elicited by the experimental alteration of the redox environment of young cells, suggesting that changes in the intracellular redox balance may cause reduced T production. Hypogonadism is estimated to affect about 5 million American men, including both aged and young. This condition has been linked to mood changes, worsening cognition, fatigue, depression, decreased lean body mass, reduced bone mineral density, increased visceral fat, metabolic syndrome, decreased libido, and sexual dysfunction. Exogenous T administration is now used widely to elevate serum T levels in hypogonadal men and thus to treat symptoms of hypogonadism. However, recent evidence suggests that men who take exogenous T may face increased risk of stroke, heart attack, and prostate tumorigenesis. Moreover, it is well established that administered T can have suppressive effects on LH, resulting in lower Leydig cell T production, reduced intratesticular T concentration, and reduced spermatogenesis. This makes exogenous T administration inappropriate for men who wish to father children. There are promising new approaches to increase serum T by directly stimulating Leydig cell T production rather than by exogenous T therapy, thus potentially avoiding some of its negative consequences.

  13. In utero-exposed di(n-butyl) phthalate induce dose dependent, age-related changes of morphology and testosterone-biosynthesis enzymes/associated proteins of Leydig cell mitochondria in rats.

    PubMed

    Motohashi, Masaya; Wempe, Michael F; Mutou, Tomoko; Okayama, Yuya; Kansaku, Norio; Takahashi, Hiroyuki; Ikegami, Masahiro; Asari, Masao; Wakui, Shin

    2016-04-01

    Female pregnant Sprague-Dawley rats were intragastrically (ig) administered di(n-butyl) phthalate (DBP) at four doses (0, 10, 50 and 100 mg/kg) during gestation days (GD) 12-21 (n = 5 per group). The age-related morphological changes of Leydig cell mitochondrion (LC-Mt) and testosterone biosynthesis enzymes/associated genes/proteins expression levels were investigated. As compared to the control (no DBP), the 10 mg, and 50 mg DBP dose groups, the 100 mg DBP dose group at weeks 5 and 7 showed a significant amount of small LC-Mt. Thereafter, from weeks 9 to 17, the LC-Mt size and quantity in the 100 mg DBP dose group increased and became statistically similar to the other dose groups; hence, dose and time-dependent LC-Mt changes were observed. Throughout the study, the 100 mg DBP dose group had significantly lower testosterone levels. In addition, the 100 mg DBP dose group displayed lower StAR (StAR, steroidogenic acute regulatory protein) and P450scc (CYP11a1, cholesterol side-chain cleavage enzyme) levels at weeks 5 and 7, but they became statistically similar to all other dose groups at weeks 9 to 17; in contrast, the SR-B1 (Sarb1, scavenger receptor class B member 1) levels were similar for all DBP dose groups. The rats in utero 100 mg DBP /kg/day (GD 12-21) exposure results from this study indicate a dose-dependent, age-related morphological change in LC-Mt which are linked to reductions in testosterone biosynthesis genes / proteins expression, specifically StAR and P450scc.

  14. Advantage of Guaraná (Paullinia cupana Mart.) supplementation on cadmium-induced damages in testis of adult Wistar rats.

    PubMed

    Leite, Rodrigo P; Predes, Fabrícia S; Monteiro, Juliana C; Freitas, Karine M; Wada, Ronaldo S; Dolder, Heidi

    2013-01-01

    Paullinia cupana is an Amazonian bush whose seeds have long been used in folk medicine. However, most of the therapeutic properties attributed to this plant are broad and nonspecific, although an antioxidant activity has been reported.  On the other hand, cadmium is a heavy metal known for increasing free radicals, hence resulting in cellular oxidative damages. This study was designed to evaluate whether Paullinia cupana is able to reduce cadmium-induced morphological impairment in Wistar rat testis. Adult male Wistar rats 110 days old were ip injected with cadmium (1.15 mg/kg BW [body weight]) and subsequently treated with P. cupana during 56 days.  Furthermore, groups receiving either P. cupana extract or cadmium are mentioned. After the treatment period, testis samples were subjected to histological and stereological analyses. Moderate to severe testicular impairments were shown by the animals exposed to cadmium. However, the animals supplemented with P. cupana after cadmium exposure showed a significant decrease in the proportion of damaged seminiferous tubules. Also, P. cupana supplementation was effective in maintaining the number of Leydig cells per testis in the animals exposed to cadmium. In conclusion, P. cupana supplementation was partially efficient in preventing cadmium from damaging the testis of adult Wistar rats.

  15. Immunolocalization of aromatase in stallion Leydig cells and seminiferous tubules.

    PubMed

    Sipahutar, Herbert; Sourdaine, Pascal; Moslemi, Safa; Plainfossé, Bruno; Séralini, Gilles-Eric

    2003-03-01

    High levels of plasma estrogens constitute an endocrine peculiarity of the adult stallion. This is mostly due to testicular cytochrome p450 aromatase, the only irreversible enzyme responsible for the bioconversion of androgens into estrogens. To identify more precisely the testicular aromatase synthesis sites in the stallion, testes from nine horses (2-5 years) were obtained during winter or spring. Paraplast-embedded sections were processed using rabbit anti-equine aromatase, followed by biotinylated goat anti-rabbit antibodies, and amplified with a streptavidin-peroxidase complex. Immunoreactivity was detected with diaminobenzidine. Immunofluorescence detection, using fluoroisothiocyanate-conjugated goat anti-rabbit antibodies, was also applied. Specific aromatase immunoreactivity was observed intensely in Leydig cells but also for the first time, to a lesser extent, in the cytoplasm surrounding germ cells at the junction with Sertoli cells. Interestingly, the immunoreactivity in Sertoli cells appears to vary with the spermatogenic stages in the basal compartment (with spermatogonia) as well as in the adluminal one (with spermatids). Relative staining intensity in Leydig and Sertoli cells and testicular microsomal aromatase activity increased with age. The present study in stallions indicates that in addition to Leydig cells, Sertoli cells also appear to participate in estrogen synthesis, and this could play a paracrine role in the regulation of spermatogenesis.

  16. INHIBITION OF TESTICULAR STEROIDOGENESIS BY THE XENOESTROGEN BISPHENOL A IS ASSOCIATED WITH REDUCED PITUITARY LH SECRETION AND DECREASED STEROIDOGENIC ENZYME GENE EXPRESSION IN RAT LEYDIG CELLS

    EPA Science Inventory

    Exposure of humans to bisphenol A (BPA), a monomer in polycarbonate plastics and constituent of resins used in food packaging and denistry, is significant. In this report, exposure of rats to 2.4 ug/kg/day (a dose that approximates BPA levels in the environment) from postnatal da...

  17. Isolation and culture of highly enriched populations of Leydig cells from guinea-pig (Cavia porcellus) testes.

    PubMed

    Kukucka, M A; Misra, H P

    1994-01-01

    Leydig cells were isolated from adult male guinea-pig testes using a multi-step procedure involving enzymatic dissociation and Percoll-gradient centrifugation. The following description is the first account of a successful isolation of adolescent guinea-pig Leydig cells. The enriched Leydig-cell preparation routinely isolated from six intact testicles yielded approximately 5.0 x 10(6) +/- 0.7 x 10(6) (+/- SEM) Leydig cells with a viability of 98.0 +/- 0.4% as determined using the trypan-blue exclusion method. The purity of the isolated cell population as assessed by 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) staining averaged 82.5 +/- 0.8%. Under light microscopy, guinea-pig Leydig cells were polyhedral in shape with a large prominent nucleus and a distinct nucleolus. The acidophilic cytoplasm contained numerous lipid-filled vesicles. Ultrastructurally, guinea-pig Leydig cells displayed an eccentrically located ovoid nucleus with dark-staining peripheral heterochromatin. Large quantities of mitochondria, smooth endoplasmic reticulum and particulate-laden lipid droplets were also evident. The steroidogenic potential of the isolated Leydig cells was verified using a maximally stimulating dose of ovine LH (100 ng ml-1) and human CG (200 mIU ml-1). Leydig cells incubated in a shaking (120 cycles min-1) water bath for 3 h at 37 degrees C in capped polypropylene microcentrifuge tubes produced 233 +/- 21 ng and 223 +/- 18 ng testosterone per 1 x 10(6) cells when maximally stimulated with oLH or hCG, respectively. The inclusion of low (1-5 microM) levels of sodium ascorbate during culture enhanced significantly Leydig-cell viability vs. control values.

  18. Interactions between respiratory oscillators in adult rats

    PubMed Central

    Huckstepp, Robert TR; Henderson, Lauren E; Cardoza, Kathryn P; Feldman, Jack L

    2016-01-01

    Breathing in mammals is hypothesized to result from the interaction of two distinct oscillators: the preBötzinger Complex (preBötC) driving inspiration and the lateral parafacial region (pFL) driving active expiration. To understand the interactions between these oscillators, we independently altered their excitability in spontaneously breathing vagotomized urethane-anesthetized adult rats. Hyperpolarizing preBötC neurons decreased inspiratory activity and initiated active expiration, ultimately progressing to apnea, i.e., cessation of both inspiration and active expiration. Depolarizing pFL neurons produced active expiration at rest, but not when inspiratory activity was suppressed by hyperpolarizing preBötC neurons. We conclude that in anesthetized adult rats active expiration is driven by the pFL but requires an additional form of network excitation, i.e., ongoing rhythmic preBötC activity sufficient to drive inspiratory motor output or increased chemosensory drive. The organization of this coupled oscillator system, which is essential for life, may have implications for other neural networks that contain multiple rhythm/pattern generators. DOI: http://dx.doi.org/10.7554/eLife.14203.001 PMID:27300271

  19. Long-term (6-wk) hindlimb suspension inhibits spermatogenesis in adult male rats.

    PubMed

    Tash, Joseph S; Johnson, Donald C; Enders, George C

    2002-03-01

    The International Space Station will allow extended habitation in space and long-term exposure to microgravity (microG). A concern is the impact of long-term microG exposure on the ability of species to reproduce. The model often used to simulate microG is rat hindlimb suspension (HLS), where the hindlimbs are elevated above the cage floor with a tail harness. Experiments described here are the first to examine the effect of long-term HLS on testicular function in adult male rats. Free-roaming (controls), animals with only the tail harnessed but hindlimbs in contact with the cage floor (TO), and HLS animals were tested for 6 wk. Cryptorchidism was prevented in TO and HLS animals by partial constriction of the inguinal canal with sutures. All parameters were compared at the end of the 6-wk experiment. Testicular weights and spermatogenesis were significantly reduced by HLS, such that no spermatogenic cells beyond round spermatids were present and epididymides were devoid of mature sperm. In many tubules, loss of all germ cells, except a few spermatogonia, resulting in histopathology similar to the Sertoli cell, was observed. Spermatogenesis appeared unaffected in control and TO animals. Sertoli and Leydig cell appearance, testosterone, luteinizing hormone, and follicle-stimulating hormone levels, and epididymal and seminal vesicle weight were unchanged by HLS. Cortisone was not elevated by HLS; thus stress may not be a factor. These results demonstrate that spermatogenesis is severely inhibited by long-term HLS, whereas testicular androgen production is not. These results have significant implications regarding serious effects of long-term exposure to microG on the reproductive capability of scrotal mammals, including humans.

  20. Long-term (6-wk) hindlimb suspension inhibits spermatogenesis in adult male rats

    NASA Technical Reports Server (NTRS)

    Tash, Joseph S.; Johnson, Donald C.; Enders, George C.

    2002-01-01

    The International Space Station will allow extended habitation in space and long-term exposure to microgravity (microG). A concern is the impact of long-term microG exposure on the ability of species to reproduce. The model often used to simulate microG is rat hindlimb suspension (HLS), where the hindlimbs are elevated above the cage floor with a tail harness. Experiments described here are the first to examine the effect of long-term HLS on testicular function in adult male rats. Free-roaming (controls), animals with only the tail harnessed but hindlimbs in contact with the cage floor (TO), and HLS animals were tested for 6 wk. Cryptorchidism was prevented in TO and HLS animals by partial constriction of the inguinal canal with sutures. All parameters were compared at the end of the 6-wk experiment. Testicular weights and spermatogenesis were significantly reduced by HLS, such that no spermatogenic cells beyond round spermatids were present and epididymides were devoid of mature sperm. In many tubules, loss of all germ cells, except a few spermatogonia, resulting in histopathology similar to the Sertoli cell, was observed. Spermatogenesis appeared unaffected in control and TO animals. Sertoli and Leydig cell appearance, testosterone, luteinizing hormone, and follicle-stimulating hormone levels, and epididymal and seminal vesicle weight were unchanged by HLS. Cortisone was not elevated by HLS; thus stress may not be a factor. These results demonstrate that spermatogenesis is severely inhibited by long-term HLS, whereas testicular androgen production is not. These results have significant implications regarding serious effects of long-term exposure to microG on the reproductive capability of scrotal mammals, including humans.

  1. Stem cell therapy for the treatment of Leydig cell dysfunction in primary hypogonadism

    PubMed Central

    Peak, Taylor C; Haney, Nora M; Wang, William; DeLay, Kenneth J; Hellstrom, Wayne J

    2016-01-01

    The production of testosterone occurs within the Leydig cells of the testes. When production fails at this level from either congenital, acquired, or systemic disorders, the result is primary hypogonadism. While numerous testosterone formulations have been developed, none are yet fully capable of replicating the physiological patterns of testosterone secretion. Multiple stem cell therapies to restore androgenic function of the testes are under investigation. Leydig cells derived from bone marrow, adipose tissue, umbilical cord, and the testes have shown promise for future therapy for primary hypogonadism. In particular, the discovery and utilization of a group of progenitor stem cells within the testes, known as stem Leydig cells (SLCs), has led not only to a better understanding of testicular development, but of treatment as well. When combining this with an understanding of the mechanisms that lead to Leydig cell dysfunction, researchers and physicians will be able to develop stem cell therapies that target the specific step in the steroidogenic process that is deficient. The current preclinical studies highlight the complex nature of regenerating this steroidogenic process and the problems remain unresolved. In summary, there appears to be two current directions for stem cell therapy in male primary hypogonadism. The first method involves differentiating adult Leydig cells from stem cells of various origins from bone marrow, adipose, or embryonic sources. The second method involves isolating, identifying, and transplanting stem Leydig cells into testicular tissue. Theoretically, in-vivo re-activation of SLCs in men with primary hypogonadism due to age would be another alternative method to treat hypogonadism while eliminating the need for transplantation. PMID:27822338

  2. Effects of date palm pollen (Phoenix dactylifera L.) and Astragalus ovinus on sperm parameters and sex hormones in adult male rats

    PubMed Central

    Mehraban, Fouad; Jafari, Mehrzad; Akbartabar Toori, Mehdi; Sadeghi, Hossein; Joodi, Behzad; Mostafazade, Mostafa; Sadeghi, Heibatollah

    2014-01-01

    Background: Date Palm Pollen (DPP) and Astragalus genus are used in some countries for the treatment of infertility. Objective: This study was designed to investigate effects of DPP and Astragalus ovinus (A.Ovinus) on fertility in healthy adult male rats. Materials and Methods: Thirty-six rats were divided into six groups (n=6) including control and five treatment groups. DPP (120, 240 and 360 mg/kg) and A.ovinus (100, 500 mg/ kg) were orally given to the treatment groups. After thirty-five days, blood samples were taken to determine serum levels of FSH, LH, testosterone and estradiol. Weight of testis and epididymis, sperm count, sperm motility, seminiferous tubules diameter (STD), germinal cell layer thickness (GCLT), sertoli, leydig and spermatogonia cells were also evaluated. Results: DPP at the of 120 and 240 mg/kg doses significantly raised the ratio of testis or epididymis to body weight, sperm count, sperm motility , and estradiol level compared to the control group (p<0.05). LH and testosterone levels only noticeably increased at 120 mg/kg of DPP (p<0.01 and p<0.001 respectively). STD increased in the three applied doses (p=0.001). A. ovinus extract at the indicated doses produced a significant reduction in the ratio of testis or epididymis to body weight and sperm motility (p<0.05). Sperm count, spermatogonia, leydig cells and FSH level decreased at dose of 500 mg/kg. Furthermore, GCLT, spermatogonia cells, and serum estradiol level increased at 100 mg/kg dose of A. ovinus. Conclusion: Our findings indicate that DPP could improve fertility factors, while A.ovinus can exhibit deleterious effects on gonad and sperm parameters in rats. PMID:25469129

  3. Influence of germ cells upon Sertoli cells during continuous low-dose rate gamma-irradiation of adult rats.

    PubMed

    Pinon-Lataillade, G; Vélez de la Calle, J F; Viguier-Martinez, M C; Garnier, D H; Folliot, R; Maas, J; Jégou, B

    1988-07-01

    The effects of continuous gamma-irradiation of adult rats at two low-dose rates (7 cGy and 12 cGy/day; up to a total dose of 9.1 Gy and 10.69 Gy 60Co gamma-ray, respectively) were investigated. Over a period of 3-131 days of irradiation, groups of experimental and control animals were killed. Body weight, testis, epididymis, prostate and seminal vesicle weights, the number of germ cells and Sertoli cells, tubular ultrastructure, epididymal and testicular levels of biologically active androgen-binding protein (ABP), and the plasma concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone were monitored. Irradiation had no effect on body weight, whereas testicular and epididymal weight began to decrease following 35 and 50 days of irradiation at 7 and 12 cGy, respectively. At 7 cGy the target cells of the gamma-rays were essentially A spermatogonia, whereas at 12 cGy A spermatogonia and preleptotene spermatocytes were primarily affected. This resulted in a progressive and sequential dose-related reduction in the number of pachytene spermatocytes, round spermatids and late spermatids (LS). Under both irradiation procedures the Sertoli cell number remained unchanged whereas partial (7 cGy) or no change (12 cGy) was seen at the Leydig cell level. Whatever the irradiation protocol, from the time LS numbers decreased, vacuolisation of the Sertoli cell cytoplasm progressively occurred, followed by thickening and folding of the peritubular tissue. Moreover, in parallel to the drop in the number of these germ cell types, ABP production fell whereas FSH levels rose. A highly significant positive correlation was found between LS numbers and these Sertoli cell parameters. This study supports our previous concept of a control of certain important aspects of Sertoli cell function by late spermatids in the adult rat.

  4. Low-dose and combined effects of oral exposure to bisphenol A and diethylstilbestrol on the male reproductive system in adult Sprague-Dawley rats.

    PubMed

    Jiang, Xiao; Chen, Hong-Qiang; Cui, Zhi-Hong; Yin, Li; Zhang, Wen-Long; Liu, Wen-Bin; Han, Fei; Ao, Lin; Cao, Jia; Liu, Jin-Yi

    2016-04-01

    Study of the joint action of xenobiotics is important to fully explore their toxicity and complete risk analysis. In this study, we investigated the effects of low-dose and combined exposure of bisphenol A (BPA) and diethylstilbestrol (DES) on the reproductive system in adult male rats. The results showed that the sperm motility decreased in the BPA/DES and combined groups. Sperm deformity ratios and histological lesions of the testes were significantly higher and more significant, respectively, in the combined group compared with the single treated groups. No dose-effect relationship or significant additive effect on serum hormone levels was observed after combined exposure to BPA/DES. Ultrastructural results showed lesions of the Sertoli and Leydig cells, mainly in the endoplasmic reticulum (ER), in all treated groups. ER stress molecular sensor IRE1 was phosphorylated and activated after BPA and DES treatment in this study. The protein levels of ES stress molecular marker CHOP were significantly up-regulated after exposure to BPA, DES, and BPA and DES combined. These findings indicate that ER stress is important in BPA/DES-induced damage in rat testes. Low-dose and combined exposure to BPA and DES may have toxic effects on male fertility in the adult population.

  5. A Transgenic Rat for Specifically Inhibiting Adult Neurogenesis123

    PubMed Central

    Grigereit, Laura; Pickel, James

    2016-01-01

    Abstract The growth of research on adult neurogenesis and the development of new models and tools have greatly advanced our understanding of the function of newborn neurons in recent years. However, there are still significant limitations in the ability to identify the functions of adult neurogenesis in available models. Here we report a transgenic rat (TK rat) that expresses herpes simplex virus thymidine kinase in GFAP+ cells. Upon treating TK rats with the antiviral drug valganciclovir, granule cell neurogenesis can be completely inhibited in adulthood, in both the hippocampus and olfactory bulb. Interestingly, neurogenesis in the glomerular and external plexiform layers of the olfactory bulb was only partially inhibited, suggesting that some adult-born neurons in these regions derive from a distinct precursor population that does not express GFAP. Within the hippocampus, blockade of neurogenesis was rapid and nearly complete within 1 week of starting treatment. Preliminary behavioral analyses indicate that general anxiety levels and patterns of exploration are generally unaffected in neurogenesis-deficient rats. However, neurogenesis-deficient TK rats showed reduced sucrose preference, suggesting deficits in reward-related behaviors. We expect that TK rats will facilitate structural, physiological, and behavioral studies that complement those possible in existing models, broadly enhancing understanding of the function of adult neurogenesis. PMID:27257630

  6. Role of 11β-OH-C(19) and C(21) steroids in the coupling of 11β-HSD1 and 17β-HSD3 in regulation of testosterone biosynthesis in rat Leydig cells.

    PubMed

    Latif, Syed A; Shen, Mae; Ge, Ren-Shan; Sottas, Chantal M; Hardy, Matthew P; Morris, David J

    2011-06-01

    Here we describe further experiments to support our hypothesis that bidirectional 11β-HSD1-dehydrogenase in Leydig cells is a NADP(H) regenerating system. In the absence of androstenedione (AD), substrate for 17β-HSD3, incubation of Leydig cells with corticosterone (B) or several C(19)- and C(21)-11β-OH-steroids, in the presence of [(3)H]-11-dehydro-corticosterone (A), stimulated 11β-HSD1-reductase activity. However, in presence of 30 μM AD, testosterone (Teso) synthesis is stimulated from 4 to 197 picomole/25,000 cells/30 min and concomitantly inhibited 11β-HSD1-reductase activity, due to competition for the common cofactor NADPH needed for both reactions. Testo production was further significantly increased (p<0.05) to 224-267 picomole/25,000 cells/30 min when 10 μM 11β-OH-steroids (in addition to 30 μM AD) were also included. Similar results were obtained in experiments conducted with lower concentrations of AD (5 μM), and B or A (500 nM). Incubations of 0.3-6.0 μM of corticosterone (plus or minus 30 μM AD) were then performed to test the effectiveness of 17β-HSD3 as a possible NADP(+) regenerating system. In the absence of AD, increasing amounts (3-44 pmol/25,000 cells/30 min) of 11-dehydro-corticosterone were produced with increasing concentrations of corticosterone in the medium. When 30 μM AD was included, the rate of 11-dehydro-corticosterone formation dramatically increased 1.3-5-fold producing 4-210 pmol/25,000 cells/30 min of 11-dehydro-corticosterone. We conclude that 11β-HSD1 is enzymatically coupled to 17β-HSD3, utilizing NADPH and NADP in intermeshed regeneration systems.

  7. Physiological responses during whole body suspension of adult rats

    NASA Technical Reports Server (NTRS)

    Steffen, J. M.; Fell, R. D.; Musacchia, X. J.

    1987-01-01

    The objective of this study was to characterize responses of adult rats to one and two weeks of whole body suspension. Body weights and food and water intakes were initially reduced during suspension, but, while intake of food and water returned to presuspension levels, body weight remained depressed. Diuresis was evident, but only during week two. Hindlimb muscle responses were differential, with the soleus exhibiting the greatest atrophy and the EDL a relative hypertrophy. These findings suggest that adult rats respond qualitatively in a manner similar to juveniles during suspension.

  8. Hypertension after bilateral kidney irradiation in young and adult rats

    SciTech Connect

    Jongejan, H.T.; van der Kogel, A.J.; Provoost, A.P.; Molenaar, J.C.

    1987-09-01

    The mechanism of a rise in blood pressure after kidney irradiation is unclear but most likely of renal origin. We have investigated the role of the renin-angiotensin system and dietary salt restriction in the development of systolic hypertension after bilateral kidney irradiation in young and adult rats. Three to 12 months after a single X-ray dose of 7.5 or 12.5 Gy to both kidneys of young and adult rats, the systolic blood pressure (SBP) and plasma renin concentration (PRC) were measured regularly. A single X-ray dose of 12.5 Gy caused a moderate rise in SBP and a slight reduction in PRC in both young and adult rats. A dose of 7.5 Gy did not significantly alter the SBP or PRC during the follow-up period of 1 year. In a second experiment, the kidneys of young rats received an X-ray dose of 20 Gy. Subsequently, rats were kept on a standard diet (110 mmol sodium/kg) or a sodium-poor diet (10 mmol sodium/kg). On both diets, SBP started to rise rapidly 3 months after kidney irradiation. Sodium balance studies carried out at that time revealed an increased sodium retention in the irradiated rats compared to controls on the same diet. In rats on a low sodium intake, there was neither a delay nor an alleviation in the development of hypertension. Compared to controls, the PRC tended to be lower in irradiated rats up to 4 months after irradiation. Subsequently, malignant hypertension developed in all 20 Gy rats, resulting in pressure natriuresis, stimulating the renin-angiotensin system. Our findings indicated that hypertension after bilateral kidney irradiation was not primarily the result of an activation of the renin-angiotensin system. Although there were some indications that sodium retention played a role, dietary sodium restriction did not influence the development of hypertension.

  9. Ultrasonic Vocalizations by Adult Rats (Rattus norvegicus)

    DTIC Science & Technology

    1991-12-01

    during aggression in rats and some other myomorph species (e.g., Acomys cahirinus, Apcdemus sylvati- cus). Other species (e.g., MusM muau_...which occur when the young are handled. The author reports that, unlike rats, other rodent species (e.g., lab mice, Acomys cahirinus, Clethrionomys gajj... Acomys was removed from the mother’s cage, and during exploratory behavior in Apodemus gyiL vaticus. i1 Sewell, G.D. Ultrasonic signals from rodents

  10. Potassium currents in adult rat intracardiac neurones.

    PubMed Central

    Xi-Moy, S X; Dun, N J

    1995-01-01

    1. Properties of K+ currents were studied in isolated adult rat parasympathetic intracardiac neurones with the use of single-electrode voltage-clamp techniques. 2. A hyperpolarization-activated inward rectifier current was revealed when the membrane was clamped close to the resting level (-60 mV). The slowly developing inward relaxation had a mean amplitude of 450 pA at -150 mV, an activation threshold of -60 to -70 mV and a relaxation time constant of 41 ms at -120 mV. The current was reversibly blocked by Cs+ (1 mM) and became smaller with reduced [K+]o and [Na+]o, indicating that this inward rectifier current probably is a time- and voltage-dependent Na(+)-K+ current. 3. Step depolarizations from the holding potential of -80 mV evoked a transient (< 100 ms at -40 mV) outward K+ current (IA) which was blocked by 4-aminopyridine (4-AP, 1 mM). The time constants for IA inactivation were 20 ms at -50 mV and 16 ms at -20 mV. The steady-state activation and (removal of) inactivation curve showed a small overlap between -70 and -40 mV; the reversal potential of IA was close to EK. 4. Step hyperpolarizations from the depolarized potentials, i.e. -30 mV, revealed a slow inward relaxation associated with the deactivation of a time- and voltage-dependent current. The inward relaxation became faster at more hyperpolarized potentials and reversed at -85 and -53 mV in 4.7 and 15 mM [K+]o. This current was blocked by muscarine (20 microM) and Ba2+ (1 mM) but not affected by Cs+ (1 mM); this current may correspond to the M-current (IM). 5. Depolarization-activated outward K+ currents were evoked by holding the membrane close to the resting potential in the presence of tetrodotoxin (TTX, 3 microM), 4-AP (1 mM) and Ba2+ (1 mM). The amplitude of the outward relaxation and the tail current became smaller as the [K+]o was elevated. The outward tail current was reduced in a Ca(2+)-free solution and the residual current was eliminated by the addition of tetraethylammonium (TEA, 10 m

  11. Adrenal and gonadal function in hypothyroid adult male rats.

    PubMed

    Tohei, A; Akai, M; Tomabechi, T; Mamada, M; Taya, K

    1997-01-01

    The functional relationship between thyroid, adrenal and gonadal hormones was investigated using adult male rats. Hypothyroidism was produced by the administration of 4-methyl-2-thiouracil (thiouracil) in the drinking water for 2 weeks. Plasma concentrations of TSH dramatically increased, whereas plasma concentrations of tri-iodothyronine and thyroxine decreased in thiouraciltreated rats as compared with euthyroid rats. Hypothyroidism increased basal levels of plasma ACTH and pituitary content of ACTH. The pituitary responsiveness to CRH for ACTH release markedly increased, whereas the adrenal responsiveness to ACTH for corticosterone release decreased. These results indicated that hypothyroidism causes adrenal dysfunction in adult male rats. Pituitary contents of LH and prolactin decreased in hypothyroid rats as compared with euthyroid rats. In addition, hypothyroidism lowered pituitary LH responsiveness to LHRH. Testicular responsiveness to human chorionic gonadotrophin for testosterone release, however, was not different between euthyroid and hypothyroid animals. These results indicated that hypothyroidism causes adrenal dysfunction and results in hypersecretion of ACTH from the pituitary gland. Adrenal dysfunction may contribute to the inhibition of LHRH secretion from the hypothalamus, possibly mediated by excess CRH.

  12. Ontogenetic noradrenergic lesion alters histaminergic activity in adult rats.

    PubMed

    Nowak, Przemyslaw; Jochem, Jerzy; Zwirska-Korczala, Krystyna; Josko, Jadwiga; Noras, Lukasz; Kostrzewa, Richard M; Brus, Ryszard

    2008-04-01

    To determine whether noradrenergic nerves might have a modulatory role on the sensitivity or reactivity of histaminergic receptor systems in brain, behavioral effects of the respective histamine H1, H2 and H3 antagonists S(+)chlorpheniramine, cimetidine and thioperimide in control adult rats were compared to the effects in adult rats that had been lesioned as neonates with the noradrenergic neurotoxin DSP-4. On the 1st and 3rd days after birth rat pups were treated with either saline or DSP-4 (50 mg/kg sc), then returned to their home cages with the dam. At 8 weeks when rats were tested, S(+)chlorpheniramine (10 mg/kg ip) was found to increase locomotor activity in intact and DSP-4 lesioned rats, while cimetidine (5 mg/kg, ip) and thioperimide (5 mg/kg, ip) increased activity several-fold solely in the DSP-4 group. Exploratory activity, nociceptive activity, and irritability were little altered by the histamine antagonists, although oral activity was increased by thioperimide in intact and lesioned rats, and by cimetidine or S(+)chlorpheniramine in DSP-4 rats. High performance liquid chromatography with electrochemical detection was used to determine that DSP-4 produced a 90% reduction in frontal cortex, hippocampus and hypothalamus, with a 90% elevation of NE in cerebellum--reflecting reactive sprouting of noradrenergic fibers consequent to lesion of noradrenergic tracts projecting to proximal brain regions. These findings indicate that perinatal noradrenergic fiber lesioning in rat brain is associated with an altered behavioral spectrum by histamine H1, H2 and H3 receptor antagonists, thereby implicating histaminergic systems as modulators of noradrenergic systems in brain.

  13. [In vitro organotypic cultivation of adult newt and rat retinas].

    PubMed

    Novikova, Iu P; Aleĭnikova, K S; Krasnov, M S; Poplinskaia, V A; Grigorian, E N

    2010-01-01

    Adult rat and newt retinas were studied during long organotypic 3D cultivation. A high proliferation level was discovered in the region of growth by applying DNA synthesis markers and in vitro mitosis registration in newt retina. Aggregates were formed in the retina spheroid cavity because dedifferentiated cells migrated into this region. Small cell populations in nuclear layers also had dividing and migration capacity. Rosette formation has been shown in newt retina. It is a characteristic of fetal retinal development under pathological conditions. The antiG FAP antibody dye demonstrated an increase in the parent M@uller cell population and generation of a small cell pool with short GFAP-extensions de novo. Recoverin expression studies detected its translocation from photoreceptor extensions to the cell bodies. Moreover, protein was presented in some cells inside the spheroid. It has been shown for the first time that cell proliferation occurred in the developing adult rat retinal spheroid in vitro; BrdU-positive cells and multiple mitoses were revealed in this zone. However, the source of proliferation was not in the peripheral retina, and stable macrophages and glial cells located among neurons of the inner nuclear layer had the ability to divide. The antiGFAP antibody showed an increase in GFAP fibers in the rat retina as well as in the newt retina. Recoverin translocated into photoreceptor perikaryons and the outer plexiform layer in cultivated rat retina. Interestingly, some cells with probably de novo expression of recoverin were discovered in rat and newt retinas.

  14. Involvement of tumor necrosis factor-alpha in the pathogenesis of autoimmune orchitis in rats.

    PubMed

    Suescun, María O; Rival, Claudia; Theas, María S; Calandra, Ricardo S; Lustig, Livia

    2003-06-01

    We studied the testicular macrophages of rats with experimental autoimmune orchitis (EAO) and analyzed whether the tumor necrosis factor-alpha (TNFalpha) is involved in germ cell apoptosis and in Leydig cell steroidogenesis. The EAO was induced in adult male Sprague-Dawley rats by active immunization with testicular homogenate and adjuvants. In the experimental group, a severe orchitis was observed 80 days after the first immunization. ED1- and ED2-positive macrophages were quantified by immunohistochemistry. The TNFalpha concentration of conditioned media from testicular macrophages (TMCM) was determined by ELISA. The number of apoptotic TNF receptor 1 (TNFR1)-positive germ cells was identified by combining in situ end labeling of apoptotic DNA and immunohistochemical techniques. The effect of TNFalpha on Leydig cell testosterone production was determined by RIA. In rats with EAO, we observed a significant increase in the number of TNFalpha-positive testicular macrophages, the TNFalpha concentration in TMCM, and the number of TNFR1-positive germ cells. Sixty percent of TNFR1-positive germ cells were apoptotic. These results suggest that TNFalpha could be involved in the pathogenesis of EAO. Acting together with other local factors such as Fas-FasL, TNFalpha could trigger germ cell apoptosis. We also demonstrated that TNFalpha inhibited in vitro testosterone production in basal and hCG-stimulated Leydig cells from rats with orchitis.

  15. Endotoxemia in newborn rats attenuates acute pancreatitis at adult age.

    PubMed

    Jaworek, J; Konturek, S J; Macko, M; Kot, M; Szklarczyk, J; Leja-Szpak, A; Nawrot-Porabka, K; Stachura, J; Tomaszewska, R; Siwicki, A; Pawlik, W W

    2007-03-01

    Bacterial endotoxin (lipopolysaccharide, LPS), at high concentration is responsible for sepsis, and neonatal mortality, however low concentration of LPS protected the pancreas against acute damage. The aim of this study was to investigate the effect of exposition of suckling rats to LPS on the course of acute pancreatitis at adult age. Suckling rat (30-40g) received intraperitoneal (i.p.) injection of saline (control) or LPS from Escherichia coli or Salmonella typhi (5, 10 or 15 mg/kg-day) during 5 consecutive days. Two months later these rats have been subjected to i.p. cearulein infusion (25 microg/kg) to produce caerulein-induced pancreatitis (CIP). The following parameters were tested: pancreatic weight and morphology, plasma amylase and lipase activities, interleukin 1beta (IL-1 beta), interleukin 6 (IL-6), and interleukin 10 (IL-10) plasma concentrations. Pancreatic concentration of superoxide dismutase (SOD) and lipid peroxidation products; malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) have been also measured. Caerulein infusion produced CIP in all animals tested, that was confirmed by histological examination. In the rats, which have been subjected in the neonatal period of life to LPS at doses 10 or 15 mg/kg-day x 5 days, all manifestations of CIP have been reduced. In these animals acute inflammatory infiltration of pancreatic tissue and pancreatic cell vacuolization have been significantly diminished. Also pancreatic weight, plasma lipase and alpha-amylase activities, as well as plasma concentrations of IL-1beta and IL-6 have been markedly decreased, whereas plasma anti-inflammatory IL-10 concentration was significantly increased in these animals as compared to the control rats, subjected in the infancy to saline injection instead of LPS. Caerulein-induced fall in pancreatic SOD concentration was reversed and accompanied by significant reduction of MDA + 4 HNE in the pancreatic tissue. The effects of LPS derived from E. coli or S. typhi were similar

  16. Ketone-body utilization by homogenates of adult rat brain

    SciTech Connect

    Lopes-Cardozo, M.; Klein, W.

    1982-06-01

    The regulation of ketone-body metabolism and the quantitative importance of ketone bodies as lipid precursors in adult rat brain has been studied in vitro. Utilization of ketone bodies and of pyruvate by homogenates of adult rat brain was measured and the distribution of /sup 14/C from (3-/sup 14/C)ketone bodies among the metabolic products was analysed. The rate of ketone-body utilization was maximal in the presence of added Krebs-cycle intermediates and uncouplers of oxidative phosphorylation. The consumption of acetoacetate was faster than that of D-3-hydroxybutyrate, whereas, pyruvate produced twice as much acetyl-CoA as acetoacetate under optimal conditions. Millimolar concentrations of ATP in the presence of uncoupler lowered the consumption of ketone bodies but not of pyruvate. Indirect evidence is presented suggesting that ATP interferes specifically with the mitochondrial uptake of ketone bodies. Interconversion of ketone bodies and the accumulation of acid-soluble intermediates (mainly citrate and glutamate) accounted for the major part of ketone-body utilization, whereas only a small part was oxidized to CO/sub 2/. Ketone bodies were not incorporated into lipids or protein. We conclude that adult rat-brain homogenates use ketone bodies exclusively for oxidative purposes.

  17. Effects of environmental tobacco smoke on adult rat brain biochemistry.

    PubMed

    Fuller, Brian F; Gold, Mark S; Wang, Kevin K W; Ottens, Andrew K

    2010-05-01

    Environmental tobacco smoke (ETS) has been linked to deleterious health effects, particularly pulmonary and cardiac disease; yet, the general public considers ETS benign to brain function in adults. In contrast, epidemiological data have suggested that ETS impacts the brain and potentially modulates neurodegenerative disease. The present study begins to examine yet unknown biochemical effects of ETS on the adult mammalian brain. In the developed animal model, adult male rats were exposed to ETS 3 h a day for 3 weeks. Biochemical data showed altered glial fibrillary acid protein levels as a main treatment effect of ETS, suggestive of reactive astrogliosis. Yet, markers of oxidative and cell stress were unaffected by ETS exposure in the brain regions examined. Increased proteolytic degradation of alphaII-spectrin by caspase-3 and the dephosphorylation of serine(116) on PEA-15 indicated greater apoptotic cell death modulated by the extrinsic pathway in the brains of ETS-exposed animals. Further, beta-synuclein was upregulated by ETS, a neuroprotective protein previously reported to exhibit anti-apoptotic and anti-fibrillogenic properties. These findings demonstrate that ETS exposure alters the neuroproteome of the adult rat brain, and suggest modulation of inflammatory and cell death processes.

  18. Contextual fear conditioning differs for infant, adolescent, and adult rats

    PubMed Central

    Esmorís-Arranz, Francisco J.; Méndez, Cástor; Spear, Norman E.

    2009-01-01

    Contextual fear conditioning was tested in infant, adolescent, and adult rats in terms of Pavlovian conditioned suppression. When a discrete auditory conditioned stimulus (CS) was paired with footshock (unconditioned stimulus, US) within the largely olfactory context, infants and adolescents conditioned to the context with substantial effectiveness but adult rats did not. When unpaired presentations of the CS and US occurred within the context, contextual fear conditioning was strong for adults, weak for infants, but about as strong for adolescents as when pairings of CS and US occurred in the context. Nonreinforced presentations of either the CS or context markedly reduced contextual fear conditioning in infants, but, in adolescents, CS extinction had no effect on contextual fear conditioning, although context extinction significantly reduced it. Neither CS extinction nor context extinction affected responding to the CS-context compound in infants, suggesting striking discrimination between the compound and its components. Female adolescents showed the same lack of effect of component extinction on response to the compound as infants, but CS extinction reduced responding to the compound in adolescent males, a sex difference seen also in adults. Theoretical implications are discussed for the development of perceptual-cognitive processing and hippocampus role. PMID:18343048

  19. Plexin a4 expression in adult rat cranial nerves.

    PubMed

    Gutekunst, Claire-Anne; Gross, Robert E

    2014-11-01

    PlexinsA1-A4 participate in class 3 semaphorin signaling as co-receptors to neuropilin 1 and 2. PlexinA4 is the latest member of the PlexinA subfamily to be identified. In previous studies, we described the expression of PlexinA4 in the brain and spinal cord of the adult rat. Here, antibodies to PlexinA4 were used to reveal immunolabeling in most of the cranial nerve surveyed. Labeling was found in the olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, and hypoglossal nerves. This is the first detailed description of the cellular and subcellular distribution of PlexinA4 in the adult cranial nerves. The findings will set the basis for future studies on the potential role of PlexinA4 in regeneration and repair of the adult central and peripheral nervous system.

  20. Diabetic rat testes: morphological and functional alterations.

    PubMed

    Ricci, G; Catizone, A; Esposito, R; Pisanti, F A; Vietri, M T; Galdieri, M

    2009-12-01

    Reproductive dysfunction is a consequence of diabetes, but the underlying mechanisms are poorly understood. This study investigated the histological and molecular alterations in the testes of rats injected with streptozotocin at prepuperal (SPI rats) and adult age (SAI rats) to understand whether diabetes affects testicular tissue with different severity depending on the age in which this pathological condition starts. The testes of diabetic animals showed frequent abnormal histology, and seminiferous epithelium cytoarchitecture appeared altered as well as the occludin distribution pattern. The early occurrence of diabetes increased the percentage of animals with high number of damaged tubules. The interstitial compartment of the testes was clearly hypertrophic in several portions of the organs both in SPI and SAI rats. Interestingly, fully developed Leydig cells were present in all the treated animals although abnormally distributed. Besides the above-described damages, we found a similar decrease in plasma testosterone levels both in SPI and SAI rats. Oxidative stress (OS) is involved in the pathogenesis of various diabetic complications, and in our experimental models we found that manganese superoxide dismutase was reduced in diabetic animals. We conclude that in STZ-induced diabetes, the altered spermatogenesis, more severe in SPI animals, is possibly due to the effect of OS on Leydig cell function which could cause the testosterone decrease responsible for the alterations found in the seminiferous epithelium of diabetic animals.

  1. Encoding of sound envelope transients in the auditory cortex of juvenile rats and adult rats.

    PubMed

    Lu, Qi; Jiang, Cuiping; Zhang, Jiping

    2016-02-01

    Accurate neural processing of time-varying sound amplitude and spectral information is vital for species-specific communication. During postnatal development, cortical processing of sound frequency undergoes progressive refinement; however, it is not clear whether cortical processing of sound envelope transients also undergoes age-related changes. We determined the dependence of neural response strength and first-spike latency on sound rise-fall time across sound levels in the primary auditory cortex (A1) of juvenile (P20-P30) rats and adult (8-10 weeks) rats. A1 neurons were categorized as "all-pass", "short-pass", or "mixed" ("all-pass" at high sound levels to "short-pass" at lower sound levels) based on the normalized response strength vs. rise-fall time functions across sound levels. The proportions of A1 neurons within each of the three categories in juvenile rats were similar to that in adult rats. In general, with increasing rise-fall time, the average response strength decreased and the average first-spike latency increased in A1 neurons of both groups. At a given sound level and rise-fall time, the average normalized neural response strength did not differ significantly between the two age groups. However, the A1 neurons in juvenile rats showed greater absolute response strength, longer first-spike latency compared to those in adult rats. In addition, at a constant sound level, the average first-spike latency of juvenile A1 neurons was more sensitive to changes in rise-fall time. Our results demonstrate the dependence of the responses of rat A1 neurons on sound rise-fall time, and suggest that the response latency exhibit some age-related changes in cortical representation of sound envelope rise time.

  2. Evaluation of an Aqueous-Ethanolic Extract from Rosmarinus officinalis (Rosemary) for its Activity on the Hormonal and Cellular Function of Testes in Adult Male Rat.

    PubMed

    Heidari-Vala, Hamed; Ebrahimi Hariry, Reza; Sadeghi, Mohammad Reza; Akhondi, Mohammad Mehdi; Ghaffari Novin, Marefat; Heidari, Mahnaz

    2013-01-01

    Rosmarinus officinalis has been used in traditional medicine extensively. This study evaluated the hormonal and cellular effects of Rosmarinus officinalis extract on testes of adult rats. Thirty male Wistar rats (in three groups) received 50 or 100 mg/Kg b.w of Rosmarinus officinalis extract (made from the plant's leaves, flower and stem) (treatment groups) and 10 mL/Kg b.w normal saline (control group) respectively, on a daily bases by gavage route for 60 days. Then, spermatological properties, histometric parameters and sperm dynamics, testis and body weight, testicular cell population and serum testosterone level were analyzed by an acceptable method. Results showed that the mean serum testosterone level was decreased significantly in both treatment groups (50 and 100 mg/Kg b.w) during the experiment time, compared with control group (p < 0.05). However, Rosmarinus officinalis did not change the total count, motility and viability of sperm. In addition, Rosmarinus officinalis at both doses did not change body and testes weight and their ratio. Furthermore, Rosmarinus officinalis increased the number of Spermatogonia at both doses, Spermatocyte at doses of 50 mg/Kg b.w, Leydig cell and Spermatid at dose of 100 mg/Kg b.w significantly (p < 0.05). Rosmarinus officinalis did not significantly affect the number of Spermatozoid and Sertoli cells. In conclusion, it seems that Rosmarinus officinalis may have some hormonal and cellular effects on the testes which can contribute the spermatogenesis process in rat. Rosmarinus officinalis may have antiandrogenic effect potentially indicating the possibility of developing herbal male contraceptive.

  3. Evaluation of an Aqueous-Ethanolic Extract from Rosmarinus officinalis (Rosemary) for its Activity on the Hormonal and Cellular Function of Testes in Adult Male Rat

    PubMed Central

    Heidari-Vala, Hamed; Ebrahimi Hariry, Reza; Sadeghi, Mohammad Reza; Akhondi, Mohammad Mehdi; Ghaffari Novin, Marefat; Heidari, Mahnaz

    2013-01-01

    Rosmarinus officinalis has been used in traditional medicine extensively. This study evaluated the hormonal and cellular effects of Rosmarinus officinalis extract on testes of adult rats. Thirty male Wistar rats (in three groups) received 50 or 100 mg/Kg b.w of Rosmarinus officinalis extract (made from the plant’s leaves, flower and stem) (treatment groups) and 10 mL/Kg b.w normal saline (control group) respectively, on a daily bases by gavage route for 60 days. Then, spermatological properties, histometric parameters and sperm dynamics, testis and body weight, testicular cell population and serum testosterone level were analyzed by an acceptable method. Results showed that the mean serum testosterone level was decreased significantly in both treatment groups (50 and 100 mg/Kg b.w) during the experiment time, compared with control group (p < 0.05). However, Rosmarinus officinalis did not change the total count, motility and viability of sperm. In addition, Rosmarinus officinalis at both doses did not change body and testes weight and their ratio. Furthermore, Rosmarinus officinalis increased the number of Spermatogonia at both doses, Spermatocyte at doses of 50 mg/Kg b.w, Leydig cell and Spermatid at dose of 100 mg/Kg b.w significantly (p < 0.05). Rosmarinus officinalis did not significantly affect the number of Spermatozoid and Sertoli cells. In conclusion, it seems that Rosmarinus officinalis may have some hormonal and cellular effects on the testes which can contribute the spermatogenesis process in rat. Rosmarinus officinalis may have antiandrogenic effect potentially indicating the possibility of developing herbal male contraceptive. PMID:24250620

  4. Prenatal ethanol exposure increases brain cholesterol content in adult rats.

    PubMed

    Barceló-Coblijn, Gwendolyn; Wold, Loren E; Ren, Jun; Murphy, Eric J

    2013-11-01

    Fetal alcohol syndrome is the most severe expression of the fetal alcohol spectrum disorders (FASD). Although alterations in fetal and neonate brain fatty acid composition and cholesterol content are known to occur in animal models of FASD, the persistence of these alterations into adulthood is unknown. To address this question, we determined the effect of prenatal ethanol exposure on individual phospholipid class fatty acid composition, individual phospholipid class mass, and cholesterol mass in brains from 25-week-old rats that were exposed to ethanol during gestation beginning at gestational day 2. While total phospholipid mass was unaffected, phosphatidylinositol and cardiolipin mass was decreased 14 and 43 %, respectively. Exposure to prenatal ethanol modestly altered brain phospholipid fatty acid composition, and the most consistent change was a significant 1.1-fold increase in total polyunsaturated fatty acids (PUFA), in the n-3/n-6 ratio, and in the 22:6n-3 content in ethanolamine glycerophospholipids and in phosphatidylserine. In contrast, prenatal ethanol consumption significantly increased brain cholesterol mass 1.4-fold and the phospholipid to cholesterol ratio was significantly increased 1.3-fold. These results indicate that brain cholesterol mass was significantly increased in adult rats exposed prenatally to ethanol, but changes in phospholipid mass and phospholipid fatty acid composition were extremely limited. Importantly, suppression of postnatal ethanol consumption was not sufficient to reverse the large increase in cholesterol observed in the adult rats.

  5. Hydrocephalus induced via intraventricular kaolin injection in adult rats.

    PubMed

    Shaolin, Z; Zhanxiang, W; Hao, X; Feifei, Z; Caiquan, H; Donghan, C; Jianfeng, B; Feng, L; Shanghang, S

    2015-01-01

    Hydrocephalus is a common neurological disease in humans, but a uniform and particularly effective hydrocephalic animal model amenable to proper appraisal and deep study has not yet been established. In this study, we attempted to construct a high-efficiency model of hydrocephalus via intraventricular kaolin injection. Adult male Sprague-Dawley rats were randomly divided into 2 groups: the control group (n = 15) and the experimental group (n = 30). Kaolin was injected into the lateral ventricle of experimental animals. Control rats underwent the same procedure but received sterile saline injection instead of kaolin. All animals with kaolin injection into the lateral ventricle developed hydrocephalus according to magnetic resonance imaging (MRI) results (success rate up to 100%). Also, the Morris water maze (MWM) test demonstrated disturbed spatial learning and memory. Furthermore, there were significant differences between groups with respect to the histological changes in the periventricular tissue. Our results indicate that experimental hydrocephalus induced by lateral ventricle injection of kaolin in adult rats is feasible and may be widely used.

  6. Fluoxetine induces changes in the testicle and testosterone in adult male rats exposed via placenta and lactation.

    PubMed

    Monteiro Filho, Waldo Oliveira; de Torres, Sandra Maria; Amorim, Marleyne José Afonso Accioly Lins; Andrade, Anderson Joel Martino; de Morais, Rosana Nogueira; Tenorio, Bruno Mendes; da Silva Junior, Valdemiro Amaro

    2014-10-01

    Fluoxetine is a selective serotonin reuptake inhibitor used to treat depression in pregnant and nursing women. However, recent studies have shown adverse effects in the male reproductive system after fluoxetine treatment. Aiming to analyze the extent of damage caused by fluoxetine in the testicle and safe doses for treatment during the perinatal period, the present study analyzed the effects of in utero exposure and exposure during lactation to fluoxetine in spermatogenesis of male rat offspring in adulthood. Wistar rat dams were orally treated with fluoxetine (5, 10, and 20 mg/kg) from 13 days of gestation to lactation day 21 and their offspring were analyzed at 90 days old. Results showed a reduction in the weight of testes (16%), epididymis (28%), and seminal glands (18%) in animals exposed to fluoxetine 20 mg/kg compared to the control. Seminal gland weight was also reduced 25% and 30% in animals exposed to 5 mg/kg and 10 mg/kg fluoxetine, respectively. Body weight of animals exposed to 20 mg/kg fluoxetine was reduced from post-natal day 9 to 36 compared to controls but from the post-natal day 9 to 36 there was no statistical difference. The volume of seminiferous epithelium reduced 17% and the total volume of Leydig cells reduced 30% in the group exposed to fluoxetine at 20 mg/kg. Furthermore, Leydig cells volume reduced 29% in the 5 mg/kg group. The length of the seminiferous tubules reduced 17% and daily sperm production per testicle also reduced 18% in animals exposed to the highest dose of fluoxetine compared to controls. The individual area of Leydig cells increased 7% and plasma testosterone increased 49% in animals exposed to fluoxetine at 20 mg/kg. In conclusion, exposure to 20 mg/kg fluoxetine via the placenta and during lactation may change testosterone and testicular parameters important for sperm production and male fertility in adulthood.

  7. Wnt Expression in the Adult Rat Subventricular Zone After Stroke

    PubMed Central

    Morris, Daniel C.; Zhang, Zheng Geng; Wang, Ying; Zhang, Rui Lan; Greg, Sara; Liu, Xian Shuang; Chopp, Michael

    2007-01-01

    Introduction: In the adult brain, neurogenesis occurs in the subventricular zone (SVZ) of the lateral ventricle. During development, the Wnt pathways contribute to stem cell maintenance and promote neurogenesis. We hypothesized that the Wnt family genes are expressed in neural progenitor cells of the non-ischemic and ischemic SVZ of the adult rodent brain after middle cerebral artery (MCA) occlusion. Methods: Non-ischemic and ischemic cultured SVZ cells and a single population of non-ischemic and ischemic SVZ cells isolated by laser capture microdisection (LCM) were analyzed for Wnt pathway expression using real-time RT-PCR and immunostaining. Results: The number of neurospheres increased significantly (p<0.05) in SVZ cells derived from ischemic (32 ±4.7/rat) compared with the number in non-ischemic SVZ cells (18 ± 3/rat). Wnt family gene mRNA levels were detected in SVZ cells isolated from both cultured and LCM SVZ cells, however there was no upregulation between non-ischemic and ischemic SVZ cells. Immunostaining on brain sections also demonstrated no upregulation of Wnt pathway protein between ischemic and non-ischemic SVZ cells. Conclusions: Expression of the Wnt family genes in SVZ cells suggests that the Wnt pathway may be involved in neurogenesis in the adult brain. However, ischemia does not upregulate Wnt family gene expression. PMID:17400378

  8. Ih without Kir in Adult Rat Retinal Ganglion Cells

    PubMed Central

    Lee, Sherwin C.; Ishida, Andrew T.

    2011-01-01

    Antisera directed against hyperpolarization-activated mixed-cation (“Ih”) and K+ (“Kir”) channels bind to some somata in the ganglion cell layer of rat and rabbit retina. Additionally, the termination of hyperpolarizing current injections can trigger spikes in some cat retinal ganglion cells, suggesting a rebound depolarization due to activation of Ih. However, patch-clamp studies have reported that rat ganglion cells lack inward rectification, or present an inwardly rectifying K+ current. We therefore tested whether hyperpolarization activates Ih in dissociated, adult rat retinal ganglion cell somata. We report here that while we found no inward rectification in some cells, and a Kir-like current in a few cells, hyperpolarization activated Ih in roughly 75% of the cells we recorded from in voltage clamp. We show that this current is blocked by Cs+ or ZD7288 and only slightly reduced by Ba2+, that the current amplitude and reversal potential are sensitive to extracellular Na+ and K+, and that we found no evidence of Kir in cells presenting Ih. In current clamp, injecting hyperpolarizing current induced a slowly relaxing membrane hyperpolarization that rebounded to a few action potentials when the hyperpolarizing current was stopped; both the membrane potential relaxation and rebound spikes were blocked by ZD7288. These results provide the first measurement of Ih in mammalian retinal ganglion cells, and indicate that the ion channels of rat retinal ganglion cells may vary in ways not expected from previous voltage and current recordings. PMID:17488978

  9. Experimental induction of corpora amylacea in adult rat brain.

    PubMed

    Schipper, H M

    1998-10-01

    Corpora amylacea (CA) are glycoproteinaceous inclusions that accumulate in astroglia and other brain cells as a function of advancing age and, to an even greater extent, in several human neurodegenerative conditions. The mechanisms responsible for their biogenesis and their subcellular origin(s) remain unclear. We previously demonstrated that the sulfhydryl agent, cysteamine (CSH), promotes the accumulation of CA-like inclusions in cultured rat astroglia. In the present study, we show that subcutaneous administration of CSH to adult rats (150 mg/kg for 6 weeks followed by a 5-week drug-washout period) elicits the accumulation of CA in many cortical and subcortical brain regions. As in the aging human brain and in CSH-treated rat astrocyte cultures, the inclusions are periodic acid-Schiff -positive and are consistently immunostained with antibodies directed against mitochondrial epitopes and ubiquitin. Our findings support our contention that mitochondria are important structural precursors of CA, and that CSH accelerates aging-like processes in rat astroglia both in vitro and in the intact brain.

  10. Metachronous Bilateral Testicular Leydig-Like Tumors Leading to the Diagnosis of Congenital Adrenal Hyperplasia (Adrenogenital Syndrome)

    PubMed Central

    Vukina, Josip; Chism, David D.; Sharpless, Julie L.; Raynor, Mathew C.; Milowsky, Matthew I.; Funkhouser, William K.

    2015-01-01

    A 33-year-old male with a history of left testis Leydig cell tumor (LCT), 3-month status after left radical orchiectomy, presented with a rapidly enlarging (0.6 cm to 3.7 cm) right testicular mass. He underwent a right radical orchiectomy, sections interpreted as showing a similar Leydig cell-like oncocytic proliferation, with a differential diagnosis including metachronous bilateral LCT and metachronous bilateral testicular tumors associated with congenital adrenal hyperplasia (a.k.a. “testicular adrenal rest tumors” (TARTs) and “testicular tumors of the adrenogenital syndrome” (TTAGS)). Additional workup demonstrated a markedly elevated serum adrenocorticotropic hormone (ACTH) and elevated adrenal precursor steroid levels. He was diagnosed with congenital adrenal hyperplasia, 3β-hydroxysteroid dehydrogenase deficiency (3BHSD) type, and started on treatment. Metachronous bilateral testicular masses in adults should prompt consideration of adult presentation of CAH. Since all untreated CAH patients are expected to have elevated serum ACTH, formal exclusion of CAH prior to surgical resection of a testicular Leydig-like proliferation could be accomplished by screening for elevated serum ACTH. PMID:26351608

  11. Fructose-1,6-bisphosphatase from young and adult rats.

    PubMed

    Klefenz, H F; Rockstein, M

    1976-07-01

    Fructose-1,6-bisphosphatase (E.C. 3.1.3.11) was purified from the livers of young (69-86 days) and adult (370-386 days) Fisher rats. The enzyme preparations were examined for increasing amounts of missynthesized proteins by means of heat-inactivation as well as for differences in regulatory properties. No significant difference with respect to the fraction of rapidly heat-inactivated enzyme or Km- and Ki-values was found. These results do not support the hypothesis that error accumulation resulting in an error catastrophe is a general phenomenon underlying senescence and death.

  12. Mechanically induced orientation of adult rat cardiac myocytes in vitro

    NASA Technical Reports Server (NTRS)

    Samuel, J.-L.; Vandenburgh, H. H.

    1990-01-01

    The present study describes the spatial orientation of a population of freshly isolated adult rat cardiac myocytes using a computerized mechanical cell stimulator device for tissue cultured cells. A continuous unidirectional stretch of the substratum at 60 to 400 microns/min for 120 to 30 min, respectively, during the cell attachment period in a serum-free medium was found to induce a significant threefold increase in the number of rod-shaped myocytes oriented parallel to the direction of movement. The myocytes orient less well with unidirectional substratum stretching after their adhesion to the substratum. Adult myocytes plated onto a substratum undergoing continuous 10-percent stretch-relaxation cycling show no significant change in the myocyte orientation or cytoskeletal organization. In addition to the type of mechanical activity, orientation of rod-shaped myocytes is dependent on the speed of the substratum, the final stretch amplitude, and the timing between initiation of substratum stretching and adhesion of myocytes to the substratum.

  13. Alcohol exposure in utero perturbs retinoid homeostasis in adult rats

    PubMed Central

    Kim, Youn-Kyung; Zuccaro, Michael V.; Zhang, Changqing; Sarkar, Dipak

    2015-01-01

    Background Maternal alcohol exposure and adult alcohol intake have been shown to perturb the metabolism of various micro- and macro-nutrients, including vitamin A and its derivatives (retinoids). Therefore, it has been hypothesized that the well-known detrimental consequences of alcohol consumption may be due to deregulations of the metabolism of such nutrients rather than to a direct effect of alcohol. Alcohol exposure in utero also has long-term harmful consequences on the health of the offspring with mechanisms that have not been fully clarified. Disruption of tissue retinoid homeostasis has been linked not only to abnormal embryonic development, but also to various adult pathological conditions, including cancer, metabolic disorders and abnormal lung function. We hypothesized that prenatal alcohol exposure may permanently perturb tissue retinoid metabolism, predisposing the offspring to adult chronic diseases. Methods Serum and tissues (liver, lung and prostate from males; liver and lung from females) were collected from 60-75 day-old sprague dawley rats born from dams that were: (I) fed a liquid diet containing 6.7% alcohol between gestational day 7 and 21; or (II) pair-fed with isocaloric liquid diet during the same gestational window; or (III) fed ad libitum with regular rat chow diet throughout pregnancy. Serum and tissue retinoid levels were analyzed by reverse-phase high-performance liquid chromatography (HPLC). Serum retinol-binding protein (RBP) levels were measured by western blot analysis, and liver, lung and prostate mRNA levels of lecithin-retinol acyltransferase (LRAT) were measured by qPCR. Results Retinyl ester levels were significantly reduced in the lung of both males and females, as well as in the liver and ventral prostate of males born from alcohol-fed dams. Tissue LRAT mRNA levels remained unchanged upon maternal alcohol treatment. Conclusions Prenatal alcohol exposure in rats affects retinoid metabolism in adult life, in a tissue- and sex

  14. Myogenic regulatory factors during regeneration of skeletal muscle in young, adult, and old rats

    NASA Technical Reports Server (NTRS)

    Marsh, D. R.; Criswell, D. S.; Carson, J. A.; Booth, F. W.

    1997-01-01

    Myogenic factor mRNA expression was examined during muscle regeneration after bupivacaine injection in Fischer 344/Brown Norway F1 rats aged 3, 18, and 31 mo of age (young, adult, and old, respectively). Mass of the tibialis anterior muscle in the young rats had recovered to control values by 21 days postbupivacaine injection but in adult and old rats remained 40% less than that of contralateral controls at 21 and 28 days of recovery. During muscle regeneration, myogenin mRNA was significantly increased in muscles of young, adult, and old rats 5 days after bupivacaine injection. Subsequently, myogenin mRNA levels in young rat muscle decreased to postinjection control values by day 21 but did not return to control values in 28-day regenerating muscles of adult and old rats. The expression of MyoD mRNA was also increased in muscles at day 5 of regeneration in young, adult, and old rats, decreased to control levels by day 14 in young and adult rats, and remained elevated in the old rats for 28 days. In summary, either a diminished ability to downregulate myogenin and MyoD mRNAs in regenerating muscle occurs in old rat muscles, or the continuing myogenic effort includes elevated expression of these mRNAs.

  15. Homocysteine Induces Glial Reactivity in Adult Rat Astrocyte Cultures.

    PubMed

    Longoni, Aline; Bellaver, Bruna; Bobermin, Larissa Daniele; Santos, Camila Leite; Nonose, Yasmine; Kolling, Janaina; Dos Santos, Tiago M; de Assis, Adriano M; Quincozes-Santos, André; Wyse, Angela T S

    2017-03-02

    Astrocytes are dynamic glial cells associated to neurotransmitter systems, metabolic functions, antioxidant defense, and inflammatory response, maintaining the brain homeostasis. Elevated concentrations of homocysteine (Hcy) are involved in the pathogenesis of age-related neurodegenerative disorders, such as Parkinson and Alzheimer diseases. In line with this, our hypothesis was that Hcy could promote glial reactivity in a model of cortical primary astrocyte cultures from adult Wistar rats. Thus, cortical astrocytes were incubated with different concentrations of Hcy (10, 30, and 100 μM) during 24 h. After the treatment, we analyzed cell viability, morphological parameters, antioxidant defenses, and inflammatory response. Hcy did not induce any alteration in cell viability; however, it was able to induce cytoskeleton rearrangement. The treatment with Hcy also promoted a significant decrease in the activities of Na(+), K(+) ATPase, superoxide dismutase (SOD), and glutathione peroxidase (GPx), as well as in the glutathione (GSH) content. Additionally, Hcy induced an increase in the pro-inflammatory cytokine release. In an attempt to elucidate the putative mechanisms involved in the Hcy-induced glial reactivity, we measured the nuclear factor kappa B (NFκB) transcriptional activity and heme oxygenase 1 (HO-1) expression, which were activated and inhibited by Hcy, respectively. In summary, our findings provide important evidences that Hcy modulates critical astrocyte parameters from adult rats, which might be associated to the aging process.

  16. Amodiaquine-induced reproductive toxicity in adult male rats.

    PubMed

    Niu, Yan-Ru; Wei, Bing; Chen, Bi; Xu, Li-Hua; Jing, Xia; Peng, Cai-Ling; Ma, Tian-Zhong

    2016-02-01

    Amodiaquine (AQ) is routinely prescribed as an anti-malarial drug. Here, we evaluated AQ-induced toxicity in the male reproductive system. Eighty adult male Sprague-Dawley rats were randomly divided into four groups that received distilled water (control) or daily doses of 5 mg/kg body weight, 10 mg/kg, or 15 mg/kg AQ for 2 weeks. Testes morphology was analyzed using hematoxylin-and-eosin staining, terminal dUTP nicked-end labeling (TUNEL), and immunostaining whereas protein expression was determined by Western blotting. AQ dose-dependently led to abnormal spermatogenesis. Disruption of the blood-testis barrier and increased germ cell apoptosis were observed in all three AQ-treated groups. Interestingly, AQ-induced damage of spermatogenesis recovered over time, based on the survival of promyelocytic leukemia zinc-finger (PLZF)-positive, undifferentiated spermatogonia. Serum levels of luteinizing hormone and testosterone, as well as testicular testosterone levels, were not significantly altered in AQ-treated groups compared with controls. Collectively, our study suggests that AQ exerts substantial acute side effects on the reproductive systems of adult male rats by inducing the apoptosis of differentiating spermatogenic cells and disruption of blood-testis barrier function.

  17. Disruption of LH-induced testosterone biosynthesis in testicular Leydig cells by triclosan: probable mechanism of action.

    PubMed

    Kumar, Vikas; Balomajumder, Chandrajeet; Roy, Partha

    2008-09-04

    Triclosan (TCS) is an antimicrobial chemical widely used in different commercial preparations. The present study demonstrated the mechanism of action of TCS-induced anti-androgenicity in rat Leydig cells. Treatment of purified cells with increasing concentrations of TCS (0.001, 0.01, 0.1, 1 and 10 microM) resulted in a significantly decreased activity of adenylyl cyclase enzyme which was followed by a decreased synthesis of cAMP. This decreased cAMP level resulted in the disruption of entire steroidogenic cascade causing a depressed synthesis of testosterone. However, TCS-induced decrease in the production of testosterone returned to normalcy when cells were treated with forskolin (an adenylyl cyclase activator). Transcription followed by translational of four prominent steroidogenic enzyme/proteins, cytochrome P450 side chain cleavage (P450scc), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 17beta-hydroxysteroid dehydrogenase (17beta-HSD) and steroidogenic acute regulatory (StAR) protein, also decreased in a dose-dependent manner in TCS-treated Leydig cells as determined by RT-PCR, enzyme assay and Western blot. These results suggested that the disruption of the activity of adenylyl cyclase enzyme by TCS in turn leads to the disruption of intermediate steroidogenic cascade causing a depressed testosterone production. The study further confirmed the anti-androgenic activity of TCS in Leydig cells with highest effective concentration at 1 microM.

  18. Performance on a strategy set shifting task in rats following adult or adolescent cocaine exposure

    PubMed Central

    Kantak, Kathleen M.; Barlow, Nicole; Tassin, David H.; Brisotti, Madeline F.; Jordan, Chloe J

    2014-01-01

    Rationale Neuropsychological testing is widespread in adult cocaine abusers, but lacking in teens. Animal models may provide insight into age-related neuropsychological consequences of cocaine exposure. Objectives Determine whether developmental plasticity protects or hinders behavioral flexibility after cocaine exposure in adolescent vs. adult rats. Methods Using a yoked-triad design, one rat controlled cocaine delivery and the other two passively received cocaine or saline. Rats controlling cocaine delivery (1.0 mg/kg) self-administered for 18 sessions (starting P37 or P77), followed by 18 drug-free days. Rats next were tested in a strategy set shifting task, lasting 11–13 sessions. Results Cocaine self-administration did not differ between age groups. During initial set formation, adolescent-onset groups required more trials to reach criterion and made more errors than adult-onset groups. During the set shift phase, rats with adult-onset cocaine self-administration experience had higher proportions of correct trials and fewer perseverative + regressive errors than age-matched yoked-controls or rats with adolescent-onset cocaine self-administration experience. During reversal learning, rats with adult-onset cocaine experience (self-administered or passive) required fewer trials to reach criterion and the self-administering rats made fewer perseverative + regressive errors than yoked-saline rats. Rats receiving adolescent-onset yoked-cocaine had more trial omissions and longer lever press reaction times than age-matched rats self-administering cocaine or receiving yoked-saline. Conclusions Prior cocaine self-administration may impair memory to reduce proactive interference during set shifting and reversal learning in adult-onset but not adolescent-onset rats (developmental plasticity protective). Passive cocaine may disrupt aspects of executive function in adolescent-onset but not adult-onset rats (developmental plasticity hinders). PMID:24800898

  19. Contractile force measured in unskinned isolated adult rat heart fibres.

    PubMed

    Brady, A J; Tan, S T; Ricchiuti, N V

    1979-12-13

    A number of investigators have succeeded in preparing isolated cardiac cells by enzymatic digestion which tolerate external [Ca2+] in the millimolar range. However, a persistent problem with these preparations is that, unlike in situ adult ventricular fibres, the isolated fibres usually beat spontaneously. This spontaneity suggests persistent ionic leakage not present in situ. A preferable preparation for mechanical and electrical studies would be one which is quiescent but excitable in response to electrical stimulation and which does not undergo contracture with repeated stimulation. We report here a modified method of cardiac fibre isolation and perfusion which leaves the fibre membrane electrically excitable and moderately resistant to mechanical stress so that the attachment of suction micropipettes to the fibre is possible for force measurement and length control. Force generation in single isolated adult rat heart fibres is consistent with in situ contractile force. The negative staircase effect (treppe) characteristic of adult not heart tissue is present with increased frequency of stimulation. Isometric developed tension increases with fibre length as in in situ ventricular tissue.

  20. Acute toxicity of pesticides in adult and weanling rats.

    PubMed

    Gaines, T B; Linder, R E

    1986-08-01

    LD50 values were determined for 57 pesticides administered by the oral or dermal route to adult male and female Sherman rats. Thirty-six of the chemicals were also tested by the oral route in one sex of weanlings. Nine pesticides tested by the oral route (bufencarb, cacodylic acid, dialifor, deltamethrin, dicamba, diquat, quintozene, phoxim, pyrazon) and four tested by the dermal route (bufencarb, chlordimeform, dichlofenthion, leptophos) were more toxic to females than to males whereas famphur and 2,4,5-T (oral route) were less toxic to females. Eighteen of the test chemicals were more toxic to the adult than to the weanling and four compounds (leptophos, methidathion, pyrazon, and sulfoxide) were more toxic to the weanling. In additional studies the variability of the LD50 value over a 1-year period was examined for two typical insecticides. Six consecutive bimonthly oral LD50 determinations for parathion and DDT in adults of both sexes indicated that the LD50 values were little affected by the time of year that the tests were done.

  1. Postnatal development of Leydig cells in the opossum (Monodelphis domestica): an immunocytochemical and endocrinological study.

    PubMed

    Xie, Q; Mackay, S; Ullmann, S L; Gilmore, D P; Payne, A P; Gray, C

    1998-03-01

    This study involved characterization of Leydig cells of the opossum Monodelphis domestica, functionally by immunocytochemical identification of the enzyme 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and by measurement of testosterone levels using RIA. Immunostaining for 3 beta-HSD was first detected in a few Leydig cells on Day 16, was increased by Day 24, reached a peak at 4 mo, and was present even in senescent (3 yr) animals. Plasma testosterone was first measurable (0.35 nM) at prepuberty (3.5 mo). Prior to that, plasma testosterone concentrations were uniformly below the level of detection (< 0.3 nM) in both sexes from Day 5 to 2.5 mo. By 4 mo (puberty), plasma testosterone levels in males had risen significantly to 1.53 +/- 0.35 nM, continuing to increase to 1.79 +/- 0.4 nM at 6 mo and peaking at 2.71 +/- 0.29 nM in the adult (1-2 yr). Ovarian testosterone concentrations were consistently lower than those in the testis, as were those of adrenals of both sexes. Thus the testis would appear to be the major source of androgen production throughout life in this species. Our immunocytochemical study suggests that in Monodelphis, puberty is reached at 4 mo, and this was further supported by a rise in circulating testosterone levels at this time.

  2. Autoantibodies against Leydig cells in patients after spermatic cord torsion.

    PubMed Central

    Zanchetta, R; Mastrogiacomo, I; Graziotti, P; Foresta, C; Betterle, C

    1984-01-01

    This study is aimed at searching for the presence of circulating antibodies against frozen sections of human testis, ovary and trophoblast in patients that had spermatic cord torsion. Sixty-eight sera samples were studied. Nine patients (13.2%) were positive for organ specific anti-testis autoantibodies. Six patients were positive for antibodies against Leydig cells: five were positive only with the indirect immunofluorescence technique of complement fixing (ITT/CF), the sixth patient was positive only with the indirect immunofluorescence technique (ITT). The other three patients were positive for antibodies against germ line cells: two patients were positive with both techniques, the third was positive only with indirect immunofluorescence technique. Eight of these patients were negative for antibodies against adrenal cortex while only one case was positive with indirect immunofluorescence technique both on adrenal cortex and Leydig cells. Human lyophilized testis absorbed the reactive antibodies against Leydig cells and germ line cells, while adrenal cortex and lyophilized testosterone were ineffective. This study shows the identification of a specific antibody against Leydig cells and germ line cells in patients after spermatic cord torsion. PMID:6362937

  3. Birth insult alters ethanol preference in the adult rat.

    PubMed

    Boksa, P

    1998-05-08

    While genetic factors clearly play a role in regulating ethanol intake, the present study considered the possibility that early environmental factors which influence central nervous system development and long-term function might also alter ethanol intake. The specific aim of the study was to test whether alterations in birth condition, namely Caesarean section (C-section) birth and C-section birth with an added period of global anoxia, can affect subsequent ethanol preference in the adult rat. At 5 months of age, groups of experimental and vaginally born control rats were offered free choice between drinking water or various concentrations of ethanol (1-10% v/v) in water across 36 days of testing. Rats that had been born by C-section with 10 or 15 min of added global anoxia showed significant reductions in ethanol preference scores, in comparison to vaginally born controls. For the 10-min anoxia group, ethanol intake was decreased, water intake was increased and total fluid intake remained unchanged relative to values for vaginally born controls, across the entire test period. Although total fluid intake by the 15-min anoxia group also did not differ from that of vaginally born controls, the decreased ethanol preference scores in the 15-min anoxia group were mainly due to increased water intake during some test periods and a combination of reduced ethanol intake and increased water intake during others. Animals born by rapid C-section alone, with no added period of global anoxia, showed reduced ethanol preference only during a few early periods of testing, a much less pronounced effect than that observed for animals with added global anoxia. When animals were given the choice between drinking water vs. solutions of sucrose or NaCl, no group differences due to birth condition were found on measures of sucrose or NaCl preference. Together with reduced ethanol preference, the 10-min anoxia group showed a transient depression of locomotor activity in response to a low

  4. Expression of Lymphatic Markers in the Adult Rat Spinal Cord

    PubMed Central

    Kaser-Eichberger, Alexandra; Schroedl, Falk; Bieler, Lara; Trost, Andrea; Bogner, Barbara; Runge, Christian; Tempfer, Herbert; Zaunmair, Pia; Kreutzer, Christina; Traweger, Andreas; Reitsamer, Herbert A.; Couillard-Despres, Sebastien

    2016-01-01

    Under physiological conditions, lymphatic vessels are thought to be absent from the central nervous system (CNS), although they are widely distributed within the rest of the body. Recent work in the eye, i.e., another organ regarded as alymphatic, revealed numerous cells expressing lymphatic markers. As the latter can be involved in the response to pathological conditions, we addressed the presence of cells expressing lymphatic markers within the spinal cord by immunohistochemistry. Spinal cord of young adult Fisher rats was scrutinized for the co-expression of the lymphatic markers PROX1 and LYVE-1 with the cell type markers Iba1, CD68, PGP9.5, OLIG2. Rat skin served as positive control for the lymphatic markers. PROX1-immunoreactivity was detected in many nuclei throughout the spinal cord white and gray matter. These nuclei showed no association with LYVE-1. Expression of LYVE-1 could only be detected in cells at the spinal cord surface and in cells closely associated with blood vessels. These cells were found to co-express Iba1, a macrophage and microglia marker. Further, double labeling experiments using CD68, another marker found in microglia and macrophages, also displayed co-localization in the Iba1+ cells located at the spinal cord surface and those apposed to blood vessels. On the other hand, PROX1-expressing cells found in the parenchyma were lacking Iba1 or PGP9.5, but a significant fraction of those cells showed co-expression of the oligodendrocyte lineage marker OLIG2. Intriguingly, following spinal cord injury, LYVE-1-expressing cells assembled and reorganized into putative pre-vessel structures. As expected, the rat skin used as positive controls revealed classical lymphatic vessels, displaying PROX1+ nuclei surrounded by LYVE-1-immunoreactivity. Classical lymphatics were not detected in adult rat spinal cord. Nevertheless, numerous cells expressing either LYVE-1 or PROX1 were identified. Based on their localization and overlapping expression with

  5. Expression of Lymphatic Markers in the Adult Rat Spinal Cord.

    PubMed

    Kaser-Eichberger, Alexandra; Schroedl, Falk; Bieler, Lara; Trost, Andrea; Bogner, Barbara; Runge, Christian; Tempfer, Herbert; Zaunmair, Pia; Kreutzer, Christina; Traweger, Andreas; Reitsamer, Herbert A; Couillard-Despres, Sebastien

    2016-01-01

    Under physiological conditions, lymphatic vessels are thought to be absent from the central nervous system (CNS), although they are widely distributed within the rest of the body. Recent work in the eye, i.e., another organ regarded as alymphatic, revealed numerous cells expressing lymphatic markers. As the latter can be involved in the response to pathological conditions, we addressed the presence of cells expressing lymphatic markers within the spinal cord by immunohistochemistry. Spinal cord of young adult Fisher rats was scrutinized for the co-expression of the lymphatic markers PROX1 and LYVE-1 with the cell type markers Iba1, CD68, PGP9.5, OLIG2. Rat skin served as positive control for the lymphatic markers. PROX1-immunoreactivity was detected in many nuclei throughout the spinal cord white and gray matter. These nuclei showed no association with LYVE-1. Expression of LYVE-1 could only be detected in cells at the spinal cord surface and in cells closely associated with blood vessels. These cells were found to co-express Iba1, a macrophage and microglia marker. Further, double labeling experiments using CD68, another marker found in microglia and macrophages, also displayed co-localization in the Iba1+ cells located at the spinal cord surface and those apposed to blood vessels. On the other hand, PROX1-expressing cells found in the parenchyma were lacking Iba1 or PGP9.5, but a significant fraction of those cells showed co-expression of the oligodendrocyte lineage marker OLIG2. Intriguingly, following spinal cord injury, LYVE-1-expressing cells assembled and reorganized into putative pre-vessel structures. As expected, the rat skin used as positive controls revealed classical lymphatic vessels, displaying PROX1+ nuclei surrounded by LYVE-1-immunoreactivity. Classical lymphatics were not detected in adult rat spinal cord. Nevertheless, numerous cells expressing either LYVE-1 or PROX1 were identified. Based on their localization and overlapping expression with

  6. Testosterone induction of prostaglandin-endoperoxide synthase 2 expression and prostaglandin F(2alpha) production in hamster Leydig cells.

    PubMed

    Matzkin, María E; Gonzalez-Calvar, Silvia I; Mayerhofer, Artur; Calandra, Ricardo S; Frungieri, Mónica B

    2009-07-01

    We have previously observed expression of prostaglandin-endoperoxide synthase 2 (PTGS2), the key enzyme in the biosynthesis of prostaglandins (PGs), in reproductively active Syrian hamster Leydig cells, and reported an inhibitory role of PGF(2alpha) on hamster testicular steroidogenesis. In this study, we further investigated PTGS2 expression in hamster Leydig cells during sexual development and photoperiodic gonadal regression. Since PTGS2 is mostly expressed in pubertal and reproductively active adult hamsters with high circulating levels of LH and androgens, we studied the role of these hormones in the regulation/maintenance of testicular PTGS2/PGF(2alpha). In active hamster Leydig cells, LH/hCG and testosterone induced PTGS2 and PGF(2alpha) production, and their actions were abolished by the antiandrogen bicalutamide (Bi). These results indicate that LH does not exert a direct effect on PG synthesis. Testosterone also stimulated phosphorylation of the mitogen-activated protein kinase isoforms 3/1 (MAPK3/1) within minutes and hours, but the testosterone metabolite dihydrotestosterone had no effect on PTGS2 and MAPK3/1. Because Bi and U0126, an inhibitor of the MAP kinase kinases 1 and 2 (MAP2K1/2), abolished testosterone actions on MAPK3/1 and PTGS2, our studies suggest that testosterone directly induces PTGS2/PGF(2alpha) in hamster Leydig cells via androgen receptors and a non-classical mechanism that involves MAPK3/1 activation. Since PGF(2alpha) inhibits testosterone production, it might imply the existence of a regulatory loop that is setting a brake on steroidogenesis. Thus, the androgen environment might be crucial for the regulation of testicular PG production at least during sexual development and photoperiodic variations in hamsters.

  7. FACS purification of immunolabeled cell types from adult rat brain.

    PubMed

    Guez-Barber, Danielle; Fanous, Sanya; Harvey, Brandon K; Zhang, Yongqing; Lehrmann, Elin; Becker, Kevin G; Picciotto, Marina R; Hope, Bruce T

    2012-01-15

    Molecular analysis of brain tissue is greatly complicated by having many different classes of neurons and glia interspersed throughout the brain. Fluorescence-activated cell sorting (FACS) has been used to purify selected cell types from brain tissue. However, its use has been limited to brain tissue from embryos or transgenic mice with promoter-driven reporter genes. To overcome these limitations, we developed a FACS procedure for dissociating intact cell bodies from adult wild-type rat brains and sorting them using commercially available antibodies against intracellular and extracellular proteins. As an example, we isolated neurons using a NeuN antibody and confirmed their identity using microarray and real time PCR of mRNA from the sorted cells. Our FACS procedure allows rapid, high-throughput, quantitative assays of molecular alterations in identified cell types with widespread applications in neuroscience.

  8. An Alternative Promoter of the Human Neuronal Nitric Oxide Synthase Gene Is Expressed Specifically in Leydig Cells

    PubMed Central

    Wang, Yang; Newton, Derek C.; Miller, Tricia L.; Teichert, Anouk-Martine; Phillips, M. James; Davidoff, Michail S.; Marsden, Philip A.

    2002-01-01

    Neuronal nitric oxide synthase (nNOS) plays a modulatory role in the biology of a variety of neuroendocrine tissues and is especially relevant to gonadal function. We have previously reported the cloning and characterization of a variant of the nNOS protein, termed testis nNOS (TnNOS), the mRNA for which was restricted in expression to male gonadal tissues. To examine the cell-specificity of the testis-specific NOS regulatory regions we defined patterns of β-galactosidase expression of an insertional transgene in which the reporter gene lacZ was under the transcriptional control of the human TnNOS promoter. β-galactosidase activity was detected exclusively in the interstitial cells of the testis in transgenic mice. These cells also evidenced positive staining for nNOS protein and were identified as androgen-producing Leydig cells by staining with the Leydig cell marker, P450scc. Expression of the promoter was absent in cells of the seminiferous tubules, specifically germline cells of different stages and Sertoli cells. In contrast to the male gonad, β-galactosidase activity was not detected in ovaries of adult female mice. Activity was also not evident in organs known to express full-length nNOS, such as skeletal muscle, kidney, or cerebellum. The same pattern of β-galactosidase staining was observed in independent transgenic founders and was distinct from that observed for an endothelial NOS promoter/reporter transgene. In the testis of male adult eNOS promoter-reporter transgenic mice, β-galactosidase activity was expressed only in endothelial cells of large- and medium-sized arterial blood vessels. Transcriptional activity of the human TnNOS promoter could not be detected in a variety of cell types, including Leydig cells, using episomal promoter-reporter constructs suggesting that a nuclear environment and higher order genomic complexity are required for appropriate promoter function. The restricted expression pattern of an nNOS variant in Leydig cells of

  9. Chordin and noggin expression in the adult rat trigeminal nuclei.

    PubMed

    Hayashi, Yutaro; Mikawa, Sumiko; Masumoto, Kazuma; Katou, Fuminori; Sato, Kohji

    2016-12-01

    Bone morphogenetic proteins (BMP) exert its biological functions by interacting with membrane bound receptors. However, functions of BMPs are also regulated in the extracellular space by secreted antagonistic regulators, such as chordin and noggin. Although the deep involvement of BMP signaling in the development and functions of the trigeminal nuclei has been postulated, little information is available for its expression in the trigeminal nuclei. We, thus, investigated chordin and noggin expression in the adult rat trigeminal nuclei using immunohistochemistry. Chordin and noggin were intensely expressed throughout the trigeminal nuclei. In addition, interesting differences are observed between chordin expression and noggin expression. For example, chordin prefers dendritic expression than noggin, suggesting that chordin is involved in the regulation of dendritic morphology and synaptic homeostasis. Furthermore, chordin and noggin were differentially expressed in the neuropil of the trigeminal nuclei. Since BMP signaling is known to play a pivotal role to make precise neural network, theses differences might be important to keep precise interneuronal connections by regulating local BMP signaling intensity in each region. Interestingly, we also detected chordin and noggin expression in axons of the trigeminal nerves. These data indicate that chordin and noggin play pivotal roles also in the adult trigeminal system.

  10. Effects of Tremella mesenterica on steroidogenesis in MA-10 mouse Leydig tumor cells.

    PubMed

    Lo, H-C; Chen, Y-W; Chien, C-H; Tseng, C-Y; Kuo, Y-M; Huang, B-M

    2005-01-01

    Tremella mesenterica (TM), a yellow jelly mushroom, has been traditionally used as food and crude medicine to improve several kinds of symptoms in Chinese society for a long time. Recent studies have illustrated that the fractions of fruiting bodies of TM exhibit a significant hypoglycemic activity in diabetic mouse models, which usually suffer from sexual dysfunction. In a previous study, we showed that TM reduced plasma testosterone production in normal rats without any positive effect in diabetic rats. It evolved a question of TM directly regulating Leydig cell steroidogenesis. In this study, MA-10 mouse Leydig tumor cells were treated with vehicle, different dosages of TM with or without human chorionic gonadotropin (hCG 50 ng/ml) to clarify the effects. Results showed that TM at different dosages (0.01-10 mg/ml) did not have any effect on MA-10 cell steroidogenesis (p > 0.05). In the presence of hCG, there was an inhibitory trend that TA suppressed MA-10 cell progesterone production at 3 hr treatment with a statistically significant difference by the 10 mg/ml TM (p < 0.05). In time course effect, TM alone did not have any effect on MA-10 cell steroidogenesis from at 1, 2, 3, 6 and 12 hr (p > 0.05). However, TM did reduce hCG-treated MA-10 cell progesterone production at 1, 2 and 3 hr (p < 0.05), respectively. To determine whether TM would have adverse effects on MA-10 cell steroidogenesis in the presence of hCG, MTT assay and recovery studies were conducted. MTT assay indicated that TM had no effect on surviving cells. In addition, with the removal of TM, and then the addition of hCG (2 and 4 hr), progesterone levels were restored within 4 hr. Taken together, present studies suggested that TM suppressed hCG-treated steroidogenesis in MA-10 cells without any toxicity effect.

  11. Chronic crude garlic-feeding modified adult male rat testicular markers: mechanisms of action

    PubMed Central

    Hammami, Imen; Amara, Souheila; Benahmed, Mohamed; El May, Michèle V; Mauduit, Claire

    2009-01-01

    Background Garlic or Allium sativum (As) shows therapeutic effects such as reduction of blood pressure or hypercholesterolemia but side-effects on reproductive functions remain poorly investigated. Because of garlic's chemical complexity, the processing methods and yield in preparations differ in efficacy and safety. In this context, we clarify the mechanisms of action of crushed crude garlic on testicular markers. Methods During one month of treatment, 24 male rats were fed 5%, 10% and 15% crude garlic. Results We showed that crude garlic-feeding induced apoptosis in testicular germ cells (spermatocytes and spermatids). This cell death process was characterized by increased levels of active CASP3 but not CASP6. Expression of the caspase inhibitors BIRC3 and BIRC2 was increased at all doses of As while expression of XIAP and BIRC5 was unchanged. Moreover, expression of the IAP inhibitor DIABLO was increased at doses 10% and 15% of As. The germ cell death process induced by As might be related to a decrease in testosterone production because of the reduced expression of steroidogenic enzymes (Star, Cyp11a, Hsd3b5 and Hsd17b). Evaluation of Sertoli markers showed that TUBB3 and GSTA2 expression was unchanged. In contrast, AMH, RHOX5 and CDKN1B expression was decreased while GATA4 expression was increased. Conclusion In summary, we showed that feeding with crude garlic inhibited Leydig steroidogenic enzyme expression and Sertoli cell markers. These alterations might induce apoptosis in testicular germ cells. PMID:19552815

  12. Quantitative evaluation of Leydig cells in testicular biopsies of men with varicocele.

    PubMed

    Francavilla, S; Bruno, B; Martini, M; Moscardelli, S; Properzi, G; Francavilla, F; Santiemma, V; Fabbrini, A

    1986-01-01

    A quantitative analysis of Leydig cells was performed in 23 testicular biopsies of men with left varicocele and sperm count ranging from zero to 95,000 sperm/mm3. The oligozoospermic patients had more Leydig cells and higher FSH and LH serum levels than the patient group with more than 10,000 sperm/mm3. The Leydig cell density appeared tightly correlated (p less than 0.01) with the serum level of LH. In oligozoospermic subjects, an altered Leydig cell function could trigger an increased LH secretion; this seems likely to be responsible for the stimulation of interstitial cells resulting in an exaggerated recruitment of mature Leydig cells from their precursors. The comparative analysis of left and right testes failed to show differences in Leydig cell density and spermatogenesis in normozoospermic and oligozoospermic patients. This suggests that the two testes are equally involved by a possible, although unknown, detrimental effect of left side varicocele.

  13. Leydig cell damage after testicular irradiation for lymphoblastic leukemia

    SciTech Connect

    Shalet, S.M.; Horner, A.; Ahmed, S.R.; Morris-Jones, P.H.

    1985-01-01

    The effect of testicular irradiation on Leydig cell function has been studied in a group of boys irradiated between 1 and 5 years earlier for a testicular relapse of acute lymphoblastic leukemia. Six of the seven boys irradiated during prepubertal life had an absent testosterone response to HCG stimulation. Two of the four boys irradiated during puberty had an appropriate basal testosterone level, but the testosterone response to HCG stimulation was subnormal in three of the four. Abnormalities in gonadotropin secretion consistent with testicular damage were noted in nine of the 11 boys. Evidence of severe Leydig cell damage was present irrespective of whether the boys were studied within 1 year or between 3 and 5 years after irradiation, suggesting that recovery is unlikely. Androgen replacement therapy has been started in four boys and will be required by the majority of the remainder to undergo normal pubertal development.

  14. The nuclear receptor NR2F2 activates star expression and steroidogenesis in mouse MA-10 and MLTC-1 Leydig cells.

    PubMed

    Mendoza-Villarroel, Raifish E; Robert, Nicholas M; Martin, Luc J; Brousseau, Catherine; Tremblay, Jacques J

    2014-07-01

    Testosterone production is dependent on cholesterol transport within the mitochondrial matrix, an essential step mediated by a protein complex containing the steroidogenic acute regulatory (STAR) protein. In steroidogenic Leydig cells, Star expression is hormonally regulated and involves several transcription factors. NR2F2 (COUP-TFII) is an orphan nuclear receptor that plays critical roles in cell differentiation and lineage determination. Conditional NR2F2 knockout prior to puberty leads to male infertility due to insufficient testosterone production, suggesting that NR2F2 could positively regulate steroidogenesis and Star expression. In this study we found that NR2F2 is expressed in the nucleus of some peritubular myoid cells and in interstitial cells, mainly in steroidogenically active adult Leydig cells. In MA-10 and MLTC-1 Leydig cells, small interfering RNA (siRNA)-mediated NR2F2 knockdown reduces basal steroid production without affecting hormone responsiveness. Consistent with this, we found that STAR mRNA and protein levels were reduced in NR2F2-depleted MA-10 and MLTC-1 cells. Transient transfections of Leydig cells revealed that a -986 bp mouse Star promoter construct was activated 3-fold by NR2F2. Using 5' progressive deletion constructs, we mapped the NR2F2-responsive element between -131 and -95 bp. This proximal promoter region contains a previously uncharacterized direct repeat 1 (DR1)-like element to which NR2F2 is recruited and directly binds. Mutations in the DR1-like element that prevent NR2F2 binding severely blunted NR2F2-mediated Star promoter activation. These data identify an essential role for the nuclear receptor NR2F2 as a direct activator of Star gene expression in Leydig cells, and thus in the control of steroid hormone biosynthesis.

  15. Transformation of adult rat cardiac myocytes in primary culture.

    PubMed

    Banyasz, Tamas; Lozinskiy, Ilya; Payne, Charles E; Edelmann, Stephanie; Norton, Byron; Chen, Biyi; Chen-Izu, Ye; Izu, Leighton T; Balke, C William

    2008-03-01

    We characterized the morphological, electrical and mechanical alterations of cardiomyocytes in long-term cell culture. Morphometric parameters, sarcomere length, T-tubule density, cell capacitance, L-type calcium current (I(Ca,L)), inward rectifier potassium current (I(K1)), cytosolic calcium transients, action potential and contractile parameters of adult rat ventricular myocytes were determined on each day of 5 days in culture. We also analysed the health of the myocytes using an apoptotic/necrotic viability assay. The data show that myocytes undergo profound morphological and functional changes during culture. We observed a progressive reduction in the cell area (from 2502 +/- 70 microm(2) on day 0 to 1432 +/- 50 microm(2) on day 5), T-tubule density, systolic shortening (from 0.11 +/- 0.02 to 0.05 +/- 0.01 microm) and amplitude of calcium transients (from 1.54 +/- 0.19 to 0.67 +/- 0.19) over 5 days of culture. The negative force-frequency relationship, characteristic of rat myocardium, was maintained during the first 2 days but diminished thereafter. Cell capacitance (from 156 +/- 8 to 105 +/- 11 pF) and membrane currents were also reduced (I(Ca,L), from 3.98 +/- 0.39 to 2.12 +/- 0.37 pA pF; and I(K1), from 34.34p +/- 2.31 to 18.00 +/- 5.97 pA pF(-1)). We observed progressive depolarization of the resting membrane potential during culture (from 77.3 +/- 2.5 to 34.2 +/- 5.9 mV) and, consequently, action potential morphology was profoundly altered as well. The results of the viability assays indicate that these alterations could not be attributed to either apoptosis or necrosis but are rather an adaptation to the culture conditions over time.

  16. Leydig cell hyperplasia in the setting of Klinefelter syndrome.

    PubMed

    Sterbis, Joseph; E-Nunu, Toritsetimiyin

    2015-07-24

    A man in his 20's with Klinefelter syndrome presented to the urology clinic with a recent history of left-sided orchalgia. Ultrasound evaluation demonstrated multiple small hypoechoic lesions bilaterally, with the largest lesion measured at 5 mm × 6 mm × 8 mm. Testis cancer tumour markers, chest radiographs and abdominal CT imaging were negative. A partial orchiectomy was performed on the largest lesion, demonstrating the presence of Leydig cell hyperplasia.

  17. Expression of gonadotropin-releasing hormone receptor in cerebral cortical neurons of embryos and adult rats.

    PubMed

    Quintanar, J Luis; Salinas, Eva; González, Rodolfo

    2007-01-03

    Mammalian gonadotropin-releasing hormone (GnRH) was initially isolated from hypothalamus and its receptor from anterior pituitary, although extrapituitary GnRH receptors have been reported. The aim of the present study was to investigate whether GnRH receptor and its mRNA are expressed in cerebral cortical neurons of rat embryos and adult rats using immunohistochemical and reverse transcriptase polymerase chain reaction (RT-PCR) techniques. The immunohistochemistry and RT-PCR analysis showed expression of GnRH receptor and presence of its mRNA, in both cerebral cortical neurons of rat embryos and cerebral cortical tissues of adult rats. Additional experiments showed a decrease in the receptor mRNA expression when cultured neurons of rat embryos were treated with GnRH. It is possible that the presence of GnRH receptors in cortical neurons of rat may be involved in other physiological roles such as neurohormone or neuromodulator.

  18. Desert Hedgehog/Patched 1 signaling specifies fetal Leydig cell fate in testis organogenesis

    PubMed Central

    Yao, Humphrey Hung-Chang; Whoriskey, Wendy; Capel, Blanche

    2002-01-01

    Establishment of the steroid-producing Leydig cell lineage is an event downstream of Sry that is critical for masculinization of mammalian embryos. Neither the origin of fetal Leydig cell precursors nor the signaling pathway that specifies the Leydig cell lineage is known. Based on the sex-specific expression patterns of Desert Hedgehog (Dhh) and its receptor Patched 1 (Ptch1) in XY gonads, we investigated the potential role of DHH/PTCH1 signaling in the origin and specification of fetal Leydig cells. Analysis of Dhh−/− XY gonads revealed that differentiation of fetal Leydig cells was severely defective. Defects in Leydig cell differentiation in Dhh−/− XY gonads did not result from failure of cell migration from the mesonephros, thought to be a possible source of Leydig cell precursors. Nor did DHH/PTCH1 signaling appear to be involved in the proliferation or survival of fetal Leydig precursors in the interstitium of the XY gonad. Instead, our results suggest that DHH/PTCH1 signaling triggers Leydig cell differentiation by up-regulating Steroidogenic Factor 1 and P450 Side Chain Cleavage enzyme expression in Ptch1-expressing precursor cells located outside testis cords. PMID:12050120

  19. Enduring and sex-specific effects of adolescent social isolation in rats on adult stress reactivity.

    PubMed

    Weintraub, Ari; Singaravelu, Janani; Bhatnagar, Seema

    2010-07-09

    In adolescence, gender differences in rates of affective disorders emerge. For both adolescent boys and girls, peer relationships are the primary source of life stressors though adolescent girls are more sensitive to such stressors. Social stressors are also powerful stressors for non-human social species like rodents. In a rat model, we examined how social isolation during adolescence impacts stress reactivity and specific neural substrates in adult male and female rats. Rats were isolated during adolescence by single housing from day 30 to 50 of age and control rats were group housed. On day 50, isolated rats and control rats were re-housed in same-treatment same-sex groups. Adult female rats isolated as adolescents exhibited increased adrenal responses to acute and to repeated stress and exhibited increased hypothalamic vasopressin mRNA and BDNF mRNA in the CA3 hippocampal subfield. In contrast, adult male rats isolated as adolescents exhibited a lower corticosterone response to acute stress, exhibited a reduced state of anxiety as assessed in the elevated plus maze and reduced Orexin mRNA compared to adult males group-housed as adolescents. These data point to a markedly different impact of isolation experienced in adolescence on endocrine and behavioral endpoints in males compared to females and identify specific neural substrates that may mediate the long-lasting effects of stress in adolescence.

  20. Androgen Action via Testicular Arteriole Smooth Muscle Cells Is Important for Leydig Cell Function, Vasomotion and Testicular Fluid Dynamics

    PubMed Central

    Welsh, Michelle; Sharpe, Richard M.; Moffat, Lindsey; Atanassova, Nina; Saunders, Philippa T. K.; Kilter, Sigrid; Bergh, Anders; Smith, Lee B.

    2010-01-01

    Regulation of blood flow through the testicular microvasculature by vasomotion is thought to be important for normal testis function as it regulates interstitial fluid (IF) dynamics which is an important intra-testicular transport medium. Androgens control vasomotion, but how they exert these effects remains unclear. One possibility is by signalling via androgen receptors (AR) expressed in testicular arteriole smooth muscle cells. To investigate this and determine the overall importance of this mechanism in testis function, we generated a blood vessel smooth muscle cell-specific AR knockout mouse (SMARKO). Gross reproductive development was normal in SMARKO mice but testis weight was reduced in adulthood compared to control littermates; this reduction was not due to any changes in germ cell volume or to deficits in testosterone, LH or FSH concentrations and did not cause infertility. However, seminiferous tubule lumen volume was reduced in adult SMARKO males while interstitial volume was increased, perhaps indicating altered fluid dynamics; this was associated with compensated Leydig cell failure. Vasomotion was impaired in adult SMARKO males, though overall testis blood flow was normal and there was an increase in the overall blood vessel volume per testis in adult SMARKOs. In conclusion, these results indicate that ablating arteriole smooth muscle AR does not grossly alter spermatogenesis or affect male fertility but does subtly impair Leydig cell function and testicular fluid exchange, possibly by locally regulating microvascular blood flow within the testis. PMID:21049031

  1. Juvenile but not adult methamphetamine exposure improves performance in the Morris Water Maze in male rats.

    PubMed

    Moenk, Michael D; Matuszewich, Leslie

    2012-06-01

    Early exposure to psychostimulants has been found to lead to long-lasting effects on cognitive processes. Our lab has previously reported that juvenile male rats administered methamphetamine showed improved performance in a spatial navigation task when tested in adulthood (McFadden and Matuszewich, 2007). What is not known, however, is if these effects are specific to the developing rat, or if a similar methamphetamine protocol given to adult rats would lead to an equally beneficial long-term change in spatial cognition. In the current study, male rats were given 1 daily injection of 2mg/kg methamphetamine or saline for 15 days during either preadolescence (PD20-34) or adulthood (PD70-84). Approximately 45 days after treatment, all rats then underwent 5 days of place training in the Morris water maze at a time when juvenile rats reached adulthood. Similar to previous findings, juvenile rats exposed to repeated methamphetamine displayed shorter latencies and distances to reach the platform throughout training compared to saline-treated rats. The juvenile rats treated with methamphetamine also swam shorter distances and had faster latencies to the hidden platform compared to adult methamphetamine-treated rats. There were no significant differences in rats treated in adulthood with methamphetamine compared to saline-treated rats. Likewise, there were no effects of prior methamphetamine treatment or age on matching-to-place trials or visible platform trials. Overall, the results show that repeated methamphetamine exposure can selectively improve spatial learning in adult male rats when administered during preadolescence, but does not significantly affect spatial learning when administered in adulthood. Furthermore, the current findings demonstrate the unique susceptibility of the developing brain to drugs that modulate dopaminergic activity, as well as the long-term behavioral impact of exposure at critical ages.

  2. Tetrahydroisoquinoline alkaloids mimic direct but not receptor-mediated inhibitory effects of estrogens and phytoestrogens on testicular endocrine function. Possible significance for Leydig cell insufficiency in alcohol addiction

    SciTech Connect

    Stammel, W.; Thomas, H. ); Staib, W.; Kuehn-Velten, W.K. )

    1991-01-01

    Possible effects of various tetrahydroisoquinolines (TIQs) on rat testicular endocrine function were tested in vitro in order to prove whether these compounds may be mediators of the development of Leydig cell insufficiency. TIQ effects on different levels of regulation of testis function were compared in vitro with estrogen effects, since both classes of compounds have structural similarities. Gonadotropin-stimulated testosterone production by testicular Leydig cells was inhibited by tetrahydropapaveroline and isosalsoline, the IC{sub 50} values being comparable to those of estradiol, 2-hydroxyestradiol, and the phytoestrogens, coumestrol and genistein; salsolinol and salsoline were less effective, and salsolidine was ineffective. None of these TIQs interacted significantly with testicular estrogen receptor as analyzed by estradiol displacement. However, tetrahydropapaveroline, isosalsoline and salsolinol competitively inhibited substrate binding to cytochrome P45OXVII, with similar efficiency as the estrogens did; salsoline and salsolidine were again much less effective.

  3. Adolescent and adult male spontaneous hyperactive rats (SHR) respond differently to acute and chronic methylphenidate (Ritalin).

    PubMed

    Barron, Elyssa; Yang, Pamela B; Swann, Alan C; Dafny, Nachum

    2009-01-01

    Eight groups of male adolescent and adult spontaneous hyperactive rats (SHR) were used in a dose response (saline, 0.6, 2.5, and 10 mg/kg) experiment of methylphenidate (MPD). Four different locomotor indices were recorded for 2 hours postinjection using a computerized monitoring system. Acutely, the 0.6 mg/kg dose of MPD did not elicit an increase in locomotor activity in either the adolescent or in the adult male SHR. The 2.5 and the 10.0 mg/kg doses increased activity in the adolescent and the adult rats. Chronically, MPD treatment when comparing adolescent and adult gave the following results: the 0.6 mg/kg dose of MPD failed to cause sensitization in the adolescent group but caused sensitization in the adult group, while the 2.5 and 10 mg/kg both caused sensitization in the adolescent and adult groups.

  4. Long-term consequences of neonatal fluoxetine exposure in adult rats.

    PubMed

    Ko, Meng-Ching; Lee, Lukas Jyuhn-Hsiarn; Li, Yang; Lee, Li-Jen

    2014-10-01

    Serotonin (5-HT) plays important roles during neural development. Administration of selective serotonin reuptake inhibitor (SSRI)-type medication during gestation may influence the maturation of the fetal brain and subsequent brain functions. To mimic the condition of late-gestation SSRI exposure, we administered fluoxetine (FLX) in neonatal rats during the first postnatal week, which roughly corresponds to the third trimester period of human gestation. FLX-exposed adult male rats exhibited reduced locomotor activity and depression-like behaviors. Furthermore, sensorimotor gating capacity was also impaired. Interestingly, increased social interaction was noticed in FLX-exposed rats. When the levels of 5-HT and tryptophan hydroxylase were examined, no significant changes were found in FLX rats compared to control (CON) rats. The behavioral phenotypes of FLX rats suggested malfunction of the limbic system. Dendritic architectures of neurons in the medial prefrontal cortex (mPFC) and basolateral amygdala (BLA) were examined. Layer II/III mPFC pyramidal neurons in FLX rats had exuberant dendritic branches with elongated terminal segments compared to those in CON rats. In BLA pyramidal neurons, the dendritic profiles were comparable between the two groups. However, in FLX rats, the density of dendritic spines was reduced in both mPFC and BLA. Together, our results demonstrated the long-lasting effects of early FLX treatment on emotional and social behaviors in adult rats in which impaired neuronal structure in the limbic system was also noticed. The risk of taking SSRI-type antidepressants during pregnancy should be considered.

  5. Neonatal manipulation of oxytocin alters oxytocin levels in the pituitary of adult rats.

    PubMed

    Young, E; Carter, C S; Cushing, B S; Caldwell, J D

    2005-07-01

    The neuropeptide oxytocin (OT) and its OT antagonists (OTA) in infant rats affect their behavior as adults. In this study we attempted to determine whether treating rats on the day of birth (postnatal day 1) with OT or OTA would affect brain OT levels of these rats as adults. Rat pups were injected with OT (3 microg), OTA (0.3 microg) or saline vehicle ip on postnatal day 1. As 60-day-old adults, treated rats were killed, and the OT content in their medial preoptic areas (MPOAs), medial hypothalami (MH) and pituitaries were assayed. In females, treatment with OTA on postnatal day 1 significantly decreased pituitary OT levels as adults. In males, by contrast, treatment with OTA on postnatal day 1 resulted in increased pituitary OT levels when they become adults compared to male rats treated with OT on postnatal day 1. There were no significant effects of neonatal treatment on OT levels in either the MH or MPOA. Day 1 postnatal treatment with OT or OTA had a long-term sexually dimorphic effect on OT levels in the pituitary.

  6. Lycium barbarum polysaccharides promotes in vivo proliferation of adult rat retinal progenitor cells

    PubMed Central

    Wang, Hua; Lau, Benson Wui-Man; Wang, Ning-li; Wang, Si-ying; Lu, Qing-jun; Chang, Raymond Chuen-Chung; So, Kwok-fai

    2015-01-01

    Lycium barbarum is a widely used Chinese herbal medicine prescription for protection of optic nerve. However, it remains unclear regarding the effects of Lycium barbarum polysaccharides, the main component of Lycium barbarum, on in vivo proliferation of adult ciliary body cells. In this study, adult rats were intragastrically administered low- and high-dose Lycium barbarum polysaccharides (1 and 10 mg/kg) for 35 days and those intragastrically administered phosphate buffered saline served as controls. The number of Ki-67-positive cells in rat ciliary body in the Lycium barbarum polysaccharides groups, in particular low-dose Lycium barbarum polysaccharides group, was significantly greater than that in the phosphate buffered saline group. Ki-67-positive rat ciliary body cells expressed nestin but they did not express glial fibrillary acidic protein. These findings suggest that Lycium barbarum polysaccharides can promote the proliferation of adult rat retinal progenitor cells and the proliferated cells present with neuronal phenotype. PMID:26889185

  7. [Transplantation of embryonic medulla oblongata into cerebella of adult rats].

    PubMed

    Nanami, T

    1989-01-01

    Pieces of medulla oblongata anlagen were dissected free from embryonic 13-20 day (E 13 to E 20) rat brain, and these were transplanted into the cerebellar vermis of adult rats (Fischer 344). After grafting, host animals survived for 4-9 months. Cytoarchitectonic organization of the graft and the relationship between host and graft were analyzed light microscopically in 34 animals using the Nissl and silver impregnation methods. Fine structures of the graft were analyzed in 4 animals using electron microscope. Grafts from E 13-14 donor tissue showed the highest survival rate (90%), which decreased as the donor embryonic age increased (i.e., E 15-16: 33%, E 17-20: 15%). In the surviving grafts, small (5-10 microns diameter), medium-sized (10-20 microns) and large (20-30 microns) neurons, whose cytoplasmic organelles appeared normal, were observed. Bundles of myelinated fibers traversed in every direction and neurons were often clustered, indicating characteristic features of the medulla oblongata. Electron microscopically, various types of synaptic formations were also observed. Degenerative profiles of nerve-fiber endings, containing dense bodies and lysosomal figures, were also seen. The degeneration seemed to be caused by the failure of their establishing connections with their proper targets in the host. In both the host tissue and the graft-host interface, neuronal processes apparently derived from the graft were frequently observed. Some axonal processes contained large-cored vesicles, and some dendritic processes were enlarged at their stalks and tips. Aberrant axon terminals of unmyelinated fibers in the host medullary layer were considered to be the graft origin. These fibers were always accompanied by prominent glial proliferation. There was no indication of forming myelinated fiber bundles that entered the host cerebellum from the donor tissue, although the former was the target of the latter. Cell bodies of host granule cells and oligodendroglia in the

  8. Differential effects of delta9-THC on learning in adolescent and adult rats.

    PubMed

    Cha, Young May; White, Aaron M; Kuhn, Cynthia M; Wilson, Wilkie A; Swartzwelder, H S

    2006-03-01

    Marijuana use remains strikingly high among young users in the U.S., and yet few studies have assessed the effects of delta9-tetrahydrocannabinol (THC) in adolescents compared to adults. This study measured the effects of THC on male adolescent and adult rats in the Morris water maze. In Experiment 1, adolescent (PD=30-32) and adult (PD=65-70) rats were treated acutely with 5.0 mg/kg THC or vehicle while trained on the spatial version of the water maze on five consecutive days. In Experiment 2, adolescent and adult rats were treated acutely with 2.5 or 10.0 mg/kg THC or vehicle while trained on either the spatial and non-spatial versions of the water maze. In Experiment 3, adolescent and adult rats were treated with 5.0 mg/kg THC or vehicle daily for 21 days, and were trained on the spatial and then the non-spatial versions of the water maze task four weeks later in the absence of THC. THC impaired both spatial and nonspatial learning more in adolescents than in adults at all doses tested. However, there were no long-lasting significant effects on either spatial or non-spatial learning in rats that had been previously exposed to THC for 21 days. This developmental sensitivity is analogous to the effects of ethanol, another commonly used recreational drug.

  9. New insights into melatonin/CRH signaling in hamster Leydig cells.

    PubMed

    Rossi, Soledad P; Matzkin, María E; Terradas, Claudio; Ponzio, Roberto; Puigdomenech, Elisa; Levalle, Oscar; Calandra, Ricardo S; Frungieri, Mónica B

    2012-08-01

    We have previously described that melatonin inhibits androgen production in hamster testes via melatonin subtype 1a (mel1a) receptors and the local corticotrophin-releasing hormone (CRH) system. This study attempted to determine the initial events of the melatonin/CRH signaling pathway. In Leydig cells from reproductively active Syrian hamsters, Western blotting, reverse transcription quantitative polymerase chain reaction (RT-qPCR) and a colorimetric assay demonstrated that melatonin and CRH activate tyrosine phosphatases and subsequently reduce the phosphorylation levels of extracellular signal-regulated kinase (erk) and c-jun N-terminal kinase (jnk), down-regulate the expression of c-jun, c-fos and steroidogenic acute regulatory (StAR), and inhibit the production of testosterone. These effects were prevented by a highly selective CRH antagonist, thus indicating that melatonin does not exert a direct role. Specific mitogen-activated protein kinase kinase (MEK) and jnk blockers inhibited expression of c-jun, c-fos, StAR and the production of testosterone, confirming that these are events triggered downstream of erk and jnk. In Leydig cells from photoperiodically regressed adult hamsters, CRH inhibited the production of androstane-3α,17β-diol (3α-diol), the main androgen produced, through the same signaling pathway. Testicular melatonin concentration was 3-4-fold higher in reproductively inactive hamsters than that detected in active animals. Since melatonin, CRH, and their receptors are present not only in hamster testes but also in testicular biopsies of infertile men, we can conjecture about the relevance of this previously uncharacterized pathway in human fertility disorders. In summary, our study identifies crucial intracellular events triggered by melatonin/CRH in the testis that lead to a down-regulation of the steroidogenic process.

  10. Two distinct origins for Leydig cell progenitors in the fetal testis

    PubMed Central

    DeFalco, Tony; Takahashi, Satoru; Capel, Blanche

    2011-01-01

    During the differentiation of the mammalian embryonic testis, two compartments are defined: the testis cords and the interstitium. The testis cords give rise to the adult seminiferous tubules, whereas steroidogenic Leydig cells and other less well characterized cell types differentiate in the interstitium (the space between testis cords). Although the process of testis cord formation is essential for male development, it is not entirely understood. It has been viewed as a Sertoli-cell driven process, but growing evidence suggests that interstitial cells play an essential role during testis formation. However, little is known about the origin of the interstitium or the molecular and cellular diversity within this early stromal compartment. To better understand the process of mammalian gonad differentiation, we have undertaken an analysis of developing interstitial/stromal cells in the early mouse testis and ovary. We have discovered molecular heterogeneity in the interstitium and have characterized new markers of distinct cell types in the gonad: MAFB, C-MAF, and VCAM1. Our results show that at least two distinct progenitor lineages give rise to the interstitial/stromal compartment of the gonad: the coelomic epithelium and specialized cells along the gonad-mesonephros border. We demonstrate that both these populations give rise to interstitial precursors that can differentiate into fetal Leydig cells. Our analysis also reveals that perivascular cells migrate into the gonad from the mesonephric border along with endothelial cells and that these vessel-associated cells likely represent an interstitial precursor lineage. This study highlights the cellular diversity of the interstitial cell population and suggests that complex cell-cell interactions among cells in the interstitium are involved in testis morphogenesis. PMID:21255566

  11. Nandrolone and stanozolol induce Leydig cell tumor proliferation through an estrogen-dependent mechanism involving IGF-I system.

    PubMed

    Chimento, Adele; Sirianni, Rosa; Zolea, Fabiana; De Luca, Arianna; Lanzino, Marilena; Catalano, Stefania; Andò, Sebastiano; Pezzi, Vincenzo

    2012-05-01

    Several substances such as anabolic androgenic steroids (AAS), peptide hormones like insulin-like growth factor-I (IGF-I), aromatase inhibitors and estrogen antagonists are offered via the Internet, and are assumed without considering the potential deleterious effects that can be caused by their administration. In this study we aimed to determine if nandrolone and stanozolol, two commonly used AAS, could have an effect on Leydig cell tumor proliferation and if their effects could be potentiated by the concomitant use of IGF-I. Using a rat Leydig tumor cell line, R2C cells, as experimental model we found that nandrolone and stanozolol caused a dose-dependent induction of aromatase expression and estradiol (E2) production. When used in combination with IGF-I they were more effective than single molecules in inducing aromatase expression. AAS exhibited estrogenic activity and induced rapid estrogen receptor (ER)-dependent pathways involving IGF1R, AKT, and ERK1/2 phosphorylation. Inhibitors for these kinases decreased AAS-dependent aromatase expression. Up-regulated aromatase levels and related E2 production increased cell proliferation as a consequence of increased cyclin E expression. The observation that ER antagonist ICI182,780 was also able to significantly reduce ASS- and AAS + IGF-induced cell proliferation, confirmed a role for estrogens in AAS-dependent proliferative effects. Taken together these data clearly indicate that the use of high doses of AAS, as it occurs in doping practice, enhances Leydig cell proliferation, increasing the risk of tumor development. This risk is higher when AAS are used in association with IGF-I. To our knowledge this is the first report directly associating AAS and testicular cancer.

  12. Safety of Intracerebroventricular Copper Histidine in Adult Rats

    PubMed Central

    Lem, Kristen E.; Brinster, Lauren R.; Tjurmina, Olga; Lizak, Martin; Lal, Simina; Centeno, Jose A.; Liu, Po-Ching; Godwin, Sarah C.; Kaler, Stephen G.

    2007-01-01

    Classical Menkes disease is an X-linked recessive neurodegenerative disorder caused by mutations in a P-type ATPase (ATP7A) that normally delivers copper to the developing central nervous system. Infants with large deletions, or other mutations in ATP7A that incapacitate copper transport to the brain, show poor clinical outcomes and subnormal brain copper despite early subcutaneous copper histidine (CuHis) injections. These findings suggest a need for direct central nervous system approaches in such patients. To begin to evaluate an aggressive but potentially useful new strategy for metabolic improvement of this disorder, we studied the acute and chronic effects of CuHis administered by intracerebroventricular (ICV) injection in healthy adult rats. Magnetic resonance imaging (MRI) after ICV CuHis showed diffuse T1-signal enhancement, indicating wide brain distribution of copper after ICV administration, and implying the utility of this paramagnetic metal as a MRI contrast agent. The maximum tolerated dose (MTD) of CuHis, defined as the highest dose that did not induce overt toxicity, growth retardation, or reduce lifespan, was 0.5 mcg. Animals receiving multiple infusions of this MTD showed increased brain copper concentrations, but no significant differences in activity, behavior, and somatic growth, or brain histology compared to saline-injected controls. Based on estimates of the brain copper deficit in Menkes disease patients, CuHis doses 10-fold lower than the MTD found in this study may restore proper brain copper concentration. Our results suggest that ICV CuHis administration have potential as a novel treatment approach in Menkes disease infants with severe mutations. Future trials of direct CNS copper administration in mouse models of Menkes disease will be informative. PMID:17336116

  13. RODENT LEYDIG CELL TUMORIGENESIS: A REVIEW OF THE PHYSIOLOGY, PATHOLOGY, MECHANISMS, AND RELEVANCE TO HUMANS

    EPA Science Inventory

    Leydig cells (LCs) are the cells of the testis that have as their primary function the production of testosterone. LCs are a common target of compounds tested in rodent carcinogenicity bioassays. The number of reviews on Leydig cell tumors (LCTs) has increased in recent years bec...

  14. The effects of acute alcohol on motor impairments in adolescent, adult, and aged rats.

    PubMed

    Ornelas, Laura C; Novier, Adelle; Van Skike, Candice E; Diaz-Granados, Jaime L; Matthews, Douglas B

    2015-03-01

    Acute alcohol exposure has been shown to produce differential motor impairments between aged and adult rats and between adolescent and adult rats. However, the effects of acute alcohol exposure among adolescent, adult, and aged rats have yet to be systematically investigated within the same project using a dose-dependent analysis. We sought to determine the age- and dose-dependent effects of acute alcohol exposure on gross and coordinated motor performance across the rodent lifespan. Adolescent (PD 30), adult (PD 70), and aged (approximately 18 months) male Sprague-Dawley rats were tested on 3 separate motor tasks: aerial righting reflex (ARR), accelerating rotarod (RR), and loss of righting reflex (LORR). In a separate group of animals, blood ethanol concentrations (BEC) were determined at multiple time points following a 3.0 g/kg ethanol injection. Behavioral tests were conducted with a Latin square repeated-measures design in which all animals received the following doses: 1.0 g/kg or 2.0 g/kg alcohol or saline over 3 separate sessions via intraperitoneal (i.p.) injection. During testing, motor impairments were assessed on the RR 10 min post-injection and on ARR 20 min post-injection. Aged animals spent significantly less time on the RR when administered 1.0 g/kg alcohol compared to adult rats. In addition, motor performance impairments significantly increased with age after 2.0 g/kg alcohol administration. On the ARR test, aged rats were more sensitive to the effects of 1.0 g/kg and 2.0 g/kg alcohol compared to adolescents and adults. Seven days after the last testing session, animals were given 3.0 g/kg alcohol and LORR was examined. During LORR, aged animals slept longer compared to adult and adolescent rats. This effect cannot be explained solely by BEC levels in aged rats. The present study suggests that acute alcohol exposure produces greater motor impairments in older rats when compared to adolescent and adult rats and begins to establish a

  15. Nicotine produces long-term increases in cocaine reinforcement in adolescent but not adult rats.

    PubMed

    Reed, Stephanie Collins; Izenwasser, Sari

    2017-01-01

    Studies have shown that many smokers begin using nicotine during adolescence, yet the influence of early nicotine use on the response to other drugs of abuse in adulthood is not fully understood. In the current study, nicotine was administered to adolescent and adult rats for seven days. Thirty days later, cocaine-induced locomotor activity and cocaine self-administration were examined when the rats pretreated as adolescents were adults. Rats exposed to nicotine during early adolescence were sensitized thirty days later to the locomotor-activating effects of cocaine and self-administered a greater number of cocaine infusions than adolescent rats pretreated with vehicle. As a result of this increased intake, the cocaine self-administration dose-response curve was shifted upward indicating an increase in cocaine reinforcement. Rats pretreated with nicotine as adults, however, did not show a difference in locomotor activity or cocaine self-administration thirty days later compared to adult rats pretreated with vehicle. These findings suggest that early exposure to nicotine has long-term consequences on cocaine use. These data further suggest that nicotine use may carry a greater risk during adolescence than adulthood and adolescents who smoke may be particularly vulnerable to stimulant use. This article is part of a Special Issue entitled SI: Adolescent plasticity.

  16. Induction of maternal behavior in adult female rats following chronic morphine exposure during puberty.

    PubMed

    Byrnes, Elizabeth M; Rigero, Beth A; Bridges, Robert S

    2003-12-01

    The peripubertal period in the female rat is the time when the stimulatory effects of opioids on prolactin (PRL) secretion develop. In the adult rat, the administration of chronic high-dose morphine has been shown to attenuate the ability of opiates to stimulate PRL secretion. One function of PRL in adult virgin rats is the induction of maternal behavior. The present study examined whether chronic high-dose morphine exposure during the peripubertal period alters PRL-mediated induction of maternal behavior in adult female rats. Two groups of juvenile female rats were administered increasing doses of morphine or vehicle (s.c.) from age 30 to 50 days. As adults, these females either remained intact, or were ovariectomized and treated with a PRL-dependent, steroid hormone regimen that stimulates a rapid onset of maternal behavior. All females were then exposed daily to rat foster pups to determine whether peripubertal morphine exposure affected their latencies to induce maternal behavior. Morphine treatment resulted in a delay in vaginal opening and a temporary reduction in the rate of weight gain; however, the rate of onset of maternal behavior was unaffected by peripubertal morphine treatment. Thus, chronic morphine exposure in the pubertal female did not impact the expression of pup-induced maternal care.

  17. The Role of Foxo3 in Leydig Cells

    PubMed Central

    Choi, Young Suk; Song, Joo Eun; Kong, Byung Soo; Hong, Jae Won; Novelli, Silvia

    2015-01-01

    Purpose Foxo3 in female reproduction has been reported to regulate proliferation of granulose cells that form follicles. There are no reports so far that discuss on the role of Foxo3 in males. This study was designed to outline the role of Foxo3 in the testes. Materials and Methods Testes from mice at birth to postpartum week (PPW) 5 were isolated and examined for the expression of Foxo3 using immunostaining. To elucidate role of Foxo3 in Leydig cells, R2C cells were treated with luteinizing hormone (LH) and the phosphorylation of Foxo3. Testosterone and steroidogenic acute regulatory (StAR) protein levels were measured after constitutive active [triple mutant (TM)] human FOXO3 adenovirus was transduced and StAR promoter assay was performed. Results Foxo3 expression in the testicles started from birth and lasted until PPW 3. After PPW 3, most Foxo3 expression occurred in the nuclei of Leydig cells; however, at PPW 5, Foxo3 was expressed in both the nucleus and cytoplasm. When R2C cells were treated with luteinizing hormone, Foxo3 phosphorylation levels by AKT increased. After blocking the PI3K pathway, LH-induced phosphorylated Foxo3 levels decreased, indicating that LH signaling regulates Foxo3 localization. When active FOXO3-TM adenovirus was introduced into a Leydig tumor cell line, the concentrations of testosterone and StAR protein decreased. When FOXO3 and a StAR promoter vector were co-transfected into HEK293 cells for a reporter assay, FOXO3 inhibited the StAR promoter. Conclusion FOXO3 affects testosterone synthesis by inhibiting the formation of StAR protein. LH hormone, meanwhile, influences Foxo3 localization, mediating its function. PMID:26446641

  18. Acute and adaptive motor responses to caffeine in adolescent and adult rats.

    PubMed

    Rhoads, Dennis E; Huggler, April L; Rhoads, Lucas J

    2011-07-01

    Caffeine is a psychostimulant with intake through foods or beverages tending to increase from childhood through adolescence. The goals of the present study were to examine the effects of caffeine on young adolescent Long-Evans rats and to compare the motor-behavioral responses of adolescent and adult rats to acute and chronic caffeine. Adolescent rats had a biphasic dose-response to caffeine comparable to that reported for adult rats. The magnitude of the motor response to a challenge dose of caffeine (30mg/kg, ip) was similar between adolescent and adult rats. Administration of caffeine in the drinking water (1mg/ml) for a period of 2 weeks led to overall consumption of caffeine which was not significantly different between adolescents and adults when normalized to body mass. There were no impacts of caffeinated drinking water on volume of fluid consumed nor weight gain in either age group compared to age matched controls drinking non-caffeinated tap water. Following this period of caffeine consumption, return to regular drinking water (caffeine withdrawal) led to a significant decrease in baseline movement compared to caffeine-naïve rats. This effect inversion was observed for adolescents but not adults. In addition, the response of the adolescents to the challenge dose of caffeine (30mg/kg, ip) was reduced significantly after chronic caffeine consumption and withdrawal. This apparent tolerance to the caffeine challenge dose was not seen with the adults. Thus, the developing brain of these adolescents may show similar sensitivity to adults in acute caffeine exposure but greater responsiveness to adaptive changes associated with chronic caffeine consumption.

  19. Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species

    PubMed Central

    Amrein, Irmgard; Becker, Anton S.; Engler, Stefanie; Huang, Shih-hui; Müller, Julian; Slomianka, Lutz; Oosthuizen, Maria K.

    2014-01-01

    African mole-rats (family Bathyergidae) are small to medium sized, long-lived, and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN) correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of 1 year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin). Solitary Cape mole-rats (Georychus capensis), social highveld mole-rats (Cryptomys hottentotus pretoriae), and eusocial naked mole-rats (Heterocephalus glaber) were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean rodents. PMID

  20. Effects of Neonatal Overfeeding on Juvenile and Adult Feeding and Energy Expenditure in the Rat

    PubMed Central

    Stefanidis, Aneta; Spencer, Sarah J.

    2012-01-01

    Overfeeding during perinatal life leads to an overweight phenotype that persists throughout the juvenile stage and into adulthood, however, the mechanim(s) underlying this effect are poorly understood. We hypothesized that obesity due to neonatal overfeeding is maintained by changes in energy expenditure and that these changes differ between males and females. We investigated feeding, physical activity, hormonal and metabolic alterations that occur in adult rats made obese by having been nursed in small litters (SL) compared with those from control litters (CL). There were no differences in absolute food intake between the groups, and juvenile and adult SL rats ate less chow per gram body weight than the CL did in the dark (active) phase. Juvenile, but not adult SL rats did have reduced whole body energy expenditure, but there were no differences between the groups by the time they reached adulthood. Adult SL females (but not males) had reduced brown adipose tissue (BAT) temperatures compared with CL in the first half of the dark phase. Our results indicate a persistent overweight phenotype in rats overfed as neonates is not associated with hyperphagia at any stage, but is reflected in reduced energy expenditure into the juvenile phase. The reduced dark phase BAT activity in adult SL females is not sufficient to reduce total energy expenditure at this stage of life and there is an apparently compensatory effect that prevents SL and CL from continuing to diverge in weight that appears between the juvenile and adult stages. PMID:23251693

  1. The Effect of Early Mosquito Insecticides Exposure on Spraque Dawley Rat Testis: A Histopathological Feature Towards Malignancy?

    NASA Astrophysics Data System (ADS)

    Indah Winarni, Tri; Auzan Aziman, Milzam; Abshar Andar, Anindyo; Pawitra, Ika

    2017-02-01

    The incidence of health problems associated with endocrine-disruption have increased. Many studies suggesting that endocrine disruptor chemicals (EDC) do contribute to cancer through estrogen-related receptors. Many chemicals have EDCs properties including insecticides. Early life exposure to EDCs can increased the risk of testicular cancer have been reported in the last decade. This study was aimed to determine the effect of insecticides exposure on histopathological tumor cell development of germ and Leydig cell. True experiment research design with posttest only control group design was applied. Sprague Dawley (SD) rat (n = 25) were randomly divided into 5 groups (control group, 25 mg β estradiol 3-benzoate, spiral mosquito coil repellent, 3 ml of liquid mosquito repellent, and 4 ml of liquid mosquito repellent). The exposure were administered for 20 days started at aged 3 days. At the age of 100 days (older adult), testis was stained using Hematoxyllin Eosin (HE) and histological features predicting malignancy were observed. The number of tumor cell development in both testicular germ cells and Leydig cells significantly increased in all treated group compared to those of control and the changes towards malignancy were also observed in all treated group. Exposure to mosquito insecticides causes significant changes in testicular germ and Leydig cell histological features that leads to malignancy.

  2. Individual and combined effect of chlorpyrifos and cypermethrin on reproductive system of adult male albino rats.

    PubMed

    Alaa-Eldin, Eman Ahmad; El-Shafei, Dalia Abdallah; Abouhashem, Nehal S

    2017-01-01

    Commercial mixtures of chlorpyrifos and cypermethrin pesticides are widely used to enhance the toxic effects of cypermethrin on target insects. So, the purpose of the current study was to evaluate the individual and combined toxic effects of chlorpyrifos (CPF) and cypermethrin (CYP) on reproductive system of adult male albino rats. Forty adult male albino rats were randomized into main four groups: group I (control group) included 16 rats, subdivided into negative and positive control; group II (eight rats) received chlorpyrifos 6.75 mg/kg b.w./orally∕daily); group III (eight rats) (received cypermethrin 12.5 mg/kg b.w./orally∕daily); and group IV (eight rats) (received chlorpyrifos and cypermethrin at the same previously mentioned doses). All treatments were given by oral gavage for 12 weeks. We found that single CPF and CYP exposures significantly have adverse effects on reproductive function of adult male albino rats manifested by reduced testicular weight, decreased sperm count, motility and viability, significantly increased percent of morphologically abnormal spermatozoa, and significant increments in sperm DNA fragmentation index (DFI) with respect to control group. Furthermore, serum follicle stimulating hormone, luteinizing hormone, and testosterone levels were decreased significantly compared to control group. This was accompanied with histopathological changes in the testis of rats such as necrosis, degeneration, decreasing number of spermatogenic cells in some seminiferous tubules, edema, congested blood vessels, and exudate in interstitial tissue of the testis. Notably, all these changes were exaggerated in rats treated concomitantly with chlorpyrifos and cypermethrin rendering the mixture more toxic than the additive effects of each compound and causing greater damage on the reproductive system of male albino rats than the individual pesticides.

  3. Characterization of membrane currents in dissociated adult rat pineal cells.

    PubMed Central

    Aguayo, L G; Weight, F F

    1988-01-01

    1. Membrane currents, particularly the outward components, were studied in pineal cells acutely dissociated from adult rats using the whole-cell variant of the patch-clamp technique. 2. In current clamp, outward constant current elicited a transient graded depolarizing response. A sustained membrane rectification developed within 20 ms; this phenomenon was reduced in cells internally dialysed with 120 mM-CsCl. 3. Study of the membrane current revealed the existence of a transient and a delayed outward current. These currents were virtually eliminated when the cell was internally dialysed with CsCl. 4. The delayed outward current, isolated from a holding potential of -50 mV, activated at potentials near -20 mV, reached a steady-state current amplitude within 60 ms and had little or no decay during steps up to 400 ms in duration. This component was reduced by 80% or more with the addition of 5 mM-TEA. 5. From -100 mV, the transient outward current reached a peak within 15 ms and decayed with a single-exponential time course. The mean decay time constant was 66 +/- 10 ms (at -33 mV) and it showed little voltage sensitivity. This current, which activated at potentials positive to -60 mV and displayed half-inactivation at -76 +/- 8 mV, was reduced by 50% with the addition of 5 mM-4-AP (4-amino-pyridine). 6. In the presence of external Ca2+, the current-voltage relationship for the delayed current did not display a region of negative-slope conductance (N-shape). Increasing the intracellular ionized Ca2+ concentration by varying the Ca-EGTA buffer ratio did not alter the dependence of the current on the membrane potential. 7. Block of outward currents with internal Cs+ revealed a small (less than 90 pA) inward Ca2+ current when the external Ca2+ concentration was increased to 10 mM. From a holding potential of -50 mV, it had a threshold at -30 mV and peaked at +5 mV. Evidence for an inward Na+ current was not obtained. 8. We conclude that acutely dissociated pineal cells

  4. Adaptations of young adult rat cortical bone to 14 days of spaceflight

    NASA Technical Reports Server (NTRS)

    Vailas, A. C.; Vanderby, R., Jr.; Martinez, D. A.; Ashman, R. B.; Ulm, M. J.; Grindeland, R. E.; Durnova, G. N.; Kaplanskii, A.

    1992-01-01

    To determine whether mature humeral cortical bone would be modified significantly by an acute exposure to weightlessness, adult rats (110 days old) were subjected to 14 days of microgravity on the COSMOS 2044 biosatellite. There were no significant changes in peak force, stiffness, energy to failure, and displacement at failure in the flight rats compared with ground-based controls. Concentrations and contents of hydroxyproline, calcium, and mature stable hydroxylysylpyridinoline and lysylpyridinoline collagen cross-links remained unchanged after spaceflight. Bone lengths, cortical and endosteal areas, and regionl thicknesses showed no significant differences between flight animals and ground controls. The findings suggest that responsiveness of cortical bone to microgravity is less pronounced in adult rats than in previous spaceflight experiments in which young growing animals were used. It is hypothesized that 14 days of spaceflight may not be sufficient to impact the biochemical and biomechanical properties of cortical bone in the mature rat skeleton.

  5. Ethanol facilitation of short-term memory in adult rats with a disturbed circadian cycle.

    PubMed

    Mikolajczak, P; Okulicz-Kozaryn, I; Nowaczyk, M; Kaminska, E

    2001-01-01

    The aim of this study was to evaluate the effect of 3-month ethanol treatment on olfactory social memory test performance using two inter-exposure intervals [30 min: short-term recognition (STR); or 120 min: long-term recognition (LTR)] in adult rats with a disturbed circadian cycle (DCC). Ethanol treatment both in ethanol-preferring and -non-preferring groups improved the STR task compared to control rats. However, LTR procedure triggered the opposite tendency. Moreover, no differences between control rats with DCC and those with normal diurnal rhythm in STR and LTR paradigms were observed. Our results suggest that, under some conditions, alcohol facilitates short-term memory in adult rats.

  6. Methylphenidate treatment increases Na(+), K (+)-ATPase activity in the cerebrum of young and adult rats.

    PubMed

    Scherer, Emilene B S; Matté, Cristiane; Ferreira, Andréa G K; Gomes, Karin M; Comim, Clarissa M; Mattos, Cristiane; Quevedo, João; Streck, Emilio L; Wyse, Angela T S

    2009-12-01

    Methylphenidate is a central nervous system stimulant used for the treatment of attention-deficit hyperactivity disorder. Na(+), K(+)-ATPase is a membrane-bound enzyme necessary to maintain neuronal excitability. Considering that methylphenidate effects on central nervous system metabolism are poorly known and that Na(+), K(+)-ATPase is essential to normal brain function, the purpose of this study was to evaluate the effect of this drug on Na(+), K(+)-ATPase activity in the cerebrum of young and adult rats. For acute administration, a single injection of methylphenidate (1.0, 2.0, or 10.0 mg/Kg) or saline was given to rats on postnatal day 25 or postnatal day 60, in the young and adult groups, respectively. For chronic administration, methylphenidate (1.0, 2.0, or 10.0 mg/Kg) or saline injections were given to young rats starting at postnatal day 25 once daily for 28 days. In adult rats, the same regimen was performed starting at postnatal day 60. Our results showed that acute methylphenidate administration increased Na(+), K(+)-ATPase activity in hippocampus, prefrontal cortex, and striatum of young and adult rats. In young rats, chronic administration of methylphenidate also enhanced Na(+), K(+)-ATPase activity in hippocampus and prefrontal cortex, but not in striatum. When tested in adult rats, Na(+), K(+)-ATPase activity was increased in all cerebral structures studied. The present findings suggest that increased Na(+), K(+)-ATPase activity may be associated with neuronal excitability caused by methylphenidate.

  7. Chloroethylmethanesulfonate-induced effects on the epididymis seem unrelated to altered Leydig cell function.

    PubMed

    Klinefelter, G R; Laskey, J W; Kelce, W R; Ferrell, J; Roberts, N L; Suarez, J D; Slott, V

    1994-07-01

    Decades ago it was reported that when male rats were exposed to chloroethylmethanesulfonate (CEMS) for 5 days prior to weekly matings with untreated females, the second mating resulted in reduced litter size. Since fertility was not assessed at earlier time points, it was not possible to determine whether CEMS exerted any effects on sperm in the epididymis. In this study, we used a 4-day exposure and assessed multiple reproductive endpoints on Day 5 to characterize effects of CEMS exposure (6.25-25 mg/kg) on Leydig cells and the epididymis. Exposure to CEMS caused a dose-related decline in serum testosterone (T) levels. This occurred at a dose lower than that required to decrease T production in vitro by testicular parenchyma. The in vitro decline was not attributed to a decrease in maximal hCG-stimulated T production, but to a decrease in unstimulated T production. CEMS was 5-fold less sensitive than ethane dimethanesulfonate (EDS) in reducing maximal hCG-stimulated T production. To control for alterations in the epididymis resulting from decreased serum T alone, T was implanted in CEMS-treated animals to maintain serum T at a concentration similar to that found in normal rats. This exogenous T failed to prevent the CEMS-induced decrease in the weight of the caput/corpus epididymidis but did prevent the CEMS-induced decrease in seminal vesicle weight. Implantation of T failed to prevent the CEMS-induced reduction in sperm reserves in the cauda epididymidis, and it failed to prevent the CEMS-induced alterations in the histology of both the corpus and proximal cauda epididymidis. The height of the epithelium in both of these regions was increased, and clear cells disappeared from the proximal cauda epididymidis. These results demonstrate that CEMS might alter the ability of the Leydig cell to respond to LH stimulation in vivo, and that alterations in the structure and function of the epididymis occur even when the serum concentration of T is maintained.

  8. Perinatal exposure to diethylstilbestrol alters the functional differentiation of the adult rat uterus.

    PubMed

    Bosquiazzo, Verónica L; Vigezzi, Lucía; Muñoz-de-Toro, Mónica; Luque, Enrique H

    2013-11-01

    The exposure to endocrine disrupters and female reproductive tract disorders has not been totally clarified. The present study assessed the long-term effect of perinatal (gestation+lactation) exposure to diethylstilbestrol (DES) on the rat uterus and the effect of estrogen replacement therapy. DES (5μg/kg bw/day) was administered in the drinking water from gestational day 9 until weaning and we studied the uterus of young adult (PND90) and adult (PND360) females. To investigate whether perinatal exposure to DES modified the uterine response to a long-lasting estrogen treatment, 12-month-old rats exposed to DES were ovariectomized and treated with 17β-estradiol for 3 months (PND460). In young adult rats (PND90), the DES treatment decreased both the proliferation of glandular epithelial cells and the percentage of glandular perimeter occupied by α-smooth muscle actin-positive cells. The other tissue compartments remained unchanged. Cell apoptosis was not altered in DES-exposed females. In control adult rats (PND360), there were some morphologically abnormal uterine glands. In adult rats exposed to DES, the incidence of glands with cellular anomalies increased. In response to estrogens (PND460), the incidence of cystic glands increased in the DES group. We observed glands with daughter glands and conglomerates of glands only on PND460 and in response to estrogen replacement therapy, independently of DES exposure. The p63 isoforms were expressed without changes on PND460. Estrogen receptors α and β showed no changes, while the progesterone receptor decreased in the subepithelial stroma of DES-exposed animals with estrogen treatment. The long-lasting effects of perinatal exposure to DES included the induction of abnormalities in uterine tissues of aged female rats and an altered response of the adult uterus to estradiol.

  9. Stress in the Adult Rat Exacerbates Muscle Pain Induced by Early-Life Stress

    PubMed Central

    Alvarez, Pedro; Green, Paul G.; Levine, Jon D.

    2013-01-01

    Background Early-life stress and exposure to stressful stimuli play a major role in the development of chronic widespread pain in adults. However, how they interact in chronic pain syndromes remains unclear. Methods Dams and neonatal litters were submitted to a restriction of nesting material (neonatal limited bedding, NLB) for one week. As adults, these rats were exposed to a painless sound stress protocol. The involvement of sympathoadrenal catecholamines, interleukin 6 (IL-6) and tumor necrosis alpha (TNFα) in nociception, was evaluated through of behavioral and ELISA assays, surgical interventions and intrathecal antisense treatments. Results Adult NLB rats exhibited mild muscle hyperalgesia, which was markedly aggravated by sound stress (peaking 15 days after exposure). Adrenal medullectomy did not modify hyperalgesia in NLB rats but prevented its aggravation by sound stress. Sustained administration of epinephrine to NLB rats mimicked sound stress effect. Intrathecal treatment with antisense directed to IL-6-receptor subunit gp130, but not to TNFα type 1 receptor (TNFR1), inhibited hyperalgesia in NLB rats. However, antisense against either gp130 or TNFR1 inhibited sound stress-induced enhancement of hyperalgesia. Compared to control rats, NLB rats exhibit increased plasma levels of IL-6 but decreased levels of TNFα, whereas sound stress increases IL-6 plasma levels in control but not in NLB rats. Conclusions Early-life stress induces a persistent elevation of IL-6, hyperalgesia and susceptibility to chronic muscle pain, which is unveiled by exposure to stress in adults. This probably depends on an interaction between adrenal catecholamines and pro-inflammatory cytokines acting at muscle nociceptor level. PMID:23706525

  10. Ultrastructure of human Leydig cells at early gonadal embryogenesis.

    PubMed

    Makabe, S; Naguro, T; Heyn, R; Motta, P M

    1995-01-01

    The ultrastructure of human Leydig cells at different stages of the testicular prenatal development is described by means of transmission and scanning electron microscopy. Between 5 and 7 weeks of gestation (w.g.) the interstitial tissue of the gonad is filled with small undifferentiated mesenchymal cells, migrating primordial germ cells and blood vessels. When the embryo is 7 to 8 weeks-old Leydig cells (LC) appear in basically two morphological patterns, light and dark cells. Their most significative feature is the development of the smooth endoplasmic reticulum (SER) as a dense tubulo-vesicular network and the presence of numerous pleomorphic mitochondria with mainly lamellar cristae. At 14 and 16 w.g. the testicular interstitium reaches the maximum development; the cytoplasm of the LC shows a widespread network of anastomosing tubules of the SER and mitochondria with tubular cristae. Fetal LC show a partial cell coat, lack the crystals of Reinke, have few lipid droplets and show no signs of massive cell degeneration, at least until 16 w.g. These ultrastructural modifications in fetal LC are in accordance with the changes in both steroidogenic activity and hCG levels reported by the literature to occur at this stage of development. Junctional complexes were often observed among LC from 7 to 8 w.g. onwards.

  11. Identification of Stem Leydig Cells Derived from Pig Testicular Interstitium

    PubMed Central

    Yu, Shuai; Zhang, Pengfei; Dong, Wuzi; Zeng, Wenxian

    2017-01-01

    Stem Leydig cells (SLCs), located in the testicular interstitial compartment in the mammalian testes, are capable of differentiating to testosterone-synthesizing Leydig cells (LCs), thus providing a new strategy for treating testosterone deficiency. However, no previous reports have identified and cultured SLCs derived from the pig. The aim of the current study was to isolate, identify, and culture SLCs from pigs. Haematoxylin and eosin staining and immunochemical analysis showed that SLCs were present and that PDGFRα was mainly expressed in the pig testicular interstitium, indicating that PDGFRα was a marker for SLCs in the neonatal pig. In addition, reverse transcription-PCR results showed that SLC markers were expressed in primary isolated LCs, indicating that they were putative SLCs. The putative SLCs were subsequently cultured with a testicular fluid of piglets (pTF) medium. Clones formed after 7 days and the cells expressed PDGFRα. However, no clones grew in the absence of pTF, but the cells expressed CYP17A1, indicating that pTF could sustain the features of porcine SLCs. To summarize, we isolated porcine SLCs and identified their basic characteristics. Taken together, these results may help lay the foundation for research in the clinical application of porcine SLCs. PMID:28243257

  12. Aristaless Related Homeobox Gene, Arx, Is Implicated in Mouse Fetal Leydig Cell Differentiation Possibly through Expressing in the Progenitor Cells

    PubMed Central

    Miyabayashi, Kanako; Katoh-Fukui, Yuko; Ogawa, Hidesato; Baba, Takashi; Shima, Yuichi; Sugiyama, Noriyuki; Kitamura, Kunio; Morohashi, Ken-ichirou

    2013-01-01

    Development of the testis begins with the expression of the SRY gene in pre-Sertoli cells. Soon after, testis cords containing Sertoli and germ cells are formed and fetal Leydig cells subsequently develop in the interstitial space. Studies using knockout mice have indicated that multiple genes encoding growth factors and transcription factors are implicated in fetal Leydig cell differentiation. Previously, we demonstrated that the Arx gene is implicated in this process. However, how ARX regulates Leydig cell differentiation remained unknown. In this study, we examined Arx KO testes and revealed that fetal Leydig cell numbers largely decrease throughout the fetal life. Since our study shows that fetal Leydig cells rarely proliferate, this decrease in the KO testes is thought to be due to defects of fetal Leydig progenitor cells. In sexually indifferent fetal gonads of wild type, ARX was expressed in the coelomic epithelial cells and cells underneath the epithelium as well as cells at the gonad-mesonephros border, both of which have been described to contain progenitors of fetal Leydig cells. After testis differentiation, ARX was expressed in a large population of the interstitial cells but not in fetal Leydig cells, raising the possibility that ARX-positive cells contain fetal Leydig progenitor cells. When examining marker gene expression, we observed cells as if they were differentiating into fetal Leydig cells from the progenitor cells. Based on these results, we propose that ARX acts as a positive factor for differentiation of fetal Leydig cells through functioning at the progenitor stage. PMID:23840809

  13. Intermittent access to beer promotes binge-like drinking in adolescent but not adult Wistar rats.

    PubMed

    Hargreaves, Garth A; Monds, Lauren; Gunasekaran, Nathan; Dawson, Bronwyn; McGregor, Iain S

    2009-06-01

    Teenagers are more likely than adults to engage in binge drinking and could be more vulnerable to long-term brain changes following alcohol abuse. We investigated the possibility of excessive adolescent drinking in a rodent model in which beer (4.44% ethanol vol/vol) is presented to adult and adolescent male Wistar rats. Experiment 1 tracked ad libitum beer and water consumption in group-housed rats from postnatal day (PND) 28-96. Rats consumed an average of 7.8 g/kg/day of ethanol during adolescence (PND 34-55) and this gradually declined to a lower level of intake in adulthood (PND 56-93) of 3.9 g/kg/day. In Experiment 2, beer was made available to both adolescent (PND 29+) and adult (PND 57+) rats for 2h each day in a custom-built "lickometer" apparatus over 75 days. Access to beer was provided either 1 day out of every 3 ("intermittent" groups) or every day ("daily" groups). Relative to body weight, adolescent rats consumed more beer than adult rats in these limited access sessions. Adolescents with intermittent access consumed more than adolescents with daily access, a "binge"-like effect that was not observed in adult groups and that disappeared in adulthood. After 3 months of daily or intermittent alcohol consumption, the preference for beer versus sucrose was assessed. Rats previously kept under an intermittent schedule displayed a higher preference for beer relative to 3% sucrose, but only when testing occurred after 2 days of abstinence. In Experiment 3, adolescent (PND 30-37) and adult (PND 58-65) rats were given 20-min access to beer and their blood alcohol concentrations (BACs) were assessed. Adolescent groups consumed more alcohol than adults and showed higher BACS that were typical of human "binge" drinking (>80 mg/dL). Despite this, the correlation between BAC and beer intake was similar in both age groups. Together these results show that the intermittent presentation of alcohol itself appears to have subtle long-lasting effects on the motivation

  14. Increased rat neonatal activity influences adult cytokine levels and relative muscle mass

    PubMed Central

    Buchowicz, Bryce; Yu, Tiffany; Nance, Dwight M.; Zaldivar, Frank P.; Cooper, Dan M.; Adams, Gregory R.

    2011-01-01

    Little is known about the effect of physical activity in early life on subsequent growth and regulation of inflammation. We previously reported that exposure of muscles in growing rats to IL-6 results in decreased muscle growth apparently due to a state of resistance to growth factors such IGF-I and that running exercise could ameliorate this growth defect. Herein we hypothesized that increased activity, for a brief period during neonatal life, would pattern the adult rat towards a less inflammatory phenotype. Neonatal rats were induced to move about their cage for brief periods from day 5 to day 15 postpartum. Additional groups were undisturbed controls (CON) and handled (HAND). Sub-groups of rats were sampled at 30 and 65 days of age. Relative to CON and HAND, neonatal exercise (EX) results in decreased circulating levels of TNFα, IL-6 and IL-1β in adulthood, primarily in male rats. In addition, adult male EX rats had lower body mass and increased skeletal muscle mass suggesting a leaner phenotype. The results of this study suggest that moderate increases in activity early in life can influence the adult toward a more healthy phenotype with regard to inflammatory mediators and relative muscle mass. PMID:20657345

  15. Early life permethrin insecticide treatment leads to heart damage in adult rats.

    PubMed

    Vadhana, M S Dhivya; Carloni, Manuel; Nasuti, Cinzia; Fedeli, Donatella; Gabbianelli, Rosita

    2011-09-01

    Early life environmental exposure to xenobiotics could represent a critical period for the onset of permanent alterations in the structure and function of different organs. Cardiovascular diseases can be related to various factors including environmental toxicants. The aim of the present study was to evaluate the effect of early life permethrin treatment (1/50 LD(50), from 6th to 21st day of life) on heart of adult rats. Increased DNA damage, decreased heart cell membrane fluidity, increased cholesterol content, protein and lipid oxidation were measured in heart cells from adult rats treated with permethrin during the neonatal period with respect to control rats. Moreover, the same group showed higher levels of cholesterol, IL-1β, IL-2, IFN-γ, rat-Rantes and IL-10 cytokines and decreased albumin content in plasma. Lower cholesterol levels and perturbation in the phospholipid lateral diffusion together with decreased GSH levels and increased GPx activity were measured in heart mitochondria of the treated group. Our findings support the evidence that the neonatal period has a critical role in the development of heart disease in adulthood. We hypothesize that the alterations observed in adult rats could depend on epigenetic changes that occurred during this period which influence gene expression throughout the rat's life, leading to alterations of certain parameters related to cardiac function.

  16. Morphine treatment during juvenile isolation increases social activity and opioid peptides release in the adult rat.

    PubMed

    Van den Berg, C L; Kitchen, I; Gerrits, M A; Spruijt, B M; Van Ree, J M

    1999-05-29

    The consequences of juvenile isolation and morphine treatment on general activity, social activity and endogenous opioid release during a social interaction test were investigated in the adult rat. Rats were either isolated or socially housed during weeks 4 and 5 of age and treated daily during this isolation period subcutaneously with either saline or morphine. Directly after a social interaction test at 10 weeks of age, rats were injected with [3H]-diprenorphine and subsequently prepared for in vivo autoradiography. The autoradiographic technique was used to visualise neuroanatomical changes in opioid receptor occupancy, probably reflecting changes in opioid peptide release, as a result of social activity. Juvenile isolation increased general activity during the social interaction test, an effect which was accompanied by a reduction of opioid receptor occupancy in many brain areas, suggesting an increased opioid peptide release as a consequence of socially-induced general activity. Morphine treatment in isolated rats caused an increase in adult social activity and enhanced opioid peptide release in some cortical regions and the ventral tegmental area as compared to saline treated rats. Both social activity and opioid receptor occupancy were unaffected by morphine treatment in non-isolated rats. The present study underscores the role of opioid systems in adult social behaviors as a consequence of juvenile isolation. The results suggest a relationship between social activity and opioid peptide release during social contact. Increased social activity seems to be accompanied by elevated opioid peptide release in distinct brain areas after morphine treatment during juvenile isolation.

  17. Gonadotropin-releasing hormone receptor in spinal cord neurons of embryos and adult rats.

    PubMed

    Quintanar, J Luis; Salinas, Eva; González, Rodolfo

    2009-09-11

    Mammalian gonadotropin-releasing hormone (GnRH) and its receptor have been found in the neuroendocrine reproductive axis. However, they can be localized in other extra-pituitary tissues as well including the central nervous system. The present study reports the expression of GnRH receptor and its mRNA in spinal cord neurons of rat embryos and adult rats, using immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). Immunohistochemistry showed that the spinal cord neurons of rat embryos and adult rats expressed the GnRH receptor. The study of GnRH receptor mRNAs revealed that both cultured spinal cord neurons of rat embryos and adult rats expressed the GnRH receptor mRNA. Additional in vitro experiments showed that the expression of GnRH receptor mRNA was less in the spinal cord neurons exposed to GnRH compared to unexposed ones. These results raise the possibility that GnRH may play other roles independently from its participation in reproductive function.

  18. Effect of different doses of Malaysian honey on reproductive parameters in adult male rats.

    PubMed

    Mohamed, M; Sulaiman, S A; Jaafar, H; Sirajudeen, K N S

    2012-05-01

    The aim of this study was to evaluate the effect of different doses of Malaysian honey on male reproductive parameters in adult rats. Thirty-two healthy adult male Sprague-Dawley rats were randomly divided into four groups (eight rats per group). Group 1 (control group) was given 0.5 ml of distilled water. Groups 2, 3 and 4 were given 0.2, 1.2 and 2.4 g kg(-1) body weight of honey respectively. The rats were treated orally by gavage once daily for 4 weeks. Honey did not significantly alter body and male reproductive organs weights. The rats in Group 3 which received honey at 1.2 g kg(-1) had significantly higher epididymal sperm count than those in Groups 1, 2 and 4. No significant differences were found for the percentage of abnormal sperm, elongated spermatid count, reproductive hormonal levels as well as the histology of the testis among the groups. In conclusion, Malaysian honey at a dose of 1.2 g kg(-1) daily significantly increased epididymal sperm count without affecting spermatid count and reproductive hormones. These findings might suggest that oral administration of honey at this dose for 4 weeks may enhance spermiogenesis in adult rats.

  19. Interleukin-6 and IL-6 receptor cell expression in testis of rats with autoimmune orchitis.

    PubMed

    Rival, Claudia; Theas, María S; Guazzone, Vanesa A; Lustig, Livia

    2006-06-01

    Experimental autoimmune orchitis (EAO) is an organ-specific model of autoimmunity characterized by an interstitial lymphomononuclear cell infiltrate as well as sloughing and apoptosis of germ cells. EAO was induced in adult male Sprague-Dawley rats by active immunization with testicular homogenate and adjuvants. Rats injected with saline solution and adjuvants were used as control group. The aim of this work was to study the expression of interleukin-6 (IL-6) and its receptor (IL-6R) in the testis of rats with EAO and analyze whether IL-6 could be involved in germ cell apoptosis. By immunohistochemistry, we detected IL-6 expression in testicular macrophages and Leydig cells of control and EAO rats. Sertoli cells showed IL-6 immunoreactivity in most of the seminiferous tubules of control rats, while a few IL-6+ Sertoli cells were found in the testis of rats with EAO. IL-6R immunoreactivity was observed in macrophages, Leydig and germ cells. A significant increase was noted in the number of IL-6R+ germ cells in rats with EAO compared to control rats. The content of IL-6 (ELISA) in the conditioned media obtained from testicular macrophages of rats with orchitis was significantly higher than in the control group. By immunofluorescence performed on isolated testicular macrophages, IL-6 was shown to be expressed by monocytes recently arrived from circulation (ED1+ cells), while resident macrophages (ED2+ cells) were negative. In vitro experiments (trypan blue and MTS assays) showed that IL-6 (50 ng/ml) reduced germ cell viability. We demonstrated also using the TUNEL technique that IL-6 added to cultures of seminiferous tubule segments induced apoptosis of germ cells. Our results suggest that IL-6 and IL-6R may be involved in the pathogenesis of autoimmune orchitis by promoting testicular inflammation and germ cell apoptosis.

  20. Early treatment with metformin induces resistance against tumor growth in adult rats.

    PubMed

    Trombini, Amanda B; Franco, Claudinéia Cs; Miranda, Rosiane A; de Oliveira, Júlio C; Barella, Luiz F; Prates, Kelly V; de Souza, Aline A; Pavanello, Audrei; Malta, Ananda; Almeida, Douglas L; Tófolo, Laize P; Rigo, Kesia P; Ribeiro, Tatiane As; Fabricio, Gabriel S; de Sant'Anna, Juliane R; Castro-Prado, Marialba Aa; de Souza, Helenir Medri; de Morais, Hely; Mathias, Paulo Cf

    2015-01-01

    It is known that antidiabetic drug metformin, which is used worldwide, has anti-cancer effects and can be used to prevent cancer growth. We tested the hypothesis that tumor cell growth can be inhibited by early treatment with metformin. For this purpose, adult rats chronically treated with metformin in adolescence or in adulthood were inoculated with Walker 256 carcinoma cells. Adult rats that were treated with metformin during adolescence presented inhibition of tumor growth, and animals that were treated during adult life did not demonstrate any changes in tumor growth. Although we do not have data to disclose a molecular mechanism to the preventive metformin effect, we present, for the first time, results showing that cancer growth in adult life is dependent on early life intervention, thus supporting a new therapeutic prevention for cancer.

  1. Perfluorododecanoic acid-induced steroidogenic inhibition is associated with steroidogenic acute regulatory protein and reactive oxygen species in cAMP-stimulated Leydig cells.

    PubMed

    Shi, Zhimin; Feng, Yixing; Wang, Jianshe; Zhang, Hongxia; Ding, Lina; Dai, Jiayin

    2010-04-01

    Perfluorododecanoic acid (PFDoA) can be detected in environmental matrices and human serum and has been shown to inhibit testicular steroidogenesis in rats. However, the mechanisms that are responsible for the toxic effects of PFDoA remain unknown. The aims of this study were to investigate the mechanism of steroidogenesis inhibition by PFDoA and to identify the molecular target of PFDoA in Leydig cells. The effects of PFDoA on steroid synthesis in Leydig cells were assessed by radioimmunoassay. The expression of key genes and proteins in steroid biosynthesis was determined by real-time PCR and Western blot analysis. Reactive oxygen species (ROS) and hydrogen peroxide (H(2)O(2)) levels were determined using bioluminescence assays. PFDoA inhibited adenosine 3',5'-cyclophosphate (cAMP)-stimulated steroidogenesis in mouse Leydig tumor cells (mLTC-1) and primary rat Leydig cells in a dose-dependent manner. However, PFDoA (1-100 microM) did not exhibit effects on cell viability and cellular ATP levels in mLTC-1 cells. PFDoA inhibited steroidogenic acute regulatory protein (StAR) promoter activity and StAR expression at the messenger RNA (mRNA) and protein levels but did not affect mRNA levels of peripheral-type benzodiazepine receptor, cholesterol side-chain cleavage enzyme, or 3beta-hydroxysteroid dehydrogenase in cAMP-stimulated mLTC-1 cells. PFDoA treatment also resulted in increased levels of mitochondrial ROS and H(2)O(2). After excessive ROS and H(2)O(2) were eliminated in PFDoA-treated mLTC-1 cells by MnTMPyP (a superoxide dismutase analog), progesterone production was partially restored and StAR mRNA and protein levels were partially recovered. These data show that PFDoA inhibits steroidogenesis in cAMP-stimulated Leydig cells by reducing the expression of StAR through a model of action involving oxidative stress.

  2. Establishment and evaluation of a stable steroidogenic goat Leydig cell line.

    PubMed

    Zhou, Jinhua; Dai, Rui; Lei, Lanjie; Lin, Pengfei; Lu, Xiaolong; Wang, Xiangguo; Tang, Keqiong; Wang, Aihua; Jin, Yaping

    2016-04-01

    Leydig cells play a key role in synthesizing androgen and regulating spermatogenesis. The dysfunction of Leydig cells may lead to various male diseases. Although primary Leydig cell cultures have been used, their finite lifespan hinders the assessment of long-term effects. In the present study, primary goat Leydig cells (GLCs) were immortalized via the transfection of a plasmid containing the human telomerase reverse transcriptase (hTERT) gene. The expressions of hTERT and telomerase activity were evaluated in transduced GLCs (hTERT-GLCs). These cells steadily expressed the hTERT gene and exhibited longer telomere lengths at passage 55 that were similar to those of HeLa cells. The hTERT-GLCs at passages 30 and 50 expressed genes that encoded key proteins, enzymes and receptors that are inherent to normal Leydig cells, for example, steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase (3β-HSD) and LH-receptor (LH-R). Additionally, the immortalized goat Leydig cells secreted detectable quantities of testosterone in response to hCG stimulation. Furthermore, this cell line appeared to proliferate more quickly than the control cells, although no neoplastic transformation occurred in vitro. We concluded that the GLCs immortalized with hTERT retained their original characteristics and might provide a useful model for the study of Leydig cell function.

  3. [Disruption of latent inhibition in adult rats after prepubertal dopamine terminals lesions in the ventral hippocampus].

    PubMed

    Loskutova, L V; Kostiunina, N V; Red'kina, A V

    2010-05-01

    Wistar rats were submitted to bilateral ventral hippocampal injection of 6-hydroxydopamine on 32nd day after birth. Latent inhibition was measured in passive or active avoidance tasks when the rats received 20 and 100 pre-exposures of conditioned stimulus. Prepubertal and adult lesioned rats showed a deficit in the latent inhibition but not in the capacity to avoidance learning in presence of the conditioned stimulus novelty. Possible mechanism of the involvement of hippocampal dopaminergic terminals in attention inhibition to irrelevant information is considered.

  4. Maternal exposure to isobutyl-paraben impairs social recognition in adult female rats.

    PubMed

    Kawaguchi, Maiko; Morohoshi, Kaori; Imai, Hideki; Morita, Masatoshi; Kato, Nobumasa; Himi, Toshiyuki

    2010-01-01

    Isobutyl-paraben (IBP), a widely used preservative, exhibits estrogenic activity. We analyzed the effects of exposure to IBP during gestation and lactation via dam on social recognition behavior in ovariectomized offspring of Sprague-Dawley rats. Offspring were ovariectomized at 7 weeks of age, and were used in a social recognition test at 16 weeks of age. Each offspring was exposed to a novel ovariectomized rat four times and to a second novel rat in a fifth exposure. We counted the investigations by offspring of intruder rats. The IBP-exposed rats showed impaired social behavior compared with controls. These data imply that early exposure to IBP may have an effect on adult social behavior, which is reported to be an autism spectrum disorders in humans.

  5. Neonatal sensory deprivation promotes development of absence seizures in adult rats with genetic predisposition to epilepsy.

    PubMed

    Sitnikova, Evgenia

    2011-03-04

    Absence epilepsy has age-related onset. In a WAG/Rij rat genetic model, absence seizures appear after puberty and they are increased with age. It is known that (1) epileptic activity in WAG/Rij rats is initiated at the perioral area in the somatosensory cortex; (2) sensory deprivation, i.e., whisker trimming during the critical period of development, could enhance excitatory activity in the somatosensory cortex. It is hypothesized that the cortex may become more excitable after neonatal vibrissae removal, and this may precipitate absence seizures in adult rats. We found that whisker trimming during the first postnatal weeks caused more rapid development of EEG seizure activity in adult WAG/Rij rats. Epileptic discharges in the trimmed rats were more numerous (vs control), showed longer duration and often appeared in desynchronized and drowsy EEG. The number of absence-like spindle-shaped EEG events (spike-wave spindles) in the whisker-trimmed rats was higher than in control, especially during the intermediate sleep state. An age-dependent increase of intermediate sleep state was found in the trimmed rats, but not in the intact animals. We discuss epigenetic factors that can modulate absence epilepsy in genetically prone subjects.

  6. The Effects of Inflammatory Tooth Pain on Anxiety in Adult Male Rats

    PubMed Central

    Raoof, Maryam; Ebrahimnejad, Hamed; Abbasnejad, Mehdi; Amirkhosravi, Ladan; Raoof, Ramin; Esmaeili Mahani, Saeed; Ramazani, Mohsen; Shokouhinejad, Noushin; Khoshkhounejad, Mehrfam

    2016-01-01

    Introduction: This study aimed to examine the effects of induced inflammatory tooth pain on anxiety level in adult male rats. Methods: The mandibular incisors of 56 adult male rats were cut off and prefabricated crowns were fixed on the teeth. Formalin and capsaicin were injected intradentally to induce inflammatory tooth pain. Diazepam treated group received diazepam 30 minutes before intradental injection. The anxiety-related behavior was evaluated with elevated plus maze test. Results: Intradental application of chemical noxious stimuli, capsaicin and formalin, significantly affected nociceptive behaviors (P<0.001). Capsaicin (P<0.001) and formalin (P<0.01) significantly increased the anxiety levels in rats by decrease in the duration of time spent in open arm and increase in the duration of time spent in closed arm. Rats that received capsaicin made fewer open arm entries compared to the control animals (P<0.05). Capsaicin (P<0.001) and formalin (P<0.01) treated rats showed more stretch attend postures compared to the control and sham operated animals. In diazepampretreated rats, capsaicin induced algesic effect was prevented (P<0.001). Conclusion: Inflammatory pulpal pain has anxiogenic effect on rats, whereas diazepam premedication showed both anxiolytic and pain reducing effects. PMID:27563419

  7. Cellular microenvironment dictates androgen production by murine fetal Leydig cells in primary culture.

    PubMed

    Carney, Colleen M; Muszynski, Jessica L; Strotman, Lindsay N; Lewis, Samantha R; O'Connell, Rachel L; Beebe, David J; Theberge, Ashleigh B; Jorgensen, Joan S

    2014-10-01

    Despite the fact that fetal Leydig cells are recognized as the primary source of androgens in male embryos, the mechanisms by which steroidogenesis occurs within the developing testis remain unclear. A genetic approach was used to visualize and isolate fetal Leydig cells from remaining cells within developing mouse testes. Cyp11a1-Cre mice were bred to mT/mG dual reporter mice to target membrane-tagged enhanced green fluorescent protein (GFP) within steroidogenic cells, whereas other cells expressed membrane-tagged tandem-dimer tomato red. Fetal Leydig cell identity was validated using double-labeled immunohistochemistry against GFP and the steroidogenic enzyme 3beta-HSD, and cells were successfully isolated as indicated by qPCR results from sorted cell populations. Because fetal Leydig cells must collaborate with neighboring cells to synthesize testosterone, we hypothesized that the fetal Leydig cell microenvironment defined their capacity for androgen production. Microfluidic culture devices were used to measure androstenedione and testosterone production of fetal Leydig cells that were cultured in cell-cell contact within a mixed population, were isolated but remained in medium contact via compartmentalized co-culture with other testicular cells, or were isolated and cultured alone. Results showed that fetal Leydig cells maintained their identity and steroidogenic activity for 3-5 days in primary culture. Microenvironment dictated proficiency of testosterone production. As expected, fetal Leydig cells produced androstenedione but not testosterone when cultured in isolation. More testosterone accumulated in medium from mixed cultures than from compartmentalized co-cultures initially; however, co-cultures maintained testosterone synthesis for a longer time. These data suggest that a combination of cell-cell contact and soluble factors constitute the ideal microenvironment for fetal Leydig cell activity in primary culture.

  8. Cellular Microenvironment Dictates Androgen Production by Murine Fetal Leydig Cells in Primary Culture1

    PubMed Central

    Carney, Colleen M.; Muszynski, Jessica L.; Strotman, Lindsay N.; Lewis, Samantha R.; O'Connell, Rachel L.; Beebe, David J.; Theberge, Ashleigh B.; Jorgensen, Joan S.

    2014-01-01

    ABSTRACT Despite the fact that fetal Leydig cells are recognized as the primary source of androgens in male embryos, the mechanisms by which steroidogenesis occurs within the developing testis remain unclear. A genetic approach was used to visualize and isolate fetal Leydig cells from remaining cells within developing mouse testes. Cyp11a1-Cre mice were bred to mT/mG dual reporter mice to target membrane-tagged enhanced green fluorescent protein (GFP) within steroidogenic cells, whereas other cells expressed membrane-tagged tandem-dimer tomato red. Fetal Leydig cell identity was validated using double-labeled immunohistochemistry against GFP and the steroidogenic enzyme 3beta-HSD, and cells were successfully isolated as indicated by qPCR results from sorted cell populations. Because fetal Leydig cells must collaborate with neighboring cells to synthesize testosterone, we hypothesized that the fetal Leydig cell microenvironment defined their capacity for androgen production. Microfluidic culture devices were used to measure androstenedione and testosterone production of fetal Leydig cells that were cultured in cell-cell contact within a mixed population, were isolated but remained in medium contact via compartmentalized co-culture with other testicular cells, or were isolated and cultured alone. Results showed that fetal Leydig cells maintained their identity and steroidogenic activity for 3–5 days in primary culture. Microenvironment dictated proficiency of testosterone production. As expected, fetal Leydig cells produced androstenedione but not testosterone when cultured in isolation. More testosterone accumulated in medium from mixed cultures than from compartmentalized co-cultures initially; however, co-cultures maintained testosterone synthesis for a longer time. These data suggest that a combination of cell-cell contact and soluble factors constitute the ideal microenvironment for fetal Leydig cell activity in primary culture. PMID:25143354

  9. Pharmacokinetics of bisphenol A in neonatal and adult Sprague-Dawley rats

    SciTech Connect

    Doerge, Daniel R.; Twaddle, Nathan C.; Vanlandingham, Michelle; Fisher, Jeffrey W.

    2010-09-01

    Bisphenol A (BPA) is an important industrial chemical used in the manufacture of polycarbonate plastic products and epoxy resin-based food can liners. The presence of BPA in urine of > 90% of Americans aged 6-60 suggests ubiquitous and frequent exposure. The current study used LC/MS/MS to measure serum pharmacokinetics of aglycone (active) and conjugated (inactive) BPA in adult and neonatal Sprague-Dawley rats by oral and injection routes. Deuterated BPA was used to avoid issues of background contamination. Linear pharmacokinetics were observed in adult rats treated orally in the range of 0-200 {mu}g/kg bw. Evidence for enterohepatic recirculation of conjugated, but not aglycone, BPA was observed in adult rats. Significant inverse relationships were observed between postnatal age and measures of internal exposures to aglycone BPA and its elimination. In neonatal rats treated orally, internal exposures to aglycone BPA were substantially lower than from subcutaneous injection. The results reinforce the critical role for first-pass Phase II metabolism of BPA in gut and liver after oral exposure that attenuates internal exposure to the aglycone form in rats of all ages. The internal exposures to aglycone BPA observed in adult and neonatal rats following a single oral dose of 100 {mu}g/kg bw are inconsistent with effects mediated by classical estrogen receptors based on binding affinities. However, an impact on alternative estrogen signaling pathways that have higher receptor affinity cannot be excluded in neonatal rats. These findings emphasize the importance of matching aglycone BPA internal dosimetry with receptor affinities in experimental animal studies reporting toxicity.

  10. Different adaptation of the motor activity rhythm to chronic phase shifts between adolescent and adult rats.

    PubMed

    Albert, Nerea; da Silva, Crhistiane; Díez-Noguera, Antoni; Cambras, Trinitat

    2013-09-01

    Chronic phase shifts is a common feature in modern societies, which may induce sleep alterations and other health problems. The effects of phase shift on the circadian rhythms have been described to be more pronounced in old than in young animals. However, few works address the effects of chronic phase shifts during adolescence. Here we tested the development of the motor activity circadian rhythm of young rats under chronic phase shifts, which consisted on 6-h advances (A), 6h delays (D) or 6h advances and delays alternated every 5 days (AD) during the first 60 days after weaning. Moreover, the rhythmic pattern was compared to that of adult rats under the same lighting conditions. Results indicate that adolescent rats, independently on the lighting environment, developed a clear circadian rhythm, whose amplitude increased the first 50 days after weaning and showed a more stable circadian rhythm than adults under the same lighting conditions. In the case of A and AD groups, circadian disruption was observed only in adult rats. In all groups, the offset of activity correlated with light pattern better than the onset, and this correlation was always higher in the case of the rhythm of the pubertal rats. When AD groups were transferred to constant darkness, the group submitted to this condition during adolescence showed shorter period than that submitted in their adulthood. In conclusion, differently from adult rats, adolescent rats submitted to chronic phase shifts did not show circadian disruption and developed a single circadian rhythm, suggesting permanent changes in the circadian system.

  11. Ventilatory phenotypes among four strains of adult rats.

    PubMed

    Hodges, Matthew R; Forster, Hubert V; Papanek, Paula E; Dwinell, Melinda R; Hogan, Genevieve E

    2002-09-01

    Our purpose in this study was to identify different ventilatory phenotypes among four different strains of rats. We examined 114 rats from three in-house, inbred strains and one outbred strain: Brown Norway (BN; n = 26), Dahl salt-sensitive (n = 24), Fawn-hooded Hypertensive (FHH: n = 27), and outbred Sprague-Dawley rats (SD; n = 37). We measured eupneic (room air) breathing and the ventilatory responses to hypoxia (12% O(2)-88% N(2)), hypercapnia (7% CO(2)), and two levels of submaximal exercise. Primary strain differences were between BN and the other strains. BN rats had a relatively attenuated ventilatory response to CO(2) (P < 0.001), an accentuated ventilatory response to exercise (P < 0.05), and an accentuated ventilatory roll-off during hypoxia (P < 0.05). Ventilation during hypoxia was lower than other strains, but hyperventilation during hypoxia was equal to the other strains (P > 0.05), indicating that the metabolic rate during hypoxia decreased more in BN rats than in other strains. Another strain difference was in the frequency and timing components of augmented breaths, where FHH rats frequently differed from the other strains, and the BN rats had the longest expiratory time of the augmented breaths (probably secondary to the blunted CO(2) sensitivity). These strain differences not only provide insight into physiological mechanisms but also indicate traits (such as CO(2) sensitivity) that are genetically regulated. Finally, the data establish a foundation for physiological genomic studies aimed at elucidating the genetics of these ventilatory control mechanisms.

  12. Similar withdrawal severity in adolescents and adults in a rat model of alcohol dependence.

    PubMed

    Morris, S A; Kelso, M L; Liput, D J; Marshall, S A; Nixon, K

    2010-02-01

    Alcohol use during adolescence leads to increased risk of developing an alcohol use disorder (AUD) during adulthood. Converging evidence suggests that this period of enhanced vulnerability for developing an AUD may be due to the adolescent's unique sensitivity and response to alcohol. Adolescent rats have been shown to be less sensitive to alcohol intoxication and withdrawal susceptibility; however, age differences in ethanol pharmacokinetics may underlie these effects. Therefore, this study investigated alcohol intoxication behavior and withdrawal severity using a modified Majchrowicz model of alcohol dependence that has been shown to result in similar blood ethanol concentrations (BECs) despite age differences. Adolescent (postnatal day, PND, 35) and adult rats (PND 70+) received ethanol according to this 4-day binge paradigm and were observed for withdrawal behavior for 17h. As expected, adolescents showed decreased sensitivity to alcohol-induced CNS depression as evidenced by significantly lower intoxication scores. Thus, adolescents received significantly more ethanol each day (12.3+/-0.1g/kg/day) than adults (9.2+/-0.2g/kg/day). Despite greater ethanol dosing in adolescent rats, both adolescent and adult groups had comparable peak BECs (344.5+/-10.2 and 338.5+/-7.8mg/dL, respectively). Strikingly, withdrawal severity was similar quantitatively and qualitatively between adolescent and adult rats. Further, this is the first time that withdrawal behavior has been reported for adolescent rats using this model of alcohol dependence. A second experiment confirmed the similarity in BECs at various time points across the binge. These results demonstrate that after consideration of ethanol pharmacokinetics between adults and adolescents by using a model that produces similar BECs, withdrawal severity is nearly identical. This study, in combination with previous reports on ethanol withdrawal in adolescents and adults, suggests only a BEC-dependent effect of ethanol on

  13. Supplemental dietary choline during development exerts antidepressant-like effects in adult female rats.

    PubMed

    Glenn, Melissa J; Adams, Raven S; McClurg, Lauren

    2012-03-14

    Perinatal choline supplementation in rats is neuroprotective against insults such as fetal alcohol exposure, seizures, and advanced age. In the present study we explored whether dietary choline supplementation may also confer protection from psychological challenges, like stress, and act as a natural buffer against stress-linked psychological disorders, like depression. We previously found that choline supplementation increased adult hippocampal neurogenesis, a function compromised by stress, lowered in depression, and boosted by antidepressants; and increased levels of growth factors linked to depression, like brain-derived neurotrophic factor. Together, these were compelling reasons to study the role of choline in depressed mood. To do this, we treated rats with a choline supplemented diet (5 mg/kg choline chloride in AIN76A) prenatally on embryonic days 10-22, on postnatal days (PD) 25-50, or as adults from PD75 onward. Outside of these treatment periods rats were fed a standard diet (1.1 mg/kg choline chloride in AIN76A); control rats consumed only this diet throughout the study. Starting on PD100 rats' anxiety-like responses to an open field, learning in a water maze, and reactivity to forced swimming were assessed. Rats given choline supplementation during pre- or post-natal development, but not adult-treated rats, were less anxious in the open field and less immobile in the forced swim test than control rats. These effects were not mediated by a learning deficit as all groups performed comparably and well in the water maze. Thus, we offer compelling support for the hypothesis that supplemental dietary choline, at least when given during development, may inoculate an individual against stress and major psychological disorders, like depression.

  14. Transgenerational Effects of Di(2-ethylhexyl) Phthalate in the SD Male Rat

    EPA Science Inventory

    In the rat, some phthalates alter sexual differentiation at relatively low dosage levels by altering fetal Leydig cell development and hormone synthesis, thereby inducing abnormalities of the testis, gubernacular ligaments, epididymis and other androgen-dependent tissues. In ...

  15. Regulatory Mechanism of Muscle Disuse Atrophy in Adult Rats

    NASA Technical Reports Server (NTRS)

    1993-01-01

    During the last phase of NAG 2-386 we completed three studies. The effects of 14 days of weightlessness; the vastus medialis (VM) from flight rats in COSMOS 2044 was compared with the VM from tail suspended rats and other controls. The type I and II fibers in the mixed fiber portion of the VM were significantly reduced in flight rats and capillary densities paralleled the fiber density changes. The results of this project compared favorably with those in the extensor digitorum longus following seven days of flight in SL 3. The cardiovascular projects focused on the blood pressure changes in head down tilted rats (HDT) and non-head down tilted (N-HDT) rats. Blood pressures (MAP, SP and DP) were significantly elevated through seven days of HDT and rapidly returned to control levels within one day after removal from the HDT position. The N-HDT showed some slight rise in blood pressure but these were not as great and they were not as rapid. The HDT rats were characterized as exhibiting transient hypertension. These results led to some of the microvascular and vascular graduate student projects of Dr. Bernhard Stepke. Also our results refute or, at least, do not agree with previous reports from other laboratories. Each animal, in our blood pressure projects, served as its own control thereby providing more accurate results. Also, our experiments focused on recovery studies which can, in and of themselves, provide guidelines for flight experiments concerned with blood pressure changes. Another experiment was conducted to examine the role of testicular atrophy in whole body suspended (WBS) and tail suspended (TS) rats. We worked in conjunction with Dr. D.R. Deaver's laboratory at Pennsylvania State University and Dr. R. P. Amann at Colorado State University. In the TS rats the testes are retracted into the abdominal cavity, unless a ligature is placed to maintain them in the external scrotal sac. The cryptorchid condition in TS rats results in atrophy of the testes and

  16. Nickel Nanoparticles Exposure and Reproductive Toxicity in Healthy Adult Rats

    PubMed Central

    Kong, Lu; Tang, Meng; Zhang, Ting; Wang, Dayong; Hu, Ke; Lu, Weiqi; Wei, Chao; Liang, Geyu; Pu, Yuepu

    2014-01-01

    Nickel is associated with reproductive toxicity. However, the reproductive toxicity of nickel nanoparticles (Ni NPs) is unclear. Our goal was to determine the association between nickel nanoparticle exposure and reproductive toxicity. According to the one-generation reproductive toxicity standard, rats were exposed to nickel nanoparticles by gavage and we selected indicators including sex hormone levels, sperm motility, histopathology, and reproductive outcome etc. Experimental results showed nickel nanoparticles increased follicle stimulating hormone (FSH) and luteinizing hormone (LH), and lowered etradiol (E2) serum levels at a dose of 15 and 45 mg/kg in female rats. Ovarian lymphocytosis, vascular dilatation and congestion, inflammatory cell infiltration, and increase in apoptotic cells were found in ovary tissues in exposure groups. For male rats, the weights decreased gradually, the ratio of epididymis weight over body weight increased, the motility of rat sperm changed, and the levels of FSH and testosterone (T) diminished. Pathological results showed the shedding of epithelial cells of raw seminiferous tubule, disordered arrangement of cells in the tube, and the appearance of cell apoptosis and death in the exposure group. At the same time, Ni NPs resulted in a change of the reproductive index and the offspring development of rats. Further research is needed to elucidate exposure to human populations and mechanism of actions. PMID:25407529

  17. Postnatal ethanol exposure disrupts signal detection in adult rats.

    PubMed

    Woolfrey, Kevin M; Hunt, Pamela S; Burk, Joshua A

    2005-01-01

    Human prenatal ethanol exposure that occurs during a period of increased synaptogenesis known as the "brain growth spurt" has been associated with significant impairments in attention, learning, and memory. The present experiment assessed whether administration of ethanol during the brain growth spurt in the rat, which occurs shortly after birth, disrupts attentional performance. Rats were administered 5.25 g/kg/day ethanol via intragastric intubation from postnatal days (PD) 4-9, sham-intubation, or no intubation (naïve). Beginning at PD 90, animals were trained to asymptotic performance in a two-lever attention task that required discrimination of brief visual signals from trials with no signal presentation. Finally, manipulations of background noise and inter-trial interval duration were conducted. Early postnatal ethanol administration did not differentially affect acquisition of the attention task. However, after rats were trained to asymptotic performance levels, those previously exposed to ethanol demonstrated a deficit in detection of signals but not of non-signals compared to sham-intubated and naïve rats. The signal detection deficit persisted whenever these animals were re-trained in the standard task, but further task manipulations failed to interact with ethanol pretreatment. The present data support the hypothesis that early postnatal ethanol administration disrupts aspects of attentional processing in the rat.

  18. Ethanol induces second-order aversive conditioning in adolescent and adult rats

    PubMed Central

    Pautassi, Ricardo Marcos; Myers, Mallory; Spear, Linda Patia; Molina, Juan Carlos; Spear, Norman E.

    2011-01-01

    Alcohol abuse and dependence is considered a developmental disorder with etiological onset during late childhood and adolescence, and understanding age-related differences in ethanol sensitivity is important. Low to moderate ethanol doses (0.5 and 2.0 g/kg, i.g.) induce single-trial, appetitive second-order place conditioning (SOC) in adolescent, but not adult, rats. Recent studies have demonstrated that adolescents may be less sensitive than adults to the aversive properties of ethanol, reflected by conditioned taste aversion. The present study assessed the aversive motivational effects of high-dose ethanol (3.0 and 3.25 g/kg, i.g., for adolescent and adults, respectively) using SOC. These doses were derived from Experiment 1, which found similar blood and brain ethanol levels in adolescent and adult rats given 3.0 and 3.25 g/kg ethanol, respectively. In Experiment 2, animals received ethanol or vehicle paired with intraoral pulses of sucrose (conditioned stimulus 1 [CS1]). After one, two, or three conditioning trials, rats were presented with the CS1 while in a distinctive chamber (CS2). When tested for CS2 preference, ethanol-treated animals exhibited reduced preference for the CS2 compared with controls. This result, indicative of ethanol-mediated aversive place conditioning, was similar for adolescents and adults, for females and males, and after one, two, or three training trials. One finding, however, suggested that adolescents were less sensitive than adults to ethanol’s aversive effects at the intermediate level of training. In conjunction with previous results, the present study showed that in adolescent rats subjected to SOC, ethanol’s hedonic effects vary from appetitive to aversive as the ethanol dose increases. Adolescent and adult animals appear to perceive the post-ingestive effects of high-dose ethanol as similarly aversive when assessed by SOC. PMID:21187242

  19. Taenia taeniaeformis: inhibition of rat testosterone production by excretory-secretory product of the cultured metacestode.

    PubMed

    Rikihisa, Y; Lin, Y C; Fukaya, T

    1985-06-01

    In 3- to 5-month-old male Sprague-Dawley rats infected with the hepatic metacestode, Taenia taeniaeformis, the serum testosterone level was significantly lower than in comparable uninfected controls. By transmission electron microscopy, testicular Leydig cells of infected rats had less smooth endoplasmic reticulum than control Leydig cells. Cultured metacestodes isolated from the hepatic cysts secreted or excreted substances into the incubation medium. The effect of the excretory-secretory product on testosterone concentration in the sera and testes of 15-day-old rats was examined. Subcutaneous injection of 50-200 micrograms of excretory-secretory product/0.1 ml saline/rat for 2 days significantly reduced human chorionic gonadotropin-stimulated serum and testicular testosterone concentrations. Furthermore, the effect of the excretory-secretory product on isolated rat Leydig cell testosterone production was examined. Rat Leydig cells produced testosterone in vitro and, in the presence of 50 IU human chorionic gonadotropin/ml incubation medium, they responded with approximately 100% increase in testosterone production. Addition of 2-10 micrograms excretory-secretory product protein/ml of culture medium significantly reduced the testosterone production by rat Leydig cells in vitro. These results indicate that excretory-secretory product of cultured T. taeniaeformis metacestodes has a direct inhibitory effect on Leydig cell testosterone production under stimulation with human chorionic gonadotropin.

  20. Muscle mechanical properties of adult and older rats submitted to exercise after immobilization

    PubMed Central

    Kodama, Fábio Yoshikazu; Camargo, Regina Celi Trindade; Job, Aldo Eloizo; Ozaki, Guilherme Akio Tamura; Koike, Tatiana Emy; Camargo Filho, José Carlos Silva

    2012-01-01

    Objectives To describe the effects of immobilization, free remobilization and remobilization by physical exercise about mechanical properties of skeletal muscle of rats of two age groups. Methods 56 Wistar rats divided into two groups according to age, an adult group (five months) and an older group (15 months). These groups were subdivided in: control, immobilized, free remobilized and remobilized by physical exercise. The pelvic limb of rats was immobilized for seven days. The exercise protocol consisted of five swimming sessions, once per day and 25 minutes per session. The gastrocnemius muscle was subjected to tensile tests, and evaluated the properties: load at the maximum limit, stretching at the maximum limit and stiffness. Results The immobilization reduced the values of load at the maximum limit and the remobilization protocols were not sufficient to restore control levels in adult group and older rats. The stretching at the maximum limit differs only in the older group. Conclusions The immobilization reduces the muscle's ability to bear loads and exercise protocol tends to restore the default at control values in adult and older rats. The age factor only interfered in the stretching at the maximum limit, inducing a reduction of this property in the post-immobilization. Level of Evidence II, Investigating the Results of Treatment. PMID:24453606

  1. Cocaine self-administration punished by intravenous histamine in adolescent and adult rats.

    PubMed

    Holtz, Nathan A; Carroll, Marilyn E

    2015-06-01

    Adolescence is a transitional phase marked by a heightened vulnerability to substances of abuse. It has been hypothesized that both increased sensitivity to reward and decreased sensitivity to aversive events may drive drug-use liability during this phase. To investigate possible age-related differences in sensitivity to the aversive consequences of drug use, adolescent and adult rats were compared on self-administration of cocaine before, during, and after a 10-day period in which an aversive agent, histamine, was added to the cocaine solution. Adult and adolescent female rats were trained to self-administer intravenous cocaine (0.4 mg/kg/infusion) over 10 sessions (2 h/session; 2 sessions/day). Histamine (4 mg/kg/infusion) was then added directly into the cocaine solution for the next 10 sessions. Finally, the cocaine/histamine solution was replaced with a cocaine-only solution, and rats continued to self-administer cocaine (0.4 mg/kg) for 20 sessions. Compared with adolescent rats, adult rats showed a greater decrease in cocaine self-administration when it was punished with intravenous histamine compared with their baseline cocaine self-administration rates. These results suggest that differences in the sensitivity to negative consequences of drug use may partially explain developmental differences in drug use vulnerability.

  2. Cocaine self-administration punished by intravenous histamine in adolescent and adult rats

    PubMed Central

    Holtz, Nathan A.; Carroll, Marilyn E.

    2016-01-01

    Adolescence is a transitional phase marked by a heightened vulnerability to substances of abuse. It has been hypothesized that both increased sensitivity to reward and decreased sensitivity to aversive events may drive drug-use liability during this phase. To investigate possible age-related differences in sensitivity to the aversive consequences of drug use, adolescent and adult rats were compared on self-administration of cocaine before, during, and after a 10-day period in which an aversive agent, histamine, was added to the cocaine solution. Adult and adolescent female rats were trained to self-administer intravenous cocaine (0.4 mg/kg/infusion) over 10 sessions (2 h/session; 2 sessions/day). Histamine (4 mg/kg/infusion) was then added directly into the cocaine solution for the next 10 sessions. Finally, the cocaine/histamine solution was replaced with a cocaine-only solution, and rats continued to self-administer cocaine (0.4 mg/kg) for 20 sessions. Compared with adolescent rats, adult rats showed a greater decrease in cocaine self-administration when it was punished with intravenous histamine compared with their baseline cocaine self-administration rates. These results suggest that differences in the sensitivity to negative consequences of drug use may partially explain developmental differences in drug use vulnerability. PMID:25769092

  3. Prenatal Choline Availability Alters the Context Sensitivity of Pavlovian Conditioning in Adult Rats

    ERIC Educational Resources Information Center

    Lamoureux, Jeffrey A.; Meck, Warren H.; Williams, Christina L.

    2008-01-01

    The effects of prenatal choline availability on Pavlovian conditioning were assessed in adult male rats (3-4 mo). Neither supplementation nor deprivation of prenatal choline affected the acquisition and extinction of simple Pavlovian conditioned excitation, or the acquisition and retardation of conditioned inhibition. However, prenatal choline…

  4. EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON THYROID HORMONE STATUS IN ADULT AND NEONATAL RATS

    EPA Science Inventory

    EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON THYROID HORMONE STATUS IN ADULT AND NEONATAL RATS. M.N. Logan1, J.R. Thibodeaux2, R.G. Hanson2, C. Lau2. 1North Carolina Central University, Durham, NC, 2Reprod. Tox. Div. NHEERL, US EPA, Research Triangle Park, NC.

    Perfluor...

  5. Prenatal exposure to vapors of gasoline-ethanol blends causes few cognitive deficits in adult rats

    EPA Science Inventory

    Developmental exposure to inhaled ethanol-gasoline fuel blends is a potential public health concern. Here we assessed cognitive functions in adult offspring of pregnant rats that were exposed to vapors of gasoline blended with a range of ethanol concentrations, including gasoli...

  6. PREPUBERTAL EXPOSURES TO COMPOUNDS THAT INCREASE PROLACTIN SECRETION IN THE MALE RAT: EFFECTS ON ADULT PROSTATE

    EPA Science Inventory

    Prepubertal exposure to compounds that increase prolactin secretion in the male rat: effects on the adult prostate.

    Stoker TE, Robinette CL, Britt BH, Laws SC, Cooper RL.

    Endocrinology Branch, Reproductive Toxicology Division, National Health and Environmental Effec...

  7. The effect of prenatal methamphetamine exposure on recognition memory in adult rats.

    PubMed

    Fialová, Markéta; Šírová, Jana; Bubeníková-Valešová, Věra; Šlamberová, Romana

    2015-01-01

    The use of methamphetamine (MA) among pregnant women is an increasing world-wide health problem. Prenatal MA exposure may cause changes in foetus but the exact effects have remained unclear. The aim of this study is to present the effect of prenatal MA exposure on recognition memory in adult rats. Adult female Wistar rats were injected daily with D-methamphetamine HCl (MA; 5 mg/kg, s.c.) during the entire gestation period. Control females were treated with saline in the same regime. Adult male offspring was administrated acutely by MA (1 mg/kg i.p.) or saline 30 minutes before beginning of an experiment. For testing recognition memory two tasks were chosen: Novel Object Recognition Test (NORT) and Object Location Test (OLT). Our results demonstrate that prenatally MA-exposed animals were worse in NORT independently on an acute administration of MA in adulthood. Prenatally MA-exposed rats did not deteriorate in OLT, but after acute administration of MA in adulthood, there was significant worsening compared to appropriate control. Prenatally saline-exposed offspring did not deteriorate in any test even after acute administration of MA. Our data suggest that prenatal MA exposure in rats cause impairment in recognition memory in adult offspring, but not in spatial memory. In addition, acute administration of MA to controls did not deteriorate either recognition or spatial memory.

  8. Trading new neurons for status: Adult hippocampal neurogenesis in eusocial Damaraland mole-rats.

    PubMed

    Oosthuizen, M K; Amrein, I

    2016-06-02

    Diversity in social structures, from solitary to eusocial, is a prominent feature of subterranean African mole-rat species. Damaraland mole-rats are eusocial, they live in colonies that are characterized by a reproductive division of labor and a subdivision into castes based on physiology and behavior. Damaraland mole-rats are exceptionally long lived and reproductive animals show delayed aging compared to non-reproductive animals. In the present study, we described the hippocampal architecture and the rate of hippocampal neurogenesis of wild-derived, adult Damaraland mole-rats in relation to sex, relative age and social status or caste. Overall, Damaraland mole-rats were found to have a small hippocampus and low rates of neurogenesis. We found no correlation between neurogenesis and sex or relative age. Social status or caste was the most prominent modulator of neurogenesis. An inverse relationship between neurogenesis and social status was apparent, with queens displaying the lowest neurogenesis while the worker mole-rats had the most. As there is no natural progression from one caste to another, social status within a colony was relatively stable and is reflected in the level of neurogenesis. Our results correspond to those found in the naked mole-rat, and may reflect an evolutionary and environmentally conserved trait within social mole-rat species.

  9. Electrophysiological properties of newborn and adult rat spinal cord glycine receptors expressed in Xenopus oocytes.

    PubMed Central

    Morales, A; Nguyen, Q T; Miledi, R

    1994-01-01

    The properties of glycine receptors (GlyRs) from newborn and adult rat spinal cord were studied in Xenopus oocytes injected with whole mRNA or the heavy (H) or light (L) mRNA fractions encoding their respective GlyRs. Mean open times and conductances of channels gated by H- or L-GlyRs were determined by noise analysis or voltage jumps. We found that adult H- and L-GlyRs opened channels that differed in their mean open time but had the same channel conductance. Both H- and L-GlyRs gated Cl- currents that displayed a similarly strong outward rectification. Nevertheless, single channels of adult H- and L-GlyRs did not rectify and their mean open times were only slightly altered by voltage. It follows that the outward rectification of adult GlyRs is due mainly to a reduction in the number of open channels. In contrast to H-GlyRs, whose characteristics seem to remain essentially unchanged with age, L-GlyRs from newborn and adult rats have different properties. Channels of newborn L-GlyRs have a higher conductance, longer open time, and greater voltage dependency than those from the adult. Interestingly, properties of newborn GlyRs expressed by whole mRNA were markedly different from those encoded by newborn or adult L or H mRNA. These results demonstrate that the functional heterogeneity of GlyRs is developmentally regulated. PMID:8159710

  10. Autonomic activation associated with ethanol self-administration in adult female P rats.

    PubMed

    Bell, Richard L; Rodd, Zachary A; Toalston, Jamie E; McKinzie, David L; Lumeng, Lawrence; Li, Ting-Kai; McBride, William J; Murphy, James M

    2008-12-01

    The present study examined changes in heart rate (HR) prior to and during limited access ethanol drinking in adult female P rats. P rats were implanted with radio-telemetric transmitters to measure HR. Daily testing involved a 90-min pre-test period (water only available) and a subsequent 90-min test period [either water (W) or ethanol available]. After a week of habituation, one ethanol group had access to ethanol for 7 weeks (CE), and another ethanol group had access for 4 weeks, was deprived for 2 weeks and then had access for a final week (DEP). Analyses of HR revealed that CE and DEP rats had significantly higher HR than W rats during test periods that ethanol was present and that DEP rats displayed higher HR during the early test period of the ethanol deprivation interval, as well. These data indicate that ethanol drinking induces HR activation in adult female P rats, and that this activation can be conditioned to the test cage environment, paralleling reports on contextual conditioning and cue-reactivity in alcoholics exposed to alcohol-associated stimuli. Therefore, this behavioral test may prove advantageous in screening pharmacotherapies for reducing craving and relapse, which are associated with cue-reactivity in abstinent alcoholics.

  11. Testicular lesions of streptozotocin diabetic rats.

    PubMed

    Oksanen, A

    1975-01-01

    Diabetes was induced in adult male albino rats by a single intravenous injection of streptozotocin (75 mg/kg body weight). The diabetes was allowed to stabilize for at least 15 days, whereafter the testicular and seminal vesicle histology was studied at various time intervals. Reduction in testis weights and tubule diameters was significant after 2 weeks of diabetes. The changes in seminiferous tubules ranged from premature sloughing of epithelium to total cessation of spermatogenesis. The testicular histology of diabetic animals frequently greatly simulated the situation described following hypophysectomy. By subjective visual assessment the number of Leydig cells was found to be normal or reduced in all of the diabetic animals. Diabetes was also demonstrated to induce seminal vesicle atrophy, which did not show any correlation with the degree of testicular lesions. The possible etiology of testicular damage in diabetic animals is discussed.

  12. Bupropion attenuates methamphetamine self-administration in adult male rats.

    PubMed

    Reichel, Carmela M; Murray, Jennifer E; Grant, Kathleen M; Bevins, Rick A

    2009-02-01

    Bupropion is a promising candidate medication for methamphetamine use disorder. As such, we used a preclinical model of drug-taking to determine the effects of bupropion on the reinforcing effects of methamphetamine (0.025, 0.05 or 0.1 mg/kg/infusion). Specificity was determined by investigating the effects of bupropion on responding maintained by sucrose. In the self-administration study, rats were surgically prepared with indwelling jugular catheters and trained to self-administer methamphetamine under an FR5 schedule. A separate group of rats was trained to press a lever for sucrose. Once responding stabilized, rats were pretreated with bupropion (0, 10, 30 and 60 mg/kg i.p.) 5 min before chamber placement in a unique testing order. Following acute testing, rats were then repeatedly pretreated with 30 and 60 mg/kg bupropion. Acute treatments of bupropion dose dependently reduced drug intake for 0.025-0.1 mg/kg methamphetamine; sucrose deliveries were only reduced with the high bupropion dose. Repeated exposure to 60 mg/kg bupropion before the session resulted in a consistent decrease in methamphetamine intake (0.05 and 0.1 mg/kg) and sucrose deliveries. Considered together, this pattern of findings demonstrates that bupropion decreases responding for methamphetamine, but the effects are only somewhat specific.

  13. Adversity before Conception Will Affect Adult Progeny in Rats

    ERIC Educational Resources Information Center

    Shachar-Dadon, Alice; Schulkin, Jay; Leshem, Micah

    2009-01-01

    The authors investigated whether adversity in a female, before she conceives, will influence the affective and social behavior of her progeny. Virgin female rats were either undisturbed (controls) or exposed to varied, unpredictable, stressors for 7 days (preconceptual stress [PCS]) and then either mated immediately after the end of the stress…

  14. Supplemental dietary choline during development exerts antidepressant-like effects in adult female rats

    PubMed Central

    Glenn, Melissa J.; Adams, Raven S.; McClurg, Lauren

    2012-01-01

    Perinatal choline supplementation in rats is neuroprotective against insults such as fetal alcohol exposure, seizures, and advanced age. In the present study we explored whether dietary choline supplementation may also confer protection from psychological challenges, like stress, and act as a natural buffer against stress-linked psychological disorders, like depression. We previously found that choline supplementation increased adult hippocampal neurogenesis, a function compromised by stress, lowered in depression, and boosted by antidepressants; and increased levels of growth factors linked to depression, like brain-derived neurotrophic factor. Together, these were compelling reasons to study the role of choline in depressed mood. To do this, we treated rats with a choline supplemented diet (5 mg/kg choline chloride in AIN76A) prenatally on embryonic days 10–22, on postnatal days (PD) 25–50, or as adults from PD75 onward. Outside of these treatment periods rats were fed a standard diet (1.1 mg/kg choline chloride in AIN76A); control rats consumed only this diet throughout the study. Starting on PD100 rats’ anxiety-like responses to an open field, learning in a water maze, and reactivity to forced swimming were assessed. Rats given choline supplementation during pre- or post-natal development, but not adult-treated rats, were less anxious in the open field and less immobile in the forced swim test than control rats. These effects were not mediated by a learning deficit as all groups performed comparably and well in the water maze. Thus, we offer compelling support for the hypothesis that supplemental dietary choline, at least when given during development, may inoculate an individual against stress and major psychological disorders, like depression. PMID:22305146

  15. Rapid neurobehavioral analysis of Pfiesteria piscicida effects in juvenile and adult rats.

    PubMed

    Levin, E D; Rezvani, A H; Christopher, N C; Glasgow, H B; Deamer-Melia, N J; Burkholder, J M; Moser, V C; Jensen, K

    2000-01-01

    The estuarine dinoflagellate Pfiesteria piscicida is known to kill fish and has been associated with neurocognitive deficits in humans. We have developed a rat model to demonstrate that exposure to Pfiesteria causes significant learning impairments. This has been repeatedly seen as a choice accuracy impairment during radial-arm maze learning. Pfiesteria-induced effects were also seen in a locomotor activity test in the figure-8 apparatus. The current studies used the short-term radial-arm maze acquisition, the figure-8 activity test, and the functional observational battery (FOB) to assess Pfiesteria-induced neurobehavioral effects in adult and juvenile rats. In study 1, the neurobehavioral potency of three different Pfiesteria cultures (Pf 113, Pf 728, and Pf Vandermere) was assessed. Ninety-six (12 per group) adult female Sprague-Dawley rats were injected subcutaneously with a single dose of Pfiesteria taken from aquarium-cultured Pfiesteria (35,600 or 106,800 Pfiesteria cells per kilogram of rat body weight). One control group (N = 12) was injected with saline and one (N = 12) with aquarium water not containing Pfiesteria. All three of the Pfiesteria samples (p < 0.05) impaired choice accuracy over the first six sessions of training. At the time of the radial-arm maze choice accuracy impairment, no overt Pfiesteria-related effects were seen using an FOB, indicating that the Pfiesteria-induced choice accuracy deficit was not due to generalized debilitation. In the figure-8 apparatus, Pfiesteria treatment caused a significant decrease in mean locomotor activity. In study 2, the neurobehavioral effects of the Pf 728 sample type were assessed in juvenile rats. Twenty-four day-old male and female rats were injected with 35,600 or 106,800 Pf-728 Pfiesteria cells per kilogram of rat body weight. As with adult females, the juvenile rats showed a significant impairment in radial-arm maze choice accuracy. No changes in locomotor activity or the FOB were detected in the

  16. Adolescent and adult male rats habituate to repeated isolation, but only adolescents sensitize to partner unfamiliarity.

    PubMed

    Hodges, Travis E; McCormick, Cheryl M

    2015-03-01

    We investigated whether adolescent male rats show less habituation of corticosterone release than adult male rats to acute vs repeated (16) daily one hour episodes of isolation stress, as well as the role of partner familiarity during recovery on social behavior, plasma corticosterone, and Zif268 expression in brain regions. Adolescents spent more time in social contact than did adults during the initial days of the repeated stress procedures, but both adolescents and adults that returned to an unfamiliar peer after isolation had higher social activity than rats returned to a familiar peer (p=0.002) or undisturbed control rats (p<0.001). Both ages showed evidence of habituation, with reduced corticosterone response to repeated than acute isolation (p=0.01). Adolescents, however, showed sensitized corticosterone release to repeated compared with an acute pairing with an unfamiliar peer during recovery (p=0.03), a difference not found in adults. Consistent with habituation of corticosterone release, the repeated isolation groups had lower Zif268 immunoreactive cell counts in the paraventricular nucleus (p<0.001) and in the arcuate nucleus (p=0.002) than did the acute groups, and adolescents had higher Zif268 immunoreactive cell counts in the paraventricular nucleus than did adults during the recovery period (p<0.001), irrespective of stress history and partner familiarity. Partner familiarity had only modest effects on Zif268 immunoreactivity, and experimental effects on plasma testosterone concentrations were only in adults. The results highlight social and endocrine factors that may underlie the greater vulnerability of the adolescent period of development.

  17. Ethanol induces second-order aversive conditioning in adolescent and adult rats.

    PubMed

    Pautassi, Ricardo Marcos; Myers, Mallory; Spear, Linda Patia; Molina, Juan Carlos; Spear, Norman E

    2011-02-01

    Alcohol abuse and dependence are considered public health problems, with an etiological onset often occurring during late childhood and adolescence, and understanding age-related differences in ethanol sensitivity is important. Low to moderate ethanol doses (0.5 and 2.0 g/kg, intragastrically [i.g.]) induce single-trial, appetitive second-order place conditioning (SOC) in adolescent, but not adult, rats. Recent studies have demonstrated that adolescents may be less sensitive than adults to the aversive properties of ethanol, reflected by conditioned taste aversion. The present study assessed the aversive motivational effects of high-dose ethanol (3.0 and 3.25 g/kg, i.g., for adolescents and adults, respectively) using SOC. Experiment 1 revealed similar blood and brain ethanol levels in adolescent and adult rats given 3.0 and 3.25 g/kg ethanol, respectively. In Experiment 2, animals received ethanol or vehicle paired with intraoral pulses of sucrose (conditioned stimulus 1 [CS1]). After one, two, or three conditioning trials, the rats were presented with the CS1 while in a distinctive chamber (CS2). When tested for CS2 preference, ethanol-treated animals exhibited reduced preference for the CS2 compared with controls. This result, indicative of ethanol-mediated aversive place conditioning, was similar for adolescents and adults; for females and males; and after one, two, or three training trials. In conjunction with previous results, the present study showed that, in adolescent rats subjected to SOC, ethanol's hedonic effects vary from appetitive to aversive as the ethanol dose increases. Adolescent and adult animals appear to perceive the postingestive effects of high-dose ethanol as similarly aversive when assessed by SOC.

  18. Effect of seven days of spaceflight on hindlimb muscle protein, RNA and DNA in adult rats

    NASA Technical Reports Server (NTRS)

    Steffen, J. M.; Musacchia, X. J.

    1985-01-01

    Effects of seven days of spaceflight on skeletal muscle (soleus, gastrocnemius, EDL) content of protein, RNA and DNA were determined in adult rats. Whereas total protein contents were reduced in parallel with muscle weights, myofibrillar protein appeared to be more affected. There were no significant changes in absolute DNA contents, but a significant (P less than 0.05) increase in DNA concentration (microgram/milligram) in soleus muscles from flight rats. Absolute RNA contents were significantly (P less than 0.025) decreased in the soleus and gastrocnemius muscles of flight rats, with RNA concentrations reduced 15-30 percent. These results agree with previous ground-based observations on the suspended rat with unloaded hindlimbs and support continued use of this model.

  19. Impairment of male reproduction in adult rats exposed to hydroxyprogesterone caproate in utero

    NASA Astrophysics Data System (ADS)

    Pushpalatha, T.; Ramachandra Reddy, P.; Sreenivasula Reddy, P.

    Hydroxyprogesterone caproate is one of the most effective and widely used drugs for the treatment of uterine bleeding and threatened miscarriage in women. Hydroxyprogesterone caproate was administered to pregnant rats in order to assess the effect of intraperitoneal exposure to supranormal levels of hydroxyprogesterone caproate on the male reproductive potential in the first generation. The cauda epididymal sperm count and motility decreased significantly in rats exposed to hydroxyprogesterone caproate during embryonic development, when compared with control rats. The levels of serum testosterone decreased with an increase in follicle stimulating hormone and luteinizing hormone in adult rats exposed to hydroxyprogesterone caproate during the embryonic stage. It was suggested that the impairment of male reproductive performance could be mediated through the inhibition of testosterone production.

  20. Mechanism of Forelimb Motor Function Restoration after Cervical Spinal Cord Hemisection in Rats: A Comparison of Juveniles and Adults.

    PubMed

    Hasegawa, Atsushi; Takahashi, Masahito; Satomi, Kazuhiko; Ohne, Hideaki; Takeuchi, Takumi; Sato, Shunsuke; Ichimura, Shoichi

    2016-01-01

    The aim of this study was to investigate forelimb motor function after cervical spinal cord injury in juvenile and adult rats. Both rats received a left segmental hemisection of the spinal cord after C3-C4 laminectomy. Behavioral evaluation of motor function was monitored and assessed using the New Rating Scale (NRS) and Forelimb Locomotor Scale (FLS) and by measuring the range of motion (ROM) of both the elbow and wrist. Complete left forelimb motor paralysis was observed in both rats. The NRS showed motor function recovery restored to 50.2 ± 24.7% in juvenile rats and 34.0 ± 19.8% in adult rats. FLS was 60.4 ± 26.8% in juvenile rats and 46.5 ± 26.9% in adult rats. ROM of the elbow and wrist were 88.9 ± 20.6% and 44.4 ± 24.1% in juvenile rats and 70.0 ± 29.2% and 40.0 ± 21.1% in adult rats. Thus, the NRS and ROM of the elbow showed a significant difference between age groups. These results indicate that left hemisection of the cervical spinal cord was not related to right-sided motor functions. Moreover, while motor paralysis of the left forelimb gradually recovered in both groups, the improvement was greater in juvenile rats.

  1. Physical exercise increases adult hippocampal neurogenesis in male rats provided it is aerobic and sustained

    PubMed Central

    Lensu, Sanna; Ahtiainen, Juha P.; Johansson, Petra P.; Koch, Lauren G.; Britton, Steven L.; Kainulainen, Heikki

    2016-01-01

    Key points Aerobic exercise, such as running, enhances adult hippocampal neurogenesis (AHN) in rodents.Little is known about the effects of high‐intensity interval training (HIT) or of purely anaerobic resistance training on AHN.Here, compared with a sedentary lifestyle, we report a very modest effect of HIT and no effect of resistance training on AHN in adult male rats.We found the most AHN in rats that were selectively bred for an innately high response to aerobic exercise that also run voluntarily and increase maximal running capacity.Our results confirm that sustained aerobic exercise is key in improving AHN. Abstract Aerobic exercise, such as running, has positive effects on brain structure and function, such as adult hippocampal neurogenesis (AHN) and learning. Whether high‐intensity interval training (HIT), referring to alternating short bouts of very intense anaerobic exercise with recovery periods, or anaerobic resistance training (RT) has similar effects on AHN is unclear. In addition, individual genetic variation in the overall response to physical exercise is likely to play a part in the effects of exercise on AHN but is less well studied. Recently, we developed polygenic rat models that gain differentially for running capacity in response to aerobic treadmill training. Here, we subjected these low‐response trainer (LRT) and high‐response trainer (HRT) adult male rats to various forms of physical exercise for 6–8 weeks and examined the effects on AHN. Compared with sedentary animals, the highest number of doublecortin‐positive hippocampal cells was observed in HRT rats that ran voluntarily on a running wheel, whereas HIT on the treadmill had a smaller, statistically non‐significant effect on AHN. Adult hippocampal neurogenesis was elevated in both LRT and HRT rats that underwent endurance training on a treadmill compared with those that performed RT by climbing a vertical ladder with weights, despite their significant gain in strength

  2. Mechanism of nuclear factor of activated T-cells mediated FasL expression in corticosterone -treated mouse Leydig tumor cells

    PubMed Central

    Chai, Wei-Ran; Chen, Yong; Wang, Qian; Gao, Hui-Bao

    2008-01-01

    Background Fas and FasL is important mediators of apoptosis. We have previously reported that the stress levels of corticosterone (CORT, glucocorticoid in rat) increase expression of Fas/FasL and activate Fas/FasL signal pathway in rat Leydig cells, which consequently leads to apoptosis. Moreover, our another study showed that nuclear factor of activated T-cells (NFAT) may play a potential role in up-regulation of FasL during CORT-treated rat Leydig cell. It is not clear yet how NFAT is involved in CORT-induced up-regulation of FasL. The aim of the present study is to investigate the molecular mechanisms of NFAT-mediated FasL expression in CORT-treated Leydig cells. Results Western blot analysis showed that NFAT2 expression is present in mouse Leydig tumor cell (mLTC-1). CORT-induced increase in FasL expression in mLTC-1 was ascertained by Western Blot analysis and CORT-induced increase in apoptotic frequency of mLTC-1 cells was detected by FACS with annexin-V labeling. Confocal imaging of NFAT2-GFP in mLTC-1 showed that high level of CORT stimulated NFAT translocation from the cytoplasm to the nucleus. RNA interference-mediated knockdown of NFAT2 significantly attenuated CORT-induced up-regulation of FasL expression in mLTC. These results corroborated our previous finding that NFAT2 is involved in CORT-induced FasL expression in rat Leydig cells and showed that mLTC-1 is a suitable model for investigating the mechanism of CORT-induced FasL expression. The analysis of reporter constructs revealed that the sequence between -201 and +71 of mouse FasL gene is essential for CORT-induced FasL expression. The mutation analysis demonstrated that CORT-induced FasL expression is mediated via an NFAT binding element located in the -201 to +71 region. Co-transfection studies with an NFAT2 expression vector and reporter construct containing -201 to +71 region of FasL gene showed that NFAT2 confer a strong inducible activity to the FasL promoter at its regulatory region. In

  3. Adult emotionality and neural plasticity as a function of adolescent nutrient supplementation in male rats

    PubMed Central

    McCall, Nora; Mahadevia, Darshini; Corriveau, Jennifer A.; Glenn, Melissa

    2016-01-01

    The present study explored the effects of supplementing male rats with either choline, omega-3 fatty acids, or phytoestrogens, from weaning into early adulthood, on emotionality and hippocampal plasticity. Because of the neuroprotective properties of these nutrients, we hypothesized that they would positively affect both behavior and hippocampal function when compared to non-supplemented control rats. To test this hypothesis, male Sprague Dawley rats were assigned to one of four nutrient conditions after weaning: 1) control (normal rat chow); 2) choline (supplemented in drinking water); 3) omega 3 fatty acids (daily oral supplements); or 4) phytoestrogens (supplemented in chow). After 4 weeks on their respective diets, a subset of rats began 3 weeks of behavioral testing, while the remaining behaviorally naïve rats were sacrificed after 6 weeks on the diets to assess numbers of adult-born hippocampal neurons using the immature neuron marker, doublecortin. The results revealed that choline supplementation affected emotional functioning; compared to rats in other diet conditions, rats in this group were less anxious in an open field and after exposure to predator odor and showed less behavioral despair after forced swimming. Similar behavioral findings were evident following supplementation with omega-3 fatty acids and phytoestrogens supplementation, though not on all tests and not to the same magnitude. Histological findings followed a pattern consistent with the behavioral findings: choline supplementation, followed by omega-3 fatty acid supplementation, but not phytoestrogen supplementation, significantly increased the numbers of new-born hippocampal neurons. Choline and omega −3 fatty acids have similar biological functions—affecting cell membranes, growth factor levels, and epigenetically altering gene transcription. Thus, the present findings suggest that targeting nutrients with these effects may be a viable strategy to combat adult psychopathologies

  4. Raloxifene prevents skeletal fragility in adult female Zucker Diabetic Sprague-Dawley rats.

    PubMed

    Hill Gallant, Kathleen M; Gallant, Maxime A; Brown, Drew M; Sato, Amy Y; Williams, Justin N; Burr, David B

    2014-01-01

    Fracture risk in type 2 diabetes is increased despite normal or high bone mineral density, implicating poor bone quality as a risk factor. Raloxifene improves bone material and mechanical properties independent of bone mineral density. This study aimed to determine if raloxifene prevents the negative effects of diabetes on skeletal fragility in diabetes-prone rats. Adult Zucker Diabetic Sprague-Dawley (ZDSD) female rats (20-week-old, n = 24) were fed a diabetogenic high-fat diet and were randomized to receive daily subcutaneous injections of raloxifene or vehicle for 12 weeks. Blood glucose was measured weekly and glycated hemoglobin was measured at baseline and 12 weeks. At sacrifice, femora and lumbar vertebrae were harvested for imaging and mechanical testing. Raloxifene-treated rats had a lower incidence of type 2 diabetes compared with vehicle-treated rats. In addition, raloxifene-treated rats had blood glucose levels significantly lower than both diabetic vehicle-treated rats as well as vehicle-treated rats that did not become diabetic. Femoral toughness was greater in raloxifene-treated rats compared with both diabetic and non-diabetic vehicle-treated ZDSD rats, due to greater energy absorption in the post-yield region of the stress-strain curve. Similar differences between groups were observed for the structural (extrinsic) mechanical properties of energy-to-failure, post-yield energy-to-failure, and post-yield displacement. These results show that raloxifene is beneficial in preventing the onset of diabetes and improving bone material properties in the diabetes-prone ZDSD rat. This presents unique therapeutic potential for raloxifene in preserving bone quality in diabetes as well as in diabetes prevention, if these results can be supported by future experimental and clinical studies.

  5. ESR1 inhibits hCG-induced steroidogenesis and proliferation of progenitor Leydig cells in mice

    PubMed Central

    Oh, Yeong Seok; Koh, Il Kyoo; Choi, Bomi; Gye, Myung Chan

    2017-01-01

    Oestrogen is an important regulator in reproduction. To understand the role of oestrogen receptor 1 (ESR1) in Leydig cells, we investigated the expression of ESR1 in mouse Leydig cells during postnatal development and the effects of oestrogen on steroidogenesis and proliferation of progenitor Leydig cells (PLCs). In Leydig cells, the ESR1 expression was low at birth, increased until postnatal day 14 at which PLCs were predominant, and then decreased until adulthood. In foetal Leydig cells, ESR1 immunoreactivity increased from birth to postnatal day 14. These suggest that ESR1 is a potential biomarker of Leydig cell development. In PLCs, 17β-estradiol and the ESR1-selective agonist propylpyrazoletriol suppressed human chorionic gonadotropin (hCG)-induced progesterone production and steroidogenic gene expression. The ESR2-selective agonist diarylpropionitrile did not affect steroidogenesis. In PLCs from Esr1 knockout mice, hCG-stimulated steroidogenesis was not suppressed by 17β-estradiol, suggesting that oestrogen inhibits PLC steroidogenesis via ESR1. 17β-estradiol, propylpyrazoletriol, and diarylpropionitrile decreased bromodeoxyuridine uptake in PLCs in the neonatal mice. In cultured PLCs, 17β-estradiol, propylpyrazoletriol, and diarylpropionitrile reduced hCG-stimulated Ki67 and Pcna mRNA expression and the number of KI67-positive PLCs, suggesting that oestrogen inhibits PLC proliferation via both ESR1 and ESR2. In PLCs, ESR1 mediates the oestrogen-induced negative regulation of steroidogenesis and proliferation. PMID:28266530

  6. Seasonal and experimental reactivation of Leydig cells of the bat Tadarida brasiliensis.

    PubMed

    Aoki, A

    1997-04-01

    The Leydig cells of the bat Tadarida brasiliensis, exhibit two well-defined periods of secretory activity that are intimately associated to the bat reproductive cycle. During the breeding season (August-September, late Winter and early Spring in the southern hemisphere), the interstitial tissue contains hypertrophic Leydig cells characterized ultrastructurally by the presence of pleomorphic mitochondria, depletion of lipid droplets, proliferation of membranes of agranular endoplasmic reticulum (AER) and enlargement of the Golgi complexes. By contrast, from Spring to Fall concurrent with regression of seminiferous tubules, the Leydig cells acquire a quiescent appearance with reduction in size and volume of AER membranes, atrophy of the Golgi complex and a massive storage of lipid droplets. The changes occurring in Leydig cells during the breeding season can be duplicated experimentally in non-breeding bats with exogenous stimulation with hCG. The gonadotropic treatment induces rapid changes in both interstitial cells and seminiferous tubules. The latter present evident signs of reactivation including proliferation of the spermatogenic cell line, permeation of the tubular lumen and depletion of lipid droplets. The Leydig cells display similar features to those found in the bat during the mating season at the peak of secretory activity. The bat T. brasiliensis is an excellent model to correlate the morphological organization of the Leydig cells with either seasonal fluctuations of its secretory activity or after experimental stimulation with gonadotropins.

  7. The role of testicular hormones and luteinizing hormone in spatial memory in adult male rats.

    PubMed

    McConnell, Sarah E A; Alla, Juliet; Wheat, Elizabeth; Romeo, Russell D; McEwen, Bruce; Thornton, Janice E

    2012-04-01

    Attempts to determine the influence of testicular hormones on learning and memory in males have yielded contradictory results. The present studies examined whether testicular hormones are important for maximal levels of spatial memory in young adult male rats. To minimize any effect of stress, we used the Object Location Task which is a spatial working memory task that does not involve food or water deprivation or aversive stimuli for motivation. In Experiment 1 sham gonadectomized male rats demonstrated robust spatial memory, but gonadectomized males showed diminished spatial memory. In Experiment 2 subcutaneous testosterone (T) capsules restored spatial memory performance in gonadectomized male rats, while rats with blank capsules demonstrated compromised spatial memory. In Experiment 3, gonadectomized male rats implanted with blank capsules again showed compromised spatial memory, while those with T, dihydrotestosterone (DHT), or estradiol (E) capsules demonstrated robust spatial memory, indicating that T's effects may be mediated by its conversion to E or to DHT. Gonadectomized male rats injected with Antide, a gonadotropin-releasing hormone receptor antagonist which lowers luteinizing hormone levels, also demonstrated spatial memory, comparable to that shown by T-, E-, or DHT-treated males. These data indicate that testicular androgens are important for maximal levels of spatial working memory in male rats, that testosterone may be converted to E and/or DHT to exert its effects, and that some of the effects of these steroid hormones may occur via negative feedback effects on LH.

  8. Effect of morphine, naloxone and histamine system on water intake in adult male rats.

    PubMed

    Eidi, Maryam; Oryan, Shahrbanoo; Eidi, Akram; Sepehrara, Leili

    2003-10-08

    The present study investigated the interaction between histamine and opioid systems on water intake in adult male rats. Intracerebroventricular (i.c.v.) injections were carried out in all experiments. Water intake was measured 1 h after drug injections. Administration of histamine (40-80 microg/rat) and naloxone (0.5-1 microg/rat) increased, while morphine (2.5 microg/rat), pyrilamine (25-50 microg/rat), the histamine H1 receptor antagonist, and ranitidine (10-20 microg/rat), the histamine H2 receptor antagonist, decreased water intake in isolated rats. Blockade of histamine H1 and H2 receptors attenuated the histamine-induced response. Pyrilamine, but not ranitidine, increased the inhibitory effect induced by morphine. Also, pharmacological blockade of histamine H1 and H2 receptors decreased the naloxone-induced effect on water intake. It is concluded that the histaminergic system may have a close interaction with morphine and naloxone on drinking behavior.

  9. Effect of acute ethanol and acute allopregnanolone on spatial memory in adolescent and adult rats.

    PubMed

    Chin, Vivien S; Van Skike, Candice E; Berry, Raymond B; Kirk, Roger E; Diaz-Granados, Jamie; Matthews, Douglas B

    2011-08-01

    The effects of ethanol differ in adolescent and adult rats on a number of measures. The evidence of the effects of ethanol on spatial memory in adolescents and adults is equivocal. Whether adolescents are more or less sensitive to ethanol-induced impairment of spatial memory acquisition remains unclear; with regard to the effects of acute ethanol on spatial memory retrieval there is almost no research looking into any age difference. Thus, we examined the effects of acute ethanol on spatial memory in the Morris Watermaze in adolescents and adults. Allopregnanolone (ALLO) is a modulator of the GABA(A) receptor and has similar behavioral effects as ethanol. We sought to also determine the effects of allopreganolone on spatial memory in adolescent and adults. Male adolescent (post natal [PN]28-30) and adult (PN70-72) rats were trained in the Morris Watermaze for 6 days and acute doses of ethanol (saline, 1.5 and 2.0 g/kg) or ALLO (vehicle, 9 and 18 mg/kg) were administered on Day 7. A probe trial followed on Day 8. As expected, there were dose effects; higher doses of both ethanol and ALLO impaired spatial memory. However, in both the ethanol and ALLO conditions adolescents and adults had similar spatial memory impairments. The current results suggest that ethanol and ALLO both impair hippocampal-dependent spatial memory regardless of age in that once learning has occurred, ethanol or ALLO does not differentially impair the retrieval of spatial memory in adolescents and adults. Given the mixed results on the effect of ethanol on cognition in adolescent rats, additional research is needed to ascertain the factors critical for the reported differential results.

  10. Beer promotes high levels of alcohol intake in adolescent and adult alcohol-preferring rats.

    PubMed

    Hargreaves, Garth A; Wang, Emyo Y J; Lawrence, Andrew J; McGregor, Iain S

    2011-08-01

    Previous studies suggest that high levels of alcohol consumption can be obtained in laboratory rats by using beer as a test solution. The present study extended these observations to examine the intake of beer and equivalent dilute ethanol solutions with an inbred line of alcohol-preferring P rats. In Experiment 1, male adolescent P rats and age-matched Wistar rats had access to either beer or equivalent ethanol solutions for 1h daily in a custom-built lickometer apparatus. In subsequent experiments, adolescent (Experiment 2) and adult (Experiment 3) male P rats were given continuous 24-h home cage access to beer or dilute ethanol solutions, with concomitant access to lab chow and water. In each experiment, the alcohol content of the beer and dilute ethanol solutions was gradually increased from 0.4, 1.4, 2.4, 3.4, 4.4, 5 to 10% EtOH (vol/vol). All three experiments showed a major augmentation of alcohol intake when rats were given beer compared with equivalent ethanol solutions. In Experiment 1, the overall intake of beer was higher in P rats compared with Wistar rats, but no strain difference was found during the 1-h sessions with plain ethanol consumption. Experiment 1 also showed that an alcohol deprivation effect was more readily obtained in rats with a history of consuming beer rather than plain ethanol solutions. In Experiments 2 and 3, voluntary beer intake in P rats represented ethanol intake of 10-15 g/kg/day, among the highest reported in any study with rats. This excessive consumption was most apparent in adolescent rats. Beer consumption markedly exceeded plain ethanol intake in these experiments except at the highest alcohol concentration (10%) tested. The advantage of using beer rather than dilute ethanol solutions in both selected and nonselected rat strains is therefore confirmed. Our findings encourage the use of beer with alcohol-preferring rats in future research that seeks to obtain high levels of alcohol self-administration.

  11. Aging-Dependent Changes in the Radiation Response of the Adult Rat Brain

    SciTech Connect

    Schindler, Matthew K. Forbes, M. Elizabeth; Robbins, Mike E.; Riddle, David R.

    2008-03-01

    Purpose: To assess the impact of aging on the radiation response in the adult rat brain. Methods and Materials: Male rats 8, 18, or 28 months of age received a single 10-Gy dose of whole-brain irradiation (WBI). The hippocampal dentate gyrus was analyzed 1 and 10 weeks later for sensitive neurobiologic markers associated with radiation-induced damage: changes in density of proliferating cells, immature neurons, total microglia, and activated microglia. Results: A significant decrease in basal levels of proliferating cells and immature neurons and increased microglial activation occurred with normal aging. The WBI induced a transient increase in proliferation that was greater in older animals. This proliferation response did not increase the number of immature neurons, which decreased after WBI in young rats, but not in old rats. Total microglial numbers decreased after WBI at all ages, but microglial activation increased markedly, particularly in older animals. Conclusions: Age is an important factor to consider when investigating the radiation response of the brain. In contrast to young adults, older rats show no sustained decrease in number of immature neurons after WBI, but have a greater inflammatory response. The latter may have an enhanced role in the development of radiation-induced cognitive dysfunction in older individuals.

  12. Cross-sensitization between testosterone and cocaine in adolescent and adult rats.

    PubMed

    Engi, Sheila A; Cruz, Fabio C; Crestani, Carlos C; Planeta, Cleopatra S

    2015-11-01

    Cocaine and anabolic-androgenic steroids are substances commonly co-abused. The use of anabolic steroids and cocaine has increased among adolescents. However, few studies investigated the consequences of the interaction between anabolic-androgenic steroids in animals' model of adolescence. We examined the effects of acute and repeated testosterone administration on cocaine-induced locomotor activity in adult and adolescent rats. Rats received ten once-daily subcutaneous (s.c.) injections of testosterone (10mg/kg) or vehicle. Three days after the last testosterone or vehicle injections rats received an intraperitoneal (i.p.) challenge injection of either saline or cocaine (10mg/kg). A different subset of rats was treated with a single injection of testosterone (10mg/kg) or vehicle and three days later was challenged with cocaine (10mg/kg, i.p.) or saline. Immediately after cocaine or saline injections the locomotor activity was recorded during forty minutes. Our results demonstrated that repeated testosterone induced locomotor sensitization to cocaine in adolescent but not adult rats.

  13. Behavioral changes in preweaning and adult rats exposed prenatally to low ionizing radiation

    SciTech Connect

    Norton, S.

    1986-04-01

    Seven behavioral tests were used to evaluate the postnatal behavior of rats after exposure on gestational Day 15 to 0, 25, 50, 75, or 125 r, whole body irradiation of the pregnant rat. Three tests were administered in the first 2 postnatal weeks (righting reflex, negative geotaxis, and reflex suspension); three tests were administered on postnatal Day 21 (modified open field, spatial maze, and continuous corridor). As adults, the rats were retested with the same tests as at 21 days and also in the running wheel. Dose-response decreases in body weight were greater in the younger rats. Some behavioral tests were not altered by irradiation, while others showed clear dose-response relationships, starting as low as 25 r. The early changes were characterized by light body weight, delays in behavioral development and hypoactivity, followed by recovery of some parameters with maturation. Eventually hyperactivity developed in adult rats after gestational irradiation. However, it cannot be concluded that either morphological or behavioral tests are more sensitive than neonatal body weight change for detection of damage from gestational irradiation.

  14. Toluene effects on the motor activity of adolescent, young-adult, middle-age and senescent male Brown Norway rats.

    PubMed

    MacPhail, R C; Farmer, J D; Jarema, K A

    2012-01-01

    Life stage is an important risk factor for toxicity. Children and aging adults, for example, are more susceptible to certain chemicals than are young adults. In comparison to children, relatively little is known about susceptibility in older adults. Additionally, few studies have compared toxicant susceptibility across a broad range of life stages. Results are presented for behavioral evaluations of male Brown Norway rats obtained as adolescents (1 month), or young (4 months), middle-age (12 months) and senescent (24 months) adults. Motor activity was evaluated in photocell devices during 30-min sessions. Age-related baseline characteristics and sensitivity to toluene (0, 300, 650, or 1000mg/kg, p.o.) were determined. In Experiment 1, young-adult, middle-age and senescent rats were treated with corn-oil vehicle before five weekly test sessions. Baselines of horizontal and vertical activity decreased with age, but each age-group's averages remained stable across weeks of testing. Baseline activity of older rats was more variable than that of the young adults; older rats were also more variable individually from week to week. Toluene (1000mg/kg) increased horizontal activity proportionately more in senescent rats (ca. 300% of control) than in middle-age or young-adult rats (ca.145-175% of control). Experiment 2 established toluene dose-effect functions in individual adolescent, young-adult, middle-age and senescent rats; each rat received all treatments, counterbalanced across four weekly sessions. Toluene produced dose-related increases in horizontal activity that increased proportionately with age. Experiment 3 replicated the effects of toluene (1000mg/kg) in Experiment 1, showing that toluene-induced increases in horizontal activity were greatest in the oldest rats. Collectively, the results show that aging increased susceptibility to toluene and also increased variability in toluene response. Given the rapid growth of the aged population, further research is

  15. Chronic nicotine differentially alters cocaine-induced locomotor activity in adolescent vs. adult male and female rats.

    PubMed

    Collins, Stephanie L; Izenwasser, Sari

    2004-03-01

    Tobacco use is prevalent in the adolescent population. It is a major concern because tobacco is highly addictive and has also been linked to illicit drug use. There is not much research, however, on the interaction between nicotine and other stimulant drugs in animal models of early adolescence. This study examined the effects of chronic nicotine alone and on cocaine-stimulated activity in male and female periadolescent rats compared to male and female adult rats. During the seven-day nicotine pretreatment period, nicotine increased locomotor activity in all groups compared to vehicle controls. Male and female adult rats and female periadolescent rats developed sensitization to the locomotor-activating effects of nicotine over the 7-day treatment period, while male periadolescent rats did not. All groups treated with nicotine, however, exhibited sensitization to nicotine-induced repetitive motion over the 7-day nicotine treatment period. On day 8, male periadolescent rats pretreated with nicotine were more markedly sensitized to the locomotor-activating effects of cocaine than male adult rats, while female rats pretreated with nicotine were not sensitized to cocaine. In contrast, male and female periadolescent rats, but not adult rats, had increased amounts of repetitive beam breaks induced by cocaine after nicotine pretreatment. Overall, it appears that cross-sensitization to cocaine is greater in periadolescent than in adult rats, and that males are more sensitized than females. Thus, it may be that nicotine use during adolescence carries a greater risk than during adulthood and that male adolescents may be particularly vulnerable to the risk of cocaine abuse after nicotine use. This information should be taken into account so as to help us better understand the development of drug addiction in adolescents compared to adults.

  16. Effect of amphetamine on adult male and female rats prenatally exposed to methamphetamine.

    PubMed

    Šlamberová, Romana; Macúchová, Eva; Nohejlová, Kateryna; Štofková, Andrea; Jurčovičová, Jana

    2014-01-01

    The aim of the present study was to examine the cross-sensitization induced by prenatal methamphetamine (MA) exposure to adult amphetamine (AMP) treatment in male and female rats. Rat mothers received a daily injection of MA (5 mg/kg) or saline throughout the gestation period. Adult male and female offspring (prenatally MA- or saline-exposed) were administered with AMP (5 mg/kg) or saline (1 ml/kg) in adulthood. Behaviour in unknown environment was examined in open field test (Laboras), active drug-seeking behaviour in conditioned place preference test (CPP), spatial memory in the Morris water maze (MWM), and levels of corticosterone (CORT) were analyzed by enzyme immunoassay (EIA). Our data demonstrate that in Laboras test, AMP treatment in adulthood increased general locomotion (time and distance travelled) regardless of the prenatal exposure and sex, while AMP increased exploratory activity (rearing) only in prenatally MA-exposed animals. AMP induced sensitization only in male rats, but not in females when tested drug-seeking behaviour in the CPP test. In the spatial memory MWM test, AMP worsened the performance only in females, but not in males. On the other hand, males swam faster after chronic AMP treatment regardless of the prenatal drug exposure. EIA analysis of CORT levels demonstrated higher level in females in all measurement settings. In males, prenatal MA exposure and chronic adult AMP treatment decreased CORT levels. Thus, our data demonstrated that adult AMP treatment affects behaviour of adult rats, their spatial memory and stress response in sex-specific manner. The effect is also influenced by prenatal drug exposure.

  17. Prenatal hypoxia impairs circadian synchronisation and response of the biological clock to light in adult rats

    PubMed Central

    Joseph, Vincent; Mamet, Julie; Lee, Fuchun; Dalmaz, Yvette; Van Reeth, Olivier

    2002-01-01

    The aim of this study was to test the hypothesis that prenatal hypoxia in rats might lead to consistent changes in the entrainment of the circadian clock by light. Pregnant female rats were placed in a chamber provided with hypoxic gas (10 % O2-90 % N2) at gestational day 5 and returned to normoxia before delivery. Once adult, rats born to hypoxic mothers had significant alterations in their circadian rhythm of locomotor activity (recorded in freely accessible running wheels). Under a regular 12/12 light/dark (LD) cycle, they showed a phase advance of their rhythm of activity (mean phase advance of 87 min) and were less active than control rats. After an abrupt 6 h phase delay in the LD cycle, rats from the prenatal hypoxic group (PNH) took significantly more time to resynchronise to the new LD cycle compared to controls (+53 %; 6.0 ± 1.5 vs. 9.2 ± 0.5 days respectively). Under constant darkness, PNH and control rats had a similar period of activity (24.27 ± 0.20 vs. 24.40 ± 0.13) but the response of PNH rats to a light pulse in the early subjective night was less marked than that of control rats (101 ± 9 vs. 158 ± 13 min). When submitted to acute restraint stress, PNH rats had a prolonged secretion of corticosterone compared to controls. These results indicate that prenatal hypoxia is a factor that has long lasting consequences for the functional output of the biological clock and the hormonal response to stress. PMID:12181309

  18. Propolis attenuates cobalt induced-nephrotoxicity in adult rats and their progeny.

    PubMed

    Garoui, El Mouldi; Troudi, Afef; Fetoui, Hamadi; Soudani, Nejla; Boudawara, Tahia; Zeghal, Najiba

    2012-11-01

    The aim of this study was to evaluate the biochemical changes in cobalt-exposed rats and to investigate the potential role of Tunisian propolis against the cobalt-induced renal damages. Twenty-four pregnant Wistar rats were divided into four groups and were treated as follows: group 1 (control) received distilled water; group 2 received 350 ppm of CoCl(2) in drinking water; group 3 received 350 ppm CoCl(2) in drinking water and a propolis-supplemented diet (1 g/100 g of diet); group 4 received a propolis-supplemented diet (1 g/100 g of diet) without cobalt. In the cobalt group, a significant decrease in body, absolute and relative weights was noted when compared to controls. The administration of cobalt to pregnant rats from the 14th day of pregnancy until day 14 after delivery resulted in an increased level of renal malondialdehyde, a decreased renal content of glutathione and antioxidant enzyme activities such as superoxide dismutase, catalase and glutathione peroxidase in lactating rats and their pups. A statistically significant increase in plasma urea and creatinine serum levels was seen in treated female rats and their pups. Histopathologically, the cobalt-administration induced degenerative changes in the kidney of lactating rats and their pups. When compared with cobalt-treated rats, those receiving the propolis supplementation (along with cobalt-treatment) had lower malondialdehyde levels, higher antioxidant activities and the cobalt-related histopathological changes in the kidneys were at lower severity. Our results suggested that the propolis might be a potential candidate agent against cobalt-induced nephrotoxicity in adult and juvenile rats when administered to female rats during the late pregnancy and the early postnatal period.

  19. Noise exposure during early development influences the acoustic startle reflex in adult rats.

    PubMed

    Rybalko, Natalia; Bureš, Zbyněk; Burianová, Jana; Popelář, Jiří; Grécová, Jolana; Syka, Josef

    2011-03-28

    Noise exposure during the critical period of postnatal development in rats results in anomalous processing of acoustic stimuli in the adult auditory system. In the present study, the behavioral consequences of an acute acoustic trauma in the critical period are assessed in adult rats using the acoustic startle reflex (ASR) and prepulse inhibition (PPI) of ASR. Rat pups (strain Long-Evans) were exposed to broad-band noise of 125 dB SPL for 8 min on postnatal day 14; at the age of 3-5 months, ASR and PPI of ASR were examined and compared with those obtained in age-matched controls. In addition, hearing thresholds were measured in all animals by means of auditory brainstem responses. The results show that although the hearing thresholds in both groups of animals were not different, a reduced strength of the startle reflex was observed in exposed rats compared with controls. The efficacy of PPI in exposed and control rats was also markedly different. In contrast to control rats, in which an increase in prepulse intensity was accompanied by a consistent increase in the efficacy of PPI, the PPI function in the exposed animals was characterized by a steep increase in inhibitory efficacy at low prepulse intensities of 20-30 dB SPL. A further increase of prepulse intensity up to 60-70 dB SPL caused only a small and insignificant change of PPI. Our findings demonstrate that brief noise exposure in rat pups results in altered behavioral responses to sounds in adulthood, indicating anomalies in intensity coding and loudness perception.

  20. PROLONGED PERFORMANCE OF A HIGH REPETITION LOW FORCE TASK INDUCES BONE ADAPTATION IN YOUNG ADULT RATS, BUT LOSS IN MATURE RATS

    PubMed Central

    Massicotte, Vicky S; Frara, Nagat; Harris, Michele Y; Amin, Mamta; Wade, Christine K; Popoff, Steven N; Barbe, Mary F

    2015-01-01

    We have shown that prolonged repetitive reaching and grasping tasks lead to exposure-dependent changes in bone microarchitecture and inflammatory cytokines in young adult rats. Since aging mammals show increased tissue inflammatory cytokines, we sought here to determine if aging, combined with prolonged performance of a repetitive upper extremity task, enhances bone loss. We examined the radius, forearm flexor muscles, and serum from 16 mature (14–18 mo of age) and 14 young adult (2.5–6.5 mo of age) female rats after performance of a high repetition low force (HRLF) reaching and grasping task for 12 weeks. Young adult HRLF rats showed enhanced radial bone growth (e.g., increased trabecular bone volume, osteoblast numbers, bone formation rate, and mid-diaphyseal periosteal perimeter), compared to age-matched controls. Mature HRLF rats showed several indices of radial bone loss (e.g., decreased trabecular bone volume, and increased cortical bone thinning, porosity, resorptive spaces and woven bone formation), increased osteoclast numbers and inflammatory cytokines, compared to age-matched controls and young adult HRLF rats. Mature rats weighed more yet had lower maximum reflexive grip strength, than young adult rats, although each age group was able to pull at the required reach rate (4 reaches/min) and required submaximal pulling force (30 force-grams) for a food reward. Serum estrogen levels and flexor digitorum muscle size were similar in each age group. Thus, mature rats had increased bone degradative changes than in young adult rats performing the same repetitive task for 12 weeks, with increased inflammatory cytokine responses and osteoclast activity as possible causes. PMID:26517953

  1. Resveratrol improves reproductive parameters of adult rats varicocelized in peripuberty.

    PubMed

    Mendes, Talita Biude; Paccola, Camila Cicconi; de Oliveira Neves, Flávia Macedo; Simas, Joana Noguères; da Costa Vaz, André; Cabral, Regina Elisabeth L; Vendramini, Vanessa; Miraglia, Sandra Maria

    2016-07-01

    The aim of this study was to investigate the protective action of resveratrol against the reproductive damage caused by left-sided experimental varicocele. There was a reduction of testicular major axis in the varicocele group when compared with the other groups; the testicular volume was reduced in varicocele group in comparison to the sham-control and resveratrol groups. The frequency of morphologically abnormal sperm was higher in varicocele and varicocele treated with resveratrol groups than in sham-control and resveratrol groups. The frequency of sperm with 100% of mitochondrial activity and normal acrosome integrity were lower in varicocele group than in varicocele treated with resveratrol, sham-control and resveratrol groups. Sperm motility was also reduced in varicocele group than in other groups. The sperm DNA fragmentation was higher in varicocele group than in other groups. Testicular levels of malondialdehyde were higher in varicocele and varicocele treated with resveratrol groups. The varicocele and varicocele treated with resveratrol groups had a significantly higher frequency of TUNEL-positive cells than sham-control and resveratrol groups; however, immunolabeling of the testes from varicocele treated with resveratrol group showed a lower number of apoptotic germ cells in comparison with the left testis of rats of the varicocele group. Reproductive alterations produced by varicocele from peripuberty were reduced by resveratrol in adulthood. Resveratrol should be better investigated as an adjuvant in the treatment of varicocele. Daily administration of resveratrol to rats with varicocele from peripuberty improves sperm quality in the adulthood.

  2. Social and non-social anxiety in adolescent and adult rats after repeated restraint.

    PubMed

    Doremus-Fitzwater, Tamara L; Varlinskaya, Elena I; Spear, Linda P

    2009-06-22

    Adolescence is associated with potentially stressful challenges, and adolescents may differ from adults in their stress responsivity. To investigate possible age-related differences in stress responsiveness, the consequences of repeated restraint stress (90 min/day for 5 days) on anxiety, as indexed using the elevated plus-maze (EPM) and modified social interaction (SI) tests, were assessed in adolescent and adult Sprague-Dawley male and female rats. Control groups at each age included non-stressed and socially deprived animals, with plasma corticosterone (CORT) levels also measured in another group of rats on days 1 and 5 of stress (sampled 0, 30, 60, 90, and 120 min following restraint onset). While repeatedly restrained animals exhibited similar anxiety levels compared to non-stressed controls in the EPM, restraint stress increased anxiety at both ages in the SI test (as indexed by reduced social investigation and social preference). Daily weight gain measurements, however, revealed more marked stress-related suppression of body weight in adolescents versus adults. Analysis of stress-induced increases in CORT likewise showed that adolescents demonstrated less habituation than adults, embedded within typical sex differences in CORT magnitude (females greater than males) and age differences in CORT recovery (adolescents slower than adults). Despite no observable age-related differences in the behavioral response to restraint, adolescents were more sensitive to the repeated stressor in terms of physiological indices of attenuated weight gain and habituation of stress-induced CORT.

  3. Effect of the antioxidant dibunol on adrenocortical, thyroid, and adenohypopyseal function in adult and old rats

    SciTech Connect

    Gorban', E.N.

    1986-04-01

    This paper studies the effect of dibunol (4-methyl-2,6-di-tert-butylphenol) (D) on the function of the adrenal cortex, thyroid gland, and adenhypophysis, which produces trophic hormones for the other two glands. Experiments were carried out on adult rats. After injection of D concentrations of corticosterone (CS), triodothyronine (T/sub 3/), ACTH, and thyrotrophin (TSH) in the blood plasma and the CS concentration in tssue of the adenohypophysis were determined. It is shown that injection of D caused biphasic changes in the CS concentration in both tissues studied in adult and old animals.

  4. Effects of cyclophosphamide on the kaolin consumption (pica behavior) in five strains of adult male rats.

    PubMed

    Tohei, Atsushi; Kojima, Shu-ichi; Ikeda, Masashi; Hokao, Ryoji; Shinoda, Motoo

    2011-07-01

    It is known that pica, the consumption of non-nutritive substances such as kaolin, can be induced by administration of toxins or emetic agents in rats. In the present study, we examined the effects of intraperitoneal (i.p.) administration of cyclophosphamide on pica behavior and on the concentration of 5-hydroxyindoleacetic acids (5HIAA) in cerebrospinal fluid (CSF) in the following five strains of adult male rats: Sprague Dawley (SD), Wistar, Fischer 344 (F344), Wistar-Imamichi (WI) and Long Evans (LE). Cyclophosphamide (25 mg or 50 mg/kg) was injected (i.p.) into the rats and kaolin and food intake were measured at 24 hr after injection. The animals were anesthetized with urethane (1 g/kg) at 3 hr after injection of cyclophosphamide, and CSF was collected from the cisterna magna. WI and LE rats clearly showed pica behavior as compared with the other strains. In LE rats, the concentration of 5HIAA in CSF also increased in a dose-dependent manner of cyclophosphamide. The pretreatment with ondansetron (5-HT(3) antagonist) restored both changes (kaolin consumption and 5HIAA levels) induced by cyclophosphamide. These results suggest that the LE rat is sensitive to cyclophosphamide, that pica induced by cyclophosphamide mimics many aspects of emesis including the serotonergic response in the central nervous system and that use of the pica model would be a practical method for evaluating the effects of antiemetic drugs in addition to the mechanism of emesis.

  5. Novel Targets for the Transcription Factors MEF2 in MA-10 Leydig Cells.

    PubMed

    Di-Luoffo, Mickaël; Daems, Caroline; Bergeron, Francis; Tremblay, Jacques J

    2015-07-01

    Testosterone production by Leydig cells is a tightly regulated process requiring synchronized expression of several steroidogenic genes by numerous transcription factors. Myocyte enhancer factor 2 (MEF2) are transcription factors recently identified in somatic cells of the male gonad. In other tissues, MEF2 factors are essential regulators of organogenesis and cell differentiation. So far in the testis, MEF2 factors were found to regulate Leydig cell steroidogenesis by controlling Nr4a1 and Star gene expression. To expand our understanding of the role of MEF2 in Leydig cells, we performed microarray analyses of MEF2-depleted MA-10 Leydig cells, and the results were analyzed using Partek and Ingenuity Pathway Analysis software. Several genes were differentially expressed in MEF2-depleted Leydig cells, and 16 were validated by quantitative RT-PCR. A large number of these genes are known to be involved in fertility, gonad morphology, and steroidogenesis. These include Ahr, Bmal1, Cyp1b1, Hsd3b1, Hsd17b7, Map2k1, Nr0b2, Pde8a, Por, Smad4, Star, and Tsc22d3, which were all downregulated in the absence of MEF2. In silico analyses revealed the presence of MEF2-binding sites within the first 2 kb upstream of the transcription start site of the Por, Bmal1, and Nr0b2 promoters, suggesting direct regulation by MEF2. Using transient transfections in MA-10 Leydig cells, small interfering RNA knockdown, and a MEF2-Engrailed dominant negative, we found that MEF2 activates the Por, Bmal1, and Nr0b2 promoters and that this requires an intact MEF2 element. Our results identify novel target genes for MEF2 and define MEF2 as an important regulator of Leydig cell function and male reproduction.

  6. The effect of midazolam on mouse Leydig cell steroidogenesis and apoptosis.

    PubMed

    So, Edmund Cheung; Chang, Ya-Ting; Hsing, Chung-His; Poon, Paul Wai-Fung; Leu, Sew-Fen; Huang, Bu-Miin

    2010-02-01

    The peripheral-type benzodiazepine receptor (PBR), a putative receptor in Leydig cells, modulates steroidogenesis. Since benzodiazepines are commonly used in regional anesthesia, their peripheral effects need to be defined. Therefore, this study set out to investigate in vitro effects of the benzodiazepine midazolam (MDZ) on Leydig cell steroidogenesis, and the possible underlying mechanisms. The effects of MDZ on steroidogenesis in primary mouse Leydig cells and MA-10 Leydig tumor cells were determined by radioimmunoassay. PBR, P450scc, 3beta-HSD and StAR protein expression induced by MDZ was determined by Western blotting. Inhibitors of the signal transduction pathway and a MDZ antagonist were used to investigate the intracellular cascades activated by MDZ. In both cell types, MDZ-stimulated steroidogenesis in dose- and time-dependent manners, and induced the expression of PBR and StAR proteins, but had no effect on P450scc and 3beta-HSD expressions. Moreover, H89 (PKA inhibitor) and GF109203X (PKC inhibitor) attenuated MDZ-stimulated steroid production. Interestingly, the MDZ antagonist (flumazenil) did not decrease MDZ-induced steroid production in both cell types. These results highly indicated that MDZ-induced steroidogenesis in mouse Leydig cells via PKA and PKC pathways, along with the expression of PBR and StAR proteins. In addition, MDZ at high dosages induced rounding-up, membrane blebbing, and then death in MA-10 cells. In conclusion, midazolam could induce Leydig tumor cell steroidogenesis, and high dose of midazolam could induce apoptosis in Leydig tumor cells.

  7. Perfluorooctane sulfonate effects on the reproductive axis in adult male rats.

    PubMed

    López-Doval, S; Salgado, R; Pereiro, N; Moyano, R; Lafuente, A

    2014-10-01

    Perfluorooctane sulfonate (PFOS) is a neurotoxic agent and it can disrupt the endocrine system activity. This work was undertaken to evaluate the possible effects of PFOS exposure on the hypothalamic-pituitary-testicular axis (HPT) in adult male rats, and to evaluate the possible morphological alterations induced by PFOS in the endocrine tissues of this axis. Adult male rats were orally treated with 0.5; 1.0; 3.0 and 6.0 mg of PFOS/kg/day for 28 days. After PFOS exposure, hypothalamic noradrenaline concentration increased in the anterior hypothalamus and in the median eminence, not changing in the mediobasal hypothalamus. PFOS treated rats presented a decrease of the gonadotropin releasing hormone (GnRH) gene expression, increasing the mRNA levels of the luteinizing hormone (LH) in rats treated with all doses administered except with the dose of 6 mg/kg/day. PFOS also induced a raise of the follicle stimulating hormone (FSH) gene expression in the animals exposed to 0.5 and 1.0 mg of PFOS/kg/day. After PFOS exposure, hypothalamic GnRH concentration was modified, LH and testosterone release was inhibited and FSH secretion was stimulated. Moreover, PFOS induced several histopathological alterations in the hypothalamus, pituitary gland and testis. The results obtained in the present study suggest in general terms that PFOS can inhibit the physiological activity of the reproductive axis in adult male rats, which could be explained, at least in part, by the structural alterations showed in the animals exposed to this chemical: very dense chromatin, condensed ribosomes and a loss of the morphology in the hypothalamus; a degeneration of the gonadotrophic cells, as well as a loss and degeneration of the spermatozoids and a very marked edema in the testis.

  8. Airborne particles of the california central valley alter the lungs of healthy adult rats.

    PubMed Central

    Smith, Kevin R; Kim, Seongheon; Recendez, Julian J; Teague, Stephen V; Ménache, Margaret G; Grubbs, David E; Sioutas, Constantinos; Pinkerton, Kent E

    2003-01-01

    Epidemiologic studies have shown that airborne particulate matter (PM) with a mass median aerodynamic diameter < 10 microm (PM10) is associated with an increase in respiratory-related disease. However, there is a growing consensus that particles < 2.5 microm (PM2.5), including many in the ultrafine (< 0.1 microm) size range, may elicit greater adverse effects. PM is a complex mixture of organic and inorganic compounds; however, those components or properties responsible for biologic effects on the respiratory system have yet to be determined. During the fall and winter of 2000-2001, healthy adult Sprague-Dawley rats were exposed in six separate experiments to filtered air or combined fine (PM2.5) and ultrafine portions of ambient PM in Fresno, California, enhanced approximately 20-fold above outdoor levels. The intent of these studies was to determine if concentrated fine/ultrafine fractions of PM are cytotoxic and/or proinflammatory in the lungs of healthy adult rats. Exposures were for 4 hr/day for 3 consecutive days. The mean mass concentration of particles ranged from 190 to 847 microg/m3. PM was enriched primarily with ammonium nitrate, organic and elemental carbon, and metals. Viability of cells recovered by bronchoalveolar lavage (BAL) from rats exposed to concentrated PM was significantly decreased during 4 of 6 weeks, compared with rats exposed to filtered air (p< 0.05). Total numbers of BAL cells were increased during 1 week, and neutrophil numbers were increased during 2 weeks. These observations strongly suggest exposure to enhanced concentrations of ambient fine/ultrafine particles in Fresno is associated with mild, but significant, cellular effects in the lungs of healthy adult rats. PMID:12782490

  9. Different forms of oestrogen rapidly upregulate cell proliferation in the dentate gyrus of adult female rats.

    PubMed

    Barha, C K; Lieblich, S E; Galea, L A M

    2009-03-01

    Oestrogens are known to exert significant structural and functional effects in the hippocampus of adult rodents. The dentate gyrus of the hippocampus retains the ability to produce neurones throughout adulthood and 17beta-oestradiol has been shown to influence hippocampal neurogenesis in adult female rats. The effects of other oestrogens, such as oestrone and 17alpha-oestradiol, on neurogenesis have not been investigated. The present study aimed to investigate the effects of 17beta-oestradiol, oestradiol benzoate, oestrone, and 17alpha-oestradiol on cell proliferation in ovariectomised adult female rats at two different time points. Young ovariectomised female rats were injected with one of the oestrogens at one of three doses. In Experiment 1, rats were exposed to the hormone for 4 h and, in Experiment 2, rats were exposed to the hormone for 30 min prior to 5-bromo-2-deoxyuridine injection to label proliferating cells and their progeny. We found that young ovariectomised females responded with increased cell proliferation to most oestrogens, except oestradiol benzoate, after 30 min of exposure. However, administration of oestrogens for a longer time interval was ineffective at increasing cell proliferation. After 30 min, 17beta-oestradiol and oestrone increased cell proliferation at low (0.3 microg) and high (10 microg) doses, whereas 17alpha-oestradiol increased cell proliferation at medium (1 microg) and high doses. The results of the present study indicate that different oestrogens rapidly increase cell proliferation in a dose-dependent manner, possibly through a nonclassical, nongenomic mechanism. Future experiments should focus on further elucidating the specific pathways utilised by each oestrogen. These results have important therapeutic implications because it may be possible to use 17alpha-oestradiol and lower doses of oestrogens in hormone replacement therapies.

  10. Neuroanatomical distribution of galectin-3 in the adult rat brain.

    PubMed

    Yoo, Hong-Il; Kim, Eu-Gene; Lee, Eun-Jin; Hong, Sung-Young; Yoon, Chi-Sun; Hong, Min-Ju; Park, Sang-Jin; Woo, Ran-Sook; Baik, Tai-Kyoung; Song, Dae-Yong

    2017-04-01

    Galectin-3 is a member of the lectin subfamily that enables the specific binding of β-galactosides. It is expressed in a broad spectrum of species and organs, and is known to have various functions related to cell adhesion, signal transduction, and proinflammatory responses. Although, expression of galectin-3 in some activated neuroglia under neuroinflammation has been well documented in the central nervous system, little is known about the neuronal expression and distribution of galectin-3 in normal brain. To describe the cellular and neuroanatomical expression map of galectin-3, we performed galectin-3 immunohistochemistry on the entire normal rat brain and subsequently analyzed the neuronal distribution. Galectin-3 expression was observed not only in some neuroglia but also in neurons. Neuronal expression of galectin-3 was observed in many functional parts of the cerebral cortex and various other subcortical nuclei in the hypothalamus and brainstem. Neuroanatomical analysis revealed that robust galectin-3 immuno-signals were present in many hypothalamic nuclei related to a variety of physiological functions responsible for mediating anxiety responses, energy balance, and neuroendocrine regulation. In addition, the regions highly connected with these hypothalamic nuclei also showed intense galectin-3 expression. Moreover, multiple key regions involved in regulating autonomic functions exhibited high levels of galectin-3 expression. In contrast, the subcortical nuclei responsible for the control of voluntary motor functions and limbic system exhibited no galectin-3 immunoreactivity. These observations suggest that galectin-3 expression in the rat brain seems to be regulated by developmental cascades, and that functionally and neuroanatomically related brain nuclei constitutively express galectin-3 in adulthood.

  11. Neurones in the adult rat anterior medullary velum.

    PubMed

    Ibrahim, M; Menoud, P A; Celio, M R

    2000-03-27

    The presence of neurones in the rat anterior medullary velum (AMV) has been investigated by using antibodies to the calcium-binding proteins, parvalbumin (PV), calretinin (CR), and calbindin-D28k (CB). Disparate populations of mainly GABAergic neurones were located in the rostral and caudal regions of the AMV. The rostral region of the AMV was characterised by GABAergic CR-labelled or PV-labelled neurones. CR-labelled neurones were bipolar or multipolar with round to ovoid somata (diameters between 8 and 12 microm), and rostrocaudally running dendrites forming a network. PV-labelled neurones had round somata (diameters between 6 and 10 microm) and were bi-tufted, with beaded dendrites. Both CR-labelled and PV-labelled dendrites formed punctate pericellular associations with unlabelled somatic profiles. In the caudal region of the AMV, PV-labelled neurones were GABAergic, multipolar cells, having round somata (diameters between 9 and 12 microm), with either beaded or nonbeaded dendrites forming a network of interconnecting dendrites. PV-labelled pericellular associations were made around both PV-labelled and unlabelled somatic profiles. CR labelled unipolar brush cells (UBCs) were not GABAergic. UBCs were characterised by a round to oval somata (10-15 microm in diameter) from which a single primary dendrite emerged to form a distal expansion having small terminal dendrites. From the distal expansion, there also appeared to be CR-labelled processes emanating and extending for up to 250 microm. CB occasionally labelled "Purkinje-like cells" (PLCs). The rat AMV is a more complex structure than first envisaged with the presence of predominantly inhibitory neurones expressing different calcium-binding proteins. Functional and anatomic aspects of this circuitry are further discussed.

  12. CNS depressive role of aqueous extract of Spinacia oleracea L. leaves in adult male albino rats.

    PubMed

    Das, Sutapa; Guha, Debjani

    2008-03-01

    Treatment with Spinacia oleracea extract (SO; 400 mg/kg body weight) decreased the locomotor activity, grip strength, increased pentobarbitone induced sleeping time and also markedly altered pentylenetetrazole induced seizure status in Holtzman strain adult male albino rats. SO increased serotonin level and decreased both norepinephrine and dopamine levels in cerebral cortex, cerebellum, caudate nucleus, midbrain and pons and medulla. Result suggests that SO exerts its CNS depressive effect in PTZ induced seizure by modulating the monoamines in different brain areas.

  13. Use of the light/dark test for anxiety in adult and adolescent male rats.

    PubMed

    Arrant, Andrew E; Schramm-Sapyta, Nicole L; Kuhn, Cynthia M

    2013-11-01

    The light/dark (LD) test is a commonly used rodent test of unconditioned anxiety-like behavior that is based on an approach/avoidance conflict between the drive to explore novel areas and an aversion to brightly lit, open spaces. We used the LD test to investigate developmental differences in behavior between adolescent (postnatal day (PN) 28-34) and adult (PN67-74) male rats. We investigated whether LD behavioral measures reflect anxiety-like behavior similarly in each age group using factor analysis and multiple regression. These analyses showed that time in the light compartment, percent distance in the light, rearing, and latency to emerge into the light compartment were measures of anxiety-like behavior in each age group, while total distance traveled and distance in the dark compartment provided indices of locomotor activity. We then used these measures to assess developmental differences in baseline LD behavior and the response to anxiogenic drugs. Adolescent rats emerged into the light compartment more quickly than adults and made fewer pokes into the light compartment. These age differences could reflect greater risk taking and less risk assessment in adolescent rats than adults. Adolescent rats were less sensitive than adults to the anxiogenic effects of the benzodiazepine inverse agonist N-methyl-β-carboline-3-carboxamide (FG-7142) and the α₂ adrenergic antagonist yohimbine on anxiety-like behaviors validated by factor analysis, but locomotor variables were similarly affected. These data support the results of the factor analysis and indicate that GABAergic and noradrenergic modulation of LD anxiety-like behavior may be immature during adolescence.

  14. Axonal Elongation into Peripheral Nervous System ``Bridges'' after Central Nervous System Injury in Adult Rats

    NASA Astrophysics Data System (ADS)

    David, Samuel; Aguayo, Albert J.

    1981-11-01

    The origin, termination, and length of axonal growth after focal central nervous system injury was examined in adult rats by means of a new experimental model. When peripheral nerve segments were used as ``bridges'' between the medulla and spinal cord, axons from neurons at both these levels grew approximately 30 millimeters. The regenerative potential of these central neurons seems to be expressed when the central nervous system glial environment is changed to that of the peripheral nervous system.

  15. Localization of Sonic hedgehog secreting and receiving cells in the developing and adult rat adrenal cortex.

    PubMed

    Guasti, Leonardo; Paul, Alex; Laufer, Ed; King, Peter

    2011-04-10

    Sonic hedgehog signaling was recently demonstrated to play an important role in murine adrenal cortex development. The organization of the rat adrenal differs from that of the mouse, with the zona glomerulosa and zona fasciculata separated by an undifferentiated zone in the rat, but not in the mouse. In the present study we aimed to determine the mRNA expression patterns of Sonic hedgehog and the hedgehog signaling pathway components Patched-1 and Gli1 in the developing and adult rat adrenal. Sonic hedgehog expression was detected at the periphery of the cortex in cells lacking CYP11B1 and CYP11B2 expression, while signal-receiving cells were localized in the overlying capsule mesenchyme. Using combined in situ hybridization and immunohistochemistry we found that the cells expressing Sonic hedgehog lie between the CYP11B2 and CYP11B1 layers, and thus Sonic hedgehog expression defines one cell population of the undifferentiated zone.

  16. Biochemical effect of a ketogenic diet on the brains of obese adult rats.

    PubMed

    Mohamed, Hoda E; El-Swefy, Sahar E; Rashed, Leila A; Abd El-Latif, Sally K

    2010-07-01

    Excess weight, particularly abdominal obesity, can cause or exacerbate cardiovascular and metabolic disease. Obesity is also a proven risk factor for Alzheimer's disease (AD). Various studies have demonstrated the beneficial effects of a ketogenic diet (KD) in weight reduction and in modifying the disease activity of neurodegenerative disorders, including AD. Therefore, in this study we examined the metabolic and neurodegenerative changes associated with obesity and the possible neuroprotective effects of a KD in obese adult rats. Compared with obese rats fed a control diet, obese rats fed a KD showed significant weight loss, improvement in lipid profiles and insulin resistance, and upregulation of adiponectin mRNA expression in adipose tissue. In addition, the KD triggered significant downregulation of brain amyloid protein precursor, apolipoprotein E and caspase-3 mRNA expression, and improvement of brain oxidative stress responses. These findings suggest that a KD has anti-obesity and neuroprotective effects.

  17. On Again, Off Again Effects of Gonadectomy on the Acoustic Startle Reflex in Adult Male Rats

    PubMed Central

    Turvin, J.C.; Messer, W.S.

    2007-01-01

    Numerous studies have shown sex and/or estrous cycle differences in the acoustic startle reflex (ASR) and its prepulse inhibition (PPI) in humans and animals. However, few have examined the effects of hormone manipulations on these behaviors. This study paired gonadectomy (GDX) in adult male rats with testing for ASR and PPI at 2, 4, 9, 16, 23, 30 and 37 days after surgery. Initial studies of control, GDX and GDX rats given testosterone propionate revealed no group differences in PPI, but did reveal phasic facilitation of the ASR in GDX rats that was greatest on the first and final testing sessions and that was attenuated by testosterone. A second study addressing roles for estrogen and androgen signaling tested new control and GDX rats along with GDX rats given estradiol or the non-aromatizable androgen, 5-alpha-dihydrotestosterone and revealed no group differences in PPI, and increases in ASR in GDX rats that were largest during the first and final testing sessions and that were attenuated by both hormone replacements. However, while responses in GDX rats given testosterone were similar to those of controls, ASR in estradiol- and to a lesser extent in dihydrotestosterone-treated GDX rats were typically lower than in controls. This may suggest that hormone modulation of the ASR requires synergistic estrogen and androgen actions. In the male brain where this can be achieved by local steroid metabolism, the enzymes responsible, e.g., aromatase, could help identify loci in the startle circuitry that may be especially relevant for the hormone modulation observed. PMID:17169383

  18. Reproductive toxicity of a single dose of 1,3-dinitrobenzene in two ages of young adult male rats

    EPA Science Inventory

    These studies evaluated the reproductive response and the possible influence of testicular maturation on the reproductive parameters, in male rats treated with 1,3-dinitrobenzene (m-DNB). Young adult male rats (75 or 105 days of age) were given a single oral dose of 0, 8, 16, 24,...

  19. Leptin Attenuates the Contractile Function of Adult Rat Cardiomyocytes Involved in Oxidative Stress and Autophagy

    PubMed Central

    Luo, Liu-Jin; Liu, Ying-Ping; Yuan, Xun; Zhang, Gui-Ping; Hou, Ning; Wu, Xiao-Qian; Luo, Jian-Dong; Zhang, Gen-Shui

    2016-01-01

    Background Leptin has been identified as an important protein involved in obesity. As a chronic metabolic disorder, obesity is associated with a high risk of developing cardiovascular and metabolic diseases, including heart failure. The aim of this paper was to investigate the effects and the mechanism of leptin on the contractile function of cardiomyocytes in the adult rat. Methods Isolated adult rat cardiomyocytes were exposed to leptin (1, 10, and 100 nmol/L) for 1 hour. The calcium transients and the contraction of adult rat cardiomyocytes were recorded with SoftEdge MyoCam system. Apocynin, tempol and rapamycin were added respectively, and Western blotting was employed to evaluate the expression of LC3B and Beclin-1. Results The peak shortening and maximal velocity of shortening/relengthening (± dL/dtmax) of cell shortening were significantly decreased, and the time to 50% relengthening was prolonged with leptin perfusion. Leptin also significantly reduced the baseline, peak and time to 50% baseline of calcium transient. Leptin attenuated autophagy as indicated by decreased LC3-II and Beclin-1. All of the abnormalities were significantly attenuated by apocynin, tempol or rapamycin. Conclusions Our results indicated that leptin depressed the intracellular free calcium and myocardial systolic function via increasing oxidative stress and inhibiting autophagy. PMID:27899860

  20. Morphological alterations of central nervous system (CNS) myelin in vanadium (V)-exposed adult rats.

    PubMed

    García, Graciela B; Quiroga, Ariel D; Stürtz, Nelson; Martinez, Alejandra I; Biancardi, María E

    2004-08-01

    In the present work we show morphological data of the in vivo susceptibility of CNS myelin to sodium metavanadate [V(+5)] in adult rats. The possible role of vanadium in behavioral alterations and in brain lipid peroxidation was also investigated. Animals were injected intraperitoneally (i.p.) with 3 mg/kg body weight (bw) of sodium metavanadate [1.25 V/kg bw/day] for 5 consecutive days. Open field and rotarod tests were performed the day after the last dose had been administered and then animals were sacrificed by different methods for histological and lipid peroxidation studies. The present results show that intraperitoneal administration of V(+5) to adult rats resulted in changes in locomotor activity, specific myelin stainings and lipid peroxidation in some brain areas. They support the notion that CNS myelin could be a preferential target of V(+5)-mediated lipid peroxidation in adult rats. The mechanisms underlying this action could affect the myelin sheath leading to behavioral perturbations.

  1. A new protocol for cultivation of predegenerated adult rat Schwann cells.

    PubMed

    Pietrucha-Dutczakv, Marita; Marcol, Wiesław; Francuz, Tomasz; Gołka, Dariusz; Lewin-Kowalik, Joanna

    2014-09-01

    The purpose of this study was to optimize the methodology of cultivation of predegenerated Schwann cells (SCs). SCs were isolated from 7-day-predegenerated sciatic nerves of adult rats. We applied commercially available culture medium for cultivation of endothelial cells endothelial cell culture medium (EBM-2) instead of Dulbecco's Modified Eagle's Medium commonly used to culture adult Schwann cells. Additionally, cell culture medium was supplemented with factors specifically supporting SCs growth as: bovine pituitary extract (5 μg/ml), heregulin (40 ng/ml) and insulin (2.5 ng/ml). Similarly to the reports of others authors, we did not observe any beneficial effects of Forskolin application, so we didn't supplement our medium with it. Cell culture purity was determined by counting the ratio of GFAP, N-Cadherin and NGFR p75-positive cells to total number of cells. About 94-97 % of cells were confirmed as Schwann cells. As a result, we obtained sufficient number and purity of Schwann cells to be applied in different experimental models in rats. EBM-2 medium coated with fibronectin was the best for cultivation of adult rat Schwann cells.

  2. Antipsychotic-induced suppression of locomotion in juvenile, adolescent and adult rats.

    PubMed

    Wiley, Jenny L

    2008-01-14

    Schizophrenia is a serious psychiatric disorder that is most frequently treated with the administration of antipsychotics. Although onset of schizophrenia typically occurs in late adolescence, the majority of preclinical research on the behavioral effects of antipsychotics and their mechanism(s) of action has been conducted on adult male animals. In this study, the acute effects of haloperidol (0.03-0.3 mg/kg, i.p.) and clozapine (1-10 mg/kg, i.p.) on locomotor activity were examined in juvenile [postnatal day 22 (PN22)], adolescent (PN40), and adult (>PN70) rats of both sexes. Subsequently, in order to determine whether tolerance to the activity suppressive effects of these drugs would occur in adolescents, PN40 rats were dosed and assessed for an additional nine days. While all groups exhibited some degree of suppression following acute administration of both drugs, juvenile rats were considerably more sensitive to this effect. With sub-chronic administration during late adolescent development (PN40-PN49), tolerance failed to develop. These results emphasize the importance of age in pharmacological characterization of antipsychotics and suggest that pre-adolescents may have enhanced sensitivity to the motor effects of these drugs. Further, they suggest that, similar to adults, older adolescents may not develop tolerance to the activity suppression induced by these two antipsychotics.

  3. Perinatal thiamine restriction affects central GABA and glutamate concentrations and motor behavior of adult rat offspring.

    PubMed

    Ferreira-Vieira, Talita Hélen; de Freitas-Silva, Danielle Marra; Ribeiro, Andrea Frozino; Pereira, Sílvia Rejane Castanheira; Ribeiro, Ângela Maria

    2016-03-23

    The purposes of the present study were to investigate the effects of perinatal thiamine deficiency, from the 11th day of gestation until the 5th day of lactation, on motor behavior and neurochemical parameters in adult rat offspring, using 3-month-old, adult, male Wistar rats. All rats were submitted to motor tests, using the rotarod and paw print tasks. After behavioral tests, their thalamus, cerebellum and spinal cord were dissected for glutamate and GABA quantifications by high performance liquid chromatography. The thiamine-restricted mothers (RM) group showed a significant reduction of time spent on the rotarod at 25 rpm and an increase in hind-base width. A significant decrease of glutamate concentration in the cerebellum and an increase of GABA concentrations in the thalamus were also observed. For the offspring from control mothers (CM) group there were significant correlations between thalamic GABA concentrations and both rotarod performance and average hind-base width. In addition, for rats from the RM group a significant correlation between stride length and cerebellar GABA concentration was found. These results show that the deficiency of thiamine during an early developmental period affects certain motor behavior parameters and GABA and glutamate levels in specific brain areas. Hence, a thiamine deficiency episode during an early developmental period can induce motor impairments and excitatory and inhibitory neurotransmitter changes that are persistent and detectable in later periods of life.

  4. Neonatal Maternal Separation Augments Carotid Body Response to Hypoxia in Adult Males but Not Female Rats

    PubMed Central

    Soliz, Jorge; Tam, Rose; Kinkead, Richard

    2016-01-01

    Perinatal exposure to adverse experiences disrupts brain development, including the brainstem network that regulates breathing. At adulthood, rats previously subjected to stress (in the form of neonatal maternal separation; NMS) display features reported in patients suffering from sleep disordered breathing, including an increased hypoxic ventilatory response and hypertension. This effect is also sex-specific (males only). Based on these observations, we hypothesized that NMS augments the carotid body's O2-chemosensitivity. Using an isolated and perfused ex vivo carotid body preparation from adult rats we compared carotid sinus nerve (CSN) responses to hypoxia and hypercapnia in carotid bodies harvested from adult rats that either experienced control conditions (no experimental manipulation) or were subjected to NMS (3 h/day from postnatal days 3 to 12). In males, the CSN response to hypoxia measured in preparations from NMS males was 1.5 fold higher than controls. In control rats, the female's response was similar to that of males; however, the increase in CSN activity measured in NMS females was 3.0 times lower than controls. The CSN response to hypercapnia was not influenced by stress or sex. We conclude that NMS is sufficient to have persistent and sex-specific effects on the carotid body's response to hypoxia. Because NMS also has sex-specific effects on the neuroendocrine response to stress, we propose that carotid body function is influenced by stress hormones. This, in turn, leads to a predisposition toward cardio-respiratory disorders. PMID:27729873

  5. Impaired acclimatization to chronic hypoxia in adult male and female rats following neonatal hypoxia.

    PubMed

    Lumbroso, Delphine; Joseph, Vincent

    2009-08-01

    We tested the hypothesis that neonatal exposure to hypoxia alters acclimatization to chronic hypoxia later in life. Rat pups were exposed to normobaric hypoxia (12% O(2); nHx group) in a sealed chamber, or to normoxia (21% O(2); nNx group) from the day before birth to postnatal day 10. The animals were then raised in normal conditions until reaching 12 wk of age. At this age, we assessed ventilatory and hematological acclimatization to chronic hypoxia by exposing male and female nHx and nNx rats for 2 wk to 10% O(2). Minute ventilation, metabolic rate, hypoxic ventilatory response, hematocrit, and hemoglobin levels were measured both before and after acclimatization. We also quantified right ventricular hypertrophy as an index of pulmonary hypertension both before and after acclimatization. There was a significant effect of neonatal hypoxia that decreases ventilatory response (relative to metabolic rate, VE/VCO(2)) to acute hypoxia before acclimatization in males but not in females. nHx rats had an impaired acclimatization to chronic hypoxia characterized by altered respiratory pattern and elevated hematocrit and hemoglobin levels after acclimatization, in both males and females. Right ventricular hypertrophy was present before and after acclimatization in nHx rats, indicating that neonatal hypoxia results in pulmonary hypertension in adults. We conclude that neonatal hypoxia impairs acclimatization to chronic hypoxia in adults and may be a factor contributing to the establishment of chronic mountain sickness in humans living at high altitude.

  6. Distribution of constitutively expressed MEF-2A in adult rat and human nervous systems.

    PubMed

    Ruffle, Rebecca A; Mapley, Andrew C; Malik, Manmeet K; Labruzzo, Salvatore V; Chabla, Janet M; Jose, Riya; Hallas, Brian H; Yu, Han-Gang; Horowitz, Judith M; Torres, German

    2006-06-15

    Myocyte enhancer factor 2A (MEF-2A) is a calcium-regulated transcription factor that promotes cell survival during nervous system development. To define and further characterize the distribution pattern of MEF-2A in the adult mammalian brain, we used a specific polyclonal antiserum against human MEF-2A to identify nuclear-localized MEF-2A protein in hippocampal and frontal cortical regions. Western blot and immunocytochemical analyses showed that MEF-2A was expressed not only in laminar structures but also in blood vessels of rat and human brains. MEF-2A was colocalized with doublecortin (DCX), a microtubule-associated protein expressed by migrating neuroblasts, in CA1 and CA2 boundaries of the hippocampus. MEF-2A was expressed heterogeneously in additional structures of the rat brain, including the striatum, thalamus, and cerebellum. Furthermore, we found a strong nuclear and diffuse MEF-2A labeling pattern in spinal cord cells of rat and human material. Finally, the neurovasculature of adult rats and humans not only showed a strong expression of MEF-2A but also labeled positive for hyperpolarization-activated, cyclic nucleotide-regulated (HCN) channels. This study further characterizes the distribution pattern of MEF-2A in the mammalian nervous system, demonstrates that MEF-2A colocalizes with DCX in selected neurons, and finds MEF-2A and HCN1 proteins in the neurovasculature network.

  7. Repeated-dose liver micronucleus test of 4,4'-methylenedianiline using young adult rats.

    PubMed

    Sanada, Hisakazu; Koyama, Naomi; Wako, Yumi; Kawasako, Kazufumi; Hamada, Shuichi

    2015-03-01

    Liver micronucleus (MN) tests using partial hepatectomized rats or juvenile rats have been shown to be useful for the detection of hepatic carcinogens. Moreover, Narumi et al. established the repeated-dose liver MN test using young adult rats for integration into general toxicity. In the present study, in order to examine the usefulness of the repeated-dose liver MN test, we investigated MN induction with a 14 or 28 day treatment protocol using young adult rats treated with 4,4′-methylenedianiline (MDA), a known hepatic carcinogen. MDA dose-dependently induced micronuclei in hepatocytes in 14- and 28-day repeated-dose tests. However, although statistically significant increases in micronuclei were observed in bone marrow cells at two dose levels in the 14-day study, there was no dose response and no increases in micronuclei in the 28-day study. These results indicate that the evaluation of genotoxic effects using hepatocytes is effective in cases where chromosomal aberrations are not clearly detectable in bone marrow cells. Moreover, the repeated-dose liver MN test allows evaluation at a dose below the maximum tolerable dose, which is required for the conventional MN test because micronucleated hepatocytes accumulate. The repeated-dose liver MN test employed in the present study can be integrated into the spectrum of general toxicity tests without further procedural modifications.

  8. Juvenile exposure to methamphetamine attenuates behavioral and neurochemical responses to methamphetamine in adult rats.

    PubMed

    McFadden, Lisa M; Carter, Samantha; Matuszewich, Leslie

    2012-04-01

    Previous research has shown that children living in clandestine methamphetamine (MA) labs are passively exposed to the drug [1]. The long-term effects of this early exposure on the dopaminergic systems are unknown, but may be important for adult behaviors mediated by dopamine, such as drug addiction. The current study sought to determine if juvenile exposure to low doses of MA would lead to altered responsiveness to the stimulant in adulthood. Young male and female rats (PD20-34) were injected daily with 0 or 2 mg/kg MA or left undisturbed and then tested at PD90. In the open field, adult rats exposed to MA during preadolescence had reduced locomotor activity compared to control non-exposed rats following an acute injection of MA (2 mg/kg). Likewise, methamphetamine-induced dopamine increases in the dorsal striatum were attenuated in male and female rats that had been exposed to MA as juveniles, although there were no changes in basal in vivo or ex vivo dopamine levels. These findings suggest that exposure of juveniles to MA leads to persistent changes in the behavioral and neurochemical responses to stimulants in adulthood.

  9. Effect of medroxyprogesterone acetate on thyrotropin secretion in adult and old female rats.

    PubMed

    Moreira, R M; Borges, P P; Lisboa, P C; Curty, F H; Moura, E G; Pazos-Moura, C C

    2000-09-01

    Steroid hormones have been implicated in the modulation of TSH secretion; however, there are few and controversial data regarding the effect of progesterone (Pg) on TSH secretion. Medroxyprogesterone acetate (MPA) is a synthetic alpha-hydroxyprogesterone analog that has been extensively employed in therapeutics for its Pg-like actions, but that also has some glucocorticoid and androgen activity. Both hormones have been shown to interfere with TSH secretion. The objective of the present study was to investigate the effects of MPA or Pg administration to ovariectomized (OVX) rats on in vivo and in vitro TSH release and pituitary TSH content. The treatment of adult OVX rats with MPA (0. 25 mg/100 g body weight, sc, daily for 9 days) induced a significant (P<0.05) increase in the pituitary TSH content, which was not observed when the same treatment was used with a 10 times higher MPA dose or with Pg doses similar to those of MPA. Serum TSH was similar for all groups. MPA administered to OVX rats at the lower dose also had a stimulatory effect on the in vitro basal and TRH-induced TSH release. The in vitro basal and TRH-stimulated TSH release was not significantly affected by Pg treatment. Conversely, MPA had no effect on old OVX rats. However, in these old rats, ovariectomy alone significantly reduced (P<0.05) basal and TRH-stimulated TSH release in vitro, as well as pituitary TSH content. The results suggest that in adult, but not in old OVX rats, MPA but not Pg has a stimulatory effect on TSH stores and on the response to TRH in vitro.

  10. Imipramine reverses alterations in cytokines and BDNF levels induced by maternal deprivation in adult rats.

    PubMed

    Réus, Gislaine Z; Dos Santos, Maria Augusta B; Abelaira, Helena M; Ribeiro, Karine F; Petronilho, Fabrícia; Vuolo, Francieli; Colpo, Gabriela D; Pfaffenseller, Bianca; Kapczinski, Flávio; Dal-Pizzol, Felipe; Quevedo, João

    2013-04-01

    A growing body of evidence is pointing toward an association between immune molecules, as well brain-derived neurotrophic factor (BDNF) and the depression. The present study was aimed to evaluate the behavioral and molecular effects of the antidepressant imipramine in maternally deprived adult rats. To this aim, maternally deprived and non-deprived (control group) male rats were treated with imipramine (30mg/kg) once a day for 14 days during their adult phase. Their behavior was then assessed using the forced swimming test. In addition to this, IL-10, TNF-α and IL-1β cytokines were assessed in the serum and cerebrospinal fluid (CSF). In addition, BDNF protein levels were assessed in the prefrontal cortex, hippocampus and amygdala. In deprived rats treated with saline was observed an increase on immobility time, compared with non-deprived rats treated with imipramine (p<0.05). Deprived rats treated with saline presented a decrease on BDNF levels in the amygdala (p<0.05), compared with all other groups. The IL-10 levels were decreased in the serum (p<0.05). TNF-α and IL-1β levels were increased in the serum and CSF of deprived rats treated with saline (p<0.05). Interestingly, imipramine treatment reversed the effects of maternal deprivation on BDNF and cytokines levels (p<0.05). Finally, these findings further support a relationship between immune activation, neurotrophins and the depression, and considering the action of imipramine, it is suggested that classic antidepressants could exert their effects by modulating the immune system.

  11. Histological effects of oral administration of nutmeg on the kidneys of adult Wister rats

    PubMed Central

    Eweka, Andrew Osayame; Eweka, Abieyuwa

    2010-01-01

    Aims: The effects of oral administration of nutmeg commonly used as spice in various dishes, as components of teas and soft drinks or mixed in milk and alcohol on the kidneys of adult Wistar rats were carefully studied. Material and Methods: Rats of both sexes (n = 24), with average weight of 220g were randomly assigned into two treatments (A & B) of (n=16) and Control (c) (n=8) groups. The rats in the treatment groups (A & B) received 0.1g (500mg/kg body weight) and 0.2g (1000mg/kg body weight) of nutmeg thoroughly mixed with the feeds respectively on a daily basis for forty-two days. The control group (c) received equal amount of feeds daily without nutmeg added for forty-two days. The growers’ mash feeds was obtained from Edo Feeds and Flour Mill Limited, Ewu, Edo state, Nigeria and the rats were given water liberally. The rats were sacrificed by cervical dislocation on the forty-third day of the experiment. The kidneys were carefully dissected out and quickly fixed in 10% buffered formaldehyde for routine histological study after hematoxylin and eosin method. Result: The histological findings in the treated sections of the kidneys showed distortion of the renal cortical structures, vacuolations appearing in the stroma and some degree of cellular necrosis, with degenerative and atrophic changes when compared to the control group. Conclusion: These findings indicate that oral administration of nutmeg may have some deleterious effects on the kidneys of adult Wistar rats at higher doses and by extension may affect its excretory and other metabolic functions. It is recommended that caution should therefore be advocated in the intake of this product and further studies be carried out to examine these findings. PMID:22624138

  12. A spaceflight study of synaptic plasticity in adult rat vestibular maculas

    NASA Technical Reports Server (NTRS)

    Ross, M. D.

    1994-01-01

    Behavioral signs of vestibular perturbation in altered gravity have not been well correlated with structural modifications in neurovestibular centers. This ultrastructural research investigated synaptic plasticity in hair cells of adult rat utricular maculas exposed to microgravity for nine days on a space shuttle. The hypothesis was that synaptic plasticity would be more evident in type II hair cells because they are part of a distributed modifying macular circuitry. All rats were shared with other investigators and were subjected to treatments unrelated to this experiment. Maculas were obtained from flight and control rats after shuttle return (R + 0) and nine days post-flight (R + 9). R + 9 rats had chromodacryorrhea, a sign of acute stress. Tissues were prepared for ultrastructural study by conventional methods. Ribbon synapses were counted in fifty serial sections from medial utricular macular regions of three rats of each flight and control group. Counts in fifty additional consecutive sections from one sample in each group established method reliability. All synapses were photographed and located to specific cells on mosaics of entire sections. Pooled data were analyzed statistically. Flown rats showed abnormal posture and movement at R + 0. They had statistically significant increases in total ribbon synapses and in sphere-like ribbons in both kinds of hair cells; in type II cells, pairs of synapses nearly doubled and clusters of 3 to 6 synapses increased twelve-fold. At R + 9, behavioral signs were normal. However, synapse counts remained high in both kinds of hair cells of flight maculas and were elevated in control type II cells. Only counts in type I cells showed statistically significant differences at R + 9. High synaptic counts at R + 9 may have resulted from stress due to experimental treatments. The results nevertheless demonstrate that adult maculas retain the potential for synaptic plasticity. Type II cells exhibited more synaptic plasticity, but

  13. Chronic intermittent hypoxia promotes expression of 3-mercaptopyruvate sulfurtransferase in adult rat medulla oblongata.

    PubMed

    Li, Mingqiang; Nie, Lihong; Hu, Yajie; Yan, Xiang; Xue, Lian; Chen, Li; Zhou, Hua; Zheng, Yu

    2013-12-01

    The present experiments were carried out to investigate the expression of 3-mercaptopyruvate sulfurtransferase (3MST) in medulla oblongata of rats and effects of chronic intermittent hypoxia (CIH) on its expression. Sprague Dawley adult rats were randomly divided into two groups, including control (Con) group and CIH group. The endogenous production of hydrogen sulfide (H2S) in medulla oblongata tissue homogenates was measured using the methylene blue assay method, 3MST mRNA and protein expression were analyzed by RT-PCR and Western blotting, respectively, and the expression of 3MST in the neurons of respiratory-related nuclei in medulla oblongata of rats was investigated with immunohistochemical technique. CIH elevated the endogenous H2S production in rat medulla oblongata (P<0.01). The RT-PCR and Western blotting analyses showed that 3MST mRNA and protein were expressed in the medulla oblongata of rats and CIH promoted their expression (P<0.01). Immunohistochemical staining indicated that 3MST existed in the neurons of pre-Bötzinger complex (pre-BötC), hypoglossal nucleus (12N), ambiguous nucleus (Amb), facial nucleus (FN) and nucleus tractus solitarius (NTS) in the animals and the mean optical densities of 3MST-positive neurons in the pre-BötC, 12N and Amb, but not in FN and NTS, were significantly increased in CIH group (P<0.05). In conclusion, 3MST exists in the neurons of medullary respiratory nuclei and its expression can be up-regulated by CIH in adult rat, suggesting that 3MST-H2S pathway may be involved in regulation of respiration and protection on medullary respiratory centers from injury induced by CIH.

  14. Effects of Nandrolone Stimulation on Testosterone Biosynthesis in Leydig Cells

    PubMed Central

    Barone, Rosario; Marino Gammazza, Antonella; Sangiorgi, Claudia; Barone, Fulvio; Pitruzzella, Alessandro; Locorotondo, Nicola; Di Gaudio, Francesca; Salerno, Monica; Maglietta, Francesca; Sarni, Antonio Luciano; Di Felice, Valentina; Cappello, Francesco; Turillazzi, Emanuela

    2015-01-01

    Anabolic androgenic steroids (AAS) are among the drugs most used by athletes for improving physical performance, as well as for aesthetic purposes. A number of papers have showed the side effects of AAS in different organs and tissues. For example, AAS are known to suppress gonadotropin‐releasing hormone, luteinizing hormone, and follicle‐stimulating hormone. This study investigates the effects of nandrolone on testosterone biosynthesis in Leydig cells using various methods, including mass spectrometry, western blotting, confocal microscopy and quantitative real‐time PCR. The results obtained show that testosterone levels increase at a 3.9 μM concentration of nandrolone and return to the basal level a 15.6 μM dose of nandrolone. Nandrolone‐induced testosterone increment was associated with upregulation of the steroidogenic acute regulatory protein (StAR) and downregulation of 17a‐hydroxylase/17, 20 lyase (CYP17A1). Instead, a 15.6 µM dose of nandrolone induced a down‐regulation of CYP17A1. Further in vivo studies based on these data are needed to better understand the relationship between disturbed testosterone homeostasis and reproductive system impairment in male subjects. J. Cell. Physiol. 231: 1385–1391, 2016. © 2015 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc. PMID:26626779

  15. IGF-I redirects doublecortin-positive cell migration in the normal adult rat brain.

    PubMed

    Maucksch, C; McGregor, A L; Yang, M; Gordon, R J; Yang, M; Connor, B

    2013-06-25

    The migration of subventricular zone (SVZ)-derived neural precursor cells through the rostral migratory stream (RMS) to the olfactory bulb is tightly regulated by local micro-environmental cues. Insulin-like Growth Factor-I (IGF-I) can stimulate the migration of several neuronal cell types and acts as a 'departure' factor in the avian SVZ. To establish whether IGF-I can also act as a migratory factor for adult neuronal precursor cells in vivo, in addition to its well established role in precursor cell proliferation and differentiation, we used AAV2-mediated gene transfer to produce ectopic expression of IGF-I in the normal adult rat striatum. We then assessed whether the expression of IGF-I would recruit SVZ-derived neuronal precursor cells from the RMS into the striatum. Ectopic expression of IGF-I in the normal adult rat brain significantly increased the number of doublecortin (Dcx)-positive cells and the extent of their migration into the striatum 4 and 8 weeks after AAV2-IGF-I injection but did not promote neuronal differentiation. In vitro migration assays confirmed that IGF-I is an inducer of migration and directs SVZ-derived adult neuronal precursor cell migration by both chemotaxis and chemokinesis. These results demonstrate that overexpression of IGF-I in the normal adult rat brain can override the normal cues directing precursor cell migration along the RMS and can redirect precursor cell migration into a non-neurogenic region. Enhanced expression of IGF-I following brain injury may therefore act as a diffusible factor mediating precursor cell migration to areas of neuronal cell damage.

  16. Toxic effects of Mn2O3 nanoparticles on rat testis and sex hormone

    PubMed Central

    Negahdary, Masoud; Arefian, Zahra; Dastjerdi, Hajar Akbari; Ajdary, Marziyeh

    2015-01-01

    Background and Objective: The safety of Mn2O3 nanoparticles (which are extensively used in industries) on male reproductive system is not known. Hence, we investigated the effects of Mn2O3 nanoparticles on male reproductive system. Materials and Methods: A total of 40 Wistar adult male rats were randomly assigned to four groups of 10 rats each. Three groups received Mn2O3 solution in concentrations of 100, 200, and 400 ppm orally for 14 days; the control group received equal volume of saline solution. Blood samples and testicles were collected for analysis. Results: Significant reduction in luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, spermatogonial cells, primary spermatocyte, spermatid and Leydig cell was observed in the Mn2O3 nanoparticles treated groups compared with controls. Conclusion: Mn2O3 nanoparticles significantly reduce FSH, LH, and testosterone levels resulting in a significant reduction in testicular cytology. PMID:26283824

  17. Sexual dimorphism in thyroid function and type 1 iodothyronine deiodinase activity in pre-pubertal and adult rats.

    PubMed

    Marassi, Michelle P; Fortunato, Rodrigo S; da Silva, Alba C Matos; Pereira, Valmara S; Carvalho, Denise P; Rosenthal, Doris; da Costa, Vânia M Corrêa

    2007-01-01

    Iodothyronine deiodinase activities are regulated by sex steroids; however, the mechanisms underlying the reported sexual dimorphism are poorly defined. In the present report, we aimed to investigate whether type 1 deiodinase (D1) sexual dimorphism exists early in sexual development by studying pre-pubertal male (Pm) and female (Pf) rats, as well as adult controls (C) and gonadectomized male and females rats. Adult male Wistar rats were studied 21 days after orchiectomy (Tex), and adult females were studied 21 days after ovariectomy (Ovx), and after estradiol benzoate (Eb) replacement. Serum total triiodothyronine (T3) was higher in pre-pubertal (P) rats than in the matching adults, with no difference between genders, although in adult males T3 was significantly lower than in females. There were no sex or age differences in serum total T4. Serum TSH in pre-pubertal (P) rats was within the adult female range, and both were significantly lower than in adult males. D1 activity in liver was greater in Pm than in Pf. In adult females, liver D1 activity was lower, while in adult males it was higher than in P rats. The same pattern of D1 activity was found in kidney. In thyroid and pituitary, D1 activity was similar in Pm, Pf, and adult females, which were all significantly lower than in the adult male. There were no differences in serum T3 and T4 between C and Tex males, but serum TSH was significantly decreased in Tex rats. Hepatic and renal D1 activities were lower in Tex than in C, but no changes were detected in thyroid and pituitary. In Ovx females, T3 was significantly lower than in the C group. Serum T4 was significantly decreased by estradiol replacement therapy in Ovx rats, in both doses used, whereas TSH was unchanged. Eb replacement increased liver and thyroid D1 activity, but in the kidney, only the highest estradiol dose promoted a significant D1 increase. In conclusion, in males, hepatic and renal D1 activity appears to be significantly influenced by

  18. Morphometric studies of Leydig cells in chinchillas (Chinchilla lanigera) during high and low fertility seasons.

    PubMed

    Surmacki, Piotr; Sulik, Małgorzata; Seremak, Beata

    2011-01-01

    The aim of this study was to examine morphometric data of Leydig cells of 10 male chinchillas. Testes, cut into 5-microm thick sections, were stained using the p.a.S. and Masson's methods. Some 3800 Leydig cells have been evaluated. Their dimensions, as well as the diameters of their nuclei and the distances of the nuclei from the boundaries of the cells, have been measured. The areas of the surface and volumes of the nuclei of Leydig cells have been calculated, as well as the areas of the surface of the Leydig cells themselves. The following data have been obtained. The Nuclei of Leydig Cells. The largest diameters: longer cells - 12 microm; shorter cells - 10 microm. Mean diameters: longer cells - 5.67 +/- 3.44 microm, shorter cells - 4.45 +/- 3.44 microm. The largest surface area - 120 microm2, the mean surface area - 28.27 +/- 11.21 microm2. The largest volume - 1200 microm3, the mean volume of nucleus - 171.8 +/- 65.82 microm3. Mean distances of Leydig cell nuclei from the opposite boundaries of the cells amounted to 1.29 +/- 1.41 microm, 4.24 +/- 2.39 microm, 4.09 +/- 2.23 microm, 6.12 +/- 2.33 microm. Leydig cells. The largest diameters: longer cells - 24 microm, shorter cells - 22 microm. Mean dimensions: longer cells - 13.86 +/- 2.76 microm, shorter cells - 10.89 +/- 2.44 microm. The largest area of surface - 528 microm2, the mean area of surface - 155.44 +/- 59.78 microm2. Morphometric analysis confirmed cytologic observations that the shape of the nuclei of Leydig cells is somewhat ellipsoidal. The nuclei are located off-centre and are not situated in the greatest agglomeration of cytoplasm. The shape of Leydig cells is irregular. The obtained results may provide insight on the infertility of chinchilla males, as well as in research on the annual cyclic fertility of these animals. They may be put to use in practice for the purpose of improving breeding of this species.

  19. Excitation and inhibition jointly regulate cortical reorganization in adult rats.

    PubMed

    Benali, Alia; Weiler, Elke; Benali, Youssef; Dinse, Hubert R; Eysel, Ulf T

    2008-11-19

    The primary somatosensory cortex (SI) retains its capability for cortical reorganization after injury or differential use into adulthood. The plastic response of SI cells to peripheral stimulation is characterized by extension of cortical representations accompanied by changes of the receptive field size of neurons. We used intracortical microstimulation that is known to enforce local, intracortical synchronous activity, to induce cortical reorganization and applied immunohistochemical methods in the same individual animals to investigate how plasticity in the cortical topographic maps is linked to changes in the spatial layout of the inhibitory and excitatory neurotransmitter systems. The results reveal a differential spatiotemporal pattern of upregulation and downregulation of specific factors for an excitatory (glutamatergic) and an inhibitory (GABAergic) system, associated with changes of receptive field size and reorganization of the somatotopic map in the rat SI. Predominantly local mechanisms are the specific reduction of the calcium-binding protein parvalbumin in inhibitory neurons and the low expression of the activity marker c-Fos. Reorganization in the hindpaw representation and in the adjacent SI cortical areas (motor cortex and parietal cortex) is accompanied by a major increase of the excitatory transmitter glutamate and c-Fos. The spatial extent of the reorganization appears to be limited by an increase of glutamic acid decarboxylase and the inhibitory transmitter GABA. The local and medium-range net effects are excitatory and can facilitate receptive field enlargements and cortical map expansion. The longer-range increase of inhibition appears suited to limit these effects and to prevent neurons from pathological hyperexcitability.

  20. Perinatal exposure to xenoestrogens affects pain in adult female rats.

    PubMed

    Ceccarelli, Ilaria; Fiorenzani, Paolo; Della Seta, Daniele; Massafra, Cosimo; Cinci, Giuliano; Bocci, Anna; Aloisi, Anna Maria

    2009-01-01

    Estrogens have a variety of effects in addition to their action on reproductive structures, including permanent effects on the Central Nervous System (CNS). Therefore environmental chemicals with estrogenic activity (xenoestrogens) can potentially affect a number of CNS functions. In the present experiment, female rats receiving ethynylestradiol (EE) or methoxychlor (MXC) via the mothers during pregnancy (pre) or lactation (post) were tested in comparison with females born from mothers treated with OIL. The Object Recognition, Plantar and Formalin tests were carried out to evaluate the effects of these compounds on integrated functions such as memory and pain. Testosterone and estradiol plasma levels were determined by RIA. The results of the Object Recognition and Plantar tests did not differ among groups. However the groups differed in the Formalin test since flexing duration was higher in the EE- and MXC-pre groups than in the EE- and MXC-post and OIL groups. Estradiol plasma levels were higher in EE-pre than in the other groups. These results confirm the possibility that estrogen-like compounds (EE and MXC) can affect complex neural processes like pain when taken during critical stages of CNS development.

  1. Phosphoenolpyruvate Carboxykinase and Glucose-6-phosphatase Are Required for Steroidogenesis in Testicular Leydig Cells*

    PubMed Central

    Ahn, Seung Won; Gang, Gil-Tae; Tadi, Surendar; Nedumaran, Balachandar; Kim, Yong Deuk; Park, Ji Hoon; Kweon, Gi Ryang; Koo, Seung-Hoi; Lee, Keesook; Ahn, Ryun-Sup; Yim, Yong-Hyeon; Lee, Chul-Ho; Harris, Robert A.; Choi, Hueng-Sik

    2012-01-01

    Cyclic AMP (cAMP) induces steroidogenic enzyme gene expression and stimulates testosterone production in Leydig cells. Phosphoenolpyruvate carboxykinase (PEPCK) is expressed in Leydig cells, but its role has not been defined. In this study, we found that PEPCK and glucose-6-phosphatase (Glc-6-Pase) are increased significantly following cAMP treatment of mouse Leydig cells. Moreover, cAMP treatment increased recruitment of the cAMP-response element-binding transcription factor and decreased recruitment of the corepressor DAX-1 on the pepck promoter. Furthermore, cAMP induced an increase in ATP that correlated with a decrease in phospho-AMP-activated protein kinase (AMPK). In contrast, knockdown or inhibition of PEPCK decreased ATP and increased phospho-AMPK. Treatment with an AMPK activator or overexpression of the constitutively active form of AMPK inhibited cAMP-induced steroidogenic enzyme promoter activities and gene expression. Liver receptor homolog-1 (LRH-1) was involved in cAMP-induced steroidogenic enzyme gene expression but was inhibited by AMPK activation in Leydig cells. Additionally, inhibition or knockdown of PEPCK and Glc-6-Pase decreased cAMP-mediated induction of steroidogenic enzyme gene expression and steroidogenesis. Finally, pubertal mouse (8-week-old) testes and human chorionic gonadotropin-induced prepubertal mouse testes showed increased PEPCK and Glc-6-Pase gene expression. Taken together, these results suggest that induction of PEPCK and Glc-6-Pase by cAMP plays an important role in Leydig cell steroidogenesis. PMID:23074219

  2. Adolescent TBI-induced hypopituitarism causes sexual dysfunction in adult male rats.

    PubMed

    Greco, Tiffany; Hovda, David A; Prins, Mayumi L

    2015-02-01

    Adolescents are at greatest risk for traumatic brain injury (TBI) and repeat TBI (RTBI). TBI-induced hypopituitarism has been documented in both adults and juveniles and despite the necessity of pituitary function for normal physical and brain development, it is still unrecognized and untreated in adolescents following TBI. TBI induced hormonal dysfunction during a critical developmental window has the potential to cause long-term cognitive and behavioral deficits and the topic currently remains unaddressed. The purpose of this study was to determine if four mild TBIs delivered to adolescent male rats disrupts testosterone production and adult behavioral outcomes. Plasma testosterone was quantified from 72 hrs preinjury to 3 months postinjury and pubertal onset, reproductive organ growth, erectile function and reproductive behaviors were assessed at 1 and 2 months postinjury. RTBI resulted in both acute and chronic decreases in testosterone production and delayed onset of puberty. Significant deficits were observed in reproductive organ growth, erectile function and reproductive behaviors in adult rats at both 1 and 2 months postinjury. These data suggest adolescent RTBI-induced hypopituitarism underlies abnormal behavioral changes observed during adulthood. The impact of undiagnosed hypopituitarism following RTBI in adolescence has significance not only for growth and puberty, but also for brain development and neurobehavioral function as adults.

  3. Age and sex differences in reward behavior in adolescent and adult rats.

    PubMed

    Hammerslag, Lindsey R; Gulley, Joshua M

    2014-05-01

    Compared to adults, adolescents are at heightened risk for drug abuse and dependence. One of the factors contributing to this vulnerability may be age-dependent differences in reward processing, with adolescents approaching reward through stimulus-directed, rather than goal-directed, processes. However, the empirical evidence for this in rodent models of adolescence, particularly those that investigate both sexes, is limited. To address this, male and female rats that were adolescents (P30) or adults (P98) at the start of the experiment were trained in a Pavlovian approach (PA) task and were subsequently tested for the effects of reward devaluation, extinction, and re-acquisition. We found significant interactions between age and sex: females had enhanced acquisition of PA and poorer extinction, relative to males, while adolescents and females were less sensitive to reward devaluation than male adults. These results suggest that females and adolescents exhibit reward behavior that is more stimulus-directed, rather than goal-directed.

  4. Ginkgo biloba extract facilitates recovery from penetrating brain injury in adult male rats.

    PubMed

    Attella, M J; Hoffman, S W; Stasio, M J; Stein, D G

    1989-07-01

    Adult, male Sprague-Dawley rats received 100 mg/kg Ginkgo biloba extract (GBE) intraperitoneally for 30 days. GBE reduced overall activity and decreased sensitivity to light in the open field maze. The rats were also less responsive to noxious stimuli after 13 days of treatment with GBE. After the last injection, all subjects were trained on a delayed-spatial alternation task. Subsequent to acquisition of the spatial task, the rats received either sham operations and saline or bilateral frontal cortex lesions treated with either saline or GBE. Thirty additional days of treatment began on the day of injury, and open field behavior, analgesia, and metabolic activity measurements were again measured. The rats with lesions treated with saline were more active than their GBE-treated counterparts and sham controls but there were no differences in response to illumination or noxious stimuli. Retention of the delayed-spatial alternation indicated that rats with lesions treated with GBE were less impaired than brain-injured subjects receiving saline treatment. Histological examination showed that GBE reduced the extent of brain swelling in response to the injury.

  5. Effect of restraint and copper deficiency on blood pressure and mortality of adult rats

    SciTech Connect

    Klevay, L.M.; Halas, E.S. )

    1989-02-01

    The etiology of most hypertension is unknown; stress is thought to elevate blood pressure. Male, weanling Sprague-Dawley rats were fed a purified diet plus a drinking solution containing 10{mu}g Zn and 2{mu}g Cu/ml (acetate sulfate, respectively). Systolic blood pressure was measured without anesthesia. After being matched by mean weight (280g) and blood pressure into 4 groups of 15, groups 1 and 2 received a drinking solution without copper. After 24 days rats in groups 2 and 4 were restrained for 45 min. daily (A.M.) for 23 days in a small plastic cage (19{times}6{times}6 cm). Final pressures were affected both by stress and dietary Cu: group 1, 119; group 2, 131; group 3, 114; group 4, 123 mm Hg. One rat in each of groups 1, 3, 4 and 10 rats in group 2, died. Among these latter hemorrhage was prominent, blood being found in bladder (2), gut (2), peritoneum (2) and scrotum (1). Copper deficiency decreased cooper in both adrenal gland and liver by 58% and in heart by 29% restraint was without effect. Cardiac sodium was increased 6% only by deficiency. Results confirm the hypertensive effect of copper deficiency in adult rats and reveal that the stress of restraint increases blood pressure. Copper deficiency plus stress is harmful.

  6. Adolescent and adult rat cortical protein kinase A display divergent responses to acute ethanol exposure

    PubMed Central

    Gigante, Eduardo D.; Santerre, Jessica L.; Carter, Jenna M.; Werner, David F.

    2014-01-01

    Adolescent rats display reduced sensitivity to many dysphoria-related effects of alcohol (ethanol) including motor ataxia and sedative hypnosis, but the underlying neurobiological factors that contribute to these differences remain unknown. The cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) pathway, particularly the type II regulatory subunit (RII), has been implicated in ethanol-induced molecular and behavioral responses in adults. Therefore, the current study examined cerebral cortical PKA in adolescent and adult ethanol responses. With the exception of early adolescence, PKA RIIα and RIIβ subunit levels largely did not differ from adult levels in either whole cell lysate or P2 synaptosomal expression. However, following acute ethanol exposure, PKA RIIβ P2 synaptosomal expression and activity were increased in adults, but not in adolescents. Behaviorally, intracerebroventricular administration of the PKA activator Sp-cAMP and inhibitor Rp-cAMP prior to ethanol administration increased adolescent sensitivity to the sedative-hypnotic effects of ethanol compared to controls. Sp-cAMP was ineffective in adults whereas Rp-cAMP suggestively reduced loss of righting reflex (LORR) with paralleled increases in blood ethanol concentrations. Overall, these data suggest that PKA activity modulates the sedative/hypnotic effects of ethanol and may potentially play a wider role in the differential ethanol responses observed between adolescents and adults. PMID:24874150

  7. Adolescent and adult rat cortical protein kinase A display divergent responses to acute ethanol exposure.

    PubMed

    Gigante, Eduardo D; Santerre, Jessica L; Carter, Jenna M; Werner, David F

    2014-08-01

    Adolescent rats display reduced sensitivity to many dysphoria-related effects of alcohol (ethanol) including motor ataxia and sedative hypnosis, but the underlying neurobiological factors that contribute to these differences remain unknown. The cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) pathway, particularly the type II regulatory subunit (RII), has been implicated in ethanol-induced molecular and behavioral responses in adults. Therefore, the current study examined cerebral cortical PKA in adolescent and adult ethanol responses. With the exception of early adolescence, PKA RIIα and RIIβ subunit levels largely did not differ from adult levels in either whole cell lysate or P2 synaptosomal expression. However, following acute ethanol exposure, PKA RIIβ P2 synaptosomal expression and activity were increased in adults, but not in adolescents. Behaviorally, intracerebroventricular administration of the PKA activator Sp-cAMP and inhibitor Rp-cAMP prior to ethanol administration increased adolescent sensitivity to the sedative-hypnotic effects of ethanol compared to controls. Sp-cAMP was ineffective in adults whereas Rp-cAMP suggestively reduced loss of righting reflex (LORR) with paralleled increases in blood ethanol concentrations. Overall, these data suggest that PKA activity modulates the sedative/hypnotic effects of ethanol and may potentially play a wider role in the differential ethanol responses observed between adolescents and adults.

  8. Effect of supraphysiological dose of Nandrolone Decanoate on the testis and testosterone concentration in mature and immature male rats: A time course study

    PubMed Central

    Jannatifar, Rahil; Shokri, Saeed; Farrokhi, Ahmad; Nejatbakhsh, Reza

    2015-01-01

    Background: Most studies on anabolic-androgenic steroids abuse have been done in adult rats, but few data are available to immature. Objective: This study was conducted to assay the effect of Nandrolone Decanoate (ND) on the testis and testosterone concentration in male immature rats compare with mature ones in short and long time. Materials and Methods: 40 mature rats were divided into 4 groups: group A (short term) and group B (long-term) received 10 mg/kg/day ND interaperitoneally for 35 and 70 days, respectively. Group C (control) without any treatment, and group D (vehicle) received dimethyl sulfoxide (DMSO) solution in two periods 35 and 70 days. 40 immature rats were divided into 4 groups same as mature ones. After surgery body weight, testis size, histomorphometry of testis, and serum testosterone level were evaluated. Results: Our results showed that ND decreased the number of Leydig cells in group B (39.9 ±. 919), group A (43.4 ±. 120), and long term (40.6 ±. 299) immature rats, which could result in a reduction of testosterone concentration significantly in all experimental groups except short term mature group. Number of sertoli cells, testis size, and diameter of seminiferous tubules decreased in the long-term immature group. Eventually, the number of sperm was decreased in mature and immature groups, but a severe depletion of sperm was occurred in both mature and immature in long time in comparison to the control group (p< 0.05). Conclusion: This time course study showed that supraphysiological dose of ND may negatively affect the number of Leydig cells, sperm cell, and testosterone concentration of immature rats in the same matter of mature rats. However, the number of sertoli cell, testis size, and seminferous diameter were decreased only in the long immature rats. PMID:27141538

  9. Circadian rhythm of intraocular pressure in the adult rat.

    PubMed

    Lozano, Diana C; Hartwick, Andrew T E; Twa, Michael D

    2015-05-01

    Ocular hypertension is a risk factor for developing glaucoma, which consists of a group of optic neuropathies characterized by progressive degeneration of retinal ganglion cells and subsequent irreversible vision loss. Our understanding of how intraocular pressure damages the optic nerve is based on clinical measures of intraocular pressure that only gives a partial view of the dynamic pressure load inside the eye. Intraocular pressure varies over the course of the day and the oscillator regulating these daily changes has not yet been conclusively identified. The purpose of this study was to compare and contrast the circadian rhythms of intraocular pressure and body temperature in Brown Norway rats when these animals are housed in standard light-dark and continuous dim light (40-90 lux) conditions. The results from this study show that the temperature rhythm measured in continuous dim light drifted forward relative to external time, indicating that the rhythm was free running and being regulated by an internal biological clock. Also, the results show that there is a persistent, but dampened, circadian rhythm of intraocular pressure in continuous dim light and that the circadian rhythms of temperature and intraocular pressure are not synchronized by the same central oscillator. We conclude that once- or twice-daily clinical measures of intraocular pressure are insufficient to describe intraocular pressure dynamics. Similarly, our results indicate that, in experimental animal models of glaucoma, the common practice of housing animals in constant light does not necessarily eliminate the potential influence of intraocular pressure rhythms on the progression of nerve damage. Future studies should aim to determine whether an oscillator within the eye regulates the rhythm of intraocular pressure and to better characterize the impact of glaucoma on this rhythm.

  10. Differential Effects of Inhaled Toluene on Locomotor Activity in Adolescent and Adult Rats

    PubMed Central

    Batis, Jeffery C.; Hannigan, John H.; Bowen, Scott E.

    2010-01-01

    Inhalant abuse is a world-wide public health concern among adolescents. Most preclinical studies have assessed inhalant effects in adult animals leaving unclear how behavioral effects differ in younger animals. We exposed adolescent (postnatal day [PN] 28) and adult (PN90) male rats to toluene using 1 of 3 exposure patterns. These patterns modeled those reported in toluene abuse in teens and varied concentration, number and length of exposures, as well as the inter-exposure interval. Animals were exposed repeatedly over 12 days to toluene concentrations of 0, 8,000 or 16,000 parts per million (ppm). Locomotor activity was quantified during toluene exposures and for 30 min following completion of the final daily toluene exposure. For each exposure pattern, there were significant toluene concentration-related increases and decreases in locomotor activity compared to the 0-ppm “air” controls at both ages. These changes depended upon when activity was measured – during or following exposure. Compared to adults, adolescents displayed greater locomotor activity on the first day and generally greater increases in activity over days than adults during toluene exposure. Adults displayed greater locomotor activity than adolescents in the “recovery” period following exposure on the first and subsequent days. Age group differences were clearest following the pattern of paced, brief (5-min) repeated binge exposures. The results suggest that locomotor behavior in rats during and following inhalation of high concentrations of toluene depends on age and the pattern of exposure. The results are consistent with dose-dependent shifts in sensitivity and sensitization or tolerance to repeated toluene in the adolescent animals compared to the adult animals. Alternate interpretations are possible and our interpretation is limited by the range of very high concentrations of toluene used. The results imply that both pharmacological and psychosocial factors contribute to the teen

  11. Efficacy of Retigabine on Acute Limbic Seizures in Adult Rats

    PubMed Central

    Friedman, LK; Slomko, AM; Wongvravit, JP; Naseer, Z; Hu, S; Wan, WY; Ali, SS

    2015-01-01

    Background and Purpose: The efficacy of retigabine (RGB), a positive allosteric modulator of K+ channels indicated for adjunct treatment of partial seizures, was studied in two adult models of kainic acid (KA)-induced status epilepticus to determine it’s toleratbility. Methods: Retigabine was administered systemiclly at high (5 mg/kg) and low (1–2 mg/kg) doses either 30 min prior to or 2 hr after KA-induced status epilepticus. High (1 µg/µL) and low (0.25 µg/µL) concentrations of RGB were also delivered by intrahippocampal microinjection in the presence of KA. Results: Dose-dependent effects of RGB were observed with both models. Lower doses increased seizure behavior latency and reduced the number of single spikes and synchronized burst events in the electroencephalogram (EEG). Higher doses worsened seizure behavior, produced severe ataxia, and increased spiking activity. Animals treated with RGB that were resistant to seizures did not exhibit significant injury or loss in GluR1 expression; however if stage 5–6 seizures were reached, typical hippocampal injury and depletion of GluR1 subunit protein in vulernable pyramidal fields occurred. Conclusions: RGB was neuroprotective only if seizures were significantly attenuated. GluR1 was simultaneously suppressed in the resistant granule cell layer in presence of RGB which may weaken excitatory transmission. Biphasic effects observed herein suggest that the human dosage must be carefully scrutinized to produce the optimal clinical response. PMID:26819936

  12. Noise exposure during early development impairs the processing of sound intensity in adult rats.

    PubMed

    Bures, Zbynek; Grécová, Jolana; Popelár, Jirí; Syka, Josef

    2010-07-01

    During the early postnatal development of rats, the structural and functional maturation of the central auditory nuclei strongly relies on the natural character of the incoming neural activity. Even a temporary deprivation in the critical period results in a deterioration of neuronal responsiveness in adult animals. We demonstrate that besides the poorer frequency selectivity of neurons in the impaired animals reported previously [Grecova et al. (2009)Eur. J. Neurosci. 29, 1921-1930], the neuronal representation of sound intensity is significantly affected. Rate-intensity functions of inferior colliculus neurons were recorded in anaesthetized adult rats that were exposed to intense noise at postnatal day 14, and compared with those obtained in age-matched controls. Although the response thresholds were similar in the exposed and control rats, the neurons in the exposed animals had a longer first-spike latency, a narrower dynamic range, lower maximum response magnitudes and a steeper slope of the rate-intensity functions. The percentage of monotonic neurons was significantly lower in the exposed animals. The observed anomalies were confined to the mid- and high-frequency regions, whereas no significant changes were found in the low-frequency neurons. The altered parameters of the individual rate-intensity functions led also to differences in the cumulative responses. We conclude that a brief noise exposure during the critical period leads to a frequency-dependent alteration of the sound intensity representation in the inferior colliculus of adult rats. The results suggest that such impairments may appear in individuals with normal hearing thresholds, but with a history of noise exposure very early in childhood.

  13. Neonatal hyperleptinaemia programmes adrenal medullary function in adult rats: effects on cardiovascular parameters.

    PubMed

    Trevenzoli, I H; Valle, M M R; Machado, F B; Garcia, R M G; Passos, M C F; Lisboa, P C; Moura, E G

    2007-04-15

    Epidemiological studies have shown a strong correlation between stressful events (nutritional, hormonal or environmental) in early life and development of adult diseases such as obesity, diabetes and cardiovascular failure. It is known that gestation and lactation are crucial periods for healthy growth in mammals and that the sympathoadrenal system is markedly influenced by environmental conditions during these periods. We previously demonstrated that neonatal hyperleptinaemia in rats programmes higher body weight, higher food intake and hypothalamic leptin resistance in adulthood. Using this model of programming, we investigated adrenal medullary function and effects on cardiovascular parameters in male rats in adulthood. Leptin treatment during the first 10 days of lactation (8 microg 100 g(-1) day(-1), s.c.) resulted in lower body weight (6.5%, P < 0.05), hyperleptinaemia (10-fold, P < 0.05) and higher catecholamine content in adrenal glands (18.5%, P < 0.05) on the last day of treatment. In adulthood (150 days), the rats presented higher body weight (5%, P < 0.05), adrenal catecholamine content (3-fold, P < 0.05), tyrosine hydroxylase expression (35%, P < 0.05) and basal and caffeine-stimulated catecholamine release (53% and 100%, respectively, P < 0.05). Systolic blood pressure and heart rate were also higher in adult rats (7% and 6%, respectively, P < 0.05). Our results show that hyperleptinaemia in early life increases adrenal medullary function in adulthood and that this may alter cardiovascular parameters. Thus, we suggest that imprinting factors which increase leptin and catecholamine levels during the neonatal period could be involved in development of adult chronic diseases.

  14. Impact of chronic nicotine administration on bone mineral content in young and adult rats: a comparative study.

    PubMed

    Farag, Mahmoud M; Selima, Eman A; Salama, Mona A

    2013-11-15

    The aim of this study was to evaluate the effects of chronic nicotine administration on bone mineral homeostasis in rapidly growing young rats in comparison to effects in adult male rats. Two doses of nicotine (3 and 4.5mg/kg/day, as nicotine hydrogen tartrate) were used and rat treatment was continued for 6 months. In this study, all nicotine-treated rats weighed less than control rats and the effect was dose-dependent. Also, rats treated with nicotine had lower femoral wet weight and showed a significant reduction in femoral mid-shaft cortical width and femoral and lumbar vertebral ash weights. These effects were associated with a significant reduction of ash calcium and phosphorus contents of the femora and lumbar vertebrae. The bone mineral-lowering effects of nicotine were more severe in the lumbar vertebral spongy bone than in the femoral compact bone and these changes were more marked in adult rats than in young rats. An additional interesting observation was that the femora of young rats treated with nicotine were significantly shorter than those of control young rats. Also, the values of the femoral ash weight per unit length were significantly decreased in nicotine-treated adult rats but not in nicotine-treated young rats. Thus, these results show that nicotine-induced changes in bone vary with age. The clinical relevance of this study is that it may provide justification to insist that all people in general and the risky young group in particular should be warned against the hazards of the negative effects of nicotine on bone.

  15. Acute and Chronic Effects of Dietary Lactose in Adult Rats Are not Explained by Residual Intestinal Lactase Activity.

    PubMed

    van de Heijning, Bert J M; Kegler, Diane; Schipper, Lidewij; Voogd, Eline; Oosting, Annemarie; van der Beek, Eline M

    2015-07-08

    Neonatal rats have a high intestinal lactase activity, which declines around weaning. Yet, the effects of lactose-containing products are often studied in adult animals. This report is on the residual, post-weaning lactase activity and on the short- and long-term effects of lactose exposure in adult rats. Acutely, the postprandial plasma response to increasing doses of lactose was studied, and chronically, the effects of a 30% lactose diet fed from postnatal (PN) Day 15 onwards were evaluated. Intestinal lactase activity, as assessed both in vivo and in vitro, was compared between both test methods and diet groups (lactose vs. control). A 50%-75% decreased digestive capability towards lactose was observed from weaning into adulthood. Instillation of lactose in adult rats showed disproportionally low increases in plasma glucose levels and did not elicit an insulin response. However, gavages comprising maltodextrin gave rise to significant plasma glucose and insulin responses, indicative of a bias of the adult GI tract to digest glucose polymers. Despite the residual intestinal lactase activity shown, a 30% lactose diet was poorly digested by adult rats: the lactose diet rendered the animals less heavy and virtually devoid of body fat, whereas their cecum tripled in size, suggesting an increased bacterial fermentation. The observed acute and chronic effects of lactose exposure in adult rats cannot be explained by the residual intestinal lactase activity assessed.

  16. SEXUAL INTERACTIONS WITH UNFAMILIAR FEMALES REDUCE HIPPOCAMPAL NEUROGENESIS AMONG ADULT MALE RATS

    PubMed Central

    Spritzer, Mark D.; Curtis, Molly G.; DeLoach, Julia P.; Maher, Jack; Shulman, Leanne M.

    2016-01-01

    Recent experiments have shown that sexual interactions prior to cell proliferation cause an increase in neurogenesis in adult male rats. Because adult neurogenesis is critical for some forms of memory, we hypothesized that sexually induced changes in neurogenesis may be involved in mate recognition. Sexually naive adult male rats were either exposed repeatedly to the same sexual partner (familiar group) or to a series of novel sexual partners (unfamiliar group), while control males never engaged in sexual interactions. Ovariectomized female rats were induced into estrus every four days. Males were given two injections of BrdU (200 mg/kg) to label proliferating cells, and the first sexual interactions occurred three days later. Males in the familiar and unfamiliar groups engaged in four, 30 min sexual interactions at four-day intervals, and brain tissue was collected the day after the last sexual interaction. Immunohisotchemistry followed by microscopy was used to quantify BrdU-labeled cells. Sexual interactions with unfamiliar females caused a significant reduction in neurogenesis in the dentate gyrus compared to males that interacted with familiar females and compared to the control group. The familiar group showed no difference in neurogenesis compared to the control group. There were no differences in the amount of sexual behavior (mounts, intromissions, ejaculations, or contact time) that the familiar and unfamiliar groups engaged in, indicating that the differences in neurogenesis were not due to the relative amounts of sexual activity. In a second experiment, we tested whether this effect was unique to sexual interactions by replicating the entire procedure using anestrus females. We found that interactions with unfamiliar anestrus females reduced neurogenesis relative to the other groups, but this effect was not statistically significant. In combination, these results indicate that interactions with unfamiliar females reduce adult neurogenesis and the effect

  17. Sexual interactions with unfamiliar females reduce hippocampal neurogenesis among adult male rats.

    PubMed

    Spritzer, M D; Curtis, M G; DeLoach, J P; Maher, J; Shulman, L M

    2016-03-24

    Recent experiments have shown that sexual interactions prior to cell proliferation cause an increase in neurogenesis in adult male rats. Because adult neurogenesis is critical for some forms of memory, we hypothesized that sexually induced changes in neurogenesis may be involved in mate recognition. Sexually naive adult male rats were either exposed repeatedly to the same sexual partner (familiar group) or to a series of novel sexual partners (unfamiliar group), while control males never engaged in sexual interactions. Ovariectomized female rats were induced into estrus every four days. Males were given two injections of 5-bromo-2'-deoxyuridine (BrdU) (200mg/kg) to label proliferating cells, and the first sexual interactions occurred three days later. Males in the familiar and unfamiliar groups engaged in four, 30-min sexual interactions at four-day intervals, and brain tissue was collected the day after the last sexual interaction. Immunohistochemistry followed by microscopy was used to quantify BrdU-labeled cells. Sexual interactions with unfamiliar females caused a significant reduction in neurogenesis in the dentate gyrus compared to males that interacted with familiar females and compared to the control group. The familiar group showed no difference in neurogenesis compared to the control group. Males in the familiar group engaged in significantly more sexual behavior (ejaculations and intromissions) than did males in the unfamiliar group, suggesting that level of sexual activity may influence neurogenesis levels. In a second experiment, we tested whether this effect was unique to sexual interactions by replicating the entire procedure using anestrus females. We found that interactions with unfamiliar anestrus females reduced neurogenesis relative to the other groups, but this effect was not statistically significant. In combination, these results indicate that interactions with unfamiliar females reduce adult neurogenesis and the effect is stronger for sexual

  18. Histological correlates of N40 auditory evoked potentials in adult rats after neonatal ventral hippocampal lesion: animal model of schizophrenia.

    PubMed

    Romero-Pimentel, A L; Vázquez-Roque, R A; Camacho-Abrego, I; Hoffman, K L; Linares, P; Flores, G; Manjarrez, E

    2014-11-01

    The neonatal ventral hippocampal lesion (NVHL) is an established neurodevelopmental rat model of schizophrenia. Rats with NVHL exhibit several behavioral, molecular and physiological abnormalities that are similar to those found in schizophrenics. Schizophrenia is a severe psychiatric illness characterized by profound disturbances of mental functions including neurophysiological deficits in brain information processing. These deficits can be assessed by auditory evoked potentials (AEPs), where schizophrenics exhibit abnormalities in amplitude, duration and latency of such AEPs. The aim of the present study was to compare the density of cells in the temporal cerebral cortex and the N40-AEP of adult NVHL rats versus adult sham rats. We found that rats with NVHL exhibit significant lower amplitude of the N40-AEP and a significant lower number of cells in bilateral regions of the temporal cerebral cortex compared to sham rats. Because the AEP recordings were obtained from anesthetized rats, we suggest that NVHL leads to inappropriate innervation in thalamic-cortical pathways in the adult rat, leading to altered function of cortical networks involved in processing of primary auditory information.

  19. Chronic nicotine alters cannabinoid-mediated locomotor activity and receptor density in periadolescent but not adult male rats

    PubMed Central

    Werling, Linda L.; Reed, Stephanie Collins; Wade, Dean; Izenwasser, Sari

    2009-01-01

    A significant number of youths use cigarettes, and more than half of the youths who smoke daily also use illicit drugs. The focus of these studies is on how exposure to nicotine affects subsequent responses to both nicotine and cannabinoids in adolescents compared with adults. We have shown previously that chronic treatment with nicotine produces sensitization to its locomotor-activating effects in female and adult rats but not male adolescent rats. To better understand the effects of nicotine on adolescent and adult rats, rats were injected with nicotine or saline for 7 days and, on day 8, either challenged with delta-9-tetrahydrocannabinol (Δ9-THC) or the cannabinoid agonist CP 55,940 and tested for locomotor activity, or the brains were removed for quantitative autoradiography studies of the cannabinoid1 receptor. A separate group of rats was treated with nicotine plus the cannabinoid antagonist AM 251 and then challenged with CP 55,940. In adolescent male rats, nicotine administration led to sensitization to the locomotor-decreasing effects of both Δ9-THC and CP 55,940, but in adult male rats, the response to either drug was unchanged compared to controls. The effect of nicotine on CP 55,940-mediated locomotor activity was blocked by co-administration of AM 251 with the nicotine. Further, cannabinoid receptor density was increased in the prelimbic prefrontal cortex, ventral tegmental area, and select regions of the hippocampus in adolescent male rats pretreated with nicotine compared to vehicle-treated controls. There were no significant changes in cannabinoid receptor binding, however, in any of the brain regions examined in adult males pretreated with nicotine. The prelimbic prefrontal cortex and the hippocampus have been shown previously to be involved in stimulant reinforcement; thus it is possible that these changes contribute to the unique behavioral effects of chronic nicotine and subsequent drug administration in adolescents compared with adults. PMID

  20. Changes in mouse Leydig cells ultrastructure and testosterone secretion after diethylcarbamazine administration.

    PubMed

    Saraiva, Karina Lidianne Alcântara; Silva, Valdemiro Amaro Da; Torres, Dilênia De Oliveira Cipriano; Donato, Mariana Aragão Matos; Peres, Newton Gil; Souza, José Roberto Botelho De; Peixoto, Christina Alves

    2008-07-01

    Diethylcarbamazine (DEC) has been proven to be highly effective against lymphatic filariasis, although its effect on vertebrate cells remains uncertain. Mice Leydig cells after treatment with 200mg/kg of DEC for 12 days showed numerous lipid droplets, degenerated mitochondria, residual bodies and several giant whorl-like smooth endoplasmic reticulum, some of them encircling large lipids droplets. Treatment with lower dosages showed similar alterations on Leydig cells and the morphological effects decreased directly proportional to the drug concentration. Serum testosterone levels were significantly lower only in 200 mg/kg DEC-treated group when compared to the controls. However, no significant changes were observed in the pregnancy rates and offspring number of DEC-treated male-mated female mice in any doses studied. The results obtained in the present study are consistent with the hypothesis that DEC has some effects on mice Leydig cells, although they were not sufficient enough to interfere with the rodent fertility.

  1. Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

    SciTech Connect

    Kheradmand, Arash; Dezfoulian, Omid; Alirezaei, Masoud; Rasoulian, Bahram

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. Black-Right-Pointing-Pointer Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. Black-Right-Pointing-Pointer Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. Black-Right-Pointing-Pointer Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P < 0.01) in the ghrelin-treated group on day 10, while despite of 30% increment in the Bax level of spermatocytes in the treated rats on day 30, however, it was not statistically significant. During the experimental period, only a few spermatogonia represented Bax expression and the changes of Bax immunolabling cells were negligible upon ghrelin treatment. Likewise, there were immunostaining cells against Bcl-2 in each germ cell neither in the control nor in the treated animals. In fact

  2. Gender differences in the effect of adult amphetamine on cognitive functions of rats prenatally exposed to methamphetamine.

    PubMed

    Macúchová, E; Nohejlová, K; Slamberová, R

    2014-08-15

    Psychostimulants have been shown to affect brain regions involved in the process of learning and memory consolidation. It has been shown that females are more sensitive to the effects of drugs than males. The aim of our study was to investigate how prenatal methamphetamine (MA) exposure and application of amphetamine (AMP) in adulthood would affect spatial learning of adult female and male rats. Mothers of the tested offspring were exposed to injections of MA (5mg/kg) or saline (SA) throughout the entire gestation period. Cognitive functions of adult rats were evaluated in the Morris Water Maze (MWM) tests. Adult offspring were injected daily with AMP (5mg/kg) or SA through the period of MWM testing. Our data from the MWM tests demonstrates the following. Prenatal MA exposure did not change the learning ability of adult male and female rats. However, AMP administration to adult animals affected cognitive function in terms of exacerbation of spatial learning (increasing the latency to reach the hidden platform, the distance traveled and the search error) only in female subjects. There were sex differences in the speed of swimming. Prenatal MA exposure and adult AMP treatment increased the speed of swimming in female groups greater than in males. Overall, the male subjects showed a better learning ability than females. Thus, our results indicate that the adult AMP treatment affects the cognitive function and behavior of rats in a sex-specific manner, regardless of prenatal exposure.

  3. Evidence of lactoferrin transportation into blood circulation from intestine via lymphatic pathway in adult rats.

    PubMed

    Takeuchi, Takashi; Kitagawa, Hiroshi; Harada, Etsumori

    2004-05-01

    Using adult rats, the characteristic transporting system for lactoferrin (LF) from intestinal lumen into the blood circulation was investigated. The rats were randomly divided into two groups, a non-collected thoracic lymph (NC) group and a collected thoracic lymph (LC) group. Peripheral blood and thoracic lymph were collected from a jugular vein and a thoracic lymph duct, respectively, under anaesthesia. Bovine LF (bLF) was infused into the duodenal lumen by needle over a 1-min period at a dose of 1 g kg(-1). The transported bLF in the plasma and lymph was assayed quantitatively by double-antibody enzyme-linked immunosorbent assay (ELISA). Morphological investigation was also carried out in the intestine, lymph node, and liver. Following intraduodenal administration of bLF, the transported bLF in the NC group was detected in the plasma, and reached a peak value at 2 h. Furthermore, the bLF concentration in the thoracic duct lymph fluid in the LC group increased significantly, and peaked 2 h after the administration. In addition, bLF was not detected in the plasma of the LC group. Immunohistochemical analysis clearly showed anti-bLF positive particles in the epithelial cells of the apical villi. The striated border and baso-lateral membrane were also bLF positive. These results suggest that intraduodenally infused bLF is transported into the blood circulation via the lymphatic pathway, not via portal circulation in adult rats.

  4. Lead Exposure Induces Weight Gain in Adult Rats, Accompanied by DNA Hypermethylation

    PubMed Central

    Zhao, Li; Li, Qin; Cang, Zhen; Chen, Chi; Lu, Meng; Cheng, Jing; Zhai, Hualing; Xia, Fangzhen; Ye, Lin; Lu, Yingli

    2017-01-01

    Objective Previous studies have revealed the association of lead (Pb) exposure with obesity. DNA methylation alteration has been suggested to be one of the regulatory mechanisms of obesity. We aimed to explore whether Pb exposure is related with weight gain and DNA methylation alteration. Methods Male adult 8 week Wistar rats were divided into 5 groups: the normal chow diet (NCD); the NCD+0.05%Pb; the NCD+0.15%Pb; the NCD+0.45%Pb and the high fat diet. Rats were exposed to different dosages of Pb through drinking water for 21 weeks. Body weight, fasted blood glucose level, fasted insulin level, homeostasis assessment of insulin resistance (HOMA-IR) index and lipid profile were detected. Intra-peritoneal glucose tolerance test (IPGTT) was constructed to evaluate the glucose tolerance. Lipid accumulation of liver was detected and liver DNA underwent whole genome bisulfite sequencing. Results The NCD+0.05%Pb group had significantly greater weight, HOMA-IR and triglycerides, and lower glucose intolerance than the NCD group (P <0.05). This group also showed hepatic lipid accumulation. These metabolic changes were not observed in the other two Pb dosage groups. Furthermore, DNA hypermethylation extended along pathways related to glucose and lipid metabolism in NCD+0.05%Pb group. Conclusion Pb exposure resulted in dose-specific weight gain in adult Wistar rats, accompanied by alteration of DNA methylation. PMID:28107465

  5. Variability in the distribution of callosal projection neurons in the adult rat parietal cortex.

    PubMed

    Ivy, G O; Gould, H J; Killackey, H P

    1984-07-23

    Previous reports have shown that the barrel field area of the parietal cortex of the adult rat contains relatively few callosal projection neurons, even though callosal projection neurons are abundant in this cortical region in the neonatal rat. Furthermore, it has been shown that many of the callosal neurons which seem to disappear as the animal matures do not die, but project to ipsilateral cortical areas. These findings rely on the ability of retrograde transport techniques which utilize injections of horseradish peroxidase (HRP) or of fluorescent dyes into one hemisphere. We now show that several technical modifications of the HRP technique yield a wider distribution of HRP-containing neurons in the contralateral barrel field area of the adult rat than previously reported. These include implants of HRP pellets into transected axons of the corpus callosum, the addition of DMSO and nonidet P40 to Sigma VI HRP, wheat germ agglutinin HRP and the use of tetramethyl benzidine as the chromogen in the reaction procedure. Our findings have implications for transport studies in general and for the development of the cortical barrel field in particular.

  6. Effects of moderate zinc deficiency on cognitive performance in young adult rats.

    PubMed

    Massaro, T F; Mohs, M; Fosmire, G

    1982-07-01

    Two experiments were conducted to establish a dietary zinc level which approximates a moderate deficiency in the young adult rat and to determine if a concurrent zinc deficiency affects cognitive performance. Male rats were fed varying levels of zinc in diet throughout a 17-day period. The lowest dietary level that depressed serum and bone zinc without influencing food consumption or body weight gains was observed to be 5.8 microgram Zn/g diet. Young adult rats maintained on either a zinc adequate (24.4 microgram Zn/g) or low-zinc (5.3 microgram Zn/g) diet were tested in a modified Skinner Box involving tests of visual, auditory, association, and discrimination learning. No differences were observed in the visual discrimination performance of the zinc deficient animals when compared with control counterparts. Deficits in the ability to transfer a learned association between visual and auditory stimuli were observed, however, in the deficient group during the transfer test phase. The latter performed better during the final auditory discrimination task in transferring a learned food-relevant cue.

  7. A rare ovarian tumor, leydig stromal cell tumor, presenting with virilization: a case report

    PubMed Central

    Aminimoghaddam, Soheila; Hashemi, Forough

    2012-01-01

    Leydig stromal cell tumor is a rare ovarian tumor that belongs to the group of sex-cord stromal tumors. They produce testosterone leading to hyperandrogenism. We present a 41yr old woman with symptoms of virilization and a mass of right adenex via ultra Sonography, and a rise of total and free serum testosterone. An ovarian source of androgen was suspected and a surgery performed. A diagnosis of leydig-stromal cell tumor was confirmed. Our report is a reminder that although idiopathic hirsutism and other benign androgen excess disorder like Polycystic Ovarian Syndrome (PCOs) are common, ovarian mass should be considered in differential diagnosis. PMID:23482693

  8. Prolactin inhibition at the end of lactation programs for a central hypothyroidism in adult rat.

    PubMed

    Bonomo, Isabela Teixeira; Lisboa, Patrícia Cristina; Passos, Magna Cottini Fonseca; Alves, Simone Bezerra; Reis, Adelina Martha; de Moura, Egberto Gaspar

    2008-08-01

    Malnutrition during lactation is associated with hypoprolactinemia and failure in milk production. Adult rats whose mothers were malnourished presented higher body weight and serum tri-iodothyronine (T(3)). Maternal hypoprolactinemia at the end of lactation caused higher body weight in adult life, suggesting an association between maternal prolactin (PRL) level and programming of the offspring's adult body weight. Here, we studied the consequences of the maternal PRL inhibition at the end of lactation by bromocriptine (BRO) injection, a dopaminergic agonist, upon serum TSH and thyroid hormones, thyroid iodide uptake, liver mitochondrial alpha-glycerophosphate dehydrogenase (mGPD), liver and pituitary de-iodinase activities (D1 and/or D2), and in vitro post-TRH TSH release in the adult offspring. Wistar lactating rats were divided into BRO - injected with 1 mg/twice a day, daily for the last 3 days of lactation, and C - control, saline-injected with the same frequency. At 180 days of age, the offspring were injected with (125)I i.p. and after 2 h, they were killed. Adult animals whose mothers were treated with BRO at the end of lactation presented lower serum TSH (-51%), T(3) (-23%), and thyroxine (-21%), lower thyroid (125)I uptake (-41%), liver mGPD (-55%), and pituitary D2 (-51%) activities, without changes in the in vitro post-TRH TSH release. We show that maternal PRL suppression at the end of lactation programs a hypometabolic state in adulthood, in part due to a thyroid hypofunction, caused by a central hypothyroidism, probably due to decreased TRH secretion. We suggest that PRL during lactation can regulate the hypothalamus-pituitary-thyroid axis and programs its function.

  9. Homeostatic regulation of adult hippocampal neurogenesis in aging rats: long-term effects of early exercise

    PubMed Central

    Merkley, Christina M.; Jian, Charles; Mosa, Adam; Tan, Yao-Fang; Wojtowicz, J. Martin

    2014-01-01

    Adult neurogenesis is highly responsive to environmental and physiological factors. The majority of studies to date have examined short-term consequences of enhancing or blocking neurogenesis but long-term changes remain less well understood. Current evidence for age-related declines in neurogenesis warrant further investigation into these long-term changes. In this report we address the hypothesis that early life experience, such as a period of voluntary running in juvenile rats, can alter properties of adult neurogenesis for the remainder of the animal's life. The results indicate that the number of proliferating and differentiating neuronal precursors is not altered in runners beyond the initial weeks post-running, suggesting homeostatic regulation of these processes. However, the rate of neuronal maturation and survival during a 4 week period after cell division was enhanced up to 11 months of age (the end of the study period). This study is the first to show that a transient period of physical activity at a young age promotes changes in neurogenesis that persist over the long-term, which is important for our understanding of the modulation of neurogenesis by exercise with age. Functional integration of adult-born neurons within the hippocampus that resist homeostatic regulation with aging, rather than the absolute number of adult-born neurons, may be an essential feature of adult neurogenesis that promotes the maintenance of neural plasticity in old age. PMID:25071426

  10. Functional plasticity of regenerated and intact taste receptors in adult rats unmasked by dietary sodium restriction.

    PubMed

    Hill, D L; Phillips, L M

    1994-05-01

    Unilateral chorda tympani nerve sectioning was combined with institution of a sodium-restricted diet in adult rats to determine the role that environment has on the functional properties of regenerating taste receptor cells. Rats receiving chorda tympani sectioning but no dietary manipulation (cut controls) and rats receiving only the dietary manipulation (diet controls) had normal responses to a concentration series of NaCl, sodium acetate (NaAc), and NH4Cl. However, responses from the regenerated nerve in NaCl-restricted rats (40-120 d postsectioning) to NaCl and NaAc were reduced by as much as 30% compared to controls, indicating that regenerating taste receptors are influenced by environmental (dietary) factors. Responses to NH4Cl were normal; therefore, the effect appears specific to sodium salts. Surprisingly, in the same rats, NaCl responses from the contralateral, intact chorda tympani were up to 40% greater than controls. Thus, in the same rat, there was over a twofold difference in sodium responses between the right and left chorda tympani nerves. A study of the time course of the functional alterations in the intact nerve revealed that responses to NaCl were extremely low immediately following sectioning (about 20% of the normal response), and then increased monotonically during the following 50 d until relative response magnitudes became supersensitive. This function occurred even when the cut chorda tympani was prevented from reinnervating lingual epithelia, demonstrating that events related to regeneration do not play a role in the functional properties of the contralateral side of the tongue.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Impaired contextual fear extinction and hippocampal synaptic plasticity in adult rats induced by prenatal morphine exposure.

    PubMed

    Tan, Ji-Wei; Duan, Ting-Ting; Zhou, Qi-Xin; Ding, Ze-Yang; Jing, Liang; Cao, Jun; Wang, Li-Ping; Mao, Rong-Rong; Xu, Lin

    2015-07-01

    Prenatal opiate exposure causes a series of neurobehavioral disturbances by affecting brain development. However, the question of whether prenatal opiate exposure increases vulnerability to memory-related neuropsychiatric disorders in adult offspring remains largely unknown. Here, we found that rats prenatally exposed to morphine (PM) showed impaired acquisition but enhanced maintenance of contextual fear memory compared with control animals that were prenatally exposed to saline (PS). The impairment of acquisition was rescued by increasing the intensity of footshocks (1.2 mA rather than 0.8 mA). Meanwhile, we also found that PM rats exhibited impaired extinction of contextual fear, which is associated with enhanced maintenance of fear memory. The impaired extinction lasted for 1 week following extinction training. Furthermore, PM rats exhibited reduced anxiety-like behavior in the elevated plus-maze and light/dark box test without differences in locomotor activity. These alterations in PM rats were mirrored by abnormalities in synaptic plasticity in the Schaffer collateral-CA1 synapses of the hippocampus in vivo. PS rats showed blocked long-term potentiation and enabled long-term depression in CA1 synapses following contextual fear conditioning, while prenatal morphine exposure restricted synaptic plasticity in CA1 synapses. The smaller long-term potentiation in PM rats was not further blocked by contextual fear conditioning, and the long-term depression enabled by contextual fear conditioning was abolished. Taken together, our results provide the first evidence suggesting that prenatal morphine exposure may increase vulnerability to fear memory-related neuropsychiatric disorders in adulthood.

  12. Behavioural and biochemical effects in the adult rat after prolonged postnatal administration of clozapine.

    PubMed

    Cuomo, V; Cagiano, R; Mocchetti, I; Coen, E; Cattabeni, F; Racagni, G

    1983-01-01

    Rats were administered 10 mg/kg SC of clozapine (C) or vehicle solution (S) daily from day 1 after birth until 20 days of age. At 60 days of age (40 days after the postnatal treatment with C or S was interrupted) the stereotyped behaviour and the effects on locomotor activity elicited by apomorphine in S- and C-pretreated rats were investigated. The intensity of stereotyped behaviour as well as the decrement in locomotion induced by apomorphine (0.5--1 mg/kg SC) were not influenced by chronic C administration during development. Finally, at 80 days of age (60 days after the postnatal treatment with C or S was interrupted) rats were subjected to a differential reinforcement of low rates schedule (DRL15s). The results indicate that the acquisition of the DRL task performance criterion (Rs/Rf less than or equal to 2.5) was significantly more rapid in S-pretreated rats than in C-pretreated ones. In parallel biochemical experiments, homovanillic acid (HVA) content was measured in striatum in rats at 60 days of age (40 days after the postnatal treatment with C or S was interrupted). The results indicate that even if an acute challenge dose of 10 mg/kg C shows a certain degree of tolerance a single dose of 20 mg/kg C is still able to increase striatal HVA concentration in chronic C-pretreated animals. These data indicate that early postnatal administration of a non-cataleptogenic neuroleptic, like C, induces, in the adult rat, behavioural and biochemical changes which significantly differ from those elicited by a cataleptogenic neuroleptic, like haloperidol.

  13. Anti-Nogo-A Immunotherapy Does Not Alter Hippocampal Neurogenesis after Stroke in Adult Rats

    PubMed Central

    Shepherd, Daniel J.; Tsai, Shih-Yen; O'Brien, Timothy E.; Farrer, Robert G.; Kartje, Gwendolyn L.

    2016-01-01

    Ischemic stroke is a leading cause of adult disability, including cognitive impairment. Our laboratory has previously shown that treatment with function-blocking antibodies against the neurite growth inhibitory protein Nogo-A promotes functional recovery after stroke in adult and aged rats, including enhancing spatial memory performance, for which the hippocampus is critically important. Since spatial memory has been linked to hippocampal neurogenesis, we investigated whether anti-Nogo-A treatment increases hippocampal neurogenesis after stroke. Adult rats were subject to permanent middle cerebral artery occlusion followed 1 week later by 2 weeks of antibody treatment. Cellular proliferation in the dentate gyrus was quantified at the end of treatment, and the number of newborn neurons was determined at 8 weeks post-stroke. Treatment with both anti-Nogo-A and control antibodies stimulated the accumulation of new microglia/macrophages in the dentate granule cell layer, but neither treatment increased cellular proliferation or the number of newborn neurons above stroke-only levels. These results suggest that anti-Nogo-A immunotherapy does not increase post-stroke hippocampal neurogenesis. PMID:27803646

  14. GABAergic transmission and enhanced modulation by opioids and endocannabinoids in adult rat rostral ventromedial medulla

    PubMed Central

    Li, Ming-Hua; Suchland, Katherine L; Ingram, Susan L

    2015-01-01

    Neurons in the rostral ventromedial medulla (RVM) play critical and complex roles in pain modulation. Recent studies have shown that electrical stimulation of the RVM produces pain facilitation in young animals (postnatal (PN) day < 21) but predominantly inhibits pain behaviours in adults. The cellular mechanisms underlying these changes in RVM modulation of pain behaviours are not known. This is in part because whole-cell patch-clamp studies in RVM to date have been in young (PN day < 18) animals because the organization and abundance of myelinated fibres in this region make the RVM a challenging area for whole-cell patch-clamp recording in adults. Several neurotransmitter systems, including GABAergic neurotransmission, undergo developmental changes that mature by PN day 21. Thus, we focused on optimizing whole-cell patch-clamp recordings for RVM neurons in animals older than PN day 30 and compared the results to animals at PN day 10–21. Our results demonstrate that the probability of GABA release is lower and that opioid and endocannabinoid effects are more evident in adult rats (mature) compared to early postnatal (immature) rats. Differences in these properties of RVM neurons may contribute to the developmental changes in descending control of pain from the RVM to the spinal cord. PMID:25556797

  15. Amphetamine-induced incentive sensitization of sign-tracking behavior in adolescent and adult female rats.

    PubMed

    Doremus-Fitzwater, Tamara L; Spear, Linda P

    2011-08-01

    Age-specific behavioral and neural characteristics may predispose adolescents to initiate and escalate use of alcohol and drugs. Adolescents may avidly seek novel experiences, including drugs of abuse, because of enhanced incentive motivation for drugs and natural rewards, perhaps especially when that incentive motivation is sensitized by prior drug exposure. Using a Pavlovian conditioned approach (PCA) procedure, sign-tracking (ST) and goal-tracking (GT) behavior was examined in amphetamine-sensitized and control adolescent and adult female Sprague-Dawley rats, with expression of elevated ST behavior used to index enhanced incentive motivation for reward-associated cues. Rats were first exposed to a sensitizing regimen of amphetamine injections (3.0 mg/kg/ml d-amphetamine per day) or given saline (0.9% wt/vol) once daily for 4 days. Expression of ST and GT was then examined over 8 days of PCA training consisting of 25 pairings of an 8-s presentation of an illuminated lever immediately followed by response-independent delivery of a banana-flavored food pellet. Results showed that adults clearly displayed more ST behavior than adolescents, reflected via both more contacts with, and shorter latencies to approach, the lever. Prior amphetamine sensitization increased ST (but not GT) behaviors regardless of age. Thus, when indexed via ST, incentive motivation was found to be greater in adults than adolescents, with a prior history of amphetamine exposure generally sensitizing incentive motivation for cues predicting a food reward regardless of age.

  16. Maternal isobutyl-paraben exposure alters anxiety and passive avoidance test performance in adult male rats.

    PubMed

    Kawaguchi, Maiko; Irie, Kaoru; Morohoshi, Kaori; Watanabe, Gen; Taya, Kazuyoshi; Morita, Masatoshi; Kondo, Yasuhiko; Imai, Hideki; Himi, Toshiyuki

    2009-10-01

    Isobutyl-paraben (IBP), one of the most widely used preservatives, exhibits estrogenic activity. In this study, we analyzed the effects of maternal IBP treatment on the emotional behavior and learning performance in mature offspring. Pregnant female Sprague-Dawley rats were treated with IBP via a subcutaneous Silastic capsule. Consequently, the offspring were exposed to IBP during gestation through the placentae, and before weaning through the milk. Male and female offspring were tested for emotional behavior in an open field and in an elevated plus maze at five and six weeks old, respectively. IBP-exposed male (but not female) rats spent less time in the open arms of the elevated plus maze. At 11 weeks old, all females were gonadectomized and treated chronically with 17beta-estradiol or cholesterol by Silastic capsules; all males were kept intact. They were tested for learning performance in a passive avoidance test and a Morris water maze. IBP exposure impaired the performance of males in the passive avoidance test. These findings suggest that male rats are more affected by early exposure to IBP than female rats. IBP affects their adult behavior including anxiety and learning abilities.

  17. Spermatogenetic disorders in adult rats exposed to tributyltin chloride during puberty.

    PubMed

    Yu, Wook Joon; Lee, Beom Jun; Nam, Sang Yoon; Kim, Young Chul; Lee, Yong Soon; Yun, Young Won

    2003-12-01

    Adverse effects of tributyltin (TBT) chloride were investigated on the reproductive system in male adult rats as exposed during puberty. Fifty Sprague-Dawley rats at the age of 35 days were assigned to five different groups: negative control receiving vehicle, methyltestosterone (10 mg/kg B.W.), and TBT chloride treatments (5, 10, and 20 mg/kg B.W.). Animals were treated by oral gavage for ten consecutive days and sacrificed at 5 weeks after final treatment. The treatment of TBT chloride at the high dose of 20 mg/kg B.W. significantly decreased homogenization-resistant testicular sperm counts (p<0.05). The TBT chloride treatment at the doses of 10 and 20 mg/kg B.W. also significantly decreased caudal epididymal sperm counts (p<0.01). Some of motion kinematic parameters (motility, mean angular displacement, lateral head displacement, and dance) of sperms retrieved from vasa deference were significantly decreased in rats treated with the TBT chloride at the dose of 20 mg/kg B.W. (p<0.05). These results provide a further evidence that an exposure to TBT chloride during pubertal period in male rats produces spermatogenic disorders characterized by decreasing testicular and epididymal sperm counts and some motion parameters of sperms in the vasa deference.

  18. Neonatal DSP-4 treatment modifies GABAergic neurotransmission in the prefrontal cortex of adult rats.

    PubMed

    Bortel, Aleksandra; Nowak, Przemyslaw; Brus, Ryszard

    2008-01-01

    N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) is a noradrenergic neurotoxin which selectively damages noradrenergic projections originating from the locus coeruleus (LC). DSP-4 treatment of rats on the first and third days after birth produces a long-lasting lesion of noradrenergic neurons in the prefrontal cortex (PFC). In DSP-4-lesioned rats, studied as adults, we observed a decrease in norepinephrine content, with no significant change in the levels of dopamine, 5-hydroxytryptamine, and gamma-aminobutyric acid (GABA). There is now a well established interaction between noradrenergic and GABAergic systems, whereby the noradrenergic system is involved in the regulation of basal GABA release, while GABAergic neurons simultaneously exert tonic inhibitory regulation of LC norepinephrine neurons. We examined GABAergic neurotransmission in the norepinephrine-denervated PFC for a better appreciation of the interaction between these two systems. Treatment with the GABA transaminase inhibitor vigabatrine (VGB) increased the GABA level of PFC (tissue content) in both intact and lesioned groups. Additionally, VGB increased extracellular GABA concentration in the PFC in both control and DSP-4-lesioned animals, but the elevation of GABA was 2-fold higher in DSP-4 lesioned rats. These findings indicate that neonatal DSP-4 treatment increases GABAergic neurotransmission in the PFC of rats in adulthood, perhaps by decreasing reactivity of central GABA(A) receptors.

  19. Effects of estradiol and progesterone on vertebral collagen, glycosaminoglycans and phosphatases in ovariectomized adult rats.

    PubMed

    Gopala Krishnan, V; Arunakaran, J; Govindarajulu, P; Srinivasan, N

    2003-03-01

    Vertebral collagen, glycosaminoglycans (GAGs), tartrate-resistant acid phosphatase (TRAP) and alkaline phosphatase (ALP) were measured in ovariectomized (ovx) adult Wistar rats treated with estradiol (E 2 ) (10 micro g/kg BW for 35 days on alternate days, and progesterone (P 4 ) (140 micro g/kg BW for 35 days on alternate days) in E 2 + P 4 treated rats. P 4 given alone or in combination with E 2 significantly increased the levels of collagen in the vertebral bone. Neither ovx nor E 2 treatment altered the concentration of collagen in these rats. Administration of E 2 or P 4 significantly decreased the concentration of hyaluronic acid (HA), but remaining unaffected when a combination of these steroids was given. In contrast to their effect on HA, E 2 and P 4 each significantly increased the levels of chondroitin sulfate (CS) in the vertebral bone. The specific activity of ALP was decreased after ovx. E 2 and P 4 alone or in combination also registered a significant decrease in the activities of ALP and TRAP. The results suggest that E 2 and P 4 each exert definite effects on vertebral bone turnover in ovariectomized rats.

  20. Tianeptine facilitates spreading depression in well-nourished and early-malnourished adult rats.

    PubMed

    Amancio-Dos-Santos, Angela; Maia, Luciana Maria Silva de Seixas; Germano, Paula Catirina Pereira da Silva; Negrão, Yleana Danielle Dos Santos; Guedes, Rubem Carlos Araújo

    2013-04-15

    Nutritional status during development can modify the brain's electrophysiological properties and its response to drugs that reduce the serotonin availability in the synaptic cleft. Here we used cortical spreading depression (CSD) in the rat as a neurophysiological parameter to investigate the interaction between nutritional status and treatment with tianeptine, a serotonin uptake enhancer. From postnatal day 2 to 24, well-nourished and early-malnourished rat pups were s.c. injected with tianeptine (5 or 10mg/kg; 10 ml/kg) or equivalent volume of saline solution (control group). When the animals were 25-30 days old, CSD was recorded on the brain cortical surface. In the well-nourished rats, but not in the malnourished group, systemic tianeptine dose-dependently increased the CSD propagation velocity, with 10mg/kg producing a significant (P<0.05) effect. An experiment in adult rats showed that cortical topical application of tianeptine solutions (5mg/ml, 10mg/ml, and 20mg/ml) increased the CSD propagation in both the well-nourished and early-malnourished conditions. In well-nourished animals, 0.5mg/ml topical tianeptine did not affect CSD propagation, and 2mg/ml produced a small, but significant CSD acceleration. Our results indicate a facilitating action of tianeptine on CSD propagation, probably via tianeptine's pharmacological action on the serotonin system. These findings support previous data suggesting an antagonistic role of the serotoninergic system on CSD.

  1. Lifespan Changes in the Countermanding Performance of Young and Middle Aged Adult Rats

    PubMed Central

    Beuk, Jonathan; Beninger, Richard J.; Paré, Martin

    2016-01-01

    Inhibitory control can be investigated with the countermanding task, which requires subjects to make a response to a go signal and cancel that response when a stop signal is presented occasionally. Adult humans performing the countermanding task typically exhibit impaired response time (RT), stop signal response time (SSRT) and response accuracy as they get older, but little change in post-error slowing. Rodent models of the countermanding paradigm have been developed recently, yet none have directly examined age-related changes in performance throughout the lifespan. Male Wistar rats (N = 16) were trained to respond to a visual stimulus (go signal) by pressing a lever directly below an illuminated light for food reward, but to countermand the lever press subsequent to a tone (stop signal) that was presented occasionally (25% of trials) at a variable delay. Subjects were tested in 1 h sessions at approximately 7 and 12 months of age with intermittent training in between. Rats demonstrated longer go trial RT, a higher proportion of go trial errors and performed less total trials at 12, compared to 7 months of age. Consistent SSRT and post-error slowing were observed for rats at both ages. These results suggest that the countermanding performance of rats does vary throughout the lifespan, in a manner similar to humans, suggesting that rodents may provide a suitable model for behavioral impairment related to normal aging. These findings also highlight the importance of indicating the age at which rodents are tested in countermanding investigations. PMID:27555818

  2. Influx mechanisms in the embryonic and adult rat choroid plexus: a transcriptome study

    PubMed Central

    Saunders, Norman R.; Dziegielewska, Katarzyna M.; Møllgård, Kjeld; Habgood, Mark D.; Wakefield, Matthew J.; Lindsay, Helen; Stratzielle, Nathalie; Ghersi-Egea, Jean-Francois; Liddelow, Shane A.

    2015-01-01

    The transcriptome of embryonic and adult rat lateral ventricular choroid plexus, using a combination of RNA-Sequencing and microarray data, was analyzed by functional groups of influx transporters, particularly solute carrier (SLC) transporters. RNA-Seq was performed at embryonic day (E) 15 and adult with additional data obtained at intermediate ages from microarray analysis. The largest represented functional group in the embryo was amino acid transporters (twelve) with expression levels 2–98 times greater than in the adult. In contrast, in the adult only six amino acid transporters were up-regulated compared to the embryo and at more modest enrichment levels (<5-fold enrichment above E15). In E15 plexus five glucose transporters, in particular Glut-1, and only one monocarboxylate transporter were enriched compared to the adult, whereas only two glucose transporters but six monocarboxylate transporters in the adult plexus were expressed at higher levels than in embryos. These results are compared with earlier published physiological studies of amino acid and monocarboxylate transport in developing rodents. This comparison shows correlation of high expression of some transporters in the developing brain with higher amino acid transport activity reported previously. Data for divalent metal transporters are also considered. Immunohistochemistry of several transporters (e.g., Slc16a10, a thyroid hormone transporter) gene products was carried out to confirm translational activity and to define cellular distribution of the proteins. Overall the results show that there is substantial expression of numerous influx transporters in the embryonic choroid plexus, many at higher levels than in the adult. This, together with immunohistochemical evidence and data from published physiological transport studies suggests that the choroid plexus in embryonic brain plays a major role in supplying the developing brain with essential nutrients. PMID:25972776

  3. Constituent ratio of motor fibers from the C5-C7 spinal nerves in the radial nerve is greater in pup rats than in adult rats.

    PubMed

    Nie, Mingbo; Chen, Liang; Gu, Yudong

    2012-06-01

    Clinically, injuries of C5-C7 of the brachial plexus cause falling of the wrist and fingers in infants but not in adults unless 4 consecutive spinal nerves are injured. The purpose of this study was to compare the constituent difference of spinal nerves in the radial nerve between pup and adult rats.A group of 16 pup rats and a group of 16 adult rats were each divided into 2 groups of 8 (P1 and A1 groups, C5-C6 were divided; P2 and A2 groups, C5-C7 were divided]). A nerve conduction study and histological examination were performed to evaluate radial nerve innervation to the extensor digitorum communis muscle after dividing the spinal nerves. Retrograde tracing with 5% cholera toxin B for anterior horn motoneurons of the spinal cord innervating the radial nerve was performed in 8 pup rats and 8 adult rats. Results showed that the division of C5-C7 caused more significant damage to radial nerve innervation to the extensor digitorum communis in pups than in adults, although the division of C5-C6 did not. In pups, the percentages (median with interquartile) of anterior horn motoneurons of the spinal cord innervating the radial nerve were 36.4 (28.3-38.5) in C5-C6, 28.1 (24.5-32.5) in C7, and 37.5 (36.5-39.3) in C8-T1. In adults, they were 24.2 (23.6-27.8) in C5-C6, 21.8 (19.5-26.3) in C7, and 50.7 (48.7-55.5) C8-T1.This study implies that C7 innervation in the radial nerve in humans may be more critical to the function of this nerve in infants than in adults.

  4. Moderate prenatal alcohol exposure and quantification of social behavior in adult rats.

    PubMed

    Hamilton, Derek A; Magcalas, Christy M; Barto, Daniel; Bird, Clark W; Rodriguez, Carlos I; Fink, Brandi C; Pellis, Sergio M; Davies, Suzy; Savage, Daniel D

    2014-12-14

    Alterations in social behavior are among the major negative consequences observed in children with Fetal Alcohol Spectrum Disorders (FASDs). Several independent laboratories have demonstrated robust alterations in the social behavior of rodents exposed to alcohol during brain development across a wide range of exposure durations, timing, doses, and ages at the time of behavioral quantification. Prior work from this laboratory has identified reliable alterations in specific forms of social interaction following moderate prenatal alcohol exposure (PAE) in the rat that persist well into adulthood, including increased wrestling and decreased investigation. These behavioral alterations have been useful in identifying neural circuits altered by moderate PAE(1), and may hold importance for progressing toward a more complete understanding of the neural bases of PAE-related alterations in social behavior. This paper describes procedures for performing moderate PAE in which rat dams voluntarily consume ethanol or saccharin (control) throughout gestation, and measurement of social behaviors in adult offspring.

  5. The 14-day repeated dose liver micronucleus test with methapyrilene hydrochloride using young adult rats.

    PubMed

    Inoue, Kenji; Ochi, Akimu; Koda, Akira; Wako, Yumi; Kawasako, Kazufumi; Doi, Takaaki

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect genotoxic hepatocarcinogens that can be integrated into a general toxicity study. The assay methods were thoroughly validated by 19 Japanese facilities. Methapyrilene hydrochloride (MP), known to be a non-genotoxic hepatocarcinogen, was examined in the present study. MP was dosed orally at 10, 30 and 100mg/kg/day to 6-week-old male Crl:CD (SD) rats daily for 14 days. Treatment with MP resulted in an increase in micronucleated hepatocytes (MNHEPs) with a dosage of only 100mg/kg/day. At this dose level, cytotoxicity followed by regenerative cell growth was noted in the liver. These findings suggest that MP may induce clastogenic effects indirectly on the liver or hepatotoxicity of MP followed by regeneration may cause increase in spontaneous incidence of MNHEPs.

  6. Intestinal mast cells and eosinophils in relation to Strongyloides ratti adult expulsion from the small and large intestines of rats.

    PubMed

    Shintoku, Y; Kadosaka, T; Kimura, E; Takagi, H; Kondo, S; Itoh, M

    2013-04-01

    Mucosal mast cells (MMC) play a crucial role in the expulsion of Strongyloides ratti adults from the small intestine of mice. We reported the large intestinal parasitism of S. ratti in rats, and there has been no report on MMC in the large intestine of the natural host. We studied kinetics of MMC, together with eosinophils, in the upper and lower small intestines, caecum and colon of infected rats. Two distinct phases of mastocytosis were revealed: one in the upper small intestine triggered by stimulation of 'ordinary' adults, and the other in the colon stimulated by 'immune-resistant' adults that started parasitizing the colon around 19 days post-infection. In all 4 intestinal sites, the MMC peaks were observed 5-7 days after the number of adult worms became the maximum and the height of MMC peaks appeared to be dependent on the number of parasitic adults, suggesting an important role played by worms themselves in the MMC buildup.

  7. Long-term effects of repeated maternal separation and ethanol intake on HPA axis responsiveness in adult rats.

    PubMed

    Odeon, María Mercedes; Yamauchi, Laura; Grosman, Mauricio; Acosta, Gabriela Beatriz

    2017-02-15

    It has been shown that early life manipulations produce behavioral, neural, and hormonal effects. The long term consequences of repeated maternal separation (RMS) plus cold stress and ethanol intake were evaluated during adolescence and adult rats on hypothalamic-pituitary-adrenal (HPA) axis in male adult Wistar rats. RMS+ cold stress was applied from postnatal day (PD) 2 in which the pups were separated from their mothers and exposed to cold stress (4°C) 1h per day for 20days; controls remained with their mothers. Then they were exposed to either voluntary ethanol (6%) or dextrose (1%) intake for 7days: PD22-29 and PD59-66. Half of the animals were sacrificed, while the others were exposed to acute stress (AS) for 2h and then they were killed. RMS+ cold stress: a) increased voluntary ethanol intake in adolescent and adult rats; b) reduced protein expression (Western measurements) in corticotropin-releasing hormone (CRH) in hypothalamus (Hyp) and mineralocorticoid receptor (MR) in hippocampus (Hic) while increased glucocorticoid receptor (GR) in Hic; c) decreased plasmatic levels of adrenocorticotropic hormone (ACTH) and increased corticosterone (COR) levels in HPA axis, d) adult rats exposure a new AS incremented ACTH and COR levels. However, this modification did not alter the HPA axis capacity to respond to a new type of stressor. These results demonstrate the consequences of early life stress on the vulnerability of ethanol consumption and HPA axis responsiveness to a stressor in adult rats.

  8. Stress-induced suppression of hippocampal neurogenesis in adult male rats is altered by prenatal ethanol exposure

    PubMed Central

    SLIWOWSKA, J. H.; BARKER, J. M.; BARHA, C. K.; LAN, N.; WEINBERG, J.; GALEA, L. A. M.

    2016-01-01

    In adulthood, both alcohol (ethanol) and stress are known to suppress hippocampal neurogenesis in male rats. Similarly, most studies report that prenatal alcohol exposure (PAE) reduces cell proliferation and/or cell survival in the hippocampus of adult males. Furthermore, PAE is known to have marked effects on behavioral and hypothalamic–pituitary–adrenal (HPA) responsiveness to stressors. However, no studies have examined the modulation of adult hippocampal neurogenesis by stress in PAE animals. We hypothesized that, in accordance with previous data, PAE would suppress basal levels of adult hippocampal neurogenesis, and further that stress acting on a sensitized HPA axis would have greater adverse effects on adult hippocampal neurogenesis in PAE than in control rats. Adult male offspring from PAE, pair-fed (PF) control, and ad libitum-fed control (C) groups were subjected to restraint stress (9 days, 1 h/day) or left undisturbed. Rats were then injected with bromodeoxyuridine (BrdU) on day 10, perfused 24 h (proliferation) or 3 weeks (survival) later, and brains processed for BrdU immunohistochemistry. We found that (1) under non-stressed conditions, PAE rats had a small but statistically significant suppressive effect on levels of hippocampal neurogenesis and (2) unexpectedly, repeated restraint stress significantly reduced neurogenesis in C and PF, but not PAE rats. We speculate that the failure of PAE males to mount an appropriate (i.e. suppressive) neurogenic response to stressors, implies reduced plasticity and adaptability or resilience, which could impact negatively on hippocampal structure and function. PMID:20536332

  9. The longitudinal study of rat hippocampus influenced by stress: early adverse experience enhances hippocampal vulnerability and working memory deficit in adult rats.

    PubMed

    Jin, Fengkui; Li, Lei; Shi, Mei; Li, Zhenzi; Zhou, Jinghua; Chen, Li

    2013-06-01

    Epidemiologic studies indicate that early adverse experience is related to learning disabilities in adults, but the neurobiological mechanisms have not yet been identified. We used longitudinal animal experiments to test the hypothesis that early life stress enhances hippocampal vulnerability and working memory deficit in adult rats. The expression of Synaptophysin (SYN) and apoptosis (Apo) in hippocampal CA3 and dentate gyrus (DG) regions were examined to evaluate the effects of environmental factors on the hippocampus. The working memory errors via radial 8-arm maze were studied to evaluate the long-term effect of early stress on rats' spatial learning ability. Our results indicated that chronic restraint stress in early life and forced cold water swimming stress in adulthood reduced SYN expression and increased Apo levels in rat hippocampus, but the hippocampal damage tended to recover when rats returned to a non-stress environment. In addition, when the rats were exposed to forced cold water swimming stress during adulthood, SYN expression (CA3 and DG regions) and Apo levels (CA3 region) in rat hippocampus showed statistical difference between early restraint stress group and non-early restraint stress group (rats exposed to stress in adulthood only). One month after the two groups of rats returned to non-stress environment, this difference of SYN expression (CA3 and DG regions) and working memory deficit between the two groups was still statistically significant. Our study findings suggested that early adverse experience enhances hippocampal vulnerability and working memory deficit in adult rats, and reduces structural plasticity of hippocampus.

  10. Darbepoetin alfa (Aranesp) improves recognition memory in adult rats that have sustained bilateral ventral hippocampal lesions as neonates or young adults.

    PubMed

    Hori, S E; Powell, K J; Robertson, G S

    2007-01-05

    Recognition memory was assessed in adult rats that received bilateral injections of saline (sham lesions) or ibotenic acid (lesioned) in the ventral hippocampus as neonates (postnatal day 7, PD7) or young adult (42 days of age, PD42) using the Novel Object Recognition Test (NORT). Normal or sham-lesioned rats were able to distinguish novel from familiar objects over a 0.5 and 2 h delay between the sample and choice phases. Adult rats (PD70) lesioned as neonates performed progressively worse than sham-lesioned animals at delays of 0.5 and 2 h. A single injection of darbepoetin alfa (500 or 5000 U/kg, i.p.), given 1 h before the sample phase restored performance 0.5 or 2 h later in the choice phase to same levels as sham-lesioned rats. Adults lesioned on PD42 displayed deficits in NORT performance with a 2 h delay between the choice and sample phases that were completely reversed by administration of darbepoetin alfa (5000 U/kg, i.p.) 1 h before the sample phase. These results suggest that darbepoetin alfa may have utility in treating memory deficits associated with brain dysfunction related to developmental disorders such as schizophrenia.

  11. Sox9 modulates cell survival and adipogenic differentiation of multipotent adult rat mesenchymal stem cells.

    PubMed

    Stöckl, Sabine; Bauer, Richard J; Bosserhoff, Anja K; Göttl, Claudia; Grifka, Joachim; Grässel, Susanne

    2013-07-01

    Sox9 is a key transcription factor in early chondrogenesis with distinct roles in differentiation processes and during embryonic development. Here, we report that Sox9 modulates cell survival and contributes to the commitment of mesenchymal stem cells (MSC) to adipogenic or osteogenic differentiation lineages. We found that the Sox9 activity level affects the expression of the key transcription factor in adipogenic differentiation, C/EBPβ, and that cyclin D1 mediates the expression of the osteogenic marker osteocalcin in undifferentiated adult bone-marrow-derived rat MSC. Introducing a stable Sox9 knockdown into undifferentiated rat MSC resulted in a marked decrease in proliferation rate and an increase in apoptotic activity. This was linked to a profound upregulation of p21 and cyclin D1 gene and protein expression accompanied by an induction of caspase 3/7 activity and an inhibition of Bcl-2. We observed that Sox9 silencing provoked a delayed S-phase progression and an increased nuclear localization of p21. The protein stability of cyclin D1 was induced in the absence of Sox9 presumably as a function of altered p38 signalling. In addition, the major transcription factor for adipogenic differentiation, C/EBPβ, was repressed after silencing Sox9. The nearly complete absence of C/EBPβ protein as a result of increased destabilization of the C/EBPβ mRNA and the impact on osteocalcin gene expression and protein synthesis, suggests that a delicate balance of Sox9 level is not only imperative for proper chondrogenic differentiation of progenitor cells, but also affects the adipogenic and probably osteogenic differentiation pathways of MSC. Our results identified Sox9 as an important link between differentiation, proliferation and apoptosis in undifferentiated adult rat mesenchymal stem cells, emphasizing the importance of the delicate balance of a precisely regulated Sox9 activity in MSC not only for proper skeletal development during embryogenesis but probably also

  12. Effects of Maternal Behavior Induction and Pup Exposure on Neurogenesis in Adult, Virgin Female Rats

    PubMed Central

    Furuta, Miyako; Bridges, Robert S.

    2009-01-01

    The states of pregnancy and lactation bring about a range of physiological and behavioral changes in the adult mammal that prepare the mother to care for her young. Cell proliferation increases in the subventricular zone (SVZ) of the female rodent brain during both pregnancy and lactation when compared to that in cycling, diestrous females. In the present study, the effects of maternal behavior induction and pup exposure on neurogenesis in nulliparous rats were examined in order to determine whether maternal behavior itself, independent of pregnancy and lactation, might affect neurogenesis. Adult, nulliparous, Sprague-Dawley, female rats were exposed daily to foster young in order to induce maternal behavior. Following the induction of maternal behavior each maternal subject plus females that were exposed to pups for a comparable number of test days, but did not display maternal behavior, and subjects that had received no pup exposure were injected with bromodeoxyuridine (BrdU, 90 mg/kg, i.v.). Brain sections were double-labeled for BrdU and the neural marker, NeuN, to examine the proliferating cell population. Increases in the number of double-labeled cells were found in the maternal virgin brain when compared with the number of double-labeled cells present in non-maternal, pup-exposed nulliparous rats and in females not exposed to young. No changes were evident in the dentate gyrus of the hippocampus as a function of maternal behavior. These data indicate that in nulliparous female rats maternal behavior itself is associated with the stimulation of neurogenesis in the SVZ. PMID:19712726

  13. Effect of agomelatine on adult hippocampus apoptosis and neurogenesis using the stress model of rats.

    PubMed

    Yucel, Atakan; Yucel, Nermin; Ozkanlar, Seckin; Polat, Elif; Kara, Adem; Ozcan, Halil; Gulec, Mustafa

    2016-04-01

    Agomelatine (AG) is an agonist of melatonin receptors and an antagonist of the 5-HT2C-receptor subtype. The chronobiotic properties of AG are of significant interest due to the disorganization of internal rhythms, which might play a role in the pathophysiology of depression. The present study was designed to assess the effects of the antidepressant-like activity of AG, a new antidepressant drug, on adult neurogenesis and apoptosis using stress-exposed rat brains. Over the period of 1 week, the rats were exposed to light stress twice a day for 1h. After a period of 1 week, the rats were given AG treatment at a dose of either 10mg/kg or 40mg/kg for 15 days. The animals were then scarified, and the obtained tissue sections were stained with immuno-histochemical anti-BrdU, Caspase-3, and Bcl-2 antibodies. Serum brain-derived neurotrophic factor (BDNF) concentrations were measured biochemically using a BDNF Elisa kit. Biochemical BDNF analysis revealed a high concentration of BDNF in the serum of the stress-exposed group, but the concentrations of BDNF were much lower those of the AG-treated groups. Immuno-histochemical analysis revealed that AG treatment decreased the BrdU-positive and Bcl-2-positive cell densities and increased the Caspase-3-positive cell density in the hippocampus of stress-induced rats as compared to those of the stress group. The results of the study demonstrated that AG treatment ameliorated the hippocampal apoptotic cells and increased hippocampal neurogenesis. These results also strengthen the possible relationship between depression and adult neurogenesis, which must be studied further.

  14. Site- and compartment-specific changes in bone with hindlimb unloading in mature adult rats

    NASA Technical Reports Server (NTRS)

    Bloomfield, S. A.; Allen, M. R.; Hogan, H. A.; Delp, M. D.

    2002-01-01

    The purpose of this study was to examine site- and compartment-specific changes in bone induced by hindlimb unloading (HU) in the mature adult male rat (6 months old). Tibiae, femora, and humeri were removed after 14, 21, and 28 days of HU for determination of bone mineral density (BMD) and geometry by peripheral quantitative computed tomography (pQCT), mechanical properties, and bone formation rate (BFR), and compared with baseline (0 day) and aging (28 day) controls. HU resulted in 20%-21% declines in cancellous BMD at the proximal tibia and femoral neck after 28 day HU vs. 0 day controls (CON). Cortical shell BMD at these sites was greater (by 4%-6%) in both 28 day HU and 28 day CON vs. 0 day CON animals, and nearly identical to that gain seen in the weight-bearing humerus. Mechanical properties at the proximal tibia exhibited a nonsignificant decline after HU vs. those of 0 day CON rats. At the femoral neck, a 10% decrement was noted in ultimate load in 28 day HU rats vs. 28 day CON animals. Middiaphyseal tibial bone increased slightly in density and area during HU; no differences in structural and material properties between 28 day HU and 28 day CON rats were noted. BFR at the tibial midshaft was significantly lower (by 90%) after 21 day HU vs. 0 day CON; this decline was maintained throughout 28 day HU. These results suggest there are compartment-specific differences in the mature adult skeletal response to hindlimb unloading, and that the major impact over 28 days of unloading is on cancellous bone sites. Given the sharp decline in BFR for midshaft cortical bone, it appears likely that deficits in BMD, area, or mechanical properties would develop with longer duration unloading.

  15. Daily patterns of ethanol drinking in adolescent and adult, male and female, high alcohol drinking (HAD) replicate lines of rats.

    PubMed

    Dhaher, Ronnie; McConnell, Kathleen K; Rodd, Zachary A; McBride, William J; Bell, Richard L

    2012-10-01

    The rationale for our study was to determine the pattern of ethanol drinking by the high alcohol-drinking (HAD) replicate lines of rats during adolescence and adulthood in both male and female rats. Rats were given 30 days of 24 h free-choice access to ethanol (15%, v/v) and water, with ad lib access to food, starting at the beginning of adolescence (PND 30) or adulthood (PND 90). Water and alcohol drinking patterns were monitored 22 h/day with a "lickometer" set-up. The results indicated that adolescent HAD-1 and HAD-2 males consumed the greatest levels of ethanol and had the most well defined ethanol licking binges among the age and sex groups with increasing levels of ethanol consumption throughout adolescence. In addition, following the first week of adolescence, male and female HAD-1 and HAD-2 rats differed in both ethanol consumption levels and ethanol licking behavior. Adult HAD-1 male and female rats did not differ from one another and their ethanol intake or licking behaviors did not change significantly over weeks. Adult HAD-2 male rats maintained a relatively constant level of ethanol consumption across weeks, whereas adult HAD-2 female rats increased ethanol consumption levels over weeks, peaking during the third week when they consumed more than their adult male counterparts. The results indicate that the HAD rat lines could be used as an effective animal model to examine the development of ethanol consumption and binge drinking in adolescent male and female rats providing information on the long-range consequences of adolescent alcohol drinking.

  16. Effect of warm-rearing and heat acclimation on pituitary-gonadal axis in male rats.

    PubMed

    Kurowicka, B; Gajewska, A; Amarowicz, R; Kotwica, G

    2008-12-01

    Plasma gonadotrophic and testicular hormones concentrations in both immature and adult male rats exposed to 34 degrees C of ambient temperature were determined. In vitro steroidogenic ability of interstitial cells from experimental rats was also studied. Four groups of rats (n = 45) were used. Warm-reared (WR) males were housed in 34 degrees C and control-reared rats in 20 degrees C from birth to adulthood. The other groups were acclimated to 34 degrees C [warm-acclimated (WA) group] or 20 degrees C [deacclimated (DA) group] as adults. Decreased body weight and testis weight (p < 0.05) was found in heat-exposed groups, but relative testis weight was unchanged in WA and increased (p < 0.05) in WR and DA males. Plasma luteinizing hormone (LH) concentration increased in WA and DA males. Increased (p < 0.05) follicle-stimulating hormone (FSH) and prolactin plasma levels were found in DA and WR groups respectively. WA males had decreased testosterone (T) and WR rats androstenedione (A(4)) plasma concentration (p < 0.05). Interstitial cells (43% of them were Leydig cells by 3beta-hydroxysteroid dehydrogenase activity) from heat-exposed males secreted less (p < 0.05) T compared with the control group when incubated without LH (basal conditions). Androstenedione secretion decreased (p < 0.05) in WA rats. Secretion of estradiol-17beta (E(2)) was higher in WR and lower in DA cells under basal conditions. Weaker responsiveness to LH was observed in WR cells. Androgen synthesis from pregnenolone by interstitial cells increased (p < 0.05) in the WA group. We concluded that heat exposure of neonatal and adult male rats caused different pituitary-testicular axis adjustments. It seemed that long-term heat exposure of neonatal rats is less deleterious concerning the activity of pituitary-testicular axis than heat acclimation of adults.

  17. Auto-catalytic Ceria Nanoparticles Offer Neuroprotection to Adult Rat Spinal Cord Neurons

    PubMed Central

    Das, Mainak; Patil, Swanand; Bhargava, Neelima; Kang, Jung-Fong; Riedel, Lisa M.; Seal, Sudipta; Hickman, James J.

    2007-01-01

    This paper describes the evaluation of the auto-catalytic anti-oxidant behavior and biocompatibility of Cerium oxide nanoparticles for applications in spinal cord repair and other diseases of the CNS. The application of a single dose of nano-Ceria at a nano-molar concentration is biocompatible, regenerative and provides a significant neuroprotective effect on adult rat spinal cord neurons. Retention of neuronal function is demonstrated from electrophysiological recordings and the possibility of its application to prevent ischemic insult is suggested from an oxidative injury assay. A mechanism is proposed to explain the auto-catalytic properties of these nanoparticles. PMID:17222903

  18. Differentiation in boron distribution in adult male and female rats' normal brain: a BNCT approach.

    PubMed

    Goodarzi, Samereh; Pazirandeh, Ali; Jameie, Seyed Behnamedin; Khojasteh, Nasrin Baghban

    2012-06-01

    Boron distribution in adult male and female rats' normal brain after boron carrier injection (0.005 g Boric Acid+0.005 g Borax+10 ml distilled water, pH: 7.4) was studied in this research. Coronal sections of control and trial animal tissue samples were irradiated with thermal neutrons. Using alpha autoradiography, significant differences in boron concentration were seen in forebrain, midbrain and hindbrain sections of male and female animal groups with the highest value, four hours after boron compound injection.

  19. Ablating adult neurogenesis in the rat has no effect on spatial processing: evidence from a novel pharmacogenetic model.

    PubMed

    Groves, James O; Leslie, Isla; Huang, Guo-Jen; McHugh, Stephen B; Taylor, Amy; Mott, Richard; Munafò, Marcus; Bannerman, David M; Flint, Jonathan

    2013-01-01

    The function of adult neurogenesis in the rodent brain remains unclear. Ablation of adult born neurons has yielded conflicting results about emotional and cognitive impairments. One hypothesis is that adult neurogenesis in the hippocampus enables spatial pattern separation, allowing animals to distinguish between similar stimuli. We investigated whether spatial pattern separation and other putative hippocampal functions of adult neurogenesis were altered in a novel genetic model of neurogenesis ablation in the rat. In rats engineered to express thymidine kinase (TK) from a promoter of the rat glial fibrillary acidic protein (GFAP), ganciclovir treatment reduced new neurons by 98%. GFAP-TK rats showed no significant difference from controls in spatial pattern separation on the radial maze, spatial learning in the water maze, contextual or cued fear conditioning. Meta-analysis of all published studies found no significant effects for ablation of adult neurogenesis on spatial memory, cue conditioning or ethological measures of anxiety. An effect on contextual freezing was significant at a threshold of 5% (P = 0.04), but not at a threshold corrected for multiple testing. The meta-analysis revealed remarkably high levels of heterogeneity among studies of hippocampal function. The source of this heterogeneity remains unclear and poses a challenge for studies of the function of adult neurogenesis.

  20. Chronic social instability in adult female rats alters social behavior, maternal aggression and offspring development.

    PubMed

    Pittet, Florent; Babb, Jessica A; Carini, Lindsay; Nephew, Benjamin C

    2017-04-01

    We investigated the consequences of chronic social instability (CSI) during adulthood on social and maternal behavior in females and social behavior of their offspring in a rat model. CSI consisted of changing the social partners of adult females every 2-3 days for 28 days, 2 weeks prior to mating. Females exposed to CSI behaved less aggressively and more pro-socially towards unfamiliar female intruders. Maternal care was not affected by CSI in a standard testing environment, but maternal behavior of CSI females was less disrupted by a male intruder. CSI females were quicker to attack prey and did not differ from control females in their saccharin consumption indicating, respectively, no stress-induced sensory-motor or reward system impairments. Offspring of CSI females exhibited slower growth and expressed more anxiety in social encounters. This study demonstrates continued adult vulnerability to social challenges with an impact specific to social situations for mothers and offspring.

  1. Binge ethanol intoxication heightens subsequent ethanol intake in adolescent, but not adult, rats.

    PubMed

    Fabio, María Carolina; Nizhnikov, Michael E; Spear, Norman E; Pautassi, Ricardo Marcos

    2014-04-01

    A question still to be answered is whether ethanol initiation has a greater effect on ethanol consumption if it occurs during adolescence than in adulthood. This study assessed the effect of ethanol initiation during adolescence or adulthood on voluntary ethanol consumption when animals were still within the same age range. Adolescent or adult rats were given 5, 2, or 0 ethanol exposures. The animals were tested for ethanol consumption through two-bottle choice tests, before undergoing a 1-week deprivation. A two-bottle assessment was conducted after the deprivation. Adolescents, but not adults, given two ethanol administrations during initiation exhibited significantly higher ethanol intake during the pre-deprivation period. These adolescents also exhibited a threefold increase in ethanol intake after 7 days of drug withdrawal, when compared with controls. These findings suggest that very brief experience with binge ethanol intoxication in adolescence, but not in adulthood, impacts later predisposition to drink.

  2. The cortical response to sensory deprivation in adult rats is affected by gonadectomy.

    PubMed

    Mowery, Todd M; Elliott, Kevin S; Garraghty, Preston E

    2009-05-01

    The present study investigated the effects of adult-onset sensory deprivation and gonadectomy. Adult male and female rats underwent unilateral transection of the infraorbital nerve. Half of the subjects had been gonadectomized 1 week prior to the nerve injury. We found that the areas of deprived barrels were significantly reduced when compared to barrels in the contralateral control hemisphere, and that this shrinkage was independent of sex and gonadectomy. We also found significant reductions in cytochrome oxidase staining intensity in the deprived barrels. While there were no differences in the magnitude of this effect between males and females, this effect was substantially more pronounced in the gonadectomized subjects. That is, gonadal hormones appeared to play a significant neuroprotective role in the metabolic response of the barrel cortex to deprivation. Thus, either males and females have a common neuroprotective hormonal pathway, or each has a sex-specific hormone pathway that serves an equivalent neuroprotective function.

  3. Natural variation in maternal care shapes adult social behavior in rats.

    PubMed

    Starr-Phillips, Emily J; Beery, Annaliese K

    2014-07-01

    Features of the early postnatal environment profoundly shape later physical and behavioral phenotypes. The amount of licking/grooming that rat dams direct towards their offspring has durable consequences, including behavioral and physiological dimensions of stress reactivity, cognition, and reproductive behavior. We examined how natural variation in maternal care alters social behavior in adult offspring and how this relates to anxiety behavior and oxytocin receptor density. Male and female offspring of mothers who received high levels of licking spent significantly more time in social contact with unfamiliar individuals than did offspring whose dams provided less grooming. Reduced anxiety behavior was associated with greater social interaction. No differences in oxytocin receptor binding assessed by (125) I-OVTA autoradiography were detected between groups. The present investigation characterizes a novel impact of maternal care on adult social interaction behavior, replicates anxiety behavior differences, and illustrates connections between social behavior and anxiety in adulthood across maternal treatment groups.

  4. Eszopiclone and fluoxetine enhance the survival of newborn neurons in the adult rat hippocampus.

    PubMed

    Su, Xiaowei W; Li, Xiao-Yuan; Banasr, Mounira; Duman, Ronald S

    2009-11-01

    Clinical research has shown that co-administration of eszopiclone, a sedative-hypnotic sleeping agent, and fluoxetine, a serotonin uptake inhibitor, exerts an additive antidepressant action in treating patients with both depression and insomnia. Preclinical studies demonstrate that the behavioural actions of antidepressants are linked to neurogenesis in the adult hippocampus. To test the hypothesis that the additive effects of eszopiclone and fluoxetine could act via such a mechanism, the influence of combined administration of these agents on the proliferation and survival of bromodeoxyuridine (BrdU)-labelled newborn cells in the hippocampus of adult rats was determined. Chronic eszopiclone+fluoxetine co-administration significantly increased the survival, but not proliferation, of newborn neurons in dorsal hippocampus by approximately 50%, an effect greater than either drug alone. These findings are consistent with the hypothesis that eszopiclone enhances the antidepressant action of fluoxetine, in part via a novel mechanism that increases the survival of newborn neurons.

  5. Prenatal exposure to SKF-38393 alters the response to light of adult rats.

    PubMed

    Ferguson, S A; Kennaway, D J

    2000-05-15

    The current study examined the consequences of prenatal SKF-38393 exposure on the cellular response in the adult suprachiasmatic nuclei to light. Pregnant rats were injected with the dopamine agonist SKF-38393 or vehicle daily from gestational day 15 to 21. Adult offspring received a light pulse (1 min/2 lux) 4 or 8 h after lights off (ZT16 or ZT20 where ZT=zeitgeber time). Brains were processed for c-FOS-like immunoreactivity in the SCN. At ZT20 the number of cells expressing c-FOS protein after a light pulse was the same in both groups. At ZT16 the number of cells in the SCN of SKF-38393-exposed animals was 58% lower than the vehicle-treated group. The data suggest that prenatal SKF-38393 treatment may have long-term consequences for SCN function.

  6. Reproducible isolation of type II pneumocytes from fetal and adult rat lung using nycodenz density gradients.

    PubMed

    Viscardi, R M; Ullsperger, S; Resau, J H

    1992-01-01

    Isolating fresh, relatively pure type II pneumocytes from the lung, particularly of fetal origin, is a difficult process. Separation by buoyant density gradient centrifugation has been used successfully to isolate adult type II cells. There is concern, however, that Percoll, a gradient medium that is commonly used for type II cell isolation, may be toxic to cells. We evaluated a new gradient medium, Nycodenz, that is (1) a true solution, (2) transparent, (3) not metabolized by cells, and (4) nontoxic to cells. Type II pneumocytes were isolated from 19- and 21-day gestation fetal and adult rat lung by elastase digestion and separated on preformed isotonic Nycodenz gradients (2 mL each of 27.6, 20.7, 13.8, and 4.6 (w/v) solutions). Type II pneumocytes were recovered from the density range 1.057-1.061 and identified by binding of FITC-conjugated and gold-complexed Maclura pomifera lectin. Cells derived from 19-day fetal lung contained abundant glycogen and reacted with a monoclonal antibody to the cytokeratins 8 and 18, which are markers of the fetal type II cell. Adult type II cells reacted with antibodies to cytokeratins 8, 18, and 19. Type II cell purity was 79.7 +/- 2.4%, 83.8 +/- 2.8%, and 82.6 +/- 1.8% (means +/- SEM) for 19- and 21-day gestation fetal and adult lung preparations, respectively. Cell viability was greater than 95%. The final cell yield for adult preparations was 17.8 +/- 2.7 x 10(6)/rat (means +/- SEM). To determine if the freshly isolated type II pneumocytes were functionally active, the incorporation of [3H]choline into phosphatidylcholine was measured. The percent saturation of phosphatidylcholine was high for both populations of freshly isolated cells. However, adult type II pneumocytes incorporated [3H]choline into phosphatidylcholine more rapidly than 21-day gestation fetal cells (5.97 x 10(-3) dpm/10(6) cells/h vs. 0.32 x 10(-3) dpm/10(6) cells/h, P less than .005). We have demonstrated that, using the Nycodenz isolation method, it is

  7. N-Methyl-D-Aspartate Receptor-Mediated Axonal Injury in Adult Rat Corpus Callosum

    PubMed Central

    Zhang, Jingdong; Liu, Jianuo; Fox, Howard S.; Xiong, Huangui

    2013-01-01

    Damage to white matter such as corpus callosum (CC) is a pathological characteristic in many brain disorders. Glutamate (Glut) excitotoxicity through AMPA receptors on oligodendrocyte (OL) was previously considered as a mechanism for white matter damage. Recent studies have shown that N-methyl-D-aspartate receptors (NMDARs) are expressed on myelin sheath of neonatal rat OL processes and that activation of these receptors mediated demyelization. Whether NMDARs are expressed in the adult CC and are involved in excitotoxic axonal injury remains to be determined. In this study, we demonstrate the presence of NMDARs in the adult rat CC and their distributions in myelinated nerve fibers and OL somata by means of immunocytochemical staining and Western blot. Incubation of the CC slices with Glut or NMDA induced axonal injury as revealed by analyzing amplitude of CC fiber compound action potentials (CAPs) and input–output response. Both Glut and NMDA decreased the CAP amplitude and input–output responses, suggesting an involvement of NMDARs in Glut- and NMDA-induced axonal injury. The involvement of NMDAR in Glut-induced axonal injury was further assayed by detection of β-amyloid precursor protein (β-APP) in the CC axonal fibers. Treatment of the CC slices with Glut resulted in β-APP accumulation in the CC fibers as detected by Western blot, reflecting an impairment of axonal transport function. This injurious effect of Glut on CC axonal transport was significantly blocked by MK801. Taken together, these results show that NMDARs are expressed in the adult CC and are involved in excitotoxic activity in adult CC slices in vitro. PMID:23161705

  8. Neuroprotective Effect of Melatonin Against PCBs Induced Behavioural, Molecular and Histological Changes in Cerebral Cortex of Adult Male Wistar Rats.

    PubMed

    Bavithra, S; Selvakumar, K; Sundareswaran, L; Arunakaran, J

    2017-02-01

    There is ample evidence stating Polychlorinated biphenyls (PCBs) as neurotoxins. In the current study, we have analyzed the behavioural impact of PCBs exposure in adult rats and assessed the simultaneous effect of antioxidant melatonin against the PCBs action. The rats were grouped into four and treated intraperitoneally with vehicle, PCBs, PCBs + melatonin and melatonin alone for 30 days, respectively. After the treatment period the rats were tested for locomotor activity and anxiety behaviour analysis. We confirmed the neuronal damage in the cerebral cortex by molecular and histological analysis. Our data indicates that there is impairment in locomotor activity and behaviour of PCBs treated rats compared to control. The simultaneous melatonin treated rat shows increased motor coordination and less anxiety like behaviour compared to PCBs treated rats. Molecular and histological analysis supports that, the impaired motor coordination in PCBs treated rats is due to neurodegeneration in motor cortex region. The results proved that melatonin treatment improved the motor co-ordination and reduced anxiety behaviour, prevented neurodegeneration in the cerebral cortex of PCBs-exposed adult male rats.

  9. In Utero Exposure to Di-(2-Ethylhexyl) Phthalate Decreases Mineralocorticoid Receptor Expression in the Adult Testis

    PubMed Central

    Martinez-Arguelles, D. B.; Culty, M.; Zirkin, B. R.; Papadopoulos, V.

    2009-01-01

    In utero exposure to di-(2-ethylhexyl) phthalate (DEHP) has been shown to result in decreased androgen formation by fetal and adult rat testes. In the fetus, decreased androgen is accompanied by the reduced expression of steroidogenic enzymes. The mechanism by which in utero exposure results in reduced androgen formation in the adult, however, is unknown. We hypothesized that deregulation of the nuclear steroid receptors might explain the effects of in utero DEHP exposure on adult testosterone production. To test this hypothesis, pregnant Sprague Dawley dams were gavaged with 100–950 mg DEHP per kilogram per day from gestational d 14–19, and testes were collected at gestational d 20 and postnatal days (PND) 3, 21, and 60. Among the nuclear receptors studied, the mineralocorticoid receptor (MR) mRNA and protein levels were reduced in PND60 interstitial Leydig cells, accompanied by reduced mRNA expression of MR-regulated genes. Methylation-sensitive PCR showed effects on the nuclear receptor subfamilies NR3A and -3C, but only MR was affected at PND60. Pyrosequencing of two CpG islands within the MR gene promoter revealed a loss of methylation in DEHP-treated animals that was correlated with reduced MR. Because MR activation is known to stimulate Leydig cell testosterone formation, and MR inhibition to be repressive, our results are consistent with the hypothesis that in utero exposure to DEHP leads to MR dysfunction and thus to depressed testosterone production in the adult. We suggest that decreased MR, possibly epigenetically mediated, is a novel mechanism by which phthalates may affect diverse functions later in life. PMID:19819939

  10. Structural changes in the adult rat auditory system induced by brief postnatal noise exposure.

    PubMed

    Ouda, Ladislav; Burianová, Jana; Balogová, Zuzana; Lu, Hui Pin; Syka, Josef

    2016-01-01

    In previous studies (Grécová et al., Eur J Neurosci 29:1921-1930, 2009; Bures et al., Eur J Neurosci 32:155-164, 2010), we demonstrated that after an early postnatal short noise exposure (8 min 125 dB, day 14) changes in the frequency tuning curves as well as changes in the coding of sound intensity are present in the inferior colliculus (IC) of adult rats. In this study, we analyze on the basis of the Golgi-Cox method the morphology of neurons in the IC, the medial geniculate body (MGB) and the auditory cortex (AC) of 3-month-old Long-Evans rats exposed to identical noise at postnatal day 14 and compare the results to littermate controls. In rats exposed to noise as pups, the mean total length of the neuronal tree was found to be larger in the external cortex and the central nucleus of the IC and in the ventral division of the MGB. In addition, the numerical density of dendritic spines was decreased on the branches of neurons in the ventral division of the MGB in noise-exposed animals. In the AC, the mean total length of the apical dendritic segments of pyramidal neurons was significantly shorter in noise-exposed rats, however, only slight differences with respect to controls were observed in the length of basal dendrites of pyramidal cells as well as in the neuronal trees of AC non-pyramidal neurons. The numerical density of dendritic spines on the branches of pyramidal AC neurons was lower in exposed rats than in controls. These findings demonstrate that early postnatal short noise exposure can induce permanent changes in the development of neurons in the central auditory system, which apparently represent morphological correlates of functional plasticity.

  11. Neonatal stress alters LTP in freely moving male and female adult rats.

    PubMed

    Kehoe, P; Bronzino, J D

    1999-01-01

    We previously reported that neonatal isolation stress significantly changes measures of hippocampal long-term potentiation (LTP) in male and female juvenile rats, i.e., at 30 days of age. The changes in dentate granule population measures, i.e., excitatory postsynaptic potential (EPSP) and population spike amplitude (PSA), evoked by tetanization of the medial perforant pathway, indicated that juvenile rats exposed to neonatal isolation exhibit different enhancement profiles with respect to both the magnitude and duration of LTP in a sex-specific manner. Isolated males showed a significantly greater enhancement of LTP, while female "isolates" showed significantly longer LTP duration when compared to all other groups. The present study was designed to determine whether the effects of the neonatal isolation stress paradigm endures into adulthood. Rats isolated from their mothers for 1 h per day during postnatal days 2-9 were surgically prepared at 70-90 days of age, with stimulating and recording electrodes placed in the medial perforant pathway and the hippocampal dentate gyrus, respectively. Prior to tetanization, no significant effect of sex or treatment was obtained for baseline measures of EPSP slope or PSA. In order to rule out baseline differences in hippocampal cell excitability in female adult rats, we measured the response of dentate granule cells for one estrus cycle and found no pretetanization enhancement in the evoked response in either controls or previously stressed rats. Following tetanization, there was a significant treatment and sex effect. During the induction of LTP, PSA values were significantly enhanced in both isolated males and females and had significantly longer LTP duration when compared to the unhandled control group. Additionally, we observed that females took longer to reach baseline levels than males. Taken together, these results indicate that repeated infant isolation stress enhances LTP induction and duration in both males and

  12. Sustained increase in adult neurogenesis in the rat hippocampal dentate gyrus after transient brain ischemia.

    PubMed

    Wang, Congmin; Zhang, Mingguang; Sun, Chifei; Cai, Yuqun; You, Yan; Huang, Liping; Liu, Fang

    2011-01-13

    It is known that the number of newly generated neurons is increased in the young and adult rodent subventricular zone (SVZ) and dentate gyrus (DG) after transient brain ischemia. However, it remains unclear whether increase in neurogenesis in the adult DG induced by ischemic stroke is transient or sustained. We here reported that from 2 weeks to 6 months after transient middle cerebral artery occlusion (MCAO), there were more doublecortin positive (DCX+) cells in the ipsilateral compared to the sham-control and contralateral DG of the adult rat. After the S-phase marker 5-bromo-2'-deoxyuridine (BrdU) was injected 2 days after MCAO to label newly generated cells, a large number of BrdU-labeled neuroblasts differentiated into mature granular neurons. These BrdU-labeled neurons survived for at least 6 months. When BrdU was injected 6 weeks after injury, there were still more newly generated neuroblasts differentiated into mature neurons in the ipsilateral DG. Altogether, our data indicate that transient brain ischemia initiates a prolonged increase in neurogenesis and promotes the normal development of the newly generated neurons in the adult DG.

  13. Testis and epididymis of the Indian wall lizard (Hemidactylus flaviviridis): effects of flutamide on FSH and testosterone influenced spermatogenesis, Leydig cell, and epididymis.

    PubMed

    Rai, U; Haider, S

    1991-08-01

    To determine the separate spermatogenic actions of FSH and testosterone, adult male lizards Hemidactylus flaviviridis with recrudescent testes were administered the non-steroidal antiandrogen flutamide either alone or in combination with FSH or testosterone, and the histology and histochemistry of the testes and ductus epididymides were studied. Flutamide-treated animals displayed a marked hypertrophy of Leydig cells. A few spermatids were also seen in testis of more than half the animals treated with flutamide. Flutamide also produced a significant increase of primary spermatocytes; no spermatids were observed in controls. A significant inhibition of spermatogenesis was noted in lizards treated either with testosterone alone or in combination with flutamide. Ovine FSH treatment caused a significant stimulation of spermatogenesis, as indicated by the increase of primary and secondary spermatocytes and the transformation of secondary spermatocytes into spermatids or, in a few cases, into spermatozoa. A considerable depletion of sudanophilic lipid and moderate delta 5-3 beta-hydroxysteroid dehydrogenase activity was noted in the Leydig cells of FSH-treated animals indicating enhanced steroidogenesis. Similar results were obtained when lizards were treated with flutamide + FSH. The effects of simultaneous treatment of flutamide with FSH or testosterone on ductus epididymidis revealed that flutamide markedly inhibited the epithelial cell height and lumen diameter with a loss of luminal content when compared to FSH or testosterone-treated lizards.

  14. Maternal exposure to cadmium during gestation perturbs the vascular system of the adult rat offspring

    SciTech Connect

    Ronco, Ana Maria; Montenegro, Marcela; Castillo, Paula; Urrutia, Manuel; Saez, Daniel; Hirsch, Sandra; Zepeda, Ramiro; Llanos, Miguel N.

    2011-03-01

    Several cardiovascular diseases (CVD) observed in adulthood have been associated with environmental influences during fetal growth. Here, we show that maternal exposure to cadmium, a ubiquitously distributed heavy metal and main component of cigarette smoke is able to induce cardiovascular morpho-functional changes in the offspring at adult age. Heart morphology and vascular reactivity were evaluated in the adult offspring of rats exposed to 30 ppm of cadmium during pregnancy. Echocardiographic examination shows altered heart morphology characterized by a concentric left ventricular hypertrophy. Also, we observed a reduced endothelium-dependent reactivity in isolated aortic rings of adult offspring, while endothelium-independent reactivity remained unaltered. These effects were associated with an increase of hem-oxygenase 1 (HO-1) expression in the aortas of adult offspring. The expression of HO-1 was higher in females than males, a finding likely related to the sex-dependent expression of the vascular cell adhesion molecule 1 (VCAM-1), which was lower in the adult female. All these long-term consequences were observed along with normal birth weights and absence of detectable levels of cadmium in fetal and adult tissues of the offspring. In placental tissues however, cadmium levels were detected and correlated with increased NF-{kappa}B expression - a transcription factor sensitive to inflammation and oxidative stress - suggesting a placentary mechanism that affect genes related to the development of the cardiovascular system. Our results provide, for the first time, direct experimental evidence supporting that exposure to cadmium during pregnancy reprograms cardiovascular development of the offspring which in turn may conduce to a long term increased risk of CVD.

  15. Modulation of mouse Leydig cell steroidogenesis through a specific arginine-vasopressin receptor

    SciTech Connect

    Tahri-Joutei, A.; Pointis, G.

    1988-01-01

    Characterization of specific vasopressin binding sites was investigated in purified mouse Leydig cells using tritiated arginine-vasopressin. Binding of radioligand was saturable, time- and temperature-dependent and reversible. (/sup 3/H)-AVP was found to bind to a single class of sites with high affinity and low capacity. Binding displacements with specific selection analogs of AVP indicated the presence of V/sub 1/ subtype receptors on Leydig cells. The ability of AVP to displace (/sup 3/H)-AVP binding was greater than LVP and oxytocin. The unrelated peptides, somatostatin and substance P, were less potent, while neurotensin and LHRH did not displace (/sup 3/H)-AVP binding. The time-course effects of AVP-pretreatment on basal and hCG-stimulated testosterone and cAMP accumulations were studied in primary culture of Leydig cells. Basal testosterone accumulation was significantly increased by a 24 h AVP-pretreatment of Leydig cells. This effect was potentiated by the phosphodiesterase inhibitor (MIX) and was concomitantly accompanied by a slight but significant increase in cAMP accumulation. AVP-pretreatment of the cells for 72 h had no effect on basal testosterone accumulation, but exerted a marked inhibitory effect on the hCG-stimulated testosterone accumulation. This reduction of testosterone accumulation occurred even in the presence of MIX and was not accompanied by any significant change of cAMP levels.

  16. Mumps virus-induced innate immune responses in mouse Sertoli and Leydig cells.

    PubMed

    Wu, Han; Shi, Lili; Wang, Qing; Cheng, Lijing; Zhao, Xiang; Chen, Qiaoyuan; Jiang, Qian; Feng, Min; Li, Qihan; Han, Daishu

    2016-01-18

    Mumps virus (MuV) infection frequently causes orchitis and impairs male fertility. However, the mechanisms underlying the innate immune responses to MuV infection in the testis have yet to be investigated. This study showed that MuV induced innate immune responses in mouse Sertoli and Leydig cells through TLR2 and retinoic acid-inducible gene I (RIG-I) signaling, which result in the production of proinflammatory cytokines and chemokines, including TNF-α, IL-6, MCP-1, CXCL10, and type 1 interferons (IFN-α and IFN-β). By contrast, MuV did not induce the cytokine production in male germ cells. In response to MuV infection, Sertoli cells produced higher levels of proinflammatory cytokines and chemokines but lower levels of type 1 IFNs than Leydig cells did. The MuV-induced cytokine production by Sertoli and Leydig cells was significantly reduced by the knockout of TLR2 or the knockdown of RIG-I signaling. The local injection of MuV into the testis triggered the testicular innate immune responses in vivo. Moreover, MuV infection suppressed testosterone synthesis by Leydig cells. This is the first study examining the innate immune responses to MuV infection in testicular cells. The results provide novel insights into the mechanisms underlying the MuV-induced innate immune responses in the testis.

  17. Mumps virus-induced innate immune responses in mouse Sertoli and Leydig cells

    PubMed Central

    Wu, Han; Shi, Lili; Wang, Qing; Cheng, Lijing; Zhao, Xiang; Chen, Qiaoyuan; Jiang, Qian; Feng, Min; Li, Qihan; Han, Daishu

    2016-01-01

    Mumps virus (MuV) infection frequently causes orchitis and impairs male fertility. However, the mechanisms underlying the innate immune responses to MuV infection in the testis have yet to be investigated. This study showed that MuV induced innate immune responses in mouse Sertoli and Leydig cells through TLR2 and retinoic acid-inducible gene I (RIG-I) signaling, which result in the production of proinflammatory cytokines and chemokines, including TNF-α, IL-6, MCP-1, CXCL10, and type 1 interferons (IFN-α and IFN-β). By contrast, MuV did not induce the cytokine production in male germ cells. In response to MuV infection, Sertoli cells produced higher levels of proinflammatory cytokines and chemokines but lower levels of type 1 IFNs than Leydig cells did. The MuV-induced cytokine production by Sertoli and Leydig cells was significantly reduced by the knockout of TLR2 or the knockdown of RIG-I signaling. The local injection of MuV into the testis triggered the testicular innate immune responses in vivo. Moreover, MuV infection suppressed testosterone synthesis by Leydig cells. This is the first study examining the innate immune responses to MuV infection in testicular cells. The results provide novel insights into the mechanisms underlying the MuV-induced innate immune responses in the testis. PMID:26776505

  18. True Precocious Puberty Following Treatment of a Leydig Cell Tumor: Two Case Reports and Literature Review

    PubMed Central

    Verrotti, Alberto; Penta, Laura; Zenzeri, Letizia; Lucchetti, Laura; Giovenali, Paolo; De Feo, Pierpaolo

    2015-01-01

    Leydig cell testicular tumors are a rare cause of precocious pseudopuberty in boys. Surgery is the main therapy and shows good overall prognosis. The physical signs of precocious puberty are expected to disappear shortly after surgical removal of the mass. We report two children, 7.5 and 7.7 year-old boys, who underwent testis-sparing surgery for a Leydig cell testicular tumor causing precocious pseudopuberty. During follow-up, after an immediate clinical and laboratory regression, both boys presented signs of precocious puberty and ultimately developed central precocious puberty. They were successfully treated with gonadotropin-releasing hormone (GnRH) analogs. Only six other cases have been described regarding the development of central precocious puberty after successful treatment of a Leydig cell tumor causing precocious pseudopuberty. Gonadotropin-dependent precocious puberty should be considered in children treated for a Leydig cell tumor presenting persistent or recurrent physical signs of puberty activation. In such cases, therapy with GnRH analogs appears to be the most effective medical treatment. PMID:26579503

  19. Effects of T-2 toxin on the regulation of steroidogenesis in mouse Leydig cells.

    PubMed

    Yang, Jian Ying; Zhang, Yong Fa; Li, Yuan Xiao; Guan, Gui Ping; Kong, Xiang Feng; Liang, Ai Min; Ma, Kai Wang; Da Li, Guang; Bai, Xue Fei

    2016-10-01

    T-2 toxin is one of the mycotoxins, a group of type A trichothecenes produced by several fungal genera including Fusarium species, which may lead to the decrease of testosterone secretion in primary Leydig cells derived from mouse testis. The previous study demonstrated T-2 toxin decrease the testosterone biosynthesis in the primary Leydig cells derived from the mouse testis directly. In this study, we further examined the direct biological effects of T-2 toxin on the process of steroidogenesis, primarily in Leydig cells of mice. Leydig cells of mature mouse were purified by Percoll gradient centrifugation and the cell purity was determined by 3β-hydroxysteroid dehydrogenase (3β-HSD) staining. To examine the decrease in T-2 toxin-induced testosterone secretion, we measured the transcription level of three key steroidogenic enzymes including 3β-HSD-1, cytochrome P450 side-chain cleavage (P450scc) enzyme, and steroidogenic acute regulatory (StAR) protein in T-2 toxin/human chorionic gonadotropin (hCG) co-treated cells. Our previous study showed that T-2 toxin (10(-7), 10(-8), and 10(-9) M) significantly suppressed hCG (10 ng/ml)-induced testosterone secretion. The studies demonstrated that the suppressive effect is correlated with a decrease in the level of transcription of 3β-HSD-1, P450scc, and StAR (p < 0.05).

  20. Inhibition by dietary D-psicose of body fat accumulation in adult rats fed a high-sucrose diet.

    PubMed

    Ochiai, Masaru; Nakanishi, Yosuke; Yamada, Takako; Iida, Tetsuo; Matsuo, Tatsuhiro

    2013-01-01

    We investigated the anti-obesity effects of dietary D-psicose on adult rats fed a high-sucrose diet. Wistar rats (16 weeks old) that had previously been fed a high-sucrose diet (HSD) were fed HSD or a high-starch diet (HTD) with or without 5% D-psicose for 8 weeks. The food efficiency, carcass fat percentage, abdominal fat accumulation, and body weight gain were all significantly suppressed by dietary D-psicose.

  1. DOPAMINE RECEPTOR INACTIVATION IN THE CAUDATE-PUTAMEN DIFFERENTIALLY AFFECTS THE BEHAVIOR OF PREWEANLING AND ADULT RATS

    PubMed Central

    DER-GHAZARIAN, T.; GUTIERREZ, A.; VARELA, F. A.; HERBERT, M. S.; AMODEO, L. R.; CHARNTIKOV, S.; CRAWFORD, C. A.; MCDOUGALL, S. A.

    2012-01-01

    The irreversible receptor antagonist N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) has been used to study the ontogeny of dopamine (DA) receptor functioning in the young and adult rat. Most notably, systemic administration of EEDQ blocks the DA agonist-induced behaviors of adult rats, while leaving the behavior of preweanling rats unaffected. The purpose of the present study was to: (a) determine whether the age-dependent actions of EEDQ involve receptors located in the dorsal caudate-putamen (CPu) and (b) confirm that EEDQ's behavioral effects result from the inactivation of DA receptors rather than some other receptor type. In Experiment 1, EEDQ or DMSO were bilaterally infused into the CPu on PD 17 or PD 84. After 24 h, rats were given bilateral microinjections of the full DA agonist R(–)-propylnorapomorphine (NPA) or vehicle into the dorsal CPu and behavior was assessed for 40 min. In Experiment 2, preweanling rats were treated as just described, except that DA receptors were protected from EEDQ-induced alkylation by administering systemic injections of D1 (SCH23390) and D2 (sulpiride) receptor antagonists. As predicted, microinjecting EEDQ into the dorsal CPu attenuated the NPA-induced locomotor activity and stereotypy of adult rats. In contrast, rats given bilateral EEDQ infusions on PD 17 exhibited a potentiated locomotor response when treated with NPA. Experiment 2 showed that DA receptor inactivation was responsible for NPA's actions. A likely explanation for these results is that EEDQ inactivates a sizable percentage of DA receptors on PD 17, but leaves the remaining receptors in a supersensitive state. This receptor supersensitivity, which probably involves alterations in G protein coupling, could account for NPA-induced locomotor potentiation. Either adult rats do not show a similar EEDQ-induced change in receptor dynamics or DA receptor inactivation was more complete in older animals and effectively eliminated the expression of DA agonist

  2. Localization of NGF and nNOS in varicocele-induced rat testis.

    PubMed

    Celik-Ozenci, Ciler; Bayram, Zubeyde; Akkoyunlu, Gokhan; Korgun, Emin Turkay; Erdogru, Tibet; Seval, Yasemin; Ustunel, Ismail; Baykara, Mehmet; Demir, Ramazan

    2006-01-01

    Nerve growth factor (NGF) is synthesized in male germ cells. The presence of neuronal nitric oxide synthase (nNOS) in Leydig cells is related to its role in the regulation of testosterone release. Varicocele is often characterized by abnormal sperm quality and influences the fertilizing capacity of the haploid gamete. We investigated the localization of NGF and nNOS in testes of adult Wistar rats with experimentally induced varicocele after 9, 11, and 13 weeks, as well as in sham-operated controls by immunohistochemistry and Western blot. In control testis, we detected NGF in nuclei of Sertoli cells and also as small vesicular-like structures in the cytoplasm of primary spermatocytes, and in round and elongating spermatids. Varicocele-induction revealed a slight decrease of NGF at 13 weeks, especially in Sertoli cells. In control tissue, nNOS protein was present mainly in Leydig cells and in Sertoli cell cytoplasm. Additionally, nNOS immunoreactivity was present in the heads of elongated spermatids. Western blot results revealed that the decrease of NGF was not significant in the 13-week varicocele group, moreover, the amount of nNOS was not altered in any of the varicocele groups. In conclusion, NGF and nNOS have important roles for normal gametogenesis and our data for the first time indicates that varicocele induction does not necessarily affect the expression of NGF and nNOS. Thus, these two molecules do not appear to be related to varicocele induction.

  3. Prenatal ethanol exposure impairs temporal ordering behaviours in young adult rats.

    PubMed

    Patten, Anna R; Sawchuk, Scott; Wortman, Ryan C; Brocardo, Patricia S; Gil-Mohapel, Joana; Christie, Brian R

    2016-02-15

    Prenatal ethanol exposure (PNEE) causes significant deficits in functional (i.e., synaptic) plasticity in the dentate gyrus (DG) and cornu ammonis (CA) hippocampal sub-regions of young adult male rats. Previous research has shown that in the DG, these deficits are not apparent in age-matched PNEE females. This study aimed to expand these findings and determine if PNEE induces deficits in hippocampal-dependent behaviours in both male and female young adult rats (PND 60). The metric change behavioural test examines DG-dependent deficits by determining whether an animal can detect a metric change between two identical objects. The temporal order behavioural test is thought to rely in part on the CA sub-region of the hippocampus and determines whether an animal will spend more time exploring an object that it has not seen for a larger temporal window as compared to an object that it has seen more recently. Using the liquid diet model of FASD (where 6.6% (v/v) ethanol is provided through a liquid diet consumed ad libitum throughout the entire gestation), we found that PNEE causes a significant impairment in the temporal order task, while no deficits in the DG-dependent metric change task were observed. There were no significant differences between males and females for either task. These results indicate that behaviours relying partially on the CA-region may be more affected by PNEE than those that rely on the DG.

  4. Characterization of strychnine-sensitive glycine receptors in acutely isolated adult rat basolateral amygdala neurons.

    PubMed

    McCool, B A; Botting, S K

    2000-03-24

    Large concentrations of the beta-amino acid, taurine, can be found in many forebrain areas such as the basolateral amygdala, a portion of the limbic forebrain intimately associated with the regulation of fear/anxiety-like behaviors. In addition to its cytoprotective and osmoregulatory roles, taurine may also serve as an agonist at GABA(A)- and strychnine-sensitive glycine receptors. In this latter context, the present study demonstrates that application of taurine to acutely isolated neurons from the basolateral amygdala of adult rats causes significant alterations in resting membrane current, as measured by whole-cell patch clamp electrophysiology. Using standard pharmacological approaches, we find that currents gated by concentrations of taurine adult rats.

  5. Cortical neurogenesis in adult rats after ischemic brain injury: most new neurons fail to mature.

    PubMed

    Li, Qing-Quan; Qiao, Guan-Qun; Ma, Jun; Fan, Hong-Wei; Li, Ying-Bin

    2015-02-01

    The present study examines the hypothesis that endogenous neural progenitor cells isolated from the neocortex of ischemic brain can differentiate into neurons or glial cells and contribute to neural regeneration. We performed middle cerebral artery occlusion to establish a model of cerebral ischemia/reperfusion injury in adult rats. Immunohistochemical staining of the cortex 1, 3, 7, 14 or 28 days after injury revealed that neural progenitor cells double-positive for nestin and sox-2 appeared in the injured cortex 1 and 3 days post-injury, and were also positive for glial fibrillary acidic protein. New neurons were labeled using bromodeoxyuridine and different stages of maturity were identified using doublecortin, microtubule-associated protein 2 and neuronal nuclei antigen immunohistochemistry. Immature new neurons coexpressing doublecortin and bromodeoxyuridine were observed in the cortex at 3 and 7 days post-injury, and semi-mature and mature new neurons double-positive for microtubule-associated protein 2 and bromodeoxyuridine were found at 14 days post-injury. A few mature new neurons coexpressing neuronal nuclei antigen and bromodeoxyuridine were observed in the injured cortex 28 days post-injury. Glial fibrillary acidic protein/bromodeoxyuridine double-positive astrocytes were also found in the injured cortex. Our findings suggest that neural progenitor cells are present in the damaged cortex of adult rats with cerebral ischemic brain injury, and that they differentiate into astrocytes and immature neurons, but most neurons fail to reach the mature stage.

  6. Diazepam affects the nuclear thyroid hormone receptor density and their expression levels in adult rat brain.

    PubMed

    Constantinou, Caterina; Bolaris, Stamatis; Valcana, Theony; Margarity, Marigoula

    2005-07-01

    Thyroid hormones (THs) are involved in the occurrence of anxiety and affective disorders; however, the effects following an anxiolytic benzodiazepine treatment, such as diazepam administration, on the mechanism of action of thyroid hormones has not yet been investigated. The effect of diazepam on the in vitro nuclear T3 binding, on the relative expression of the TH receptors (TRs) and on the synaptosomal TH availability were examined in adult rat cerebral hemispheres 24 h after a single intraperitoneal dose (5 mg/kg BW) of this tranquillizer. Although, diazepam did not affect the availability of TH either in blood circulation or in the synaptosomal fraction, it decreased (33%) the nuclear T3 maximal binding density (B(max)). No differences were observed in the equilibrium dissociation constant (K(d)). The TRalpha2 variant (non-T3-binding) mRNA levels were increased by 33%, whereas no changes in the relative expression of the T3-binding isoforms of TRs (TRalpha1, TRbeta1) were observed. This study shows that a single intraperitoneal injection of diazepam affects within 24 h, the density of the nuclear TRs and their expression pattern. The latest effect occurs in an isoform-specific manner involving specifically the TRalpha2 mRNA levels in adult rat brain.

  7. Altered adult hippocampal neuronal maturation in a rat model of fetal alcohol syndrome.

    PubMed

    Gil-Mohapel, Joana; Boehme, Fanny; Patten, Anna; Cox, Adrian; Kainer, Leah; Giles, Erica; Brocardo, Patricia S; Christie, Brian R

    2011-04-12

    Exposure to ethanol during pregnancy can be devastating to the developing nervous system, leading to significant central nervous system dysfunction. The hippocampus, one of the two brain regions where neurogenesis persists into adulthood, is particularly sensitive to the teratogenic effects of ethanol. In the present study, we tested a rat model of fetal alcohol syndrome (FAS) with ethanol administered via gavage throughout all three trimester equivalents. Subsequently, we assessed cell proliferation, as well as neuronal survival, and differentiation in the dentate gyrus of the hippocampus of adolescent (35 days old), young adult (60 days old) and adult (90 days old) Sprague-Dawley rats. Using both extrinsic (bromodeoxyuridine) and intrinsic (Ki-67) markers, we observed no significant alterations in cell proliferation and survival in ethanol-exposed animals when compared with their pair-fed and ad libitum controls. However, we detected a significant increase in the number of new immature neurons in animals that were exposed to ethanol throughout all three trimester equivalents. This result might reflect a compensatory mechanism to counteract the deleterious effects of prenatal ethanol exposure or an ethanol-induced arrest of the neurogenic process at the early neuronal maturation stages. Taken together these results indicate that exposure to ethanol during the period of brain development causes a long-lasting dysregulation of the neurogenic process, a mechanism that might contribute, at least in part, to the hippocampal deficits that have been reported in rodent models of FAS.

  8. Prenatal choline supplementation attenuates neuropathological response to status epilepticus in the adult rat hippocampus.

    PubMed

    Wong-Goodrich, Sarah J E; Mellott, Tiffany J; Glenn, Melissa J; Blusztajn, Jan K; Williams, Christina L

    2008-05-01

    Prenatal choline supplementation (SUP) protects adult rats against spatial memory deficits observed after excitotoxin-induced status epilepticus (SE). To examine the mechanism underlying this neuroprotection, we determined the effects of SUP on a variety of hippocampal markers known to change in response to SE and thought to underlie ensuing cognitive deficits. Adult offspring from rat dams that received either a control or SUP diet on embryonic days 12-17 were administered saline or kainic acid (i.p.) to induce SE and were euthanized 16 days later. SUP markedly attenuated seizure-induced hippocampal neurodegeneration, dentate cell proliferation, and hippocampal GFAP mRNA expression levels, prevented the loss of hippocampal GAD65 protein and mRNA expression, and altered growth factor expression patterns. SUP also enhanced pre-seizure hippocampal levels of BDNF, NGF, and IGF-1, which may confer a neuroprotective hippocampal microenvironment that dampens the neuropathological response to and/or helps facilitate recovery from SE to protect cognitive function.

  9. Effects of chronic treatment with methylphenidate on oxidative stress and inflammation in hippocampus of adult rats.

    PubMed

    Motaghinejad, Majid; Motevalian, Manijeh; Shabab, Behnaz

    2016-04-21

    Methylphenidate (MPH) is a central stimulant, prescribed for the treatment of attention deficit/hyperactivity disorder. The long-term behavioral consequences of MPH treatment are unknown. In this study, the oxidative stress and neuroinflammation induced by various doses of MPH were investigated. Forty adult male rats were divided into 5 groups; and treated with different doses of MPH for 21 days. Twenty four hours after drug treatment, Open Field Test (OFT) was performed in all animals. At the end of the study, blood cortisol level (BCL) was measured and hippocampus was isolated and oxidative stress and inflammation parameters and histological changes were analyzed. Chronic MPH at all doses decreased central square entries, number of rearing, ambulation distance and time spent in central square in OFT. BCL increased in doses 10 and 20mg/kg of MPH. Furthermore, MPH in all doses markedly increased lipid peroxidation, mitochondrial oxidized glutathione (GSSG) level, Interleukin 1β (IL-1β) and Tumor Necrosis Factor α (TNF-α) in isolated hippocampus. MPH (10 and 20mg/kg) treated groups had decreased mitochondrial reduced glutathione (GSH) content, and reduced superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRx) activities. 10 and 20mg/kg of MPH change cell density and morphology of cells in Dentate Gyrus (DG) and CA1 areas of hippocampus. Chronic treatment with high doses of MPH can cause oxidative stress, neuroinflammation and neurodegeneration in hippocampus of adult rats.

  10. Effects of antipsychotic drugs on neurogenesis in the forebrain of the adult rat.

    PubMed

    Wang, Hui-Dong; Dunnavant, Floyd D; Jarman, Tabitha; Deutch, Ariel Y

    2004-07-01

    The generation of new cells in the adult mammalian brain may significantly modify pathophysiological processes in neuropsychiatric disorders. We examined the ability of chronic treatment with the antipsychotic drugs (APDs) olanzapine and haloperidol to increase the number and survival of newly generated cells in the prefrontal cortex (PFC) and striatal complex of adult male rats. Animals were treated with olanzapine or haloperidol for 3 weeks and then injected with 5-bromo-2'-deoxyuridine (BrdU) to label mitotic cells. Half of the animals continued on the same APD for two more weeks after BrdU challenge, with the other half receiving vehicle during this period. Olanzapine but not haloperidol significantly increased both the total number and density of BrdU-labeled cells in the PFC and dorsal striatum; no effect was observed in the nucleus accumbens. Continued olanzapine treatment after the BrdU challenge did not increase the survival of newly generated cells. The newly generated cells in the PFC did not express the neuronal marker NeuN. Despite the significant increase in newly generated cells in the PFC of olanzapine-treated rats, the total number of these cells is low, suggesting that the therapeutic effects of atypical APD treatment may not be due to the presence of newly generated cells that have migrated to the cortex.

  11. Astrocytes from adult Wistar rats aged in vitro show changes in glial functions.

    PubMed

    Souza, Débora Guerini; Bellaver, Bruna; Raupp, Gustavo Santos; Souza, Diogo Onofre; Quincozes-Santos, André

    2015-11-01

    Astrocytes, the most versatile cells of the central nervous system, play an important role in the regulation of neurotransmitter homeostasis, energy metabolism, antioxidant defenses and the anti-inflammatory response. Recently, our group characterized cortical astrocyte cultures from adult Wistar rats. In line with that work, we studied glial function using an experimental in vitro model of aging astrocytes (30 days in vitro after reaching confluence) from newborn (NB), adult (AD) and aged (AG) Wistar rats. We evaluated metabolic parameters, such as the glucose uptake, glutamine synthetase (GS) activity, and glutathione (GSH) content, as well as the GFAP, GLUT-1 and xCT expression. AD and AG astrocytes take up less glucose than NB astrocytes and had decreased GLUT1 expression levels. Furthermore, AD and AG astrocytes exhibited decreased GS activity compared to NB cells. Simultaneously, AD and AG astrocytes showed an increase in GSH levels, along with an increase in xCT expression. NB, AD and AG astrocytes presented similar morphology; however, differences in GFAP levels were observed. Taken together, these results improve the knowledge of cerebral senescence and represent an innovative tool for brain studies of aging.

  12. Bisphenol A exposure at an environmentally relevant dose induces meiotic abnormalities in adult male rats.

    PubMed

    Liu, Chuan; Duan, Weixia; Zhang, Lei; Xu, Shangcheng; Li, Renyan; Chen, Chunhai; He, Mindi; Lu, Yonghui; Wu, Hongjuan; Yu, Zhengping; Zhou, Zhou

    2014-01-01

    Whether environmental exposure to bisphenol A (BPA) may induce reproductive disorders is still controversial but certain studies have reported that BPA may cause meiotic abnormalities in C. elegans and female mice. However, little is known about the effect of BPA on meiosis in adult males. To determine whether BPA exposure at an environmentally relevant dose could induce meiotic abnormalities in adult male rats, we exposed 9-week-old male Wistar rats to BPA by gavage at 20 μg/kg body weight (bw)/day for 60 consecutive days. We found that BPA significantly increased the proportion of stage VII seminiferous epithelium and decreased the proportion of stage VIII. Consequently, spermiation was inhibited and spermatogenesis was disrupted. Further investigation revealed that BPA exposure delayed meiosis initiation in the early meiotic stage and induced the accumulation of chromosomal abnormalities and meiotic DNA double-strand breaks (DSBs) in the late meiotic stage. The latter event subsequently activated the phosphatidylinositol 3-kinase-related protein kinase (ATM). Our results suggest that long-term exposure to BPA may lead to continuous meiotic abnormalities and ultimately put mammalian reproductive health at risk.

  13. Hindlimb Stretching Alters Locomotor Function Post-Spinal Cord Injury in the Adult Rat

    PubMed Central

    Caudle, Krista L.; Atkinson, Darryn A.; Brown, Edward H.; Donaldson, Katie; Seibt, Erik; Chea, Tim; Smith, Erin; Chung, Karianne; Shum-Siu, Alice; Cron, Courtney C.; Magnuson, David S. K.

    2014-01-01

    Background Stretching is a widely accepted standard-of-care therapy following spinal cord injury that has not been systematically studied in animal models. Objective To investigate the influence of a daily stretch-based physical therapy program on locomotor recovery in adult rats with moderate T9 contusive SCI. Methods A randomized treatment and control study of stretching in an animal model of acute spinal cord injury (SCI). Moderate spinal cord injuries were delivered with the NYU Impactor. Daily stretching (30 min./day, 5 days/wk for 8 wks) was provided by a team of animal handlers. Hindlimb function was assessed using the BBB Open Field Locomotor Scale and kinematically. Passive range-of-motion for each joint was determined weekly using a goniometer. Results Declines in hindlimb function during overground stepping were observed for the first 4 weeks. BBB scores improved weeks 5–10 but remained below the control group. Stretched animals had significant deficits in knee passive ROM starting at week 4 and for the duration of the study. Kinematic assessment showed decreased joint excursion during stepping that partially recovered beginning at week 5. Conclusion Stretch-based therapy significantly impaired functional recovery in adult rats with a moderate contusive SCI at T10. The negative impact on function was greatest acutely, but persisted even after the stretching ceased at 8 weeks post-injury. PMID:25106555

  14. Impact of neonatal anoxia on adult rat hippocampal volume, neurogenesis and behavior.

    PubMed

    Takada, Silvia Honda; Motta-Teixeira, Lívia Clemente; Machado-Nils, Aline Vilar; Lee, Vitor Yonamine; Sampaio, Carlos Alberto; Polli, Roberson Saraiva; Malheiros, Jackeline Moraes; Takase, Luiz Fernando; Kihara, Alexandre Hiroaki; Covolan, Luciene; Xavier, Gilberto Fernando; Nogueira, Maria Inês

    2016-01-01

    Neonates that suffer oxygen deprivation during birth can have long lasting cognitive deficits, such as memory and learning impairments. Hippocampus, one of the main structures that participate in memory and learning processes, is a plastic and dynamic structure that conserves during life span the property of generating new cells which can become neurons, the so-called neurogenesis. The present study investigated whether a model of rat neonatal anoxia, that causes only respiratory distress, is able to alter the hippocampal volume, the neurogenesis rate and has functional implications in adult life. MRI analysis revealed significant hippocampal volume decrease in adult rats who had experienced neonatal anoxia compared to control animals for rostral, caudal and total hippocampus. In addition, these animals also had 55.7% decrease of double-labelled cells to BrdU and NeuN, reflecting a decrease in neurogenesis rate. Finally, behavioral analysis indicated that neonatal anoxia resulted in disruption of spatial working memory, similar to human condition, accompanied by an anxiogenic effect. The observed behavioral alterations caused by oxygen deprivation at birth might represent an outcome of the decreased hippocampal neurogenesis and volume, evidenced by immunohistochemistry and MRI analysis. Therefore, based on current findings we propose this model as suitable to explore new therapeutic approaches.

  15. Maternal separation exaggerates spontaneous recovery of extinguished contextual fear in adult female rats.

    PubMed

    Xiong, Gui-Jing; Yang, Yuan; Wang, Li-Ping; Xu, Lin; Mao, Rong-Rong

    2014-08-01

    Early life stress increases the risk of posttraumatic stress disorders (PTSD). Patients with PTSD show impaired extinction of traumatic memory, and in women, this occurs more often when PTSD is preceded by child trauma. However, it is still unclear how early life stress accounts for extinction impairment. Here, we studied the effects of maternal separation (MS, postnatal day 2 to 14) on contextual fear extinction in adult female rats. Additionally, to examine changes in synaptic function affected by MS, we measured long-term potentiation (LTP) in prefrontal cortex and hippocampus in vitro, both of which have been implicated in fear extinction. We found that adult female rats had been subjected to MS exhibited significant spontaneous recovery of fear to the extinguished context. Furthermore, MS exposure resulted in LTP impairment in both infralimbic prefrontal cortex layer 2/3-layer 5 and hippocampal SC-CA1 pathways. Interestingly, no obvious effects of MS on contextual fear conditioning, fear recall as well as extinction training and recall were observed. Innate fear in the elevated plus maze or open field test remained nearly unaffected. These findings provided the first evidence that MS may exaggerate spontaneous recovery after contextual fear extinction, for which LTP impairment in the medial prefrontal cortex and hippocampus may be responsible, thereby possibly leading to impaired extinction associated with PTSD.

  16. Sex mediates dopamine and adrenergic receptor expression in adult rats exposed prenatally to cocaine

    PubMed Central

    Ferris, Mark J.; Mactutus, Charles F.; Silvers, Janelle M.; Hasselrot, Ulla; Strupp, Barbara J.; Booze, Rosemarie M.

    2010-01-01

    The extent of catecholaminergic receptor and respective behavioral alterations associated with prenatal cocaine exposure varies according to exogenous factors such as the amount, frequency, and route of maternal exposure, as well as endogenous factors such as specific brain regions under consideration and sex of the species. The goal of the current study was to use autoradiography to delineate possible moderators of dopaminergic and adrenergic receptor expression in adult rat offspring exposed to cocaine in utero. The current study demonstrated sex-dependent D1 receptor, α2, and noradrenergic transporter binding alterations in prelimbic, hippocampus, and anterior cingulate regions of adult rat brains exposed to cocaine during gestational days 8–21. Of further interest was the lack of alterations in the nucleus accumbens for nearly all receptors/transporters investigated, as well as the lack of alterations in D3 receptor binding in nearly all of the regions investigated (nucleus accumbens, prelimbic region, hippocampus, and cingulate gyrus). Thus, the current investigation demonstrated persistent receptor and transporter alterations that extend well into adulthood as a result of cocaine exposure in utero. Furthermore, the demonstration that sex played a mediating role in prenatal cocaine-induced, aberrant receptor/transporter expression is of primary importance for future studies that seek to control for sex in either design or analysis. PMID:17933484

  17. Mild Thyroid Hormone Insufficiency During Development Compromises Activity-Dependent Neuroplasticity in the Hippocampus of Adult Male Rats

    EPA Pesticide Factsheets

    behavioral measures of learning and memory in adult offspring of rats treated with thyroid hormone synthesis inhibitor, propylthiouracil.Electrophysiological measures of 'memory' in form of plasticity model known as long term potentiation (LTP)Molecular changes induced by LTPThis dataset is associated with the following publication:Gilbert , M., K. Sanchez-Huerta, and C. Wood. Mild Thyroid Hormone Insufficiency During Development Compromises Activity-Dependent Neuroplasticity in the Hippocampus of Adult Make Rats. ENDOCRINOLOGY. Endocrine Society, 157(2): 774-87, (2016).

  18. Effects of Extremely Low Frequency Electromagnetic Fields on Vascular Permeability of Circumventricular Organs in the Adult Rat

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Mercado, Y. K.; Cañedo-Dorantes, L.; Bañuelos-Pineda, J.; Serrano-Luna, G.; Feria-Velasco, A.

    2008-08-01

    The present work deals with the effects of extremely low frequency electromagnetic fields (ELF-EMF) on blood vessels permeability to non liposoluble substances of the circumventricular organs (CVO) of adult rats. Male Wistar adult rats were exposed to ELF-EMF and vascular permeability to colloidal carbon was investigated with the use of histological techniques. Results were compared to corresponding data from sham-exposed and control groups of animals. Exposure to ELF-EMF increased the CVO vascular permeability to colloidal carbon intravascularly injected, particularly in the subfornical organ, the median eminence, the pineal gland and the area postrema.

  19. Increased adult hippocampal brain-derived neurotrophic factor and normal levels of neurogenesis in maternal separation rats.

    PubMed

    Greisen, Mia H; Altar, C Anthony; Bolwig, Tom G; Whitehead, Richard; Wörtwein, Gitta

    2005-03-15

    Repeated maternal separation of rat pups during the early postnatal period may affect brain-derived neurotrophic factor (BDNF) or neurons in brain areas that are compromised by chronic stress. In the present study, a highly significant increase in hippocampal BDNF protein concentration was found in adult rats that as neonates had been subjected to 180 min of daily separation compared with handled rats separated for 15 min daily. BDNF protein was unchanged in the frontal cortex and hypothalamus/paraventricular nucleus. Expression of BDNF mRNA in the CA1, CA3, or dentate gyrus of the hippocampus or in the paraventricular hypothalamic nucleus was not affected by maternal separation. All animals displayed similar behavioral patterns in a forced-swim paradigm, which did not affect BDNF protein concentration in the hippocampus or hypothalamus. Repeated administration of bromodeoxyuridine revealed equal numbers of surviving, newly generated granule cells in the dentate gyrus of adult rats from the 15 min or 180 min groups. The age-dependent decline in neurogenesis from 3 months to 7 months of age did not differ between the groups. Insofar as BDNF can stimulate neurogenesis and repair, we propose that the elevated hippocampal protein concentration found in maternally deprived rats might be a compensatory reaction to separation during the neonatal period, maintaining adult neurogenesis at levels equal to those of the handled rats.

  20. IL-1 receptor antagonist attenuates neonatal lipopolysaccharide-induced long-lasting learning impairment and hippocampal injury in adult rats

    PubMed Central

    Pang, Yi; Bhatt, Abhay J.; Fan, Lir-Wan

    2015-01-01

    We have previously reported that neonatal lipopolysaccharide (LPS) exposure resulted in an increase in interleukin-1β (IL-1β) content, injury to the hippocampus, and cognitive deficits in juvenile male and female rats, as well as female adult rats. The present study aimed to determine whether an antiinflammatory cytokine, interleukin-1 receptor antagonist (IL-1ra), protects against the neonatal LPS exposure-induced inflammatory responses, hippocampal injury, and long-lasting learning deficits in adult rats. LPS (1 mg/kg) or LPS plus IL-1ra (0.1 mg/kg) was injected intracerebrally to Sprague-Dawley male rat pups at postnatal day 5 (P5). Neurobehavioral tests were carried out on P21, P49, and P70, while neuropathological studies were conducted on P71. Our results showed that neonatal LPS exposure resulted in learning deficits in rats at both developmental and adult ages, as demonstrated by a significantly impaired performance in the passive avoidance task (P21, P49, and P70), reduced hippocampal volume, and reduced number of Nissl+ cells in the CA1 region of the middle dorsal hippocampus of P71 rat brain. Those neuropathological and neurobehavioral alterations by LPS exposure were associated with a sustained inflammatory response in the P71 rat hippocampus, indicated by increased number of activated microglia as well as elevated levels of IL-1β. Neonatal administration of IL-1ra significantly attenuated LPS-induced long-lasting learning deficits, hippocampal injury, and sustained inflammatory responses in P71 rats. Our study demonstrates that neonatal LPS exposure leads to a persistent injury to the hippocampus, resulting in long-lasting learning disabilities related to chronic inflammation in rats, and these effects can be attenuated with an IL-1 receptor antagonist. PMID:25665855

  1. IL-1 receptor antagonist attenuates neonatal lipopolysaccharide-induced long-lasting learning impairment and hippocampal injury in adult rats.

    PubMed

    Lan, Kuo-Mao; Tien, Lu-Tai; Pang, Yi; Bhatt, Abhay J; Fan, Lir-Wan

    2015-04-02

    We have previously reported that neonatal lipopolysaccharide (LPS) exposure resulted in an increase in interleukin-1β (IL-1β) content, injury to the hippocampus, and cognitive deficits in juvenile male and female rats, as well as female adult rats. The present study aimed to determine whether an anti-inflammatory cytokine, interleukin-1 receptor antagonist (IL-1ra), protects against the neonatal LPS exposure-induced inflammatory responses, hippocampal injury, and long-lasting learning deficits in adult rats. LPS (1 mg/kg) or LPS plus IL-1ra (0.1 mg/kg) was injected intracerebrally to Sprague-Dawley male rat pups at postnatal day 5 (P5). Neurobehavioral tests were carried out on P21, P49, and P70, while neuropathological studies were conducted on P71. Our results showed that neonatal LPS exposure resulted in learning deficits in rats at both developmental and adult ages, as demonstrated by a significantly impaired performance in the passive avoidance task (P21, P49, and P70), reduced hippocampal volume, and reduced number of Nissl+ cells in the CA1 region of the middle dorsal hippocampus of P71 rat brain. Those neuropathological and neurobehavioral alterations by LPS exposure were associated with a sustained inflammatory response in the P71 rat hippocampus, indicated by increased number of activated microglia as well as elevated levels of IL-1β. Neonatal administration of IL-1ra significantly attenuated LPS-induced long-lasting learning deficits, hippocampal injury, and sustained inflammatory responses in P71 rats. Our study demonstrates that neonatal LPS exposure leads to a persistent injury to the hippocampus, resulting in long-lasting learning disabilities related to chronic inflammation in rats, and these effects can be attenuated with an IL-1 receptor antagonist.

  2. Effects of morphine on thermal sensitivity in adult and aged rats.

    PubMed

    Morgan, Drake; Mitzelfelt, Jeremiah D; Koerper, Lorraine M; Carter, Christy S

    2012-06-01

    There are contradictory data regarding older individuals' sensitivity to pain stimulation and opioid administration. Adult (12-16 months; n = 10) and aged (27-31 months; n = 7) male F344xBN rats were tested in a thermal sensitivity procedure where the animal chooses to remain in one of two compartments with floors maintained at various temperatures ranging from hot (45°C) through neutral (30°C) to cold (15°C). Effects of morphine were determined for three temperature comparisons (ie, hot/neutral, cold/neutral, and hot/cold). Aged rats were more sensitive to cold stimulation during baseline. Morphine produced antinociception during hot thermal stimulation, but had no effect on cold stimulation. The antinociceptive (and locomotor-altering) effects of morphine were attenuated in aged rats. These data demonstrate age-related differences in baseline thermal sensitivity and responsiveness to opioids. Based on behavioral and physiological requirements of this procedure, it is suggested that thermal sensitivity may provide a relevant animal model for the assessment of pain and antinociception.

  3. Learning under stress in the adult rat is differentially affected by 'juvenile' or 'adolescent' stress.

    PubMed

    Tsoory, Michael; Richter-Levin, Gal

    2006-12-01

    Epidemiological studies suggest that childhood trauma is associated with a predisposition to develop both mood and anxiety disorders, while trauma during adolescence is associated mainly with anxiety disorders. We studied in the rat the long-term consequences of 'juvenile' stress, namely stress experienced in a period in which substantial remodelling occurs across species in stress-sensitive brain areas involved in emotional and learning processing. In adulthood, 'juvenile' stressed rats exhibited reduced exploration in a novel setting, and poor avoidance learning, with 41% learning mainly to escape while 28% exhibited learned helplessness-like behaviours. In adult rats that underwent 'adolescent' stress, learned helplessness-like behaviours were not evident, although decreased exploration and poor avoidance learning were observed. This suggests that in the prepubertal phase juvenility may constitute a stress-sensitive period. The results suggest that juvenile stress induces lasting impairments in stress-coping responses. The 'juvenile' stress model presented here may be of relevance to individuals' reported predisposition to anxiety and depression following childhood trauma, and their increased susceptibility only to anxiety disorders following adolescent stress.

  4. Superoxide production after acute and chronic treatment with methylphenidate in young and adult rats.

    PubMed

    Gomes, Karin M; Inácio, Cecília G; Valvassori, Samira S; Réus, Gislaine Z; Boeck, Carina R; Dal-Pizzol, Felipe; Quevedo, João

    2009-11-06

    The prescription of methylphenidate (MPH) has dramatically increased in this decade for attention deficit hyperactivity disorder (ADHD) treatment. The action mechanism of MPH is not completely understood and studies have been demonstrated that MPH can lead to neurochemical adaptations. Superoxide radical anion is not very reactive per se. However, severe species derived from superoxide radical anion mediate most of its toxicity. In this study, the superoxide level in submitochondrial particles was evaluated in response to treatment with MPH in the age-dependent manner in rats. MPH was administrated acutely or chronically at doses of 1, 2 or 10 mg/kg i.p. The results showed that the acute administration of MPH in all doses in young rats increased the production of superoxide in the cerebellum and only in the high dose (10mg/kg) in the hippocampus, while chronic treatment had no effect. However, acute treatment in adult rats had no effect on production of superoxide, but chronic treatment decreased the production of superoxide in the cerebellum at the lower doses. Our data suggest that the MPH treatment can influence on production of superoxide in some brain areas, but this effect depends on age of animals and treatment regime with MPH.

  5. Choline dietary supplementation improves LiCl-induced context aversion retention in adult rats.

    PubMed

    Moreno, Hayarelis C; Gil, Marta; Carias, Diamela; Gallo, Milagros; de Brugada, Isabel

    2012-06-25

    Previous studies have demonstrated that choline is an essential nutrient during prenatal and early postnatal developmental periods. Thus, the availability of choline during these periods produces some beneficial effects on hippocampal-dependent learning and memory in rats. However, research on the effect of adult choline supplementation on learning and memory abilities is scarce. In the present study, 3-4 month-old male Wistar rats receiving a 7-week choline-supplemented diet (4.5 fold that of a standard diet) and control rats receiving a standard diet were trained in a LiCl-induced contextual aversion task. Short and long-term context aversion retention was assessed by recording the consumption of a flavoured solution in the aversive and safe contexts over two subsequent tests. Statistical analysis showed that the supplemented group exhibited greater intake suppression in the aversive context than in the safe context when two retention tests were applied 3 and 15 days after conditioning. These results suggest that increasing dietary choline availability during adulthood may favour the retention of a context aversion.

  6. Effects of different exercise protocols on ethanol-induced spatial memory impairment in adult male rats.

    PubMed

    Hashemi Nosrat Abadi, T; Vaghef, L; Babri, S; Mahmood-Alilo, M; Beirami, M

    2013-06-01

    Chronic ethanol consumption is often accompanied by numerous cognitive deficits and may lead to long-lasting impairments in spatial learning and memory. The aim of the present study was to evaluate the therapeutic potential of regular treadmill exercise on hippocampal-dependent memory in ethanol-treated rats. Spatial memory was tested in a Morris Water Maze task. Adult male Wistar rats were exposed to ethanol (4 g/kg, 20% v/v for 4 weeks) and effects of three exercise protocols (pre-ethanol, post-ethanol and pre-to-post-ethanol treatment) were examined. Results showed that ethanol exposure resulted in longer escape latencies during the acquisition phase of the Morris Water Maze task. Moreover, all three exercise protocols significantly decreased the latency to locate the hidden platform. During the probe trial, ethanol led to decreased time spent in the target quadrant. In contrast, performance on the probe trial was significantly better in the rats that had done the post- and pre-to-post-ethanol, but not pre-ethanol, exercises. These findings suggest that treadmill running can attenuate the adverse effects of chronic ethanol exposure on spatial memory, and may serve as a non-pharmacological alcohol abuse treatment.

  7. Feeding neonatal rats with IgG antibodies leads to humoral hyporesponsiveness in the adult.

    PubMed Central

    Peppard, J V

    1992-01-01

    Feeding monoclonal IgG2a or IgG1 anti-horseradish peroxidase (HRP) antibodies to 12-16-day-old neonatal rats caused a profound suppression of the humoral anti-HRP response in these rats as adults. The hyporesponsiveness to HRP was specific and long-lasting (up to 5 months). It was shown to be dose dependent, requiring relatively large doses of IgG (100-600 micrograms) for maximum effect. Secondary IgG (IgG1, IgG2a and IgG2b) responses were most depressed. The effect could be reproduced by i.p. injection of antibody. Hyporesponsiveness was not attributable to circulating antiidiotype antibodies directed against the monoclonal IgG, nor to the continued presence of the monoclonal anti-HRP since rats receiving antibody at or some weeks after the time of weaning and gut 'closure' responded well to subsequent HRP challenge. The effect was thus dependent on IgG administered over the identical period during which the neonatal circulation is rich in maternal IgG supplied via the milk. A direct function for maternal IgG in moulding the immune repertoire of the offspring, as well as providing passive protection, is suggested by these results. PMID:1385314

  8. Anti-dopamine beta-hydroxylase immunotoxin-induced sympathectomy in adult rats

    NASA Technical Reports Server (NTRS)

    Picklo, M. J.; Wiley, R. G.; Lonce, S.; Lappi, D. A.; Robertson, D.

    1995-01-01

    Anti-dopamine beta-hydroxylase immunotoxin (DHIT) is an antibody-targeted noradrenergic lesioning tool comprised of a monoclonal antibody against the noradrenergic enzyme, dopamine beta-hydroxylase, conjugated to saporin, a ribosome-inactivating protein. Noradrenergic-neuron specificity and completeness and functionality of sympathectomy were assessed. Adult, male Sprague-Dawley rats were given 28.5, 85.7, 142 or 285 micrograms/kg DHIT i.v. Three days after injection, a 6% to 73% decrease in the neurons was found in the superior cervical ganglia of the animals. No loss of sensory, nodose and dorsal root ganglia, neurons was observed at the highest dose of DHIT. In contrast, the immunotoxin, 192-saporin (142 micrograms/kg), lesioned all three ganglia. To assess the sympathectomy, 2 wk after treatment (285 micrograms/kg), rats were anesthetized with urethane (1 g/kg) and cannulated in the femoral artery and vein. DHIT-treated animals' basal systolic blood pressure and heart rate were significantly lower than controls. Basal plasma norepinephrine levels were 41% lower in DHIT-treated animals than controls. Tyramine-stimulated release of norepinephrine in DHIT-treated rats was 27% of controls. Plasma epinephrine levels of DHIT animals were not reduced. DHIT-treated animals exhibited a 2-fold hypersensitivity to the alpha-adrenergic agonist phenylephrine. We conclude that DHIT selectively delivered saporin to noradrenergic neurons resulting in destruction of these neurons. Anti-dopamine beta-hydroxylase immunotoxin administration produces a rapid, irreversible sympathectomy.

  9. Cadmium chloride exposure modifies amino acid daily pattern in the mediobasal hypothalamus in adult male rat.

    PubMed

    Caride, A; Fernández-Pérez, B; Cabaleiro, T; Bernárdez, G; Lafuente, A

    2010-01-01

    The present study was conducted to investigate the possible effects of cadmium exposure on the daily pattern of aspartate, glutamate, glutamine, gamma-aminobutyric acid (GABA) and taurine levels in the mediobasal hypothalamus of adult male rats. For this purpose, animals were treated with cadmium at two different exposure doses (25 and 50 mg l(-1) of cadmium chloride, CdCl(2)) in the drinking water for 30 days. Control age-matched rats received CdCl(2)-free water. After the treatment, rats were killed at six different time intervals throughout a 24 h cycle. CdCl(2) exposure modified the amino acid daily pattern, as it decreased aspartate, glutamate, GABA and taurine levels at 12:00 h with both exposure doses employed. In addition, the treatment with 25 mg l(-1) of CdCl(2) induced the appearance of minimal values at 16:00 h and maximal values between 04:00 and 08:00 h for glutamate, and a peak of glutamine content at 20:00 h. The heavy metal also decreased GABA medium levels around the clock in the mediobasal hypothalamus. However, CdCl(2) did not alter the metabolic correlation between glutamate, aspartate, glutamine and GABA observed in control animals. These results suggest that CdCl(2) induced several alterations in aspartate, glutamate, glutamine, GABA and taurine daily pattern in the mediobasal hypothalamus and those changes may be related to alterations in hypothalamic function.

  10. Oral administration of leaf extracts of Momordica charantia affect reproductive hormones of adult female Wistar rats

    PubMed Central

    Adewale, Osonuga Odusoga; Oduyemi, Osonuga Ifabunmi; Ayokunle, Osonuga

    2014-01-01

    Objective To determine the effect of graded doses of aqueous leaf extracts of Momordica charantia on fertility hormones of female albino rats. Methods Twenty adult, healthy, female Wistar rats were divided into four groups: low dose (LD), moderate dose (MD) and high dose (HD) groups which received 12.5 g, 25.0 g, 50.0 g of the leaf extract respectively and control group that was given with water ad libatum. Result Estrogen levels reduced by 6.40 nmol/L, 10.80 nmol/L and 28.00 nmol/L in the LD, MD and HD groups respectively while plasma progesterone of rats in the LD, MD and HD groups reduced by 24.20 nmol/L, 40.8 nmol/L and 59.20 nmol/L respectively. Conclusion Our study has shown that the antifertility effect of Momordica charantia is achieved in a dose dependent manner. Hence, cautious use of such medication should be advocated especially when managing couples for infertility. PMID:25183143

  11. Behavioral and neuroendocrine consequences of juvenile stress combined with adult immobilization in male rats.

    PubMed

    Fuentes, Silvia; Carrasco, Javier; Armario, Antonio; Nadal, Roser

    2014-08-01

    Exposure to stress during childhood and adolescence increases vulnerability to developing several psychopathologies in adulthood and alters the activity of the hypothalamic-pituitary-adrenal (HPA) axis, the prototypical stress system. Rodent models of juvenile stress appear to support this hypothesis because juvenile stress can result in reduced activity/exploration and enhanced anxiety, although results are not always consistent. Moreover, an in-depth characterization of changes in the HPA axis is lacking. In the present study, the long-lasting effects of juvenile stress on adult behavior and HPA function were evaluated in male rats. The juvenile stress consisted of a combination of stressors (cat odor, forced swim and footshock) during postnatal days 23-28. Juvenile stress reduced the maximum amplitude of the adrenocorticotropic hormone (ACTH) levels (reduced peak at lights off), without affecting the circadian corticosterone rhythm, but other aspects of the HPA function (negative glucocorticoid feedback, responsiveness to further stressors and brain gene expression of corticotrophin-releasing hormone and corticosteroid receptors) remained unaltered. The behavioral effects of juvenile stress itself at adulthood were modest (decreased activity in the circular corridor) with no evidence of enhanced anxiety. Imposition of an acute severe stressor (immobilization on boards, IMO) did not increase anxiety in control animals, as evaluated one week later in the elevated-plus maze (EPM), but it potentiated the acoustic startle response (ASR). However, acute IMO did enhance anxiety in the EPM, in juvenile stressed rats, thereby suggesting that juvenile stress sensitizes rats to the effects of additional stressors.

  12. Circadian variations in expression of the trkB receptor in adult rat hippocampus.

    PubMed

    Dolci, Claudia; Montaruli, Angela; Roveda, Eliana; Barajon, Isabella; Vizzotto, Laura; Grassi Zucconi, Gigliola; Carandente, Franca

    2003-12-19

    The expression of brain-derived neurotrophic factor (BDNF) in the central nervous system (CNS) and the expression of its high-affinity trkB receptor on neuron surfaces are known to depend on neuron activity. The expression of BDNF (mRNA and protein) and trkB mRNA shows circadian oscillations in rat hippocampal homogenates. We investigated circadian variations in trkB expression in specific areas of the adult rat hippocampal formation by immunohistochemistry. In sets of two experiments performed in the spring, 39 2-month-old male Wistar rats were accustomed to a 12-h light-12-h dark cycle for 2 weeks. Three animals were then sacrificed every 4 h. Forty-micrometer-thick coronal sections of hippocampal formation were obtained and processed for trkB immunohistochemistry. Cell staining intensity was assessed by image analysis of different hippocampal areas on five sections per animal. Circadian rhythmicity was evaluated by the cosinor method. Statistically significant circadian variations in trkB expression were found in dentate gyrus, entorhinal cortex, and the CA3 and hilar regions of the hippocampus, with highest expression during the first half of the dark (activity) period. These findings suggest a relationship between trkB expression and the physiological neuronal activation of wakefulness. TrkB receptor expression in the hippocampal regions studied was continuous and changes were gradual over the 24-h cycle, suggesting that more complex regulatory mechanisms also intervened.

  13. Protective effects of Peganum harmala extracts on thiourea-induced diseases in adult male rat.

    PubMed

    Hamden, Khaled; Masmoudi, Hatem; Ellouz, Feriel; ElFeki, Adelfatteh; Carreau, Serge

    2008-01-01

    Cancers and hepatoprotective prevention using traditional medicines have attracted increasing interest. The aim of our study was to characterize the putative protective effects of ethanol and chloroform extracts of Peganum harmala on thiourea-induced diseases in adult male rat. We seek to determine the effects of these plant extracts on body weight, thyroid and endocrine cancer parameters. In addition the putative hepatoprotective effect was checked by the determination of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and the bilirubin level in the blood. Our data show that ethanol and chloroform extracts of Peganum harmala protected the animal against the carcinogenic effects induced by thiourea since neuron-specific enolase (NSE) and thyroglobulin (TG) levels were back to the normal range. In addition, the observed-hepatocytotoxicity after thiourea treatment was greatly reduced (AST and ALT activities were respectively 270 IU/l and 60 IU/l and in the same order of magnitude as in the untreated rats) as well as the bilirubin levels (6 micromol/l) especially for animals receiving the choroform preparation. Therefore we may suggest that extracts of Peganum harmala are efficient to reduce the toxicity induced by thiourea in male rat as far as the above parameters are concerned.

  14. Distribution of bisphenol A into tissues of adult, neonatal, and fetal Sprague-Dawley rats

    SciTech Connect

    Doerge, Daniel R.; Twaddle, Nathan C.; Vanlandingham, Michelle; Brown, Ronald P.; Fisher, Jeffrey W.

    2011-09-15

    Bisphenol A (BPA) is an important industrial chemical used in the manufacture of polycarbonate plastic products and epoxy resin-based food can liners. The presence of BPA metabolites in urine of > 90% of Americans aged 6-60 suggests ubiquitous and frequent exposure in the range of 0.02-0.2 {mu}g/kg bw/d (25th-95th percentiles). The current study used LC/MS/MS to measure placental transfer and concentrations of aglycone (receptor-active) and conjugated (inactive) BPA in tissues from Sprague-Dawley rats administered deuterated BPA (100 {mu}g/kg bw) by oral and IV routes. In adult female rat tissues, the tissue/serum concentration ratios for aglycone BPA ranged from 0.7 in liver to 5 in adipose tissue, reflecting differences in tissue perfusion, composition, and metabolic capacity. Following IV administration to dams, placental transfer was observed for aglycone BPA into fetuses at several gestational days (GD), with fetal/maternal serum ratios of 2.7 at GD 12, 1.2 at GD 16, and 0.4 at GD 20; the corresponding ratios for conjugated BPA were 0.43, 0.65, and 3.7. These ratios were within the ranges observed in adult tissues and were not indicative of preferential accumulation of aglycone BPA or hydrolysis of conjugates in fetal tissue in vivo. Concentrations of aglycone BPA in GD 20 fetal brain were higher than in liver or serum. Oral administration of the same dose did not produce measurable levels of aglycone BPA in fetal tissues. Amniotic fluid consistently contained levels of BPA at or below those in maternal serum. Concentrations of aglycone BPA in tissues of neonatal rats decreased with age in a manner consistent with the corresponding circulating levels. Phase II metabolism of BPA increased with fetal age such that near-term fetus was similar to early post-natal rats. These results show that concentrations of aglycone BPA in fetal tissues are similar to those in other maternal and neonatal tissues and that maternal Phase II metabolism, especially following oral

  15. Ultrastructural changes and nestin expression accompanying compensatory renal growth after unilateral nephrectomy in adult rats

    PubMed Central

    Eladl, Mohamed Ahmed; M Elsaed, Wael; Atef, Hoda; El-Sherbiny, Mohamed

    2017-01-01

    Background Several renal disorders affect the glomerular podocytes. Compensatory structural and functional changes have been observed in animals that have undergone unilateral renal ablation. These changes occur as a pliant response to quench the increased functional demand to maintain homeostasis of fluid and solutes. Nestin is an intermediate filament protein present in the glomerular podocytes of the adult kidney and is linked with the maintenance of its foot process structure. Structural changes in the podocytes ultimately restructure the filtration barrier. Very few studies related to the ultrastructural and histopathologic changes of the podocytes are documented. The present study aimed to assess the histopathologic changes at the ultrastructural level in the adapted kidney at different time intervals following unilateral renal ablation in adult rats and its relation with nestin. Methods Forty-eight rats were divided into four groups (n=12 in each group). The animals of Group A were control naïve rats, while the group B, group C and group D animals underwent left unilateral nephrectomy and the remaining right kidney was removed on days 10, 20 and 30, respectively. Each group included four sham-operated rats, which were sacrificed at the same time as the naïve rats. Each nephrectomized sample was weighed and its sections were subjected to hematoxylin and eosin examination, transmission electron microscopic study as well as immunostaining using the intermediate filament protein nestin. Results No difference was found between the kidney sections from the control group and the sham-operated groups. A significant increase in the weight of the right kidneys was noted in groups B, C and D (P<0.001). The ultrastructural adaptive changes seen in the glomeruli of group B were subsequently reduced in groups C and D. This finding corresponded to a similar pattern of nestin expression in the podocytes, which showed significant increase in group B followed by reduced

  16. Hypoxic pulmonary vasoconstriction, carotid body function and erythropoietin production in adult rats perinatally exposed to hyperoxia

    PubMed Central

    Prieto-Lloret, Jesus; Ramirez, Maria; Olea, Elena; Moral-Sanz, Javier; Cogolludo, Angel; Castañeda, Javier; Yubero, Sara; Agapito, Teresa; Gomez-Niño, Angela; Rocher, Asuncion; Rigual, Ricardo; Obeso, Ana; Perez-Vizcaino, Francisco; González, Constancio

    2015-01-01

    Adult mammalians possess three cell systems that are activated by acute bodily hypoxia: pulmonary artery smooth muscle cells (PASMC), carotid body chemoreceptor cells (CBCC) and erythropoietin (EPO)-producing cells. In rats, chronic perinatal hyperoxia causes permanent carotid body (CB) atrophy and functional alterations of surviving CBCC. There are no studies on PASMC or EPO-producing cells. Our aim is to define possible long-lasting functional changes in PASMC or EPO-producing cells (measured as EPO plasma levels) and, further, to analyse CBCC functional alterations. We used 3- to 4-month-old rats born and reared in a normal atmosphere or exposed to perinatal hyperoxia (55–60% O2 for the last 5–6 days of pregnancy and 4 weeks after birth). Perinatal hyperoxia causes an almost complete loss of hypoxic pulmonary vasoconstriction (HPV), which was correlated with lung oxidative status in early postnatal life and prevented by antioxidant supplementation in the diet. O2-sensitivity of K+ currents in the PASMC of hyperoxic animals is normal, indicating that their inhibition is not sufficient to trigger HPV. Perinatal hyperoxia also abrogated responses elicited by hypoxia on catecholamine and cAMP metabolism in the CB. An increase in EPO plasma levels elicited by hypoxia was identical in hyperoxic and control animals, implying a normal functioning of EPO-producing cells. The loss of HPV observed in adult rats and caused by perinatal hyperoxia, comparable to oxygen therapy in premature infants, might represent a previously unrecognized complication of such a medical intervention capable of aggravating medical conditions such as regional pneumonias, atelectases or general anaesthesia in adult life. Key points Adult animals that have been perinatally exposed to oxygen-rich atmospheres (hyperoxia), recalling those used for oxygen therapy in infants, exhibit a loss of hypoxic pulmonary vasoconstriction, whereas vasoconstriction elicited by depolarizing agents is

  17. Neonatal local noxious insult affects gene expression in the spinal dorsal horn of adult rats.

    PubMed

    Ren, Ke; Novikova, Svetlana I; He, Fang; Dubner, Ronald; Lidow, Michael S

    2005-09-22

    Neonatal noxious insult produces a long-term effect on pain processing in adults. Rats subjected to carrageenan (CAR) injection in one hindpaw within the sensitive period develop bilateral hypoalgesia as adults. In the same rats, inflammation of the hindpaw, which was the site of the neonatal injury, induces a localized enhanced hyperalgesia limited to this paw. To gain an insight into the long-term molecular changes involved in the above-described long-term nociceptive effects of neonatal noxious insult at the spinal level, we performed DNA microarray analysis (using microarrays containing oligo-probes for 205 genes encoding receptors and transporters for glutamate, GABA, and amine neurotransmitters, precursors and receptors for neuropeptides, and neurotrophins, cytokines and their receptors) to compare gene expression profiles in the lumbar spinal dorsal horn (LDH) of adult (P60) male rats that received neonatal CAR treatment within (at postnatal day 3; P3) and outside (at postnatal 12; P12) of the sensitive period. The data were obtained both without inflammation (at baseline) and during complete Freund's adjuvant induced inflammation of the neonatally injured paw. The observed changes were verified by real-time RT-PCR. This study revealed significant basal and inflammation-associated aberrations in the expression of multiple genes in the LDH of adult animals receiving CAR injection at P3 as compared to their expression levels in the LDH of animals receiving either no injections or CAR injection at P12. In particular, at baseline, twelve genes (representing GABA, serotonin, adenosine, neuropeptide Y, cholecystokinin, opioid, tachykinin and interleukin systems) were up-regulated in the bilateral LDH of the former animals. The baseline condition in these animals was also characterized by up-regulation of seven genes (encoding members of GABA, cholecystokinin, histamine, serotonin, and neurotensin systems) in the LDH ipsilateral to the neonatally-injured paw. The

  18. Perinatal Nicotine Exposure Increases Obesity Susceptibility in Adult Male Rat Offspring by Altering Early Adipogenesis.

    PubMed

    Fan, Jie; Zhang, Wan-Xia; Rao, Yi-Song; Xue, Jing-Ling; Wang, Fei-Fei; Zhang, Li; Yan, You-E

    2016-11-01

    The present study aims to evaluate whether perinatal nicotine (NIC) exposure increases obesity susceptibility in adult male rat offspring by altering early adipogenesis. NIC was sc administered (2.0 mg/kg per day) to pregnant rats from gestational day 9 to the time of weaning (postnatal day 28). At weaning, NIC-exposed male pups had an increased body weight and inguinal sc fat mass and a decreased average cell area of adipocyte, which was accompanied by an overexpression of adipogenic and lipogenic genes in the epididymal white adipose tissue. Additionally, the hepatic lipogenic gene levels from NIC-exposed male pups were also affected. At 12 and 26 weeks of age, body weight and fat mass were increased, whereas there was no change in food intake in NIC-exposed male offspring. Adipogenic and lipogenic genes, glucose transporter 4, and leptin mRNA levels were increased, whereas adiponectin mRNA levels were decreased in the epididymal white adipose tissue of NIC-exposed males. The hepatic lipogenic gene expression of NIC-exposed males was increased. NIC-exposed male offspring showed normal glycemia and a higher serum insulin level, homeostasis model assessment of insulin resistance, and homeostasis model assessment of β-cell function. Furthermore, the NIC-exposed male offspring showed higher serum lipids and Castelli index I and lower nonesterified fatty acid. At 26 weeks, in the ip glucose and insulin tolerance tests, the glucose clearance was delayed, and the area under the curve was higher in the NIC-exposed male offspring. In conclusion, perinatal NIC exposure increased obesity susceptibility in adult male rat offspring by altering early adipogenesis.

  19. Signaling by TGF-betas in tubule cultures of adult rat testis

    PubMed Central

    Chan, Kai-Hui; Galuska, Sebastian P; Kudipudi, Pradeep Kumar; Riaz, Mohammad Assad; Loveland, Kate L; Konrad, Lutz

    2017-01-01

    Although signal transduction of transforming growth factor-betas (TGF-βs) is well characterized in individual cell types, data about TGF-β signaling in a cellular context is still scarce. In this study, we used ex vivo tubule cultures from adult rat testis to investigate TGF-β signaling. We show for the first time in testicular tubules, that TGF-βs also signal via the BMP type I receptors, with ALK2 used by TGF-β1 and ALK3 and ALK6 by TGF-β2. This signal transduction is mediated via Smad3 as well as via Smad1. In contrast, BMPs (BMP2 and BMP7) do not signal via the high-affinity type I and type II TGFβ receptors, TBR1 or TBR2. Furthermore, treatment of tubule cultures with either TGF-β1 or TGF-β2 had profound significant stimulatory effects on secretion of plasminogen activator-1 (PAI-1) through utilization of TGF-β and BMP receptors. Specific inhibitors for either TBR1 or BMP receptors yielded nearly complete inhibition of TGF-β signaling. The TBR1-TBR2 signalosome was detected with Duolink upon stimulation with either TGF-β1 or TGF-β2, predominantly in spermatogenic cells of the adult rat testis, particularly in elongated spermatids. In summary, this examination of intact rat testicular tubules demonstrated for the first time that TGF-βs signal mainly through TBR1 and TBR2 but also use BMP receptors, including for secretion of PAI-1. Whereas ALK2 participates in the TGF-β1-induced TBR1-TBR2 signalosome, ALK3 and ALK6 are involved in signaling of TGF-β2. Detection of the TBR1-TBR2 signalosome in late spermiogenic cells indicates a post-meiotic activity. PMID:28386343

  20. Immune responses in sprague-dawley rats exposed to dibutyltin dichloride in drinking water as adults.

    PubMed

    DeWitt, Jamie C; Copeland, Carey B; Luebke, Robert W

    2005-07-01

    Organotins are used commercially as agricultural pesticides, antifouling agents, and stabilizers for polyvinyl chloride (PVC) pipe. Mono- and di-substituted methyl and butyltins, used in PVC pipe production, are of concern as they leach from supply pipes into drinking water and have been reported to cause multisystem toxicity, including immunotoxicity. As part of an ongoing study to evaluate immunotoxic effects of organotins, we assessed immune function in adult Sprague-Dawley (CD) rats after exposure to dibutyltin dichloride (DBTC). Individually-housed adult male and female CD rats were given drinking water containing 0, 10, or 25 mg DBTC/L (final concentration) in 0.5% Alkamuls for 28 days. Water bottles were changed and water consumption was monitored twice weekly and body weights (BW) were recorded weekly. Delayed-type hypersensitivity (DTH), primary and secondary antibody responses to sheep red blood cells, and natural killer (NK) cell activity were evaluated in separate groups of treated and control animals on day 29 of exposure. Water consumption was significantly decreased in both sexes at 25 mg DBTC/L. BW, immune organ weights, the DTH response, and NK cell activity did not vary by dose. Different results for antibody responses in male rats were obtained in two experimental replicates. In the first replicate, IgG was elevated at the highest dose whereas in the second replicate, IgM was suppressed. However, as these effects occurred at the high dose of 25 mg DBTC/L, which is a concentration a million times higher than levels of DBTC reported in drinking water, our data suggest that DBTC is unlikely to cause immunotoxicity at concentrations found in drinking water supplies.

  1. Identification of interneurons activated at different inclines during treadmill locomotion in adult rats.

    PubMed

    Tillakaratne, Niranjala J K; Duru, Paul; Fujino, Hidemi; Zhong, Hui; Xiao, Mei Si; Edgerton, V Reggie; Roy, Roland R

    2014-12-01

    By using c-fos as an activity-dependent marker, we identified the cholinergic interneurons around the central canal and lumbar interneurons throughout the gray matter that were activated after a 30-min bout of quadrupedal treadmill stepping at a 0° or 25° incline in adult rats. Increased loading (elevated treadmill incline) imposed during treadmill stepping activated more cholinergic interneurons in the proximity of the central canal, i.e., central canal cluster cells and partition neurons. Since cholinergic central canal cells are thought to modulate motoneuron excitability, these data suggest that increased load during stepping may increase motoneuronal activity through activating more cholinergic central canal cells. We identified the muscle-specific motoneurons and afferent terminals in the spinal cord by injecting cholera toxin subunit B in the soleus and tibialis anterior muscles. The number of interneurons in lumbar segments L4 (tibialis anterior) and L5 (soleus) was higher in both groups that stepped on the treadmill compared with control and was highest in rats that stepped at a 25° incline. In a majority of laminae, the distribution of total and muscle-specific activated interneurons was highest in the 25° incline group and lowest in the control group for both muscles. These data could reflect increased peripheral (proprioceptive) input as well as supraspinal drive associated with stepping and demonstrate the differences in 1) the activation of cholinergic interneurons near the central canal and 2) the laminar and segmental location of interneurons throughout the gray matter that play a role in generating stepping under different loading conditions in adult rats.

  2. Adolescent cannabis exposure alters opiate intake and opioid limbic neuronal populations in adult rats.

    PubMed

    Ellgren, Maria; Spano, Sabrina M; Hurd, Yasmin L

    2007-03-01

    Cannabis use is a hypothesized gateway to subsequent abuse of other drugs such as heroin. We currently assessed whether Delta-9-tetrahydrocannabinol (THC) exposure during adolescence modulates opiate reinforcement and opioid neural systems in adulthood. Long-Evan male rats received THC (1.5 mg/kg intraperitoneally (i.p.)) or vehicle every third day during postnatal days (PNDs) 28-49. Heroin self-administration behavior (fixed ratio-1; 3-h sessions) was studied from young adulthood (PND 57) into full adults (PND 102). THC-pretreated rats showed an upward shift throughout the heroin self-administration acquisition (30 microg/kg/infusion) phase, whereas control animals maintained the same pattern once stable intake was obtained. Heightened opiate sensitivity in THC animals was also evidenced by higher heroin consumption during the maintenance phase (30 and 60 microg/kg/infusion) and greater responding for moderate-low heroin doses (dose-response curve: 7.5, 15, 30, 60, and 100 microg/kg/injection). Specific disturbance of the endogenous opioid system was also apparent in the brain of adults with adolescent THC exposure. Striatal preproenkephalin mRNA expression was exclusively increased in the nucleus accumbens (NAc) shell; the relative elevation of preproenkephalin mRNA in the THC rats was maintained even after heroin self-administration. Moreover, mu opioid receptor (muOR) GTP-coupling was potentiated in mesolimbic and nigrostriatal brainstem regions in THC-pretreated animals. muOR function in the NAc shell was specifically correlated to heroin intake. The current findings support the gateway hypothesis demonstrating that adolescence cannabis exposure has an enduring impact on hedonic processing resulting in enhanced opiate intake, possibly as a consequence of alterations in limbic opioid neuronal populations.

  3. Subcellular distribution of ( sup 3 H)-dexamethasone mesylate binding sites in Leydig cells using electron microscope radioautography

    SciTech Connect

    Stalker, A.; Hermo, L.; Antakly, T. )

    1991-01-01

    The present view is that glucocorticoid hormones bind to their cytoplasmic receptors before reaching their nuclear target sites, which include specific DNA sequences. Although it is believed that cytoplasmic sequestration of steroid receptors and other transcription factors (such as NFKB) may regulate the overall activity of these factors, there is little information on the exact subcellular sites of steroid receptors or even of any other transcription factors. Tritiated (3H)-dexamethasone 21-mesylate (DM) is an affinity label that binds covalently to the glucocorticoid receptor (GR), thereby allowing morphological localization of the receptor at the light and electron microscope levels as well as for quantitative radioautographic (RAG) analysis. After injection of 3H-DM into the testis, a specific radioautographic signal was observed in Leydig cells, which correlated with a high level of immunocytochemically demonstrable GR in these cells at the light-microscope level. To localize the 3H-DM binding sites at the electron microscope (EM) level, the testes of 5 experimental and 3 control adrenalectomized rats were injected directly with 20 microCi 3H-DM; control rats received simultaneously a 25-fold excess of unlabeled dexamethasone; 15 min later, rats were fixed with glutaraldehyde and the tissue was processed for EM RAG analysis combined with quantitative morphometry. The radioautographs showed that the cytosol, nucleus, smooth endoplasmic reticulum (sER), and mitochondria were labeled. Since the cytosol was always adjacent to tubules of the sER, the term sER-rich cytosol was used to represent label over sER networks, which may also represent cytosol labeling due to the limited resolution of the radioautographic technique. Labeling was highest in sER-rich cytosol and mitochondria, at 53% and 31% of the total, respectively.

  4. Developmental effects of wheel running on hippocampal glutamate receptor expression in young and mature adult rats.

    PubMed

    Staples, M C; Somkuwar, S S; Mandyam, C D

    2015-10-01

    Recent evidence suggests that the behavioral benefits associated with voluntary wheel running in rodents may be due to modulation of glutamatergic transmission in the hippocampus, a brain region implicated in learning and memory. However, the expression of the glutamatergic ionotropic N-methyl-d-aspartate receptor (GluN) in the hippocampus in response to chronic sustained voluntary wheel running has not yet been investigated. Further, the developmental effects during young and mature adulthood on wheel running output and GluN expression in hippocampal subregions has not been determined, and therefore is the main focus of this investigation. Eight-week-old and 16-week-old male Wistar rats were housed in home cages with free access to running wheels and running output was monitored for 4weeks. Wheel access was terminated and tissues from the dorsal and ventral hippocampi were processed for Western blot analysis of GluN subunit expression. Young adult runners demonstrated an escalation in running output but this behavior was not evident in mature adult runners. In parallel, young adult runners demonstrated a significant increase in total GluN (1 and 2A) subunit expression in the dorsal hippocampus (DH), and an opposing effect in the ventral hippocampus (VH) compared to age-matched sedentary controls; these changes in total protein expression were not associated with significant alterations in the phosphorylation of the GluN subunits. In contrast, mature adult runners demonstrated a reduction in total GluN2A expression in the DH, without producing alterations in the VH compared to age-matched sedentary controls. In conclusion, differential running activity-mediated modulation of GluN subunit expression in the hippocampal subregions was revealed to be associated with developmental effects on running activity, which may contribute to altered hippocampal synaptic activity and behavioral outcomes in young and mature adult subjects.

  5. Neonatal handling causes impulsive behavior and decreased pharmacological response to methylphenidate in male adult wistar rats.

    PubMed

    Lazzaretti, Camilla; Kincheski, Grasielle Clotildes; Pandolfo, Pablo; Krolow, Rachel; Toniazzo, Ana Paula; Arcego, Danusa Mar; Couto-Pereira, Natividade de Sá; Zeidán-Chuliá, Fares; Galvalisi, Martin; Costa, Gustavo; Scorza, Cecilia; Souza, Tadeu Mello E; Dalmaz, Carla

    2016-03-01

    Neonatal handling has an impact on adult behavior of experimental animals and is associated with rapid and increased palatable food ingestion, impaired behavioral flexibility, and fearless behavior to novel environments. These symptoms are characteristic features of impulsive trait, being controlled by the medial prefrontal cortex (mPFC). Impulsive behavior is a key component of many psychiatric disorders such as attention deficit hyperactivity disorder (ADHD), manic behavior, and schizophrenia. Others have reported a methylphenidate (MPH)-induced enhancement of mPFC functioning and improvements in behavioral core symptoms of ADHD patients. The aims of the present study were: (i) to find in vivo evidence for an association between neonatal handling and the development of impulsive behavior in adult Wistar rats and (ii) to test whether neonatal handling could have an impact on monoamine levels in the mPFC and the pharmacological response to MPH in vivo. Therefore, experimental animals (litters) were classified as: "non-handled" and "handled" (10[Formula: see text]min/day, postnatal days 1-10). After puberty, they were exposed to either a larger and delayed or smaller and immediate reward (tolerance to delay of reward task). Acute MPH (3[Formula: see text]mg/Kg. i.p.) was used to suppress and/or regulate impulsive behavior. Our results show that only neonatally handled male adult Wistar rats exhibit impulsive behavior with no significant differences in monoamine levels in the medial prefrontal cortex, together with a decreased response to MPH. On this basis, we postulate that early life interventions may have long-term effects on inhibitory control mechanisms and affect the later response to pharmacological agents during adulthood.

  6. Differential Behavioral and Neurobiological Effects of Chronic Corticosterone Treatment in Adolescent and Adult Rats

    PubMed Central

    Li, Jitao; Xie, Xiaomeng; Li, Youhong; Liu, Xiao; Liao, Xuemei; Su, Yun-Ai; Si, Tianmei

    2017-01-01

    Adolescence is a critical period with ongoing maturational processes in stress-sensitive systems. While adolescent individuals show heightened stress-induced hormonal responses compared to adults, it is unclear whether and how the behavioral and neurobiological consequences of chronic stress would differ between the two age groups. Here we address this issue by examining the effects of chronic exposure to the stress hormone, corticosterone (CORT), in both adolescent and adult animals. Male Sprague-Dawley (SD) rats were injected intraperitoneally with CORT (40 mg/kg) or vehicle for 21 days during adolescence (post-natal day (PND) 29–49) or adulthood (PND 71–91) and then subjected to behavioral testing or sacrifice for western blot analyses. Despite of similar physical and neuroendocrine effects in both age groups, chronic CORT treatment produced a series of behavioral and neurobiological effects with striking age differences. While CORT-treated adult animals exhibited decreased sucrose preference, increased anxiety levels and cognitive impairment, CORT-treated adolescent animals demonstrated increased sucrose preference, decreased anxiety levels, and increased sensorimotor gating functions. These differential behavioral alterations were accompanied by opposite changes in the two age groups in the expression levels of brain-derived neurotrophic factor (BDNF), the phosphorylation of the obligatory subunit of the NMDA receptor, GluN1, and PSD-95 in rat hippocampus. These results suggest that prolonged glucocorticoid exposure during adolescence produces different behavioral and neurobiological effects from those in adulthood, which may be due to the complex interaction between glucocorticoids and the ongoing neurodevelopmental processes during this period. PMID:28210212

  7. Perinatal Resveratrol Supplementation to Spontaneously Hypertensive Rat Dams Mitigates the Development of Hypertension in Adult Offspring.

    PubMed

    Care, Alison S; Sung, Miranda M; Panahi, Sareh; Gragasin, Ferrante S; Dyck, Jason R B; Davidge, Sandra T; Bourque, Stephane L

    2016-05-01

    This study was undertaken to determine whether perinatal maternal resveratrol (Resv)--a phytoalexin known to confer cardiovascular protection--could prevent the development of hypertension and improve vascular function in adult spontaneously hypertensive rat offspring. Dams were fed either a control or Resv-supplemented diet (4 g/kg diet) from gestational day 0.5 until postnatal day 21. Indwelling catheters were used to assess blood pressure and vascular function in vivo; wire myography was used to assess vascular reactivity ex vivo. Perinatal Resv supplementation in dams had no effect on fetal body weights, albeit continued maternal treatment postnatally resulted in growth restriction in offspring by postnatal day 21; growth restriction was no longer evident after 5 weeks of age. Maternal perinatal Resv supplementation prevented the onset of hypertension in adult offspring (-18 mm Hg; P=0.007), and nitric oxide synthase inhibition (with L-NG-nitroarginine methyl ester) normalized these blood pressure differences, suggesting improved nitric oxide bioavailability underlies the hemodynamic alterations in the Resv-treated offspring. In vivo and ex vivo, vascular responses to methylcholine were not different between treatment groups, but prior treatment with L-NG-nitroarginine methyl ester attenuated the vasodilation in untreated, but not Resv-treated adult offspring, suggesting a shift toward nitric oxide-independent vascular control mechanisms in the treated group. Finally, bioconversion of the inactive precursor big endothelin-1 to active endothelin-1 in isolated mesenteric arteries was reduced in Resv-treated offspring (-28%; P<0.05), and this difference could be normalized by L-NG-nitroarginine methyl ester treatment. In conclusion, perinatal maternal Resv supplementation mitigated the development of hypertension and causes persistent alterations in vascular responsiveness in spontaneously hypertensive rats.

  8. The Impact of Adult Vitamin D Deficiency on Behaviour and Brain Function in Male Sprague-Dawley Rats

    PubMed Central

    Turner, Karly M.; Eyles, Darryl W.; McGrath, John J.; Burne, Thomas H. J.

    2013-01-01

    Background Vitamin D deficiency is common in the adult population, and this has been linked to depression and cognitive outcomes in clinical populations. The aim of this study was to investigate the effects of adult vitamin D (AVD) deficiency on behavioural tasks of relevance to neuropsychiatric disorders in male Sprague-Dawley rats. Methods Ten-week old male Sprague-Dawley rats were fed a control or vitamin D deficient diet for 6 weeks prior to, and during behavioural testing. We first examined a range of behavioural domains including locomotion, exploration, anxiety, social behaviour, learned helplessness, sensorimotor gating, and nociception. We then assessed locomotor response to the psychomimetic drugs, amphetamine and MK-801. Attention and vigilance were assessed using the 5 choice serial reaction time task (5C-SRT) and the 5 choice continuous performance task (5C-CPT) and, in a separate cohort, working memory was assessed using the delay match to sample (DMTS) task. We also examined excitatory and inhibitory neurotransmitters in prefrontal cortex and striatum. Results AVD-deficient rats were deficient in vitamin D3 (<10 nM) and had normal calcium and phosphate levels after 8–10 weeks on the diet. Overall, AVD deficiency was not associated with an altered phenotype across the range of behavioural domains tested. On the 5C-SRT AVD-deficient rats made more premature responses and more head entries during longer inter-trial intervals (ITI) than control rats. On the 5C-CPT AVD-deficient rats took longer to make false alarm (FA) responses than control rats. AVD-deficient rats had increases in baseline GABA levels and the ratio of DOPAC/HVA within the striatum. Conclusions AVD-deficient rats exhibited no major impairments in any of the behavioural domains tested. Impairments in premature responses in AVD-deficient rats may indicate that these animals have specific alterations in striatal systems governing compulsive or reward-seeking behaviour. PMID:23951200

  9. Teaching Adult Rats Spinalized as Neonates to Walk Using Trunk Robotic Rehabilitation: Elements of Success, Failure, and Dependence

    PubMed Central

    Udoekwere, Ubong I.; Oza, Chintan S.

    2016-01-01

    Robot therapy promotes functional recovery after spinal cord injury (SCI) in animal and clinical studies. Trunk actions are important in adult rats spinalized as neonates (NTX rats) that walk autonomously. Quadrupedal robot rehabilitation was tested using an implanted orthosis at the pelvis. Trunk cortical reorganization follows such rehabilitation. Here, we test the functional outcomes of such training. Robot impedance control at the pelvis allowed hindlimb, trunk, and forelimb mechanical interactions. Rats gradually increased weight support. Rats showed significant improvement in hindlimb stepping ability, quadrupedal weight support, and all measures examined. Function in NTX rats both before and after training showed bimodal distributions, with “poor” and “high weight support” groupings. A total of 35% of rats initially classified as “poor” were able to increase their weight-supported step measures to a level considered “high weight support” after robot training, thus moving between weight support groups. Recovered function in these rats persisted on treadmill with the robot both actuated and nonactuated, but returned to pretraining levels if they were completely disconnected from the robot. Locomotor recovery in robot rehabilitation of NTX rats thus likely included context dependence and/or incorporation of models of robot mechanics that became essential parts of their learned strategy. Such learned dependence is likely a hurdle to autonomy to be overcome for many robot locomotor therapies. Notwithstanding these limitations, trunk-based quadrupedal robot rehabilitation helped the rats to visit mechanical states they would never have achieved alone, to learn novel coordinations, and to achieve major improvements in locomotor function. SIGNIFICANCE STATEMENT Neonatal spinal transected rats without any weight support can be taught weight support as adults by using robot rehabilitation at trunk. No adult control rats with neonatal spinal

  10. Sirolimus and tacrolimus rather than cyclosporine A cause bone loss in healthy adult male rats.

    PubMed

    Rubert, Mercedes; Montero, Mercedes; Guede, David; Caeiro, Jose-Ramón; Martín-Fernández, Marta; Díaz-Curiel, Manuel; de la Piedra, Concepción

    2015-06-01

    The aim of this work was to study the effects of cyclosporine (CsA), tacrolimus (FK-506), and rapamycin (RAPA) on bone mass, femoral microstructure, femoral biomechanical properties, and bone remodeling in healthy adult male rats. Forty-eight 5-month-old male Wistar rats were used. CsA (2 mg/kg/day), FK-506 (3 mg/kg/day), RAPA (1.25 mg/kg/day), or water (0.5 ml/rat/day, control group) were administered orally for 3 months. After sacrifice, mean values of immunosuppressants in blood were: CsA (670.4 ng/ml), FK-506 (19.2 ng/ml), and RAPA (4.8 ng/ml). Levels of biochemical parameters were normal in all groups. Femoral BMD was decreased in FK-506 and RAPA groups and lumbar BMD in FK-506 group. Trabecular volume fraction (BV/TV) decreased only in FK-506 group. RAPA and CsA affected femoral cortical structure, but FK-506 did not. FK-506 produced an increase in bone remodeling, and CsA a decrease. FK-506 group showed a decrease in biomechanical parameters relative to all groups. RAPA group showed a decrease in ultimate stress vs control group, and CsA group presented an increase in biomechanical parameters versus control group. We found that administration of both RAPA and FK-506 as monotherapy for healthy rats produced osteopenia. CsA treatment only produces slight damages in the cortical zone of the femur.

  11. Calcium supplementation prevents obesity, hyperleptinaemia and hyperglycaemia in adult rats programmed by early weaning.

    PubMed

    Nobre, Jessica Lopes; Lisboa, Patricia Cristina; Lima, Natália da Silva; Franco, Juliana Gastão; Nogueira Neto, José Firmino; de Moura, Egberto Gaspar; de Oliveira, Elaine

    2012-04-01

    It is known that Ca therapy may have anti-obesity effects. Since early weaning leads to obesity, hyperleptinaemia and insulin resistance, we studied the effect of dietary Ca supplementation in a rat model. Lactating rats were separated into two groups: early weaning (EW) - dams were wrapped with a bandage to interrupt lactation in the last 3 d of lactation and control (C) - dams whose pups had free access to milk during the entire lactation period (21 d). At 120 d, EW and C offspring were subdivided into four groups: (1) C, received standard diet; (2) CCa, received Ca supplementation (10 g of calcium carbonate/kg of rat chow); (3) EW, received standard diet; (4) EWCa, received Ca supplementation similar to CCa. The rats were killed at 180 d. The significance level was at P < 0·05. Adult EW offspring displayed hyperphagia (28 %), higher body weight (9 %) and adiposity (77 %), hyperleptinaemia (twofold increase), hypertriacylglycerolaemia (64 %), hyperglycaemia (16 %), higher insulin resistance index (38 %) and higher serum 25-hydroxyvitamin D₃ (fourfold increase), but lower adiponectinaemia:adipose tissue ratio (44 %). In addition, they showed Janus tyrosine kinase 2 and phosphorylated signal transducer and activator of transcription 3 underexpression in hypothalamus (36 and 34 %, respectively), suggesting leptin resistance. Supplementation of Ca for 2 months normalised these disorders. The EW group had no change in serum insulin, thyroxine or triiodothyronine, and Ca treatment did not alter these hormones. In conclusion, we reinforced that early weaning leads to late development of some components of the metabolic syndrome and leptin resistance. Dietary Ca supplementation seems to protect against the development of endocrine and metabolic disorders in EW offspring, maybe through vitamin D inhibition.

  12. The effects of biological sex and gonadal hormones on learning strategy in adult rats.

    PubMed

    Hawley, Wayne R; Grissom, Elin M; Barratt, Harriet E; Conrad, Taylor S; Dohanich, Gary P

    2012-02-28

    When learning to navigate toward a goal in a spatial environment, rodents employ distinct learning strategies that are governed by specific regions of the brain. In the early stages of learning, adult male rats prefer a hippocampus-dependent place strategy over a striatum-dependent response strategy. Alternatively, female rats exhibit a preference for a place strategy only when circulating levels of estradiol are elevated. Notably, male rodents typically perform better than females on a variety of spatial learning tasks, which are mediated by the hippocampus. However, limited research has been done to determine if the previously reported male spatial advantage corresponds with a greater reliance on a place strategy, and, if the male preference for a place strategy is impacted by removal of testicular hormones. A dual-solution water T-maze task, which can be solved by adopting either a place or a response strategy, was employed to determine the effects of biological sex and hormonal status on learning strategy. In the first experiment, male rats made more correct arm choices than female rats during training and exhibited a bias for a place strategy on a probe trial. The results of the second experiment indicated that testicular hormones modulated arm choice accuracy during training, but not the preference for a place strategy. Together, these findings suggest that the previously reported male spatial advantage is associated with a greater reliance on a place strategy, and that only performance during the training phase of a dual-solution learning task is impacted by removal of testicular hormones.

  13. Do prenatally methamphetamine-exposed adult male rats display general predisposition to drug abuse in the conditioned place preference test?

    PubMed

    Šlamberová, R; Pometlová, M; Schutová, B; Hrubá, L; Macúchová, E; Nová, E; Rokyta, R

    2012-01-01

    Drug abuse of pregnant women is a growing problem. The effect of prenatal drug exposure may have devastating effect on development of the offsprings that may be long-term or even permanent. One of the most common drug abused by pregnant women is methamphetamine (MA), which is also the most frequently abused illicit drug in the Czech Republic. Our previous studies demonstrated that prenatal MA exposure alters behavior, cognition, pain and seizures in adult rats in sex-specific manner. Our most recent studies demonstrate that prenatal MA exposure makes adult rats more sensitive to acute injection of the same or related drugs than their controls. The aim of the present study was to examine the effect of prenatal MA exposure on drug-seeking behavior of adult male rats tested in the Conditioned place preference (CPP). Adult male rats were divided to: prenatally MA-exposed (5 mg/kg daily for the entire prenatal period), prenatally saline-exposed (1 ml/kg of physiological saline) and controls (without maternal injections). The following drugs were used in the CPP test in adulthood: MA (5 mg/kg), amphetamine (5 mg/kg), cocaine (5 and 10 mg/kg), morphine (5 mg/kg), MDMA (5 mg/kg) and THC (2 mg/kg). Our data demonstrated that prenatally MA-exposed rats displayed higher amphetamine-seeking behavior than both controls. MA as well as morphine induced drug-seeking behavior of adult male rats, however this effect did not differ based on the prenatal MA exposure. In contrast, prenatal MA exposure induced rather tolerance to cocaine than sensitization after the conditioning in the CPP. MDMA and THC did not induce significant effects. Even though the present data did not fully confirmed our hypotheses, future studies are planned to test the drug-seeking behavior also in self-administration test.

  14. The effects of perinatal tebuconazole exposure on adult neurological, immunological, and reproductive function in rats.

    PubMed

    Moser, V C; Barone, S; Smialowicz, R J; Harris, M W; Davis, B J; Overstreet, D; Mauney, M; Chapin, R E

    2001-08-01

    Studies are under way to address concerns of potential persistent immunotoxic, reproductive, and neurotoxic effects of perinatal exposure to several pesticides. Tebuconazole, a triazole fungicide, was evaluated as part of this project. Sprague-Dawley dams were administered tebuconazole (0, 6, 20, or 60 mg/kg) by oral gavage daily from gestational day 14 to postnatal day (PND)7; the pups were then dosed daily at the same levels from PND7-42. Separate groups of rats were used for testing of immunological parameters, neurobehavioral testing using a screening battery of functional tests, and cognitive evaluations. Other groups of rats were evaluated for reproductive development and function, while yet others were sacrificed at the end of the dosing period for histological analyses of major organs systems, including neuropathological assessments. Pup viability and body weight were decreased in the highest dose group. There were no differences in the fertility indices in the exposed rats mated as adults. In the sheep RBC-immunized high-dose rats, spleen weights and cellularity were increased, and the ratio of cell types was altered compared to controls. There were, however, no biologically significant changes in the immune function of these rats. At necropsy on PND46 or 152, kidney, liver, and spleen weights were altered by tebuconazole treatment, but a dose-response relationship was not clear for most organs; only decreased kidney and increased liver weights were consistent in both sexes. Histological analyses were generally unremarkable outside of the brain. One month after the end of dosing, acquisition of learning the platform location in a water tank (i.e., Morris water maze) was impaired in the high-dose group; there were no differences in neuromuscular ability, motor activity, or swim speed to account for this finding. Furthermore, there was no effect on recall of the position during a free-swim trial. Neuropathological evaluations revealed pyknotic cells across

  15. Age and Sex Differences in Reward Behavior in Adolescent and Adult Rats

    PubMed Central

    Hammerslag, Lindsey R.; Gulley, Joshua M.

    2016-01-01

    Compared to adults, adolescents are at heightened risk for drug abuse and dependence. One of the factors contributing to this vulnerability may be age-dependent differences in reward processing, with adolescents approaching reward through stimulus-directed, rather than goal-directed, processes. However, the empirical evidence for this in rodent models of adolescence, particularly those that investigate both sexes, is limited. To address this, male and female rats that were adolescents (P30) or adults (P98) at the start of the experiment were trained in a Pavlovian approach (PA) task and were subsequently tested for the effects of reward devaluation, extinction, and re-acquisition. We found significant interactions between age and sex: females had enhanced acquisition of PA and poorer extinction, relative to males, while adolescents and females were less sensitive to reward devaluation than male adults. These results suggest that females and adolescents exhibit reward behavior that is more stimulus-directed, rather than goal-directed. PMID:23754712

  16. Potent spinal parenchymal AAV9-mediated gene delivery by subpial injection in adult rats and pigs

    PubMed Central

    Miyanohara, Atsushi; Kamizato, Kota; Juhas, Stefan; Juhasova, Jana; Navarro, Michael; Marsala, Silvia; Lukacova, Nada; Hruska-Plochan, Marian; Curtis, Erik; Gabel, Brandon; Ciacci, Joseph; Ahrens, Eric T; Kaspar, Brian K; Cleveland, Don; Marsala, Martin

    2016-01-01

    Effective in vivo use of adeno-associated virus (AAV)-based vectors to achieve gene-specific silencing or upregulation in the central nervous system has been limited by the inability to provide more than limited deep parenchymal expression in adult animals using delivery routes with the most clinical relevance (intravenous or intrathecal). Here, we demonstrate that the spinal pia membrane represents the primary barrier limiting effective AAV9 penetration into the spinal parenchyma after intrathecal AAV9 delivery. We develop a novel subpial AAV9 delivery technique and AAV9-dextran formulation. We use these in adult rats and pigs to show (i) potent spinal parenchymal transgene expression in white and gray matter including neurons, glial and endothelial cells after single bolus subpial AAV9 delivery; (ii) delivery to almost all apparent descending motor axons throughout the length of the spinal cord after cervical or thoracic subpial AAV9 injection; (iii) potent retrograde transgene expression in brain motor centers (motor cortex and brain stem); and (iv) the relative safety of this approach by defining normal neurological function for up to 6 months after AAV9 delivery. Thus, subpial delivery of AAV9 enables gene-based therapies with a wide range of potential experimental and clinical utilizations in adult animals and human patients. PMID:27462649

  17. Effects of Neonatal Dexamethasone Exposure on Adult Neuropsychiatric Traits in Rats

    PubMed Central

    Robertson, Donald; Rodger, Jennifer; Martin-Iverson, Mathew T.

    2016-01-01

    The effects of early life stress in utero or in neonates has long-term consequences on hypothalamic-pituitary-adrenal (HPA) stress axis function and neurodevelopment. These effects extend into adulthood and may underpin a variety of mental illnesses and be related to various developmental and cognitive changes. We examined the potential role of neonatal HPA axis activation on adult psychopathology and dopamine sensitivity in the mature rat using neonatal exposure to the synthetic glucocorticoid receptor agonist and stress hormone, dexamethasone. We utilized a comprehensive battery of assessments for behaviour, brain function and gene expression to determine if elevated early life HPA activation is associated with adult-onset neuropsychiatric traits. Dexamethasone exposure increased startle reactivity under all conditions tested, but decreased sensitivity of sensorimotor gating to dopaminergic disruption–contrasting with what is observed in several neuropsychiatric diseases. Under certain conditions there also appeared to be mild long-term changes in stress and anxiety-related behaviours with neonatal dexamethasone exposure. Electrophysiology revealed that there were no consistent neuropsychiatric abnormalities in auditory processing or resting state brain function with dexamethasone exposure. However, neonatal dexamethasone altered auditory cortex glucocorticoid activation, and auditory cortex synchronization. Our results indicate that neonatal HPA axis activation by dexamethasone alters several aspects of adult brain function and behaviour and may induce long-term changes in emotional stress-reactivity. However, neonatal dexamethasone exposure is not specifically related to any particular neuropsychiatric disease. PMID:27936175

  18. Hippocampal adult neurogenesis is enhanced by chronic eszopiclone treatment in rats.

    PubMed

    Methippara, Melvi; Bashir, Tariq; Suntsova, Natalia; Szymusiak, Ron; McGinty, Dennis

    2010-09-01

    The adult hippocampal dentate gyrus (DG) exhibits cell proliferation and neurogenesis throughout life. We examined the effects of daily administration of eszopiclone (Esz), a commonly used hypnotic drug and gamma-aminobutyric acid (GABA) agonist, compared with vehicle, on DG cell proliferation and neurogenesis, and on sleep-wake patterns. Esz was administered during the usual sleep period of rats, to mimic typical use in humans. Esz treatment for 7 days did not affect the rate of cell proliferation, as measured by 5-bromo-2'-deoxyuridine (BrdU) immunostaining. However, twice-daily Esz administration for 2 weeks increased survival of newborn cells by 46%. Most surviving cells exhibited a neuronal phenotype, identified as BrdU-neuronal nuclei (NeuN) double-labeling. NeuN is a marker of neurons. Non-rapid eye movement sleep was increased on day 1, but not on days 7 or 14 of Esz administration. Delta electroencephalogram activity was increased on days 1 and 7 of treatment, but not on day 14. There is evidence that enhancement of DG neurogenesis is a critical component of the effects of antidepressant treatments of major depressive disorder (MDD). Adult-born DG cells are responsive to GABAergic stimulation, which promotes cell maturation. The present study suggests that Esz, presumably acting as a GABA agonist, has pro-neurogenic effects in the adult DG. This result is consistent with evidence that Esz enhances the antidepressant treatment response of patients with MDD with insomnia.

  19. Neonatal Androgen Exposure Causes Persistent Gut Microbiota Dysbiosis Related to Metabolic Disease in Adult Female Rats.

    PubMed

    Moreno-Indias, Isabel; Sánchez-Alcoholado, Lidia; Sánchez-Garrido, Miguel Ángel; Martín-Núñez, Gracia María; Pérez-Jiménez, Francisco; Tena-Sempere, Manuel; Tinahones, Francisco J; Queipo-Ortuño, María Isabel

    2016-12-01

    Alterations of gut microbiome have been proposed to play a role in metabolic disease, but the major determinants of microbiota composition remain ill defined. Nutritional and sex hormone challenges, especially during early development, have been shown to permanently alter adult female phenotype and contribute to metabolic disturbances. In this study, we implemented large-scale microbiome analyses to fecal samples from groups of female rats sequentially subjected to various obesogenic manipulations, including sex hormone perturbations by means of neonatal androgenization or adult ovariectomy (OVX), as a model of menopause, to establish whether these phenomena are related to changes in gut microbiota. Basic metabolic profiles concerning glucose/insulin homeostasis were also explored. The effects of the sex hormonal perturbations, either developmentally (androgenization) or in adulthood (OVX), clearly outshone the impact of nutritional interventions, especially concerning the gut microbiota profile. Notably, we observed a lower diversity in the androgenized group, with the highest Firmicutes to Bacteroidetes ratio, supporting the occurrence of durable alterations in gut microbiota composition, even in adulthood. Moreover, the elimination of adult ovarian secretions by OVX affected the richness of gut microbiota. Our data are the first to document the durable impact of sex steroid manipulations, and particularly early androgenization, on gut microbiota composition. Such dysbiosis is likely to contribute to the metabolic perturbations of conditions of obesity linked to gonadal dysfunction in the female.

  20. Embryonic amygdalar transplants in adult rats with motor cortex lesions: a molecular and electrophysiological analysis.

    PubMed

    Jiménez-Díaz, Lydia; Nava-Mesa, Mauricio O; Heredia, Margarita; Riolobos, Adelaida S; Gómez-Álvarez, Marcelo; Criado, José María; de la Fuente, Antonio; Yajeya, Javier; Navarro-López, Juan D

    2011-01-01

    Transplants of embryonic nervous tissue ameliorate motor deficits induced by motor cortex lesions in adult animals. Restoration of lost brain functions has been recently shown in grafts of homotopic cortical origin, to be associated with a functional integration of the transplant after development of reciprocal host-graft connections. Nevertheless little is known about physiological properties or gene expression profiles of cortical implants with functional restorative capacity but no cortical origin. In this study, we show molecular and electrophysiological evidence supporting the functional development and integration of heterotopic transplants of embryonic amygdalar tissue placed into pre-lesioned motor cortex of adult rats. Grafts were analyzed 3 months post-transplantation. Using reverse transcriptase quantitative polymerase chain reaction, we found that key glutamatergic, GABAergic, and muscarinic receptors transcripts were expressed at different quantitative levels both in grafted and host tissues, but were all continuously present in the graft. Parallel sharp electrode recordings of grafted neurons in brain slices showed a regular firing pattern of transplanted neurons similar to host amygdalar pyramidal neurons. Synaptic connections from the adjacent host cortex on grafted neurons were electrophysiologically investigated and confirmed our molecular results. Taken together, our findings indicate that grafted neurons from a non-cortical, non-motor-related, but ontogenetical similar source, not only received functionally effective contacts from the adjacent motor cortex, but also developed electrophysiological and gene expression patterns comparable to host pyramidal neurons; suggesting an interesting tool for the field of neural repair and donor tissue in adults.

  1. Parenteral magnesium load testing with /sup 28/Mg in weanling and young adult rats

    SciTech Connect

    Caddell, J.L.; Calhoun, N.R.; Howard, M.P.; Patterson, K.Y.; Smith, J.C. Jr.

    1981-06-01

    A sound diagnostic test for Mg deficiency is needed. This is a report of the parenteral Mg load test conducted in weanling and young adult rats fed a purified basal diet containing 3 mg magnesium/100 g with 150 mg of added magnesium/100 g (control) or 0 added magnesium (deficient). Weanlings were studied at about 1 week of dietary treatment and young adults at 2 weeks. The protocol included: a) a 6-hour preload urinary collection; b) an intraperitoneal load of 15 mg of magnesium/kg (weanlings) or 12 mg/kg (young adults) with 2 microCi 28Mg given simultaneously with each load; c) a 6-hour postload urinary collection; d) chemical analysis of selected tissues and urine for Mg; and e) 28Mg counting 6 and 24 hours postload. Controls all excreted large amounts of Mg pre- and postload, retaining less than 26% of nonradioactive loads. They had high urinary 28Mg counts. In Mg-deficient animals, the concentration of Mg in bone more than halved. These animals avidly conserved Mg and retained over 85% of nonradioactive Mg loads. Their 28Mg activity in vital organs was 3--6 times greater than in controls. We concluded that the parenteral Mg load test reliably identifies severe Mg deficiency.

  2. Antenatal Antioxidant Prevents Nicotine-Mediated Hypertensive Response in Rat Adult Offspring.

    PubMed

    Xiao, DaLiao; Huang, Xiaohui; Li, Yong; Dasgupta, Chiranjib; Wang, Lei; Zhang, Lubo

    2015-09-01

    Previous studies have demonstrated that perinatal nicotine exposure increased blood pressure (BP) in adult offspring. However, the underlying mechanisms were unclear. The present study tested the hypothesis that perinatal nicotine-induced programming of hypertensive response is mediated by enhanced reactive oxygen species (ROS) in the vasculature. Nicotine was administered to pregnant rats via subcutaneous osmotic mini-pumps from Day 4 of gestation to Day 10 after birth, in the absence or presence of the ROS inhibitor N-acetyl-cysteine (NAC) in the drinking water. Experiments were conducted in 8-mo-old male offspring. Perinatal nicotine treatment resulted in a significant increase in arterial ROS production in offspring, which was abrogated by NAC. Angiotensin II (Ang II)-induced BP responses were significantly higher in nicotine-treated group than in saline-treated control group, and NAC treatment blocked the nicotine-induced increase in BP response. Consistent with that, the nicotine treatment significantly increased both Ang II-induced and phorbol [12, 13]-dibutyrate (PDBu, a Prkc activator)-induced arterial contractions in adult offspring, which were blocked by NAC treatment. In addition, perinatal nicotine treatment significantly attenuated acetylcholine-induced arterial relaxation in offspring, which was also inhibited by NAC treatment. Results demonstrate that inhibition of ROS blocks the nicotine-induced increase in arterial reactivity and BP response to vasoconstrictors in adult offspring, suggesting a key role for increased oxidative stress in nicotine-induced developmental programming of hypertensive phenotype in male offspring.

  3. Adolescent nicotine exposure produces less affective measures of withdrawal relative to adult nicotine exposure in male rats

    PubMed Central

    O’Dell, Laura E.; Torres, Oscar V.; Natividad, Luis A.; Tejeda, Hugo A.

    2012-01-01

    Vulnerability to nicotine addiction is significantly increased in individuals who begin smoking during adolescence; however, the underlying mechanisms of this phenomenon remain unclear. This study examined the motivational effects of nicotine withdrawal in adolescent (PND 27–42) and adult (PND 60–75) rats using the conditioned place aversion paradigm. Male Wistar rats were tested for their initial preference for either of two distinct compartments of our conditioning apparatus. Rats were then implanted with subcutaneous (sc) pumps that produce equivalent blood plasma levels of nicotine for 14 days. Conditioning was conducted over the last 8 days of nicotine exposure. Rats received the nicotinic antagonist mecamylamine (1.5 or 3.0 mg/kg, sc) to precipitate withdrawal in their initially preferred compartment, and on alternate days they received saline in their non-preferred compartment. Following conditioning, rats were re-tested for their preference for each compartment. A subsequent study was conducted to examine potential developmental differences in learning place aversion produced by another aversive stimulus, lithium chloride (LiCl). Rats received LiCl (0, 10, 30, or 100 mg/kg, sc) in their initially preferred side using similar conditioning procedures. Adults displayed robust place aversion produced by nicotine withdrawal. This effect was lower in adolescent rats even in a group of young rats that received 7 additional days of nicotine exposure prior to conditioning. This developmental difference was specific to nicotine withdrawal since there were no differences between adolescents and adults in learning place aversion with LiCl. Our findings demonstrating reduced effects of nicotine withdrawal constitute a powerful basis for the increased vulnerability to nicotine dependence during adolescence. PMID:17184972

  4. Large moderately-differentiated ovarian Sertoli-Leydig cell tumor in a 13-year-old female: A case report

    PubMed Central

    ZHANG, HUI; HAO, JING; LI, CHUN-YAN; LI, TAO; MU, YU-LAN

    2016-01-01

    Sertoli-Leydig cell tumor of the ovary, also known as androblastoma, is a rare neoplasm from the group of sex cord-stromal tumors of the ovary. The tumor accounts for <0.5% of all primary ovarian neoplasms. The clinical signs and symptoms of Sertoli-Leydig cell tumors can be associated with either hormonal production or the presence of a mass-occupying lesion. In the current study, a 13-year-old female was diagnosed with a stage Ic ovarian Sertoli-Leydig cell tumor following abdominal pain and distension. One month after a right oophorectomy, the follow-up magnetic resonance imaging scan was negative for residual or recurrent tumor. The overall 5-year survival rate for moderately-differentiated (grade 2) and poorly-differentiated (grade 3) Sertoli-Leydig cell tumors is 80%, and long-term follow-up is therefore highly advised in this patient. PMID:26893701

  5. TGF-beta1 system in Leydig cells. Part II: TGF-beta1 and progesterone, through Smad1/5, are involved in the hyperplasia/hypertrophy of Leydig cells.

    PubMed

    Gonzalez, Candela R; Gonzalez, Betina; Rulli, Susana B; Dos Santos, Mara L; Mattos Jardim Costa, Guilherme; França, Luiz R; Calandra, Ricardo S; Gonzalez-Calvar, Silvia I

    2010-08-01

    Several reports indicate that transforming growth factor beta1 (TGF-beta1) participates in the regulation of cell cycle progression. In this work, we analyzed the in vitro effect of TGF-beta1 on Leydig cell proliferation markers and the in vivo effect of this cytokine in Leydig cell hyperplasia/hypertrophy. The in vitro effect of TGF-beta1 (1 ng/ml) plus progesterone (10(-6) M) on purified Leydig cells from 3 week-old mice increased the immunocytochem