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Sample records for cat carotid body

  1. Dual effects of nitric oxide on cat carotid body chemoreception.

    PubMed

    Iturriaga, R; Villanueva, S; Mosqueira, M

    2000-09-01

    We studied the effects of nitric oxide (NO) released by NO donors on cat carotid body (CB) chemosensory activity during normoxia and hypoxia. CBs excised from pentobarbital sodium-anaesthetized cats were perfused with Tyrode at 38 degrees C and pH 7.40. The frequency of chemosensory discharges (f(x)) was recorded from the carotid sinus nerve, and changes of NO concentration were measured by a chronoamperometric technique, with NO-selective carbon-fiber microelectrodes inserted in the CB. During steady chemosensory excitation induced by hypoxia, bolus injections of NO (DeltaNO = 0. 5-12 microM), released by S-nitroso-N-acetylpenicillamine (SNAP) and 6-(2-hydroxy-1-methyl-nitrosohydrazino)-N-methyl-1-hexanamine++ + (NOC-9), transiently reduced f(x) in a dose-dependent manner. However, during normoxia, the same concentration of NO (DeltaNO = 0. 5-13 microM) released by the NO donors increased f(x) in a dose-dependent manner. The present results show a dual effect of NO on CB chemoreception that is dependent on the PO(2) levels. During hypoxia, NO is predominantly an inhibitor of chemoreception, whereas, in normoxia, NO increased f(x). The mechanisms by which NO produces chemosensory excitation during normoxia remain to be determined. PMID:10956344

  2. Thermal effects on ventilation in cats: participation of carotid body chemoreceptors.

    PubMed

    Fadic, R; Larrain, C; Zapata, P

    1991-10-01

    In pentobarbitone anesthetized cats, raising body temperature from 37 to 40 degrees C by external heat increased respiratory frequency, tidal volume, frequency of spontaneous gasps and mean inspiratory flow. It reduced end-tidal CO2 pressure, together with inspiratory and expiratory durations. After bilateral section of the carotid nerves, raising body temperature still induced hyperventilation, but the increase in gasp frequency was less pronounced and no significant change in tidal volume was observed. In comparison to steady ventilatory values in the intact condition, significant reductions in tidal volume at 38 degrees C and in gasp frequency at 37, 39 and 40 degrees C were observed after bilateral carotid neurotomy. Brief hyperoxic tests induced transient decreases in tidal volume and increases in end-tidal CO2 pressure which were significantly larger at 40 degrees C than at 37 degrees C. These changes disappeared after bilateral carotid neurotomy. Anesthetic block of both carotid nerves produced transient reductions in tidal volume at any given temperature. We conclude that carotid body afferents contribute to the hyperventilation evoked by hyperthermia. After their interruption, such contribution is replaceable from other thermal afferents. PMID:1759053

  3. Effects of nitric oxide gas on cat carotid body chemosensory response to hypoxia.

    PubMed

    Iturriaga, R; Mosqueira, M; Villanueva, S

    2000-02-14

    It has been proposed that nitric oxide (NO) is an inhibitory modulator of carotid body (CB) chemoreception to hypoxia. However, the effects of NO gas on carotid chemoreception have not been tested yet. The role played by NO has been revealed by the use of pharmacological tools (i.e., NO donors and NO synthase inhibitors). Here, we studied the effects of NO gas (25 ppm in N(2)) on the chemosensory response to hypoxia (PO(2) approximately 30 Torr) in the cat CB perfused in vitro. During steady hypoxic chemoreceptor excitation, bolus injections or perfusion of Tyrode equilibrated with NO reduced the increased frequency of carotid chemosensory discharges (f(x)). Perfusion for 2 min of Tyrode equilibrated with NO also reduced the rate of the rise of the chemosensory response, as well as the maximal amplitude, as compared with the normal chemosensory response to hypoxia. Present results provide direct evidence that NO gas is an inhibitory modulator of CB hypoxic chemoreception. PMID:10677601

  4. Effects of cyanide and uncouplers on chemoreceptor activity and ATP content of the cat carotid body.

    PubMed

    Obeso, A; Almaraz, L; Gonzalez, C

    1989-03-01

    In cat carotid bodies (c.b.'s) incubated in vitro with [3H]tyrosine to label the stores of catecholamines, it was found that CN promotes dose- and Ca2+-dependent release of [3H]dopamine (DA) from c.b. tissues in parallel to the increased electrical activity recorded from the carotid sinus nerve (c.s.n.). Two different uncouplers, dinitrophenol (DNP) and carbonyl-cyanide-m-chlorophenyl-hydrazone (CCCP), both activate also in a dose-dependent fashion, release of DA and electrical activity in the c.s.n. However, while cyanide (CN) (10(-4) M) applied during 5 min reduced the adenosine triphosphate (ATP) content of the c.b. by 45%, DNP (2.5 x 10(-4) M) and CCCP (10(-6) M) applied for the same period of time did not modify the ATP levels of the organ. At the above concentrations, the 3 agents increased about 8-fold the electrical activity recorded from the c.s.n. Thus, contrary to the postulates of the metabolic hypotheses, our findings indicate that the decrease in the ATP content in the c.b. is not a prerequisite for the activation of the chemoreceptors. We propose alternative mechanisms to explain the chemostimulant action of the metabolic poisons. PMID:2720379

  5. Reflex carotid body chemoreceptor control of phrenic sympathetic neurons.

    PubMed

    Bałkowiec, A; Revenko, S; Szulczyk, P

    1993-04-01

    The reflex reaction of phrenic sympathetic neurons to stimulation of carotid body chemoreceptors was tested in chloralose-anesthetized and paralyzed cats with both vago-aortic nerves cut. During systemic hypoxia (animals ventilated with 10% O2 in N2) the sympathetic phrenic nerve activity increased from 100% in the control to 269%. This increase was markedly attenuated after cutting both sinus nerves. Reflex excitatory response in phrenic sympathetic neurons with the latency of 150 msec was evoked by electrical stimulation of the right carotid sinus nerve (3 pulses of 0.2 msec, 333 Hz). The central transmission time of the reflex was about 90 msec. Injecting 0.1 ml of 1 M NaHCO3 saturated with CO2 (in order to activate carotid body chemoreceptors) into the right or left carotid sinus, evoked excitatory responses in sympathetic neurons regardless of the side. The stimulation of carotid body chemoreceptors also increased somatic phrenic nerve activity. The three methods applied to the stimulation of carotid body chemoreceptors produced increase of phrenic nerve sympathetic activity. PMID:8390088

  6. Carotid body tumor: a 25-year experience.

    PubMed

    Metheetrairut, Choakchai; Chotikavanich, Chanticha; Keskool, Phawin; Suphaphongs, Nit

    2016-08-01

    Carotid body tumor is an uncommon hypervascular benign tumor in the head and neck region. It usually presents as a slow growing mass at the carotid bifurcation. Because of the high rate of neurovascular complications, resection of this tumor is considered challenging for otolaryngologists. Between 1988 and 2013, 40 carotid body tumors from 38 patients were diagnosed and underwent resection at Siriraj Hospital (25 female and 13 male patients). Their age ranged from 15 to 59 years. Seven patients had bilateral tumors simultaneously whereas six cases had familial history of carotid body tumor. Carotid angiography was performed in 29 cases; other additional diagnostic studies included CT scan, MRI, and MRA to detect the widening of carotid bifurcation, its extension, and multifocal tumors. All diagnosed tumors were successfully removed. However, internal carotid artery and carotid bifurcation were injured in 11 cases (27.5 %). Shamblin class III and previous biopsy history were considered risk factors for vascular injury. Postoperative cranial nerves deficit was found in 20 % of the cases and CNS complication occurred in two patients (5 %). There was no surgical mortality. Additionally, upon the mean follow-up period of 36 months, no recurrence or malignant transformation was detected in this study. Multidisciplinary approach, early tumor detection, meticulous preoperative evaluation, and modern vascular surgical technique are the key success factors for tumor removal. PMID:26233244

  7. Symptomatic carotid stenosis in the setting of bilateral disease and coexisting carotid body tumor: management with a carotid stent and staged excision.

    PubMed

    Smeds, Matthew; Jacobs, Donald

    2013-12-01

    The aim of the paper is to describe the management of a patient with bilateral carotid artery stenosis, symptomatic on the left, with coexisting left carotid body tumor with left carotid stenting followed by right carotid endarterectomy and excision of carotid body tumor. A 60-year-old man with significant bilateral carotid stenosis was referred to us with symptomatic left carotid disease and concomitant left carotid body tumor. A Precise nitinol carotid stent (Cordis Endovascular, Miami Lakes, FL, USA) was placed in his left carotid artery followed by interval carotid endarterectomy on the right. Excision of the carotid body tumor was then performed. Carotid stenting is a treatment option in patients with carotid stenosis and coexisting carotid body tumor. To our knowledge, this is the first reported carotid stent for symptomatic carotid stenosis in a patient with a concomitant carotid body tumor. PMID:23493283

  8. Role of. alpha. sub 2 -adrenergic receptors in the carotid body response to hypoxia

    SciTech Connect

    Kou, Y.R.; Ernsberger, P.; Cherniack, N.S.; Prabhakar, N.R. )

    1990-02-26

    Clonidine, which acts in part as an {alpha}{sub 2}-adrenergic receptor agonist, depresses ventilation. The authors examined the role of {alpha}{sub 2}-receptors in carotid chemoreceptor activity. The density of {alpha}{sub 2}-receptors was determined in membrane fractions of 18 cat carotid bodies using {sup 125}I-iodoclonidine with 0.1 mM epinephrine or 10 {mu}M SKF-86466 defining nonspecific binding. {alpha}{sub 2}-Adrenergic receptor density averaged 0.6{plus minus}0.1 fmol/carotid body (mean {plus minus} SEM) and was comparable to other sympathetic target tissues. The authors then studied the effects of an agonist (guanabenz) and an antagonist (SKF-86466; 6-Cl-N-methyl-2,3,4,5-tetrahydro-1-H3-benzazepine) specific for {alpha}{sub 2}-receptors on baseline and hypoxia-stimulated carotid body discharge, in 10 anesthetized, paralyzed and artificially ventilated cats. Intracarotid infusion of guanabenz for 5 minutes caused a dose-dependent depression of the baseline activity and reduced the chemoreceptor response to hypoxia by 88.0{plus minus}5.8% of the vehicle-injected controls. Intravenous administration of SKF-86466 reversed the effects of guanabenz on the carotid body activity. in contrast, chemoreceptor depression caused by dopamine was unaffected by SKF-86466. SKF-86466 alone increased baseline discharge and potentiated the chemoreceptor response to hypoxia by 34.0 {plus minus} 9.6% of the controls. These results demonstrate that {alpha}{sub 2}-adrenergic receptors are present in the cat carotid body and they exert an inhibitory influence on the chemoreceptor response to hypoxia.

  9. A preliminary anatomical study on carotid body of Makouei sheep

    PubMed Central

    Najafi, Gholamreza; Soltanalinejad, Farhad; Hasanzadeh, Hamed

    2013-01-01

    The carotid is a small mass of chemoreceptor's and sustentacular cells that detects changes in the composition of the arterial blood. The aim of the present study was to identify the size, color, location, blood and nerve supply of the carotid body in Makouei sheep. Fourteen heads of sheep from both sexes were collected from Urmia public slaughter-house. The exact situation and nerve supply of the carotid body was determined. Before dissection, blue latex was injected into right and left common carotid arteries. All the branches of the common carotid artery and the branch supplying carotid body were investigated. This study showed that, carotid body in sheep has been situated around the muscular branch of the occipital artery. The mean weight, width and length, thickness of carotid body were 0.01 g, 0.83 mm, 1.07 mm, and 1.06 mm respectively. Blood to the carotid body was supplied by glomic artery which was a branch of occipital artery. It was innervated by herring nerve which was a branch of glossopharyngeal nerve. PMID:25653785

  10. A preliminary anatomical study on carotid body of Makouei sheep.

    PubMed

    Najafi, Gholamreza; Soltanalinejad, Farhad; Hasanzadeh, Hamed

    2013-01-01

    The carotid is a small mass of chemoreceptor's and sustentacular cells that detects changes in the composition of the arterial blood. The aim of the present study was to identify the size, color, location, blood and nerve supply of the carotid body in Makouei sheep. Fourteen heads of sheep from both sexes were collected from Urmia public slaughter-house. The exact situation and nerve supply of the carotid body was determined. Before dissection, blue latex was injected into right and left common carotid arteries. All the branches of the common carotid artery and the branch supplying carotid body were investigated. This study showed that, carotid body in sheep has been situated around the muscular branch of the occipital artery. The mean weight, width and length, thickness of carotid body were 0.01 g, 0.83 mm, 1.07 mm, and 1.06 mm respectively. Blood to the carotid body was supplied by glomic artery which was a branch of occipital artery. It was innervated by herring nerve which was a branch of glossopharyngeal nerve. PMID:25653785

  11. Radiation therapy of carotid body tumors

    SciTech Connect

    Valdagni, R.; Amichetti, M. )

    1990-02-01

    Chemodectomas of carotid artery bifurcation are generally managed with surgery, irradiation being reserved for inoperable, bulky, and recurrent tumors. Probably due to this pretreatment selection of patients, chemodectomas are anedoctally considered radioresistant tumors, although this concept is not supported by the recent literature. From 1968 to 1987, 13 carotid body tumors in seven patients were treated with irradiation as sole treatment (10 lesions) or as postoperative modality (three lesions). Familial occurrence and bilateral presentation were observed in 3 of 7 and in 6 of 7 patients, respectively. Total dose of irradiation was of 46-60 Gy (median 50 Gy, mean 52.25 Gy) with dose per fraction of 1.8-2.5 Gy. Local control (subjective or objective) was obtained in all the patients. Clinical results following World Health Organization (WHO) criteria were: 3 of 13 complete response, 7 of 13 partial response and 3 of 13 no change. Follow-up range is 1-19 years. Acute side effects were minimal and mid- or long-term toxicity was absent.32 references.

  12. Peripheral Chemoreceptors: Function and Plasticity of the Carotid Body

    PubMed Central

    Kumar, Prem; Prabhakar, Nanduri R.

    2014-01-01

    The discovery of the sensory nature of the carotid body dates back to the beginning of the 20th century. Following these seminal discoveries, research into carotid body mechanisms moved forward progressively through the 20th century, with many descriptions of the ultrastructure of the organ and stimulus-response measurements at the level of the whole organ. The later part of 20th century witnessed the first descriptions of the cellular responses and electrophysiology of isolated and cultured type I and type II cells, and there now exist a number of testable hypotheses of chemotransduction. The goal of this article is to provide a comprehensive review of current concepts on sensory transduction and transmission of the hypoxic stimulus at the carotid body with an emphasis on integrating cellular mechanisms with the whole organ responses and highlighting the gaps or discrepancies in our knowledge. It is increasingly evident that in addition to hypoxia, the carotid body responds to a wide variety of blood-borne stimuli, including reduced glucose and immune-related cytokines and we therefore also consider the evidence for a polymodal function of the carotid body and its implications. It is clear that the sensory function of the carotid body exhibits considerable plasticity in response to the chronic perturbations in environmental O2 that is associated with many physiological and pathological conditions. The mechanisms and consequences of carotid body plasticity in health and disease are discussed in the final sections of this article. PMID:23728973

  13. Carotid body tumor imitator: An interesting case of Castleman's disease

    PubMed Central

    Shakir, Hakeem J.; Diletti, Sara M.; Hart, Alexandra M.; Meyers, Joshua E.; Dumont, Travis M.; Siddiqui, Adnan H.

    2015-01-01

    Background: There are very few reports in the literature of Castleman's disease affecting the carotid artery and a single previous report of a case of Castleman's disease of the neck originally mistaken as a carotid body tumor. Case Description: We describe a rare case of Castleman's disease, manifesting with classic radiographic hallmarks of a carotid body tumor. The postoperative pathologic examination identified the resected mass as Castleman's lymphadenopathy. The management of this particular case is discussed, and the findings are highlighted. Conclusions: We present a unique case of a tumor initially and incorrectly diagnosed as a carotid body tumor. However, after comprehensive treatment with endovascular and surgical modalities and subsequent pathologic examination, the diagnosis of this rare entity was made. PMID:26677415

  14. Surgical Excision of Carotid Body Tumor Through Modified Approach-A Case Report.

    PubMed

    Prabakaran, Sureshkannan; Subburayulu, Anand Shankar; Ravikumar, P T

    2016-06-01

    Paragangliomas arising from the carotid body in the carotid bifurcation are termed as carotid body tumors. They are usually slow growing and asymptomatic. Considering the anatomical location, invasion or pressure on the adjacent vascular and neural tissues, the importance of early diagnosis and management is critical. In this article a case of carotid body tumor excised through transverse neck skin crease incision is presented along with literature review on the diagnosis, grading and different surgical approaches. PMID:27298550

  15. Carotid body denervation prevents fasting hyperglycemia during chronic intermittent hypoxia

    PubMed Central

    Shin, Mi-Kyung; Yao, Qiaoling; Jun, Jonathan C.; Bevans-Fonti, Shannon; Yoo, Doo-Young; Han, Woobum; Mesarwi, Omar; Richardson, Ria; Fu, Ya-Yuan; Pasricha, Pankaj J.; Schwartz, Alan R.; Shirahata, Machiko

    2014-01-01

    Obstructive sleep apnea causes chronic intermittent hypoxia (IH) and is associated with impaired glucose metabolism, but mechanisms are unknown. Carotid bodies orchestrate physiological responses to hypoxemia by activating the sympathetic nervous system. Therefore, we hypothesized that carotid body denervation would abolish glucose intolerance and insulin resistance induced by chronic IH. Male C57BL/6J mice underwent carotid sinus nerve dissection (CSND) or sham surgery and then were exposed to IH or intermittent air (IA) for 4 or 6 wk. Hypoxia was administered by decreasing a fraction of inspired oxygen from 20.9% to 6.5% once per minute, during the 12-h light phase (9 a.m.–9 p.m.). As expected, denervated mice exhibited blunted hypoxic ventilatory responses. In sham-operated mice, IH increased fasting blood glucose, baseline hepatic glucose output (HGO), and expression of a rate-liming hepatic enzyme of gluconeogenesis phosphoenolpyruvate carboxykinase (PEPCK), whereas the whole body glucose flux during hyperinsulinemic euglycemic clamp was not changed. IH did not affect glucose tolerance after adjustment for fasting hyperglycemia in the intraperitoneal glucose tolerance test. CSND prevented IH-induced fasting hyperglycemia and increases in baseline HGO and liver PEPCK expression. CSND trended to augment the insulin-stimulated glucose flux and enhanced liver Akt phosphorylation at both hypoxic and normoxic conditions. IH increased serum epinephrine levels and liver sympathetic innervation, and both increases were abolished by CSND. We conclude that chronic IH induces fasting hyperglycemia increasing baseline HGO via the CSN sympathetic output from carotid body chemoreceptors, but does not significantly impair whole body insulin sensitivity. PMID:25103977

  16. Carotid body denervation prevents fasting hyperglycemia during chronic intermittent hypoxia.

    PubMed

    Shin, Mi-Kyung; Yao, Qiaoling; Jun, Jonathan C; Bevans-Fonti, Shannon; Yoo, Doo-Young; Han, Woobum; Mesarwi, Omar; Richardson, Ria; Fu, Ya-Yuan; Pasricha, Pankaj J; Schwartz, Alan R; Shirahata, Machiko; Polotsky, Vsevolod Y

    2014-10-01

    Obstructive sleep apnea causes chronic intermittent hypoxia (IH) and is associated with impaired glucose metabolism, but mechanisms are unknown. Carotid bodies orchestrate physiological responses to hypoxemia by activating the sympathetic nervous system. Therefore, we hypothesized that carotid body denervation would abolish glucose intolerance and insulin resistance induced by chronic IH. Male C57BL/6J mice underwent carotid sinus nerve dissection (CSND) or sham surgery and then were exposed to IH or intermittent air (IA) for 4 or 6 wk. Hypoxia was administered by decreasing a fraction of inspired oxygen from 20.9% to 6.5% once per minute, during the 12-h light phase (9 a.m.-9 p.m.). As expected, denervated mice exhibited blunted hypoxic ventilatory responses. In sham-operated mice, IH increased fasting blood glucose, baseline hepatic glucose output (HGO), and expression of a rate-liming hepatic enzyme of gluconeogenesis phosphoenolpyruvate carboxykinase (PEPCK), whereas the whole body glucose flux during hyperinsulinemic euglycemic clamp was not changed. IH did not affect glucose tolerance after adjustment for fasting hyperglycemia in the intraperitoneal glucose tolerance test. CSND prevented IH-induced fasting hyperglycemia and increases in baseline HGO and liver PEPCK expression. CSND trended to augment the insulin-stimulated glucose flux and enhanced liver Akt phosphorylation at both hypoxic and normoxic conditions. IH increased serum epinephrine levels and liver sympathetic innervation, and both increases were abolished by CSND. We conclude that chronic IH induces fasting hyperglycemia increasing baseline HGO via the CSN sympathetic output from carotid body chemoreceptors, but does not significantly impair whole body insulin sensitivity. PMID:25103977

  17. Inhibitory effects of NO on carotid body: contribution of neural and endothelial nitric oxide synthase isoforms.

    PubMed

    Valdés, Viviana; Mosqueira, Matías; Rey, Sergio; Del Rio, Rodrigo; Iturriaga, Rodrigo

    2003-01-01

    We tested the hypothesis that nitric oxide (NO) produced within the carotid body is a tonic inhibitor of chemoreception and determined the contribution of neuronal and endothelial nitric oxide synthase (eNOS) isoforms to the inhibitory NO effect. Accordingly, we studied the effect of NO generated from S-nitroso-N-acetylpenicillamide (SNAP) and compared the effects of the nonselective inhibitor N(omega)-nitro-l-arginine methyl ester (l-NAME) and the selective nNOS inhibitor 1-(2-trifluoromethylphenyl)-imidazole (TRIM) on chemosensory dose-response curves induced by nicotine and NaCN and responses to hypoxia (Po(2) approximately 30 Torr). CBs excised from pentobarbitone-anesthetized cats were perfused in vitro with Tyrode at 38 degrees C and pH 7.40, and chemosensory discharges were recorded from the carotid sinus nerve. SNAP (100 microM) reduced the responses to nicotine and NaCN. l-NAME (1 mM) enhanced the responses to nicotine and NaCN by increasing their duration, but TRIM (100 microM) only enhanced the responses to high doses of NaCN. The amplitude of the response to hypoxia was enhanced by l-NAME but not by TRIM. Our results suggest that both isoforms contribute to the NO action, but eNOS being the main source for NO in the cat CB and exerting a tonic effect upon chemoreceptor activity. PMID:12388352

  18. Surgical complications of carotid body tumors surgery: a review.

    PubMed

    Amato, B; Serra, R; Fappiano, F; Rossi, R; Danzi, M; Milone, M; Quarto, G; Benassai, G; Bianco, T; Amato, M; Furino, E; Compagna, R

    2015-12-01

    Carotid body tumor (CBT) is a rare neoplasm, although it represents about 65% of head and neck paragangliomas. Surgical excision is considered the appropriate therapy for CBTs. The aim of this study was to evaluate surgical outcomes on a large scale. We reviewed 19 studies between 2004 to 2014 with a total of 625 procedures. We observed a higher number of cases in women (62%). Only 3 (0,48%) deaths were reported as surgical complication. Total cranial nerve injuries were 302 (48,32%) of which 194 (31,04%) were transient and 108 (17,28%) were permanent. We found a total of 174 (27,84%) arterial injuries, most of which are external carotid artery (ECA) injuries. Cerebrovascular accident due to surgery were 15 (2,4%). We concluded that surgical resection remains the treatment of choice for these disease despite the related morbidity. PMID:26498887

  19. Carotid body chemoreceptors, sympathetic neural activation, and cardiometabolic disease.

    PubMed

    Iturriaga, Rodrigo; Del Rio, Rodrigo; Idiaquez, Juan; Somers, Virend K

    2016-01-01

    The carotid body (CB) is the main peripheral chemoreceptor that senses the arterial PO2, PCO2 and pH. In response to hypoxemia, hypercapnia and acidosis, carotid chemosensory discharge elicits reflex respiratory, autonomic and cardiovascular adjustments. The classical construct considers the CB as the main peripheral oxygen sensor, triggering reflex physiological responses to acute hypoxemia and facilitating the ventilatory acclimation to chronic hypoxemia at high altitude. However, a growing body of experimental evidence supports the novel concept that an abnormally enhanced CB chemosensory input to the brainstem contributes to overactivation of the sympathetic nervous system, and consequent pathology. Indeed, the CB has been implicated in several diseases associated with increases in central sympathetic outflow. These include hypertension, heart failure, sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome. Indeed, ablation of the CB has been proposed for the treatment of severe and resistant hypertension in humans. In this review, we will analyze and discuss new evidence supporting an important role for the CB chemoreceptor in the progression of autonomic and cardiorespiratory alterations induced by heart failure, obstructive sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome. PMID:26920146

  20. Carotid body chemosensory excitation induced by nitric oxide: involvement of oxidative metabolism.

    PubMed

    Mosqueira, Matias; Iturriaga, Rodrigo

    2002-08-01

    Nitric oxide (NO) produces a dual effect on carotid body (CB) oxygen chemoreception. At low concentration, NO inhibits chemosensory response to hypoxia, while in normoxia, medium and high [NO] increases the frequency of carotid chemosensory discharges (f(x)). Since NO and peroxynitrite inhibit mitochondrial respiration, it is plausible that the NO-induced excitation may depend on the mitochondrial oxidative metabolism. To test this hypothesis, we studied the effects of oligomycin, FCCP and antimycin A that produce selective blockade of hypoxic and NaCN-induced chemosensory responses, leaving nicotinic response less affected. CBs excised from pentobarbitone-anaesthetised cats were perfused in vitro with Tyrode (P(O(2)) approximately 125 Torr, pH 7.40 at 38 degrees C). Hypoxia (P(O(2)) approximately equal 30 Torr), NaCN and nicotine (1-100 microg) and S-nitroso-N-acetylpenicillamide (SNAP, 300-600 microg) increased f(x). Oligomycin (12.5-25 microg), antimycin A (10 microg) and FCCP (5 microM) transiently increased f(x). Subsequently, chemosensory responses to hypoxia, NaCN and SNAP were reduced or abolished, while the response to nicotine was less affected. The electron donor system tetramethyl-p-phenylene diamide and ascorbate that bypasses the electron chain blockade produced by antimycin A, restores the excitatory responses to NaCN and SNAP. Present results suggest that the chemoexcitatory effect of NO depends on the integrity of mitochondrial metabolism. PMID:12126919

  1. Regulation of carotid body oxygen sensing by hypoxia-inducible factors.

    PubMed

    Prabhakar, Nanduri R; Semenza, Gregg L

    2016-01-01

    Oxygen (O2) sensing by the carotid body and its chemosensory reflex is critical for homeostatic regulation of breathing and blood pressure. Carotid body responses to hypoxia are not uniform but instead exhibit remarkable inter-individual variations. The molecular mechanisms underlying variations in carotid body O2 sensing are not known. Hypoxia-inducible factor-1 (HIF-1) and HIF-2 mediate transcriptional responses to hypoxia. This article reviews the emerging evidence that proper expression of the HIF-α isoforms is a key molecular determinant for carotid body O2 sensing. HIF-1α deficiency leads to a blunted carotid body hypoxic response, which is due to increased abundance of HIF-2α, elevated anti-oxidant enzyme activity, and a reduced intracellular redox state. Conversely, HIF-2α deficiency results in augmented carotid body sensitivity to hypoxia, which is due to increased abundance of HIF-1α, elevated pro-oxidant enzyme activity, and an oxidized intracellular redox state. Double heterozygous mice with equally reduced HIF-1α and HIF-2α showed no abnormality in redox state or carotid body O2 sensing. Thus, mutual antagonism between HIF-α isoforms determines the redox state and thereby establishes the set point for hypoxic sensing by the carotid body. PMID:26265380

  2. Revelations about carotid body function through its pathological role in resistant hypertension.

    PubMed

    Paton, Julian F R; Ratcliffe, Laura; Hering, Dagmara; Wolf, Jacek; Sobotka, Paul A; Narkiewicz, Krzysztof

    2013-08-01

    Much recent attention has been given to the carotid body because of its potential role in cardiovascular disease states. One disease, neurogenic hypertension, characterised by excessive sympathetic activity, appears dependent on carotid body activity that may or may not be accompanied by sleep-disordered breathing. Herein, we review recent literature suggesting that the carotid body acquires tonicity in hypertension. We predict that carotid glomectomy will be a powerful way to temper excessive sympathetic discharge in diseases such as hypertension. We propose a model to explain that signalling from the 'hypertensive' carotid body is tonic, and hypothesise that there will be a sub-population of glomus cells that channel separately into reflex pathways controlling sympathetic motor outflows. PMID:23828147

  3. Cerebral foreign body reaction after carotid aneurysm stenting.

    PubMed

    Lorentzen, Anastasia Orlova; Nome, Terje; Bakke, Søren Jacob; Scheie, David; Stenset, Vidar; Aamodt, Anne Hege

    2016-02-01

    Flow diverter stents are new important tools in the treatment of large, giant, or wide-necked aneurysms. Their delivery and positioning may be difficult due to vessel tortuosity. Common adverse events include intracranial hemorrhage and ischemic stroke, which usually occurs within the same day, or the next few days after the procedure. We present a case where we encountered an unusual intracerebral complication several months after endovascular treatment of a large left internal carotid artery aneurysm, and where brain biopsy revealed foreign body reaction to hydrophilic polymer fragments distally to the stent site. Although previously described, embolization of polymer material from intravascular equipment is rare. We could not identify any other biopsy verified case in the literature, with this particular presentation of intracerebral polymer embolization--a multifocal inflammation spread out through the white matter of one hemisphere without hemorrhage or ischemic changes. PMID:26510943

  4. Carotid body, insulin, and metabolic diseases: unraveling the links.

    PubMed

    Conde, Sílvia V; Sacramento, Joana F; Guarino, Maria P; Gonzalez, Constancio; Obeso, Ana; Diogo, Lucilia N; Monteiro, Emilia C; Ribeiro, Maria J

    2014-01-01

    The carotid bodies (CB) are peripheral chemoreceptors that sense changes in arterial blood O2, CO2, and pH levels. Hypoxia, hypercapnia, and acidosis activate the CB, which respond by increasing the action potential frequency in their sensory nerve, the carotid sinus nerve (CSN). CSN activity is integrated in the brain stem to induce a panoply of cardiorespiratory reflexes aimed, primarily, to normalize the altered blood gases, via hyperventilation, and to regulate blood pressure and cardiac performance, via sympathetic nervous system (SNS) activation. Besides its role in the cardiorespiratory control the CB has been proposed as a metabolic sensor implicated in the control of energy homeostasis and, more recently, in the regulation of whole body insulin sensitivity. Hypercaloric diets cause CB overactivation in rats, which seems to be at the origin of the development of insulin resistance and hypertension, core features of metabolic syndrome and type 2 diabetes. Consistent with this notion, CB sensory denervation prevents metabolic and hemodynamic alterations in hypercaloric feed animal. Obstructive sleep apnea (OSA) is another chronic disorder characterized by increased CB activity and intimately related with several metabolic and cardiovascular abnormalities. In this manuscript we review in a concise manner the putative pathways linking CB chemoreceptors deregulation with the pathogenesis of insulin resistance and arterial hypertension. Also, the link between chronic intermittent hypoxia (CIH) and insulin resistance is discussed. Then, a final section is devoted to debate strategies to reduce CB activity and its use for prevention and therapeutics of metabolic diseases with an emphasis on new exciting research in the modulation of bioelectronic signals, likely to be central in the future. PMID:25400585

  5. Carotid body, insulin, and metabolic diseases: unraveling the links

    PubMed Central

    Conde, Sílvia V.; Sacramento, Joana F.; Guarino, Maria P.; Gonzalez, Constancio; Obeso, Ana; Diogo, Lucilia N.; Monteiro, Emilia C.; Ribeiro, Maria J.

    2014-01-01

    The carotid bodies (CB) are peripheral chemoreceptors that sense changes in arterial blood O2, CO2, and pH levels. Hypoxia, hypercapnia, and acidosis activate the CB, which respond by increasing the action potential frequency in their sensory nerve, the carotid sinus nerve (CSN). CSN activity is integrated in the brain stem to induce a panoply of cardiorespiratory reflexes aimed, primarily, to normalize the altered blood gases, via hyperventilation, and to regulate blood pressure and cardiac performance, via sympathetic nervous system (SNS) activation. Besides its role in the cardiorespiratory control the CB has been proposed as a metabolic sensor implicated in the control of energy homeostasis and, more recently, in the regulation of whole body insulin sensitivity. Hypercaloric diets cause CB overactivation in rats, which seems to be at the origin of the development of insulin resistance and hypertension, core features of metabolic syndrome and type 2 diabetes. Consistent with this notion, CB sensory denervation prevents metabolic and hemodynamic alterations in hypercaloric feed animal. Obstructive sleep apnea (OSA) is another chronic disorder characterized by increased CB activity and intimately related with several metabolic and cardiovascular abnormalities. In this manuscript we review in a concise manner the putative pathways linking CB chemoreceptors deregulation with the pathogenesis of insulin resistance and arterial hypertension. Also, the link between chronic intermittent hypoxia (CIH) and insulin resistance is discussed. Then, a final section is devoted to debate strategies to reduce CB activity and its use for prevention and therapeutics of metabolic diseases with an emphasis on new exciting research in the modulation of bioelectronic signals, likely to be central in the future. PMID:25400585

  6. Regulation of tyrosine hydroxylase gene expression in the rat carotid body by hypoxia.

    PubMed

    Czyzyk-Krzeska, M F; Bayliss, D A; Lawson, E E; Millhorn, D E

    1992-04-01

    The activity (Vmax) of tyrosine hydroxylase (TH; EC 1.14.16.2), the rate limiting enzyme in the synthesis of catecholamines, is increased in carotid body, superior cervical ganglion, and the adrenal medulla during hypoxia (i.e., reduced PaO2). The present study was undertaken to determine if the increase in TH activity in these tissues during hypoxia is regulated at the level of TH mRNA. Adult rats were exposed to hypoxia (10% O2) or room air for periods lasting from 1 to 48 h. The carotid bodies, superior cervical ganglia, and adrenals were removed and processed for in situ hybridization using 35S-labeled oligonucleotide probes. The concentration of TH mRNA was increased by hypoxia at all time points in carotid body type I cells, but not in cells of either superior cervical ganglion or adrenal medulla. The increase in TH mRNA in carotid body during hypoxia did not require innervation of the carotid body or intact adrenal glands. In addition, hypercapnia, another physiological stimulus of carotid body activity, failed to induce an increase in TH mRNA in type I cells. Our findings suggest that hypoxia stimulates TH gene expression in the carotid body by a mechanism that is intrinsic to type I cells. PMID:1347783

  7. Angiotensin AT1 receptor-mediated excitation of rat carotid body chemoreceptor afferent activity.

    PubMed

    Allen, A M

    1998-08-01

    1. A high density of angiotensin II receptors was observed in the rat carotid body by in vitro autoradiography employing 125I-[Sar1, Ile8]-angiotensin II as radioligand. Displacement studies demonstrated that the receptors were of the AT1 subtype. 2. The binding pattern indicated that the AT1 receptors occurred over clumps of glomus cells, the principal chemoreceptor cell of the carotid body. Selective lesions of the sympathetic or afferent innervation of the carotid body had little effect on the density of receptor binding, demonstrating that the majority of AT1 receptors were intrinsic to the glomus cells. 3. To determine the direct effect of angiotensin II on chemoreceptor function, without the confounding effects of the vasoconstrictor action of angiotensin II, carotid sinus nerve activity was recorded from the isolated carotid body in vitro. The carotid body was superfused with Tyrode solution saturated with carbogen (95 % O2, 5 % CO2), maintained at 36 C, and multi-unit nerve activity recorded with a suction electrode. 4. Angiotensin II elicited a dose-dependent excitation of carotid sinus nerve activity (maximum increase of 36 +/- 11 % with 10 nM angiotensin II) with a threshold concentration of 1 nM. The response was blocked by the addition of an AT1 receptor antagonist, losartan (1 microM), but not by the addition of an AT2 receptor antagonist, PD123319 (1 microM). 5. In approximately 50 % of experiments the excitation was preceded by an inhibition of activity (maximum decrease of 24 +/- 8 % with 10 nM angiotensin II). This inhibitory response was markedly attenuated by losartan but not affected by PD123319. 6. These observations demonstrate that angiotensin II, acting through AT1 receptors located on glomus cells in the carotid body, can directly alter carotid chemoreceptor afferent activity. This provides a means whereby humoral information about fluid and electrolyte homeostasis might influence control of cardiorespiratory function. PMID:9660892

  8. Angiotensin AT1 receptor-mediated excitation of rat carotid body chemoreceptor afferent activity

    PubMed Central

    Allen, A M

    1998-01-01

    A high density of angiotensin II receptors was observed in the rat carotid body by in vitro autoradiography employing 125I-[Sar1,Ile8]-angiotensin II as radioligand. Displacement studies demonstrated that the receptors were of the AT1 subtype.The binding pattern indicated that the AT1 receptors occurred over clumps of glomus cells, the principal chemoreceptor cell of the carotid body. Selective lesions of the sympathetic or afferent innervation of the carotid body had little effect on the density of receptor binding, demonstrating that the majority of AT1 receptors were intrinsic to the glomus cells.To determine the direct effect of angiotensin II on chemoreceptor function, without the confounding effects of the vasoconstrictor action of angiotensin II, carotid sinus nerve activity was recorded from the isolated carotid body in vitro. The carotid body was superfused with Tyrode solution saturated with carbogen (95% O2, 5% CO2), maintained at 36 °C, and multi-unit nerve activity recorded with a suction electrode.Angiotensin II elicited a dose-dependent excitation of carotid sinus nerve activity (maximum increase of 36 ± 11% with 10 nm angiotensin II) with a threshold concentration of 1 nm. The response was blocked by the addition of an AT1 receptor antagonist, losartan (1 μm), but not by the addition of an AT2 receptor antagonist, PD123319 (1 μm).In approximately 50% of experiments the excitation was preceded by an inhibition of activity (maximum decrease of 24 ± 8% with 10 nm angiotensin II). This inhibitory response was markedly attenuated by losartan but not affected by PD123319.These observations demonstrate that angiotensin II, acting through AT1 receptors located on glomus cells in the carotid body, can directly alter carotid chemoreceptor afferent activity. This provides a means whereby humoral information about fluid and electrolyte homeostasis might influence control of cardiorespiratory function. PMID:9660892

  9. Autoradiographic localization of alpha-bungarotoxin-binding sites in the carotid body of the rat.

    PubMed

    Chen, I; Mascorro, J A; Yates, R D

    1981-01-01

    Radioiodinated alpha-bungarotoxin (alpha-Bgt) was used to localize alpha-Bgt-acetylcholine receptors in the carotid body of the rat. The gamma spectrometer analyses indicated a high uptake of [125I] alpha-Bgt in carotid bodies incubated in vitro (1.51 fmole per organ). Incorporation of the isotope was effectively blocked by pretreatment of carotid bodies with d-tubocurarine and unlabeled alpha-Bgt, but not by atropine. Light microscopic autoradiography showed a heavy labeling of some parenchymal cells. Electron-microscopic autoradiography revealed that labeling was localized along the interface between parenchymal cells, especially where their cytoplasmic processes engage in complex interdigitations. The silver grain counts on electron-microscopic autoradiographs suggest that labelings are preferentially associated with the plasma membrane of certain Type I cells. It is suggested that these Type I cells in the rat's carotid body probably are provided with nicotinic acetylcholine receptors on their plasma membranes. PMID:7273116

  10. Magnetic resonance and computed tomography imaging of a carotid body tumor in a dog

    PubMed Central

    2012-01-01

    A 5-year-old castrated male Labrador Retriever was presented to a referring veterinarian for a swelling in the neck region. Based on the results of histopathology, a carotid body tumor, was diagnosed. The dog was referred to a medical imaging unit for further staging and follow up. This report describes the magnetic resonance (MR) and computed tomographic (CT) appearance of a carotid body tumor. PMID:22507757

  11. The Carotid Body and Arousal in the Fetus and Neonate

    PubMed Central

    2012-01-01

    Arousal from sleep is a major defense mechanism in infants against hypoxia and/or hypercapnia. Arousal failure may be an important contributor to SIDS. Areas of the brainstem that have been found to be abnormal in a majority of SIDS infants are involved in the arousal process. Arousal is sleep state dependent, being depressed during AS in most mammals, but depressed during QS in human infants. Repeated exposure to hypoxia causes a progressive blunting of arousal that may involve medullary raphe GABAergic mechanisms. Whereas CB chemoreceptors contribute heavily to arousal in response to hypoxia, serotonergic central chemoreceptors have been implicated in the arousal response to CO2. Pulmonary or chest wall mechanoreceptors also contribute to arousal in proportion to the ventilatory response and decreases in their input may contribute to depressed arousal during AS. Little is known about specific arousal pathways beyond the NTS. Whether CB chemoreceptor stimulation directly stimulates arousal centers or whether this is done indirectly through respiratory networks remains unknown. This review will focus on arousal in response to hypoxia and CO2 in the fetus and newborn and will outline what we know (and don’t know) about the involvement of the carotid body in this process. PMID:22684039

  12. Effects of specific carotid body and brain hypoxia on respiratory muscle control in the awake goat.

    PubMed Central

    Smith, C A; Engwall, M J; Dempsey, J A; Bisgard, G E

    1993-01-01

    1. We assessed the effects of specific brain hypoxia on the control of inspiratory and expiratory muscle electromyographic (EMG) activities in response to specific carotid body hypoxia in seven awake goats. We used an isolated carotid body perfusion technique that permitted specific, physiological, steady-state stimulation of the carotid bodies or maintenance of normoxia and normocapnia at the carotid bodies while varying the level of systemic, and therefore, brain oxygenation. 2. Isolated brain normocapnic hypoxia of up to 1.5 h duration increased inspired minute ventilation (VI) by means of increases in both tidal volume (VT) and respiratory frequency (fR). Electromyographic activities of both inspiratory and expiratory muscles were augmented as well. These responses were similar to those produced by low levels of whole-body normoxic hypercapnia. We conclude that moderate levels of brain hypoxia (Pa,O2 approximately 40 mmHg) in awake goats caused a net stimulation of ventilatory motor output. 3. Hypoxic stimulation of the carotid bodies alone caused comparable increases in VT and fR, and EMG augmentation of both inspiratory and expiratory muscles whether the brain was hypoxic or normoxic. These responses were quite similar to those obtained over a wide range of whole-body normoxic hypercapnia. We conclude that the integration of carotid body afferent information is not affected by moderate brain hypoxia in awake goats. 4. We found no evidence for an asymmetrical recruitment pattern of inspiratory vs. expiratory muscles in response to carotid body hypoxia or in response to brain hypoxia alone. 5. Our data support the concept that moderate brain hypoxia results in a net stimulation of respiratory motor output. These findings question the significance of 'central hypoxic depression' to the regulation of breathing under physiological levels of hypoxaemia in the awake animal. PMID:8487210

  13. Carotid body potentiation during chronic intermittent hypoxia: implication for hypertension.

    PubMed

    Del Rio, Rodrigo; Moya, Esteban A; Iturriaga, Rodrigo

    2014-01-01

    Autonomic dysfunction is involved in the development of hypertension in humans with obstructive sleep apnea, and animals exposed to chronic intermittent hypoxia (CIH). It has been proposed that a crucial step in the development of the hypertension is the potentiation of the carotid body (CB) chemosensory responses to hypoxia, but the temporal progression of the CB chemosensory, autonomic and hypertensive changes induced by CIH are not known. We tested the hypothesis that CB potentiation precedes the autonomic imbalance and the hypertension in rats exposed to CIH. Thus, we studied the changes in CB chemosensory and ventilatory responsiveness to hypoxia, the spontaneous baroreflex sensitivity (BRS), heart rate variability (HRV) and arterial blood pressure in pentobarbital anesthetized rats exposed to CIH for 7, 14, and 21 days. After 7 days of CIH, CB chemosensory and ventilatory responses to hypoxia were enhanced, while BRS was significantly reduced by 2-fold in CIH-rats compared to sham-rats. These alterations persisted until 21 days of CIH. After 14 days, CIH shifted the HRV power spectra suggesting a predominance of sympathetic over parasympathetic tone. In contrast, hypertension was found after 21 days of CIH. Concomitant changes between the gain of spectral HRV, BRS, and ventilatory hypoxic chemoreflex showed that the CIH-induced BRS attenuation preceded the HRV changes. CIH induced a simultaneous decrease of the BRS gain along with an increase of the hypoxic ventilatory gain. Present results show that CIH-induced persistent hypertension was preceded by early changes in CB chemosensory control of cardiorespiratory and autonomic function. PMID:25429271

  14. Role of the carotid bodies in chemosensory ventilatory responses in the anesthetized mouse.

    PubMed

    Izumizaki, Masahiko; Pokorski, Mieczyslaw; Homma, Ikuo

    2004-10-01

    We examined the effects of carotid body denervation on ventilatory responses to normoxia (21% O2 in N2 for 240 s), hypoxic hypoxia (10 and 15% O2 in N2 for 90 and 120 s, respectively), and hyperoxic hypercapnia (5% CO2 in O2 for 240 s) in the spontaneously breathing urethane-anesthetized mouse. Respiratory measurements were made with a whole body, single-chamber plethysmograph before and after cutting both carotid sinus nerves. Baseline measurements in air showed that carotid body denervation was accompanied by lower minute ventilation with a reduction in respiratory frequency. On the basis of measurements with an open-circuit system, no significant differences in O2 consumption or CO2 production before and after chemodenervation were found. During both levels of hypoxia, animals with intact sinus nerves had increased respiratory frequency, tidal volume, and minute ventilation; however, after chemodenervation, animals experienced a drop in respiratory frequency and ventilatory depression. Tidal volume responses during 15% hypoxia were similar before and after carotid body denervation; during 10% hypoxia in chemodenervated animals, there was a sudden increase in tidal volume with an increase in the rate of inspiration, suggesting that gasping occurred. During hyperoxic hypercapnia, ventilatory responses were lower with a smaller tidal volume after chemodenervation than before. We conclude that the carotid bodies are essential for maintaining ventilation during eupnea, hypoxia, and hypercapnia in the anesthetized mouse. PMID:15194670

  15. Carotid body chemoreflex: a driver of autonomic abnormalities in sleep apnoea.

    PubMed

    Prabhakar, Nanduri R

    2016-08-01

    What is the topic of this review? This article presents emerging evidence for heightened carotid body chemoreflex activity as a major driver of sympathetic activation and hypertension in sleep apnoea patients. What advances does it heighlight? This article discusses the recent advances on cellular, molecular and epigenetic mechanisms underlying the exaggerated chemoreflex in experimental models of sleep apnoea. The carotid bodies are the principal peripheral chemoreceptors for detecting changes in arterial blood oxygen concentration, and the resulting chemoreflex is a potent regulator of the sympathetic tone, blood pressure and breathing. Sleep apnoea is a disease of the respiratory system that affects several million adult humans. Apnoeas occur during sleep, often as a result of obstruction of the upper airway (obstructive sleep apnoea) or because of defective respiratory rhythm generation by the CNS (central sleep apnoea). Patients with sleep apnoea exhibit several co-morbidities, with the most notable among them being heightened sympathetic nerve activity and hypertension. Emerging evidence suggests that intermittent hypoxia resulting from periodic apnoea stimulates the carotid body, and the ensuing chemoreflex mediates the increased sympathetic tone and hypertension in sleep apnoea patients. Rodent models of intermittent hypoxia that simulate the O2 saturation profiles encountered during sleep apnoea have provided important insights into the cellular and molecular mechanisms underlying the heightened carotid body chemoreflex. This article describes how intermittent hypoxia affects the carotid body function and discusses the cellular, molecular and epigenetic mechanisms underlying the exaggerated chemoreflex. PMID:27474260

  16. Evidence for a carotid body homolog in the lizard Tupinambis merianae.

    PubMed

    Reichert, Michelle N; Brink, Deidre L; Milsom, William K

    2015-01-15

    The homolog to the mammalian carotid body has not yet been identified in lizards. Observational studies and evolutionary history provide indirect evidence for the existence of a chemoreceptor population at the first major bifurcation of the common carotid artery in lizards, but a chemoreceptive role for this area has not yet been definitively demonstrated. We explored this possibility by measuring changes in cardiorespiratory variables in response to focal arterial injections of the hypoxia mimic sodium cyanide (NaCN) into the carotid artery of 12 unanesthetized specimens of Tupinambis merianae. These injections elicited increases in heart rate (f(H); 101±35% increase) and respiratory rate (f(R); 620±119% increase), but not mean arterial blood pressure (MAP). These responses were eliminated by vagal denervation. Similar responses were elicited by injections of the neurotransmitters acetylcholine (ACh) and serotonin (5-HT) but not norepinephrine. Heart rate and respiratory rate increases in response to NaCN could be blocked or reduced by antagonists to ACh (atropine) and/or 5-HT (methysergide). Finally, using immunohistochemistry, we demonstrate the presence of putative chemoreceptive cells immunopositive for the cholinergic cell marker vesicular ACh transporter (VAChT) and 5-HT on internal lattice-like structures at the carotid bifurcation. These results provide evidence in lizards for the existence of dispersed chemoreceptor cells at the first carotid bifurcation in the central cardiovascular area that have similar properties to known carotid body homologs, adding to the picture of chemoreceptor evolution in vertebrates. PMID:25524981

  17. Carotid baroreceptor influence on forearm vascular resistance during low level lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Thompson, Cynthia A.; Ludwig, David A.; Convertino, Victor A.

    1991-01-01

    The degree of forearm vasoconstriction induced by low levels of lower body negative pressure (LBNP) provides a measure of the responsiveness of the cardiopulmonary baroreflex. The validity of this measurement is based on the assumption that this vasoconstriction response is not influenced by unloading of carotid baroreceptors. To test the hypothesis that arterial baroreceptor unloading does not alter the degree of forearm vascular resistance during low levels of LBNP, 12 subjects were exposed to -15 and -20 mm Hg LBNP with and without additional artificial (+ 10 mm Hg neck pressure) unloading of the carotid baroreceptors. There was no measurable influence of carotid unloading on forearm vascular resistance at either level of LBNP. It is concluded that forearm vascular resistance measured during cardiopulmonary baroreceptor unloading is unaffected by carotid baroreceptor unloading within the magnitude encountered during low levels of LBNP.

  18. Carotid body overactivity induces respiratory neurone channelopathy contributing to neurogenic hypertension.

    PubMed

    Moraes, Davi J A; Machado, Benedito H; Paton, Julian F R

    2015-07-15

    Why sympathetic activity rises in neurogenic hypertension remains unknown. It has been postulated that changes in the electrical excitability of medullary pre-sympathetic neurones are the main causal mechanism for the development of sympathetic overactivity in experimental hypertension. Here we review recent data suggesting that enhanced sympathetic activity in neurogenic hypertension is, at least in part, dependent on alterations in the electrical excitability of medullary respiratory neurones and their central modulation of sympatho-excitatory networks. We also present results showing a critical role for carotid body tonicity in the aetiology of enhanced central respiratory modulation of sympathetic activity in neurogenic hypertension. We propose a novel hypothesis of respiratory neurone channelopathy induced by carotid body overactivity in neurogenic hypertension that may contribute to sympathetic excess. Moreover, our data support the notion of targeting the carotid body as a potential novel therapeutic approach for reducing sympathetic vasomotor tone in neurogenic hypertension. PMID:25900825

  19. Spexin is expressed in the carotid body and is upregulated by postnatal hyperoxia exposure.

    PubMed

    Porzionato, Andrea; Rucinski, Marcin; Macchi, Veronica; Stecco, Carla; Sarasin, Gloria; Sfriso, Maria M; Di Giulio, Camillo; Malendowicz, Ludwik K; De Caro, Raffaele

    2012-01-01

    Spexin is a recently identified peptide which is expressed in many different endocrine and nervous tissues. Due to the absence of data regarding spexin expression in the carotid body, the first aim of the present study was to investigate, through immunohistochemistry and Real-Time PCR, the expression and distribution of spexin in the rat and human carotid body. Moreover, the carotid body is known to undergo various structural and functional modifications in response to hyperoxic stimuli during the first postnatal period. Thus, we also evaluated if hyperoxia during the first postnatal weeks may produce changes in the spexin expression. Materials consisted of carotid bodies obtained at autopsy from five human adult subjects and sampled from 10 six-weeks old Sprague-Dawley rats. Five rats were maintained in normoxia for the first six postnatal weeks; five rats were exposed to 60% hyperoxia for 2 weeks and then maintained in normoxia for other 4 weeks. Diffuse anti-spexin immunoreactivity was found in type I cells of both humans and rats. No spexin immunoreactivity was visible in the type II cells. Hyperoxia exposure during the first 2 weeks of postnatal life caused a reduction of volume in the carotid body still apparent after 4 weeks of normoxia. Using real-time PCR, spexin expression was 6-7 times higher in hyperoxia-exposed rats than in normoxia-exposed ones. The expression of spexin in type I cells suggests a possible modulator role in peripheral chemoreception. Moreover, the ascertained role of spexin in the regulation of cell proliferation in other tissues (e.g., adrenal gland cortex) suggests a possible role of spexin also in the hyperoxia-induced plasticity of the carotid body. PMID:23080164

  20. Inherent variations in CO-H2S-mediated carotid body O2 sensing mediate hypertension and pulmonary edema.

    PubMed

    Peng, Ying-Jie; Makarenko, Vladislav V; Nanduri, Jayasri; Vasavda, Chirag; Raghuraman, Gayatri; Yuan, Guoxiang; Gadalla, Moataz M; Kumar, Ganesh K; Snyder, Solomon H; Prabhakar, Nanduri R

    2014-01-21

    Oxygen (O2) sensing by the carotid body and its chemosensory reflex is critical for homeostatic regulation of breathing and blood pressure. Humans and animals exhibit substantial interindividual variation in this chemosensory reflex response, with profound effects on cardiorespiratory functions. However, the underlying mechanisms are not known. Here, we report that inherent variations in carotid body O2 sensing by carbon monoxide (CO)-sensitive hydrogen sulfide (H2S) signaling contribute to reflex variation in three genetically distinct rat strains. Compared with Sprague-Dawley (SD) rats, Brown-Norway (BN) rats exhibit impaired carotid body O2 sensing and develop pulmonary edema as a consequence of poor ventilatory adaptation to hypobaric hypoxia. Spontaneous Hypertensive (SH) rat carotid bodies display inherent hypersensitivity to hypoxia and develop hypertension. BN rat carotid bodies have naturally higher CO and lower H2S levels than SD rat, whereas SH carotid bodies have reduced CO and greater H2S generation. Higher CO levels in BN rats were associated with higher substrate affinity of the enzyme heme oxygenase 2, whereas SH rats present lower substrate affinity and, thus, reduced CO generation. Reducing CO levels in BN rat carotid bodies increased H2S generation, restoring O2 sensing and preventing hypoxia-induced pulmonary edema. Increasing CO levels in SH carotid bodies reduced H2S generation, preventing hypersensitivity to hypoxia and controlling hypertension in SH rats. PMID:24395806

  1. Towards the Sensory Nature of the Carotid Body: Hering, De Castro and Heymans†

    PubMed Central

    de Castro, Fernando

    2009-01-01

    The carotid body or glomus caroticum is a chemosensory organ bilaterally located between the external and internal carotid arteries. Although known by anatomists since the report included by Von Haller and Taube in the mid XVIII century, its detailed study started the first quarter of the XX. The Austro-German physiologist Heinrich E. Hering studied the cardio-respiratory reflexes searched for the anatomical basis of this reflex in the carotid sinus, while the Ghent School leaded by the physio-pharmacologists Jean-François Heymans and his son Corneille focussed in the cardio-aortic reflexogenic region. In 1925, Fernando De Castro, one of the youngest and more brilliant disciples of Santiago Ramón y Cajal at the Laboratorio de Investigaciones Biológicas (Madrid, Spain), profited from some original novelties in histological procedures to study the fine structure and innervation of the carotid body. De Castro unravelled them in a series of scientific papers published between 1926 and 1929, which became the basis to consider the carotid body as a sensory receptor (or chemoreceptor) to detect the chemical changes in the composition of the blood. Indeed, this was the first description of arterial chemoreceptors. Impressed by the novelty and implications of the work of De Castro, Corneille Heymans invited the Spanish neurologist to visit Ghent on two occasions (1929 and 1932), where both performed experiences together. Shortly after, Heymans visited De Castro at the Instituto Cajal (Madrid). From 1932 to 1933, Corneille Heymans focused all his attention on the carotid body his physiological demonstration of De Castro's hypothesis regarding chemoreceptors was awarded with the Nobel Prize in Physiology or Medicine in 1938, just when Spain was immersed in its catastrophic Civil War. PMID:20057927

  2. Pharmacology of pH effects on carotid body chemoreceptors in vitro.

    PubMed

    Eyzaguirre, C; Zapata, P

    1968-04-01

    1. The carotid body and the carotid nerve were removed from anaesthetized cats and placed in a small Perspex channel through which Locke solution (at various pH values and usually equilibrated with 50% O(2) in N(2)) was allowed to flow. The glomus was immersed in the flowing solution while the nerve was lifted into oil covering the saline. Sensory discharges were recorded from the nerve and their frequency was used as an index of receptor activity. At times, a small segment of carotid artery, containing pressoreceptor endings, was removed together with the glomus. In this case, pressoreceptor discharges were recorded from the nerve.2. The amplitude of either chemo- or pressoreceptor discharges was not changed by strong acid solutions. Acid decreased the frequency of the baroreceptor discharges only when pH fell to less than 4.0. Solutions at low pH increased the chemosensory discharge, but acid depressed the increased chemoreceptor discharge elicited by KCl. These experiments indicated that H(+) ions probably acted as membrane ;stabilizers' without depolarizing either the nerve fibres or endings.3. Acid solutions increased the action of acetylcholine chloride (AChCl) (100-200 mug) on chemoreceptors. This effect probably was due either to inactivation of tissue cholinesterase or to enhanced sensitivity of the sensory endings to ACh.4. Choline chloride (10(-3)M), which favours ACh synthesis, protected the preparation against decay during prolonged experimentation. Hemicholinium-3 (HC-3), which blocks ACh synthesis in low concentrations (10(-5)M), depressed the chemosensory response to acid and to hypoxia when such stimuli were applied repeatedly. This concentration of HC-3 did not change effects of applied ACh.5. Substances which affect ACh release markedly changed the chemoreceptor discharge increase induced by acidity and other forms of stimulation. In the absence of Ca(2+), acid, anoxia, and interruption of flow provoked receptor depression while receptor

  3. Immunohistochemical localization of dopamine D2 receptor in the rat carotid body.

    PubMed

    Wakai, Jun; Takayama, Anna; Yokoyama, Takuya; Nakamuta, Nobuaki; Kusakabe, Tatsumi; Yamamoto, Yoshio

    2015-10-01

    Dopamine modulates the chemosensitivity of arterial chemoreceptors, and dopamine D2 receptor (D2R) is expected to localize in the glomus cells and/or sensory nerve endings of the carotid body. In the present study, the localization of D2R in the rat carotid body was examined using double immunofluorescence for D2R with various cell markers. D2R immunoreactivity was mainly localized in glomus cells immunoreactive to tyrosine hydroxylase or dopamine β-hydroxylase (DBH), but not in S100B-immunoreactive sustentacular cells. Furthermore, D2R immunoreactivity was observed in petrosal ganglion cells and nerve bundles in the carotid body, but not in the nerve endings with P2X2 immunoreactivity. In the carotid ganglion, a few punctate D2R-immunoreactive products were detected in DBH-immunoreactive nerve cell bodies. These results showed that D2R was mainly distributed in glomus cells, and suggested that D2R plays a role in the inhibitory modulation of chemosensory activity in a paracrine and/or autocrine manner. PMID:26272445

  4. Carotid Body Chemoreflex Mediates Intermittent Hypoxia-Induced Oxidative Stress in the Adrenal Medulla

    PubMed Central

    Kumar, Ganesh K.; Peng, Ying-Jie; Nanduri, Jayasri; Prabhakar, Nanduri R.

    2016-01-01

    Intermittent hypoxia (IH) increases reactive oxygen species generation resulting in oxidative stress in the adrenal medulla (AM), a major end-organ of the sympathetic nervous system which facilitates catecholamine secretion by hypoxia. Here, we show that carotid body chemoreflex contributes to IH-induced oxidative stress in the AM. Carotid bodies were ablated by cryocoagulation of glomus cells, the putative O2 sensing cells. Carotid body ablated (CBA) and control rats were exposed to IH and the redox state of the AM was assessed biochemically. We found that IH raised reactive oxygen species levels along with an increase in NADPH oxidase (Nox), a pro-oxidant enzyme and a decrease in superoxide dismutase-2 (SOD2), an anti-oxidant enzyme. Further, IH increased hypoxia-inducible factor (HIF)-1α, whereas decreased HIF-2α, the transcriptional regulator of Nox and SOD-2, respectively. These IH-induced changes in the AM were absent in CBA rats. Moreover, IH increased splanchnic nerve activity and facilitated hypoxia-evoked catecholamine efflux from the AM and CBA prevented these effects. These findings suggest that IH-induced oxidative stress and catecholamine efflux in the AM occurs via carotid body chemoreflex involving HIF α isoform mediated imbalance in pro-, and anti-oxidant enzymes. PMID:26303481

  5. A case of congenital agenesis of the common carotid artery associated with an ectopic parathyroid adenoma mimicking a carotid body tumor.

    PubMed

    Malm, Ian-James; Olcott, Clara M; Chan, Jason Y K; Loyo, Myriam; Kim, Young J

    2013-01-01

    Ectopic parathyroid adenomas can be encountered during four gland explorations, but nearly 80% of adenomas are localized with ultrasound and sestamibi imaging. Ectopic adenomas are thought to arise from abnormal migration during development. As a cervical congenital anomaly, common carotid artery agenesis is an extremely rare anomaly characterized by separate origins of the internal and external carotid arteries directly from the aortic arch. Here we present a case of a 75 year old man with primary hyperparathyroidism who was found to have congenital agenesis of the common carotid artery associated with an ectopic parathyroid adenoma within the parapharyngeal space, which mimicked a carotid body tumor based on location and imaging. The successful identification and resection of the ectopic parathyroid adenoma presented here demonstrate the importance of preoperative imaging studies to allow appropriate operative planning as well as the utility of intraoperative parathyroid hormone assay in predicting cure during surgery. PMID:23993711

  6. Carotid body remodelling in l-NAME-induced hypertension in the rat.

    PubMed

    Felix, A S; Rocha, V N; Nascimento, A L R; de Carvalho, J J

    2012-05-01

    The carotid body (CB) is a chemoreceptor organ located at the bifurcation of the common carotid artery. It is made up of the carotid glomus, a structure containing type 1 cells surrounded by type 2 cells. The aim of this study was to evaluate the morphological changes of the CB and carotid glomus in the rat model of l-NAME-induced hypertension. Male Wistar rats were divided in two groups: control untreated rats (C) and rats receiving l-NAME 40 mg/kg/day (LN) for 6 weeks. At the end of the experiment, the systolic blood pressure was 63% higher in the LN group compared with the C group. Morphometric analysis showed that the area of the CB was 29% greater in the LN group compared with the C group. The density of nuclei in the CB was similar between groups, but it was 31% less in the carotid glomus of the LN group. Cells in the CB of the LN group displayed cytoplasmic vacuolation and expressed several biogenic amines. There were more elastic fibres, proteoglycans and collagen fibres in the LN group compared with the C group. Immunohistochemistry showed increased expression of nuclear factor kB, substance P, vascular endothelial growth factor and neuronal nitric oxide synthase in the LN group, while expression of the protein gene product 9.5 was decreased. l-NAME alters cell morphology and the expression of extracellular matrix molecules in the CB and carotid glomus in rats with l-NAME-induced hypertension. PMID:21899859

  7. Percutaneous Injection of Lidocaine Within the Carotid Body Area in Carotid Artery Stenting: An 'Old-New' Technique

    SciTech Connect

    Mourikis, Dimitrios; Chatoupis, Konstantinos; Katsenis, Konstantinos; Vlahos, Lampros; Chatziioannou, Achilles

    2008-07-15

    Severe bradycardia is a common untoward effect during balloon angioplasty when performing carotid artery stenting. Therefore atropine injection even before dilatation and the presence of an anesthesiologist are advocated in all patients. In the surgical literature, injection of a local anesthetic agent into the carotid sinus before carotid endarterectomy was performed in an attempt to ameliorate perioperative hemodynamic instability. This study was undertaken to test the hypothesis that percutaneous infiltration of the carotid sinus with local anesthetic immediately before balloon dilatation reduces bradycardia and ameliorates the need for atropine injection or the presence of an anesthesiologist. Infiltration of the carotid sinus with 5 ml of 1% lidocaine, 3 min before dilatation, was performed in 30 consecutive patients. No one exhibited any significant rhythm change that required atropine injection. The anesthesiologist did not face any hemodynamic instability during the carotid artery stenting procedure.

  8. Do the carotid body chemoreceptors mediate cardiovascular and sympathetic adjustments induced by sodium overload in rats?

    PubMed

    Pedrino, Gustavo R; Mourão, Aline A; Moreira, Marina C S; da Silva, Elaine F; Lopes, Paulo R; Fajemiroye, James O; Schoorlemmer, Guss H M; Sato, Mônica A; Reis, Ângela A S; Rebelo, Ana C S; Cravo, Sergio L

    2016-05-15

    Acute plasma hypernatremia induces several cardiovascular and sympathetic responses. It is conceivable that these responses contribute to rapid sodium excretion and restoration of normal conditions. Afferent pathways mediating these responses are not entirely understood. The present study analyses the effects of acute carotid chemoreceptor inactivation on cardiovascular and sympathetic responses induced by infusion of hypertonic saline (HS). All experiments were performed on anesthetized male Wistar rats instrumented for recording of arterial blood pressure (ABP), renal blood flow (RBF) and renal sympathetic nerve activity (RSNA). Animals were subjected to sham surgery or carotid chemoreceptor inactivation by bilateral ligation of the carotid body artery (CBA). In sham rats (n=8), intravenous infusion of HS (3 M NaCl, 1.8 ml/kg b.wt.) elicited a transient increase (9±2mmHg) in ABP, and long lasting (30 min) increases in RBF (138±5%) and renal vascular conductance (RVC) (128±5%) with concurrent decrease in RSNA (-19±4%). In rats submitted to CBA ligation (n=8), the pressor response to HS was higher (24±2mmHg; p<0.05). However, RBF and RVC responses to HS infusion were significantly reduced (113±5% and 93±4%, respectively) while RSNA was increased (13±2%). When HS (3M NaCl, 200μl) was administrated into internal carotid artery (ICA), distinct sympathetic and cardiovascular responses were observed. In sham-group, HS infusion (3M NaCl, 200μl) into ICA promoted an increase in ABP (26±8mmHg) and RSNA (29±13%). In CBA rats, ABP (-3±5.6mmHg) remained unaltered despite sympathoinhibition (-37.6±5.4%). These results demonstrate that carotid body chemoreceptors play a role in the development of hemodynamic and sympathetic responses to acute HS infusion. PMID:27060222

  9. CT AND MRI FEATURES OF CAROTID BODY PARAGANGLIOMAS IN 16 DOGS.

    PubMed

    Mai, Wilfried; Seiler, Gabriela S; Lindl-Bylicki, Britany J; Zwingenberger, Allison L

    2015-01-01

    Carotid body tumors (paragangliomas) arise from chemoreceptors located at the carotid bifurcation. In imaging studies, this neoplasm may be confused with other neck neoplasms such as thyroid carcinoma. The purpose of this retrospective, cross-sectional study was to describe computed tomographic (CT) and magnetic resonance imaging (MRI) characteristics of confirmed carotid body tumors in a multi-institutional sample of dogs. A total of 16 dogs met inclusion criteria (14 examined using CT and two with MRI). The most common reason for imaging was a palpable cervical mass or respiratory signs (i.e., dyspnea or increased respiratory noises). The most commonly affected breed was Boston terrier (n = 5). Dogs were predominantly male castrated (n = 10) and the median age was 9 years [range 3-14.5]. Most tumors appeared as a large mass centered at the carotid bifurcation, with poor margination in six dogs and discrete margins in ten dogs. Masses were iso- to hypoattenuating to adjacent muscles in CT images and hyperintense to muscles in T1- and T2-weighted MRI. For both CT and MRI, masses typically showed strong and heterogeneous contrast enhancement. There was invasion into the adjacent structures in 9/16 dogs. In six of these nine dogs, the basilar portion of the skull was affected. The external carotid artery was entrapped in seven dogs. There was invasion into the internal jugular vein in three dogs, and into the external jugular, maxillary, and linguo-facial veins in one dog. Imaging characteristics helped explain some clinical presentations such as breathing difficulties, Horner's syndrome, head tilt, or facial nerve paralysis. PMID:25846946

  10. The Role of Hypoxia-Inducible Factors in Oxygen Sensing by the Carotid Body

    PubMed Central

    Prabhakar, Nanduri R.

    2013-01-01

    Chronic intermittent hypoxia (IH) associated with sleep-disordered breathing is an important cause of hypertension, which results from carotid body-mediated activation of the sympathetic nervous system. IH triggers increased levels of reactive oxygen species (ROS) in the carotid body, which induce increased synthesis and stability of hypoxia-inducible factor 1α (HIF-1α) and calpain-dependent degradation of HIF-2α. HIF-1 activates transcription of the Nox2 gene, encoding NADPH oxidase 2, which generates superoxide. Loss of HIF-2 activity leads to decreased transcription of the Sod2 gene, encoding manganese superoxide dismutase, which converts superoxide to hydrogen peroxide. Thus, IH disrupts the balance between HIF-1-dependent pro-oxidant and HIF-2-dependent anti-oxidant activities, and this loss of redox homeostasis underlies the pathogenesis of autonomic morbidities associated with IH. PMID:23080136

  11. Presynaptic action of adenosine on a 4-aminopyridine-sensitive current in the rat carotid body

    PubMed Central

    Vandier, C; Conway, A F; Landauer, R C; Kumar, P

    1999-01-01

    Plasma adenosine concentration increases during hypoxia to a level that excites carotid body chemoreceptors by an undetermined mechanism. We have examined this further by determining the electrophysiological responses to exogenous adenosine of sinus nerve chemoafferents in vitro and of whole-cell currents in isolated type I cells.Steady-state, single-fibre chemoafferent discharge was increased approximately 5-fold above basal levels by 100 μM adenosine. This adenosine-stimulated discharge was reversibly and increasingly reduced by methoxyverapamil (D600, 100 μM), by application of nickel chloride (Ni2+, 2 mM) and by removal of extracellular Ca2+. These effects strongly suggest a presynaptic, excitatory action of adenosine on type I cells of the carotid body.Adenosine decreased whole-cell outward currents at membrane potentials above -40 mV in isolated type I cells recorded during superfusion with bicarbonate-buffered saline solution at 34–36 °C. This effect was reversible and concentration dependent with a maximal effect at 10 μM.The degree of current inhibition induced by 10 μM adenosine was voltage independent (45.39 ± 2.55% (mean ± s.e.m.) between −40 and +30 mV) and largely (∼75%), but not entirely, Ca2+ independent. 4-Aminopyridine (4-AP, 5 mM) decreased the amplitude of the control outward current by 80.60 ± 3.67% and abolished the effect of adenosine.Adenosine was without effect upon currents near the resting membrane potential of approximately −55 mV and did not induce depolarization in current-clamp experiments.We conclude that adenosine acts to inhibit a 4-AP-sensitive current in isolated type I cells of the rat carotid body and suggest that this mechanism contributes to the chemoexcitatory effect of adenosine in the whole carotid body. PMID:10050009

  12. Expression of leptin and leptin receptor isoforms in the rat and human carotid body.

    PubMed

    Porzionato, Andrea; Rucinski, Marcin; Macchi, Veronica; Stecco, Carla; Castagliuolo, Ignazio; Malendowicz, Ludwik K; De Caro, Raffaele

    2011-04-18

    Leptin is known to play a role in the modulation of metabolism and control of breathing acting mainly on central nervous structures, although additional actions on peripheral arterial chemoreceptors have also been suggested in the literature. We therefore examined by means of immunohistochemistry the expression of leptin and leptin receptors in the carotid bodies of rats and humans. Leptin expression and relative expression of leptin receptor isoforms were also studied in rats by real-time PCR. No leptin or leptin receptor immunoreactivities were visible in the type II cells of either series. In rat carotid bodies, diffuse positive stainings for leptin and leptin receptors (both with antibody recognizing all receptor isoforms and antibody specific for Ob-Rb) were observed in type I cells. In human carotid bodies, the mean percentage (±standard error) of leptin immunoreactive type I cells was 39.4%±5.1% and the percentages of leptin receptor immunoreactive type I cells were 57.3%±3.9% with antibody recognizing all receptor isoforms and 33.3%±4.2% with antibody specific for isoform Ob-Rb. Double immunofluorescences with anti-tyrosine hydroxylase (type I cell marker) and anti-glial fibrillary acidic protein (type II cell markers) confirmed the selective location of leptin and Ob-Rb in type I cells. Real-time PCR showed the expression of leptin and Ob-Ra, Ob-Rb, Ob-Rc and Ob-Rf isoform mRNA in the rat carotid body, levels of expression being Ob-Rf>Ob-Rc>Ob-Ra>Ob-Rb. Ob-Re mRNA was not detected. The above findings suggest a role of circulating or locally produced leptin in the regulation of chemoreceptor discharge and/or metabolic sensing function, by means of direct action on type I cells. PMID:21334312

  13. Gene expression and function of adenosine A(2A) receptor in the rat carotid body.

    PubMed

    Kobayashi, S; Conforti, L; Millhorn, D E

    2000-08-01

    The present study was undertaken to determine whether rat carotid bodies express adenosine (Ado) A(2A) receptors and whether this receptor is involved in the cellular response to hypoxia. Our results demonstrate that rat carotid bodies express the A(2A) and A(2B) Ado receptor mRNAs but not the A(1) or A(3) receptor mRNAs as determined by reverse transcriptase-polymerase chain reaction. In situ hybridization confirmed the expression of the A(2A) receptor mRNA. Immunohistochemical studies further showed that the A(2A) receptor is expressed in the carotid body and that it is colocalized with tyrosine hydroxylase in type I cells. Whole cell voltage-clamp studies using isolated type I cells showed that Ado inhibited the voltage-dependent Ca(2+) currents and that this inhibition was abolished by the selective A(2A) receptor antagonist ZM-241385. Ca(2+) imaging studies using fura 2 revealed that exposure to severe hypoxia induced elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)) in type I cells and that extracellularly applied Ado significantly attenuated the hypoxia-induced elevation of [Ca(2+)](i). Taken together, our findings indicate that A(2A) receptors are present in type I cells and that activation of A(2A) receptors modulates Ca(2+) accumulation during hypoxia. This mechanism may play a role in regulating intracellular Ca(2+) homeostasis and cellular excitability during hypoxia. PMID:10926550

  14. Opioid peptides in the rabbit carotid body: identification and evidence for co-utilization and interactions with dopamine.

    PubMed

    González-Guerrero, P R; Rigual, R; González, C

    1993-05-01

    The rabbit carotid body is a catecholaminergic organ that contains dopamine and norepinephrine in a proportion of nearly 5:1. Chronic (15 days) carotid sinus nerve denervation or superior cervical ganglionectomy did not modify the carotid body dopamine content (5-6 nmol/mg of protein, equivalent to 250 pmol per carotid body), but sympathectomy reduced by approximately 50% the norepinephrine content. The carotid body has also a very high content of opioid activity (250 equivalent pmol of Leu-enkephalin/mg of protein) as measured by a radioreceptor assay that detects preferentially delta-opioid activity. In the carotid body the degree of opioid posttranslational processing to low-molecular-weight peptides (mostly Leu- and Met-enkephalin) is nearly 80%. HPLC identification of opioid peptides revealed that the sequences of Met- and Leu-enkephalin were in a proportion of nearly 6:1, indicating that the main opioid precursor in the carotid body is proenkephalin A. Chronic denervations of the carotid body did not modify the levels or the degree of opioid precursor processing. Acute hypoxic exposure of the animals (8% O2 in N2; 3 h) resulted in a parallel decrease of dopamine and opioid activity, without any change in the degree of opioid processing. Norepinephrine levels were not affected by hypoxia. These findings suggest corelease of dopamine and opioids during natural hypoxic stimulation. In agreement with the analytical data, [D-Ala2, D-Leu5]enkephalin, but not [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin, reduced the in vitro release of dopamine induced by low PO2, a high external K+ concentration, and dinitrophenol. Naloxone augmented the release response elicited by low PO2 stimulation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8473894

  15. Cats

    MedlinePlus

    ... found on the skin of people and animals. Methicillin-resistant Staphylococcus aureus (MRSA) is the same bacterium that has become resistant to some antibiotics. Cats and other animals often can carry MRSA ...

  16. Retrobulbar lymphoma associated with a ballistic foreign body in a cat.

    PubMed

    Robat, C; Bemelmans, I; Marescaux, L

    2016-04-01

    A seven-year-old domestic shorthair cat, adopted 5 years previously with a corneal perforation of the left eye, was presented for investigation of a left orbital mass. Computed tomography revealed a metallic foreign body within a contrast-enhancing, heterogeneous orbital mass. Large cell lymphoma was diagnosed from a fine needle aspirate. The cat staged negatively and was treated with L-asparaginase, prednisolone and three fractions of radiation therapy. A rapid clinical remission was obtained and the cat remained in remission for 3 years after therapy. This is the first report of large cell lymphoma likely occurring secondary to a foreign body. PMID:26290463

  17. Fractal analysis of the structural complexity of the connective tissue in human carotid bodies

    PubMed Central

    Guidolin, Diego; Porzionato, Andrea; Tortorella, Cinzia; Macchi, Veronica; De Caro, Raffaele

    2014-01-01

    The carotid body (CB) may undergo different structural changes during perinatal development, aging, or in response to environmental stimuli. In the previous literature, morphometric approaches to evaluate these changes have considered quantitative first order parameters, such as volumes or densities, while changes in spatial disposition and/or complexity of structural components have not yet been considered. In the present study, different strategies for addressing morphological complexity of CB, apart from the overall amount of each tissue component, were evaluated and compared. In particular, we considered the spatial distribution of connective tissue in the carotid bodies of young control subjects, young opiate-related deaths and aged subjects, through analysis of dispersion (Morisita's index), gray level co-occurrence matrix (entropy, angular second moment, variance, correlation), and fractal analysis (fractal dimension, lacunarity). Opiate-related deaths and aged subjects showed a comparable increase in connective tissue with respect to young controls. However, the Morisita's index (p < 0.05), angular second moment (p < 0.05), fractal dimension (p < 0.01), and lacunarity (p < 0.01) permitted to identify significant differences in the disposition of the connective tissue between these two series. A receiver operating characteristic (ROC) curve was also calculated to evaluate the efficiency of each parameter. The fractal dimension and lacunarity, with areas under the ROC curve of 0.9651 (excellent accuracy) and 0.8835 (good accuracy), respectively, showed the highest discriminatory power. They evidenced higher level of structural complexity in the carotid bodies of opiate-related deaths than old controls, due to more complex branching of intralobular connective tissue. Further analyses will have to consider the suitability of these approaches to address other morphological features of the CB, such as different cell populations, vascularization, and innervation

  18. Biophysical studies of the cellular elements of the rabbit carotid body.

    PubMed

    Duchen, M R; Caddy, K W; Kirby, G C; Patterson, D L; Ponte, J; Biscoe, T J

    1988-07-01

    The carotid body is a major sensor of oxygen partial pressure in the arterial blood, and plays a role in the control of respiration. Despite extensive investigation of the structure, the cellular basis of the transduction mechanism remains poorly understood. We have developed a preparation of freshly dissociated cells from the rabbit carotid body, in which two cell types may be identified using morphological criteria. The preparation allows application of the patch clamp technique to characterize the properties of the cells which have otherwise proved difficult to study in situ. Carotid bodies of rabbits were dissociated using a combination of enzymatic and mechanical procedures. The dissociated preparation obtained consisted of clusters of spherical or ovoid cells of 12-15 microns in diameter and a distinct population of spherical cells of 8-10 microns diameter. Electron microscopic techniques were used to identify the cells present in the preparation. Again two populations of cells could be distinguished. A population of cells 10-12 microns in diameter, often found in clusters, possessed the dense-cored vesicles characteristic of Type I cells, while a population of smaller cells (diameter 5-7 microns) had peripherally condensed nuclear chromatin and fine cytoplasmic surface extensions characteristic of Type II cells. Patch clamp study of the cells showed that they represent two electrophysiologically distinct populations. The larger cells, corresponding to Type I cells, were found to be excitable, generating fast, sodium-dependent action potentials that were recorded both in the cell attached and whole cell recording configurations. The smaller Type II cells did not generate action potentials. Voltage clamp study of Type I cells allowed definition of a range of voltage-gated currents. These included an inactivating, tetrodotoxin-sensitive inward sodium current, a high threshold sustained inward calcium current, and outward potassium currents. A component of the

  19. Measurements of intracellular Ca2+ in dissociated type I cells of the rabbit carotid body.

    PubMed Central

    Biscoe, T J; Duchen, M R; Eisner, D A; O'Neill, S C; Valdeolmillos, M

    1989-01-01

    1. The carotid body chemoreceptors are stimulated in situ by cyanide (CN-), which mimics the effect of hypoxia. We have shown that CN- increases a calcium-dependent potassium conductance (gK(Ca)) in single type I cells dissociated from the carotid body of the rabbit. We have now used the Ca2(+)-sensitive fluorophore, Fura-2, to measure intracellular Ca2+ directly in single type I cells. 2. CN- reversibly increased [Ca2+]i from approximately 90 nM to a mean of approximately 200 nM. Some of this Ca2+ originated from an intracellular store, which was depleted by exposure to Ca2(+)-free solutions. Prolonged application of CN- caused a sustained increase in [Ca2+]i, suggesting that CN- impairs the removal or sequestration of Ca2+. 3. pHi measured with the dye BCECF (2,7-bis(2-carboxyethyl)-5(and-6)-carboxyfluorescein) did not change consistently in response to CN-, although pHi changed predictably in response to both ammonium chloride and to acidification of the superfusate with CO2. 4. Potassium-induced depolarization (35 mM-K+) caused a large, cadmium-sensitive rise in [Ca2+]i. The K(+)-induced Ca2+ load was used to study the regulation of [Ca2+]i. 5. The clearance of a Ca2+ load was slowed either by removal of [Na+]o or by application of CN-. This shows that both a Na+-Ca2+ exchange and an energy-dependent process or processes contribute to the regulation of [Ca2+]i. 6. Carbachol (CCh, 10-100 microM), which also hyperpolarizes type I cells, caused a small transient rise in [Ca2+]i, indicating release from an exhaustible intracellular pool. The response to CN- was unaffected by prior or continued exposure to CCh, suggesting that the two stimuli operate by distinct mechanisms. 7. The increased gK(Ca) seen in type I cells in response to CN- thus reflects a change in cellular Ca2+ homeostasis. The rise in [Ca2+]i presumably underlies the documented increase in transmitter release from the carotid body in response to CN-. If chemotransduction is a consequence of the

  20. CaV3.2 T-type Ca²⁺ channels in H₂S-mediated hypoxic response of the carotid body.

    PubMed

    Makarenko, Vladislav V; Peng, Ying-Jie; Yuan, Guoxiang; Fox, Aaron P; Kumar, Ganesh K; Nanduri, Jayasri; Prabhakar, Nanduri R

    2015-01-15

    Arterial blood O2 levels are detected by specialized sensory organs called carotid bodies. Voltage-gated Ca(2+) channels (VGCCs) are important for carotid body O2 sensing. Given that T-type VGCCs contribute to nociceptive sensation, we hypothesized that they participate in carotid body O2 sensing. The rat carotid body expresses high levels of mRNA encoding the α1H-subunit, and α1H protein is localized to glomus cells, the primary O2-sensing cells in the chemoreceptor tissue, suggesting that CaV3.2 is the major T-type VGCC isoform expressed in the carotid body. Mibefradil and TTA-A2, selective blockers of the T-type VGCC, markedly attenuated elevation of hypoxia-evoked intracellular Ca(2+) concentration, secretion of catecholamines from glomus cells, and sensory excitation of the rat carotid body. Similar results were obtained in the carotid body and glomus cells from CaV3.2 knockout (Cacna1h(-/-)) mice. Since cystathionine-γ-lyase (CSE)-derived H2S is a critical mediator of the carotid body response to hypoxia, the role of T-type VGCCs in H2S-mediated O2 sensing was examined. Like hypoxia, NaHS, a H2S donor, increased intracellular Ca(2+) concentration and augmented carotid body sensory nerve activity in wild-type mice, and these effects were markedly attenuated in Cacna1h(-/-) mice. In wild-type mice, TTA-A2 markedly attenuated glomus cell and carotid body sensory nerve responses to hypoxia, and these effects were absent in CSE knockout mice. These results demonstrate that CaV3.2 T-type VGCCs contribute to the H2S-mediated carotid body response to hypoxia. PMID:25377087

  1. The human carotid body transcriptome with focus on oxygen sensing and inflammation – a comparative analysis

    PubMed Central

    Mkrtchian, Souren; Kåhlin, Jessica; Ebberyd, Anette; Gonzalez, Constancio; Sanchez, Diego; Balbir, Alexander; Kostuk, Eric W; Shirahata, Machiko; Fagerlund, Malin Jonsson; Eriksson, Lars I

    2012-01-01

    The carotid body (CB) is the key oxygen sensing organ. While the expression of CB specific genes is relatively well studied in animals, corresponding data for the human CB are missing. In this study we used five surgically removed human CBs to characterize the CB transcriptome with microarray and PCR analyses, and compared the results with mice data. In silico approaches demonstrated a unique gene expression profile of the human and mouse CB transcriptomes and an unexpected upregulation of both human and mouse CB genes involved in the inflammatory response compared to brain and adrenal gland data. Human CBs express most of the genes previously proposed to be involved in oxygen sensing and signalling based on animal studies, including NOX2, AMPK, CSE and oxygen sensitive K+ channels. In the TASK subfamily of K+ channels, TASK-1 is expressed in human CBs, while TASK-3 and TASK-5 are absent, although we demonstrated both TASK-1 and TASK-3 in one of the mouse reference strains. Maxi-K was expressed exclusively as the spliced variant ZERO in the human CB. In summary, the human CB transcriptome shares important features with the mouse CB, but also differs significantly in the expression of a number of CB chemosensory genes. This study provides key information for future functional investigations on the human carotid body. PMID:22615433

  2. Sclerosing paraganglioma of the carotid body: a potential pitfall of malignancy.

    PubMed

    Santi, Raffaella; Franchi, Alessandro; Saladino, Valeria; Trovati, Massimo; Cenacchi, Giovanna; Squadrelli-Saraceno, Massimo; Nesi, Gabriella

    2015-06-01

    Paragangliomas (PGs) of the head and neck region are typically benign, slow-growing neuroendocrine tumours. At times, they may exhibit unusual histological features, such as prominent stromal sclerosis (sclerosing PG), which may raise concerns of malignancy. We describe a case of sclerosing PG of the carotid body, emphasizing the value of immunohistochemical stains for differential diagnosis. A 43-year-old woman presented with a painless lump on the neck. A magnetic resonance imaging scan demonstrated a hypervascular lesion of the carotid body, which was surgically excised. Grossly, the lesion measured 1.8 cm at maximum diameter. On microscopic examination, irregular nests and tiny bundles of neoplastic cells were found between thick bands of fibrous tissue. Focal nuclear cytomegaly and marked pleomorphism were noted. Neoplastic cells proved to be immunoreactive for chromogranin, synaptophysin and neuron specific enolase, but negative for cytokeratins, smooth muscle actin and CD34. Ultrastructurally, numerous mitochondria, rough endoplasmic reticulum structures and endocrine granules were seen in the cytoplasm of the tumour cells. On consideration of the above-mentioned clinico-pathological and ultrastructural findings a diagnosis of sclerosing PG was established. Sclerosing PG is a rare entity which may mimic a malignant neoplasm. The recognition of this unusual morphological variant of PG, together with appropriate immunostains, leads to the correct diagnosis. PMID:25194351

  3. Peptide receptor radionuclide therapy with (177)Lu DOTATATE in a case of recurrent carotid body paraganglioma with spinal metastases.

    PubMed

    Gupta, Santosh Kumar; Singla, Suhas; Karunanithi, Sellam; Damle, Nishikant; Bal, Chandrasekhar

    2014-05-01

    Paragangliomas are rare benign neuroendocrine tumors, and 80% of all paragangliomas are either carotid body tumors or glomus jugulare tumors. We present a case of recurrent unresectable carotid body paraganglioma with nodal and T7 vertebral metastases in a 30-year-old man 6 years postsurgery detected with Ga DOTANOC PET/CT and was administered with peptide receptor radionuclide therapy using Lu DOTATATE. After 5 cycles of Lu DOTATATE (total cumulative activity of 750 mCi [27 GBq]), significant response at the primary site on Ga DOTANOC PET/CT and complete disappearance of nodal and T7 vertebral metastases were noted. PMID:24217545

  4. The relationship between distribution of body fat mass and carotid artery intima-media thickness in Korean older adults

    PubMed Central

    Park, Jin-Kee; Park, Hyuntae; Kim, Kwi-Baek

    2015-01-01

    [Purpose] The aim of this study was to examine the relationships between the amount and distribution of body fat and the carotid intima-media thickness to explore whether coronary artery disease risk may be mediated through effects on the amount of fat mass in older adults. [Subjects and Methods] A total of 200 elderly females was participated. The percentage of body fat mass was measured by the bioelectrical impedance analysis method, and the carotid intima-media thickness was measured by B-mode ultrasound. Analysis of covariance was performed to assess independent associations between the four categories of percentage of body fat mass and the carotid intima-media thickness after multivariate adjustment. Logistic regression analyses were utilized to calculate odds ratios and 95% confidence intervals for examining independent associations between percentage of body fat mass and the estimated risk of coronary artery disease. [Results] Analysis of covariance showed that the carotid intima-media thickness was significantly thick in both obesity and overweight groups. When multivariate-adjusted OR for the estimated risk of coronary artery disease, the odds ratios for the obesity and overweight groups were 3.0 (95% confidence interval, 1.1 to 8.7) and 2.5 (95% confidence interval, 1.0 to 6.1), respectively. [Conclusion] This study demonstrates that elderly females with a high body fat mass are more likely to have the estimated risk of CAD than who fit body fat mass in elderly female. PMID:26633917

  5. The relationship between distribution of body fat mass and carotid artery intima-media thickness in Korean older adults.

    PubMed

    Park, Jin-Kee; Park, Hyuntae; Kim, Kwi-Baek

    2015-10-01

    [Purpose] The aim of this study was to examine the relationships between the amount and distribution of body fat and the carotid intima-media thickness to explore whether coronary artery disease risk may be mediated through effects on the amount of fat mass in older adults. [Subjects and Methods] A total of 200 elderly females was participated. The percentage of body fat mass was measured by the bioelectrical impedance analysis method, and the carotid intima-media thickness was measured by B-mode ultrasound. Analysis of covariance was performed to assess independent associations between the four categories of percentage of body fat mass and the carotid intima-media thickness after multivariate adjustment. Logistic regression analyses were utilized to calculate odds ratios and 95% confidence intervals for examining independent associations between percentage of body fat mass and the estimated risk of coronary artery disease. [Results] Analysis of covariance showed that the carotid intima-media thickness was significantly thick in both obesity and overweight groups. When multivariate-adjusted OR for the estimated risk of coronary artery disease, the odds ratios for the obesity and overweight groups were 3.0 (95% confidence interval, 1.1 to 8.7) and 2.5 (95% confidence interval, 1.0 to 6.1), respectively. [Conclusion] This study demonstrates that elderly females with a high body fat mass are more likely to have the estimated risk of CAD than who fit body fat mass in elderly female. PMID:26633917

  6. H2S production by reactive oxygen species in the carotid body triggers hypertension in a rodent model of sleep apnea.

    PubMed

    Yuan, Guoxiang; Peng, Ying-Jie; Khan, Shakil A; Nanduri, Jayasri; Singh, Amritha; Vasavda, Chirag; Semenza, Gregg L; Kumar, Ganesh K; Snyder, Solomon H; Prabhakar, Nanduri R

    2016-01-01

    Sleep apnea is a prevalent respiratory disease in which episodic cessation of breathing causes intermittent hypoxia. Patients with sleep apnea and rodents exposed to intermittent hypoxia exhibit hypertension. The carotid body senses changes in blood O2 concentrations, and an enhanced carotid body chemosensory reflex contributes to hypertension in sleep apnea patients. A rodent model of intermittent hypoxia that mimics blood O2 saturation profiles of patients with sleep apnea has shown that increased generation of reactive oxygen species (ROS) in the carotid body enhances the chemosensory reflex and triggers hypertension. CO generated by heme oxygenase-2 (HO-2) induces a signaling pathway that inhibits hydrogen sulfide (H2S) production by cystathionine γ-lyase (CSE), leading to suppression of carotid body activity. We found that ROS inhibited CO generation by HO-2 in the carotid body and liver through a mechanism that required Cys(265) in the heme regulatory motif of heterologously expressed HO-2. We showed that ROS induced by intermittent hypoxia inhibited CO production and increased H2S concentrations in the carotid body, which stimulated its neural activity. In rodents, blockade of H2S synthesis by CSE, by either pharmacologic or genetic approaches, inhibited carotid body activation and hypertension induced by intermittent hypoxia. Thus, our results indicate that oxidant-induced inactivation of HO-2, which leads to increased CSE-dependent H2S production in the carotid body, is a critical trigger of hypertension in rodents exposed to intermittent hypoxia. PMID:27531649

  7. 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

  8. Acrolein inhalation alters arterial blood gases and triggers carotid body-mediated cardiovascular responses in hypertensive rats

    PubMed Central

    Perez, Christina M.; Hazari, Mehdi S.; Ledbetter, Allen D.; Haykal-Coates, Najwa; Carll, Alex P.; Cascio, Wayne E.; Winsett, Darrell W.; Costa, Daniel L.; Farraj, Aimen K.

    2016-01-01

    Context Air pollution exposure affects autonomic function, heart rate, blood pressure and left ventricular function. While the mechanism for these effects is uncertain, several studies have reported that air pollution exposure modifies activity of the carotid body, the major organ that senses changes in arterial oxygen and carbon dioxide levels, and elicits downstream changes in autonomic control and cardiac function. Objective We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke and diesel exhaust, would activate the carotid body chemoreceptor response and lead to secondary cardiovascular responses in rats. Materials and methods Spontaneously hypertensive (SH) rats were exposed once for 3 h to 3 ppm acrolein gas or filtered air in whole body plethysmograph chambers. To determine if the carotid body mediated acrolein-induced cardiovascular responses, rats were pretreated with an inhibitor of cystathionine γ-lyase (CSE), an enzyme essential for carotid body signal transduction. Results Acrolein exposure induced several cardiovascular effects. Systolic, diastolic and mean arterial blood pressure increased during exposure, while cardiac contractility decreased 1 day after exposure. The cardiovascular effects were associated with decreases in pO2, breathing frequency and expiratory time, and increases in sympathetic tone during exposure followed by parasympathetic dominance after exposure. The CSE inhibitor prevented the cardiovascular effects of acrolein exposure. Discussion and conclusion Pretreatment with the CSE inhibitor prevented the cardiovascular effects of acrolein, suggesting that the cardiovascular responses with acrolein may be mediated by carotid body-triggered changes in autonomic tone. (This abstract does not reflect EPA policy.) PMID:25600140

  9. Volatile Anaesthetic Depression of the Carotid Body Chemoreflex-Mediated Ventilatory Response to Hypoxia: Directions for Future Research

    PubMed Central

    Pandit, J. J.

    2014-01-01

    In assessing whether volatile anaesthetics directly depress the carotid body response to hypoxia it is necessary to combine in meta-analysis studies of when it is “functionally isolated” (e.g., recordings are made from its afferent nerve). Key articles were retrieved (full papers in English) and subjected to quantitative analysis to yield an aggregate estimate of effect. Results from articles that did not use such methodology were assessed separately from this quantitative approach, to see what could be learned also from a nonquantitative overview. Just 7 articles met the inclusion criteria for hypoxia and just 6 articles for hypercapnia. Within these articles, the anaesthetic (mean dose 0.75, standard deviation (SD) 0.40 minimum alveolar concentration, MAC) statistically significantly depressed carotid body hypoxic response by 24% (P = 0.041), but a similar dose (mean 0.81 (0.42) MAC) did not affect the hypercapnic response. The articles not included in the quantitative analysis (31 articles), assessed qualitatively, also indicated that anaesthetics depress carotid body function. This conclusion helps direct future research on the anaesthetic effects on putative cellular/molecular processes that underlie the transduction of hypoxia in the carotid body. PMID:24808974

  10. Relevance of the Carotid Body Chemoreflex in the Progression of Heart Failure

    PubMed Central

    Andrade, David C.; Lucero, Claudia; Toledo, Camilo; Madrid, Carlos; Marcus, Noah J.; Schultz, Harold D.; Del Rio, Rodrigo

    2015-01-01

    Chronic heart failure (CHF) is a global health problem affecting millions of people. Autonomic dysfunction and disordered breathing patterns are commonly observed in patients with CHF, and both are strongly related to poor prognosis and high mortality risk. Tonic activation of carotid body (CB) chemoreceptors contributes to sympathoexcitation and disordered breathing patterns in experimental models of CHF. Recent studies show that ablation of the CB chemoreceptors improves autonomic function and breathing control in CHF and improves survival. These exciting findings indicate that alterations in CB function are critical to the progression of CHF. Therefore, better understanding of the physiology of the CB chemoreflex in CHF could lead to improvements in current treatments and clinical management of patients with CHF characterized by high chemosensitivity. Accordingly, the main focus of this brief review is to summarize current knowledge of CB chemoreflex function in different experimental models of CHF and to comment on their potential translation to treatment of human CHF. PMID:26779536

  11. KISS1 and KISS1R expression in the human and rat carotid body and superior cervical ganglion.

    PubMed

    Porzionato, A; Fenu, G; Rucinski, M; Macchi, V; Montella, A; Malendowicz, L K; De Caro, R

    2011-01-01

    KISS1 and its receptor, KISS1R, have both been found to be expressed in central nervous system, but few data are present in the literature about their distribution in peripheral nervous structures. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of KISS1 and KISS1R in the rat and human carotid bodies and superior cervical ganglia, also with particular reference to the different cellular populations. Materials consisted of carotid bodies and superior cervical ganglia were obtained at autopsy from 10 adult subjects and sampled from 10 adult Sprague-Dawley rats. Immunohistochemistry revealed diffuse expression of KISS1 and KISS1R in type I cells of both human and rat carotid bodies, whereas type II cells were negative. In both human and rat superior cervical ganglia positive anti-KISS1 and -KISS1R immunostainings were also selectively found in ganglion cells, satellite cells being negative. Endothelial cells also showed moderate immunostaining for both KISS1 and KISS1R. The expression of both kisspeptins and kisspeptin receptors in glomic type I cells and sympathetic ganglion cells supports a modulatory role of KISS1 on peripheral chemoreception and sympathetic function. Moreover, local changes in blood flow have been considered to be involved in carotid body chemoreceptor discharge and kisspeptins and kisspeptin receptors have also been found in the endothelial cells. As a consequence, a possible role of kisspeptins in the regulation of carotid body blood flow and, indirectly, in chemoreceptor discharge may also be hypothesized. PMID:22193294

  12. KISS1 and KISS1R expression in the human and rat carotid body and superior cervical ganglion

    PubMed Central

    Porzionato, A.; Fenu, G.; Rucinski, M.; Macchi, V.; Montella, A.; Malendowicz, L.K.; De Caro, R.

    2011-01-01

    KISS1 and its receptor, KISS1R, have both been found to be expressed in central nervous system, but few data are present in the literature about their distribution in peripheral nervous structures. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of KISS1 and KISS1R in the rat and human carotid bodies and superior cervical ganglia, also with particular reference to the different cellular populations. Materials consisted of carotid bodies and superior cervical ganglia were obtained at autopsy from 10 adult subjects and sampled from 10 adult Sprague-Dawley rats. Immunohistochemistry revealed diffuse expression of KISS1 and KISS1R in type I cells of both human and rat carotid bodies, whereas type II cells were negative. In both human and rat superior cervical ganglia positive anti-KISS1 and -KISS1R immunostainings were also selectively found in ganglion cells, satellite cells being negative. Endothelial cells also showed moderate immunostaining for both KISS1 and KISS1R. The expression of both kisspeptins and kisspeptin receptors in glomic type I cells and sympathetic ganglion cells supports a modulatory role of KISS1 on peripheral chemoreception and sympathetic function. Moreover, local changes in blood flow have been considered to be involved in carotid body chemoreceptor discharge and kisspeptins and kisspeptin receptors have also been found in the endothelial cells. As a consequence, a possible role of kisspeptins in the regulation of carotid body blood flow and, indirectly, in chemoreceptor discharge may also be hypothesized. PMID:22193294

  13. Brainstem PCO2 modulates phrenic responses to specific carotid body hypoxia in an in situ dual perfused rat preparation

    PubMed Central

    Day, Trevor A; Wilson, Richard J A

    2007-01-01

    Inputs from central (brainstem) and peripheral (carotid body) respiratory chemoreceptors are coordinated to protect blood gases against potentially deleterious fluctuations. However, the mathematics of the steady-state interaction between chemoreceptors has been difficult to ascertain. Further, how this interaction affects time-dependent phenomena (in which chemoresponses depend upon previous experience) is largely unknown. To determine how central PCO2 modulates the response to peripheral chemostimulation in the rat, we utilized an in situ arterially perfused, vagotomized, decerebrate preparation, in which central and peripheral chemoreceptors were perfused separately (i.e. dual perfused preparation (DPP)). We carried out two sets of experiments: in Experiment 1, we alternated steady-state brainstem PCO2 between 25 and 50 Torr in each preparation, and applied specific carotid body hypoxia (60 Torr PO2 and 40 Torr PCO2) under both conditions; in Experiment 2, we applied four 5 min bouts (separated by 5 min) of specific carotid body hypoxia (60 Torr PO2 and 40 Torr PCO2) while holding the brainstem at either 30 Torr or 50 Torr PCO2. We demonstrate that the level of brainstem PCO2 modulates (a) the magnitude of the phrenic responses to a single step of specific carotid body hypoxia and (b) the magnitude of time-dependent phenomena. We report that the interaction between chemoreceptors is negative (i.e. hypo-additive), whereby a lower brainstem PCO2 augments phrenic responses resulting from specific carotid body hypoxia. A negative interaction may underlie the pathophysiology of central sleep apnoea in populations that are chronically hypocapnic. PMID:17082232

  14. EPAC signalling pathways are involved in low PO2 chemoreception in carotid body chemoreceptor cells

    PubMed Central

    Rocher, Asuncion; Caceres, Ana I; Almaraz, Laura; Gonzalez, Constancio

    2009-01-01

    Chemoreceptor cells of the carotid bodies (CB) are activated by hypoxia and acidosis, responding with an increase in their rate of neurotransmitter release, which in turn increases the electrical activity in the carotid sinus nerve and evokes a homeostatic hyperventilation. Studies in isolated chemoreceptor cells have shown that moderate hypoxias (≈ 46 mmHg) produces smaller depolarisations and comparable Ca2+ transients but a much higher catecholamine (CA) release response in intact CBs than intense acidic/hypercapnic stimuli (20% CO2, pH 6.6). Similarly, intense hypoxia (≈ 20 mmHg) produces smaller depolarizations and Ca2+ transients in isolated chemoreceptor cells but a higher CA release response in intact CBs than a pure depolarizing stimulus (30–35 mm external K+). Studying the mechanisms responsible for these differences we have found the following. (1) Acidic hypercapnia inhibited ICa (∼60%; whole cell) and CA release (∼45%; intact CB) elicited by ionomycin and high K+. (2) Adenylate cyclase inhibition (SQ-22536; 80 μm) inhibited the hypoxic release response (>50%) and did not affect acidic/hypercapnic release, evidencing that the high gain of hypoxia to elicit neurotransmitter release is cAMP dependent. (3) The last effect was independent of PKA activation, as three kinase inhibitors (H-89, KT 5720 and Rp-cAMP; ≥ 10 × IC50) did not alter the hypoxic release response. (4) The Epac (exchange protein activated by cAMP) activator (8-pCPT-2′-O-Me-cAMP, 100 μm) reversed the effects of the cyclase inhibitor. (5) The Epac inhibitor brefeldin A (100 μm) inhibited (54%) hypoxic induced release. Our findings show for the first time that an Epac-mediated pathway mediates O2 sensing/transduction in chemoreceptor cells. PMID:19581380

  15. Management of dogs and cats with endotracheal tube tracheal foreign bodies.

    PubMed

    Nutt, Laura K; Webb, Jinelle A; Prosser, Kirsten J; Defarges, Alice

    2014-06-01

    Two cats and 3 dogs were treated for an endotracheal tube tracheal foreign body (ETFB) during recovery from general anesthesia. Bronchoscopy was used to remove the ETFB. Animals were clinically normal at discharge. While rare, ETFB can occur upon recovery from anesthesia. Bronchoscopy is an effective way to remove ETFB. PMID:24891640

  16. Variations in leopard cat (Prionailurus bengalensis) skull morphology and body size: sexual and geographic influences

    PubMed Central

    Oliveira, Luiz Flamarion B.

    2015-01-01

    The leopard cat, Prionailurus bengalensis (Kerr, 1792), is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges) were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads, the longer hind

  17. Variations in leopard cat (Prionailurus bengalensis) skull morphology and body size: sexual and geographic influences.

    PubMed

    Sicuro, Fernando L; Oliveira, Luiz Flamarion B

    2015-01-01

    The leopard cat, Prionailurus bengalensis (Kerr, 1792), is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges) were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads, the longer hind

  18. Assessment of body composition in cats and dogs.

    PubMed

    Munday, H S

    1994-06-01

    The assessment of body composition in any species is important to the understanding of subjects such as the control of obesity, the realimentation of sick animals and the evaluation of energy requirements. In most cases our requirement is to assess the chemical constituents of the body by the measurement of the fat and fat-free mass (FFM) of the subject. There may also be a requirement to break down the FFM mass into its component parts and measure the tissue distribution within the body. Clearly in the understanding of the causes and effects of obesity in companion animals, the evaluation of the actual level of obesity is fundamental. Similarly, whilst classifying the effectiveness of a weight loss programme it is vital that the reduction in weight loss and the distribution of tissue types can be accurately recorded by the veterinary surgeon or clinician. This review covers the theory of body composition measurement and the techniques which have been developed, together with their relevance to studies with companion animals. Most techniques are based on indirect methods which use the model of the body being at least two chemically distinct compartments, the fat and the FFM. In more complex analyses four and even six compartment models are considered which include concepts such as protein content, cell and osseous mineral content. The techniques to be covered include the measurement of total body water (for example by the use of isotope dilution), anthropometric techniques (skinfold thickness and dimensional evaluation), densitometry, total body potassium, muscle metabolite markers, absorptiometry, neutron activation analysis, electrical conductance, ultrasound, near infrared interactance, computed tomography and magnetic resonance imaging.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8087160

  19. Carotid body denervation improves autonomic and cardiac function and attenuates disordered breathing in congestive heart failure

    PubMed Central

    Marcus, Noah J; Rio, Rodrigo; Schultz, Evan P; Xia, Xiao-Hong; Schultz, Harold D

    2014-01-01

    In congestive heart failure (CHF), carotid body (CB) chemoreceptor activity is enhanced and is associated with oscillatory (Cheyne–Stokes) breathing patterns, increased sympathetic nerve activity (SNA) and increased arrhythmia incidence. We hypothesized that denervation of the CB (CBD) chemoreceptors would reduce SNA, reduce apnoea and arrhythmia incidence and improve ventricular function in pacing-induced CHF rabbits. Resting breathing, renal SNA (RSNA) and arrhythmia incidence were measured in three groups of animals: (1) sham CHF/sham–CBD (sham–sham); (2) CHF/sham–CBD (CHF–sham); and (3) CHF/CBD (CHF–CBD). Chemoreflex sensitivity was measured as the RSNA and minute ventilatory () responses to hypoxia and hypercapnia. Respiratory pattern was measured by plethysmography and quantified by an apnoea–hypopnoea index, respiratory rate variability index and the coefficient of variation of tidal volume. Sympatho-respiratory coupling (SRC) was assessed using power spectral analysis and the magnitude of the peak coherence function between tidal volume and RSNA frequency spectra. Arrhythmia incidence and low frequency/high frequency ratio of heart rate variability were assessed using ECG and blood pressure waveforms, respectively. RSNA and responses to hypoxia were augmented in CHF–sham and abolished in CHF–CBD animals. Resting RSNA was greater in CHF–sham compared to sham–sham animals (43 ± 5% max vs. 23 ± 2% max, P < 0.05), and this increase was not found in CHF–CBD animals (25 ± 1% max, P < 0.05 vs. CHF–sham). Low frequency/high frequency heart rate variability ratio was similarly increased in CHF and reduced by CBD (P < 0.05). Respiratory rate variability index, coefficient of variation of tidal volume and apnoea–hypopnoea index were increased in CHF–sham animals and reduced in CHF–CBD animals (P < 0.05). SRC (peak coherence) was increased in CHF–sham animals (sham–sham 0.49 ± 0.05; CHF–sham 0.79

  20. Oxygen sensing by the carotid body: mechanisms and role in adaptation to hypoxia.

    PubMed

    López-Barneo, José; González-Rodríguez, Patricia; Gao, Lin; Fernández-Agüera, M Carmen; Pardal, Ricardo; Ortega-Sáenz, Patricia

    2016-04-15

    Oxygen (O2) is fundamental for cell and whole-body homeostasis. Our understanding of the adaptive processes that take place in response to a lack of O2(hypoxia) has progressed significantly in recent years. The carotid body (CB) is the main arterial chemoreceptor that mediates the acute cardiorespiratory reflexes (hyperventilation and sympathetic activation) triggered by hypoxia. The CB is composed of clusters of cells (glomeruli) in close contact with blood vessels and nerve fibers. Glomus cells, the O2-sensitive elements in the CB, are neuron-like cells that contain O2-sensitive K(+)channels, which are inhibited by hypoxia. This leads to cell depolarization, Ca(2+)entry, and the release of transmitters to activate sensory fibers terminating at the respiratory center. The mechanism whereby O2modulates K(+)channels has remained elusive, although several appealing hypotheses have been postulated. Recent data suggest that mitochondria complex I signaling to membrane K(+)channels plays a fundamental role in acute O2sensing. CB activation during exposure to low Po2is also necessary for acclimatization to chronic hypoxia. CB growth during sustained hypoxia depends on the activation of a resident population of stem cells, which are also activated by transmitters released from the O2-sensitive glomus cells. These advances should foster further studies on the role of CB dysfunction in the pathogenesis of highly prevalent human diseases. PMID:26764048

  1. Carotid artery intima-media thickness and distensibility in children and adolescents: reference values and role of body dimensions.

    PubMed

    Doyon, Anke; Kracht, Daniela; Bayazit, Aysun K; Deveci, Murat; Duzova, Ali; Krmar, Rafael T; Litwin, Mieczyslaw; Niemirska, Anna; Oguz, Berna; Schmidt, Bernhard M W; Sözeri, Betul; Querfeld, Uwe; Melk, Anette; Schaefer, Franz; Wühl, Elke

    2013-09-01

    Carotid intima-media thickness (cIMT) and carotid artery distensibility are reliable screening methods for vascular alterations and the assessment of cardiovascular risk in adult and pediatric cohorts. We sought to establish an international reference data set for the childhood and adolescence period and explore the impact of developmental changes in body dimensions and blood pressure (BP) on carotid wall thickness and elasticity. cIMT, the distensibility coefficient, the incremental modulus of elasticity, and the stiffness index β were assessed in 1155 children aged 6 to 18 years and sex-specific reference charts normalized to age or height were constructed from 1051 nonobese and nonhypertensive children. The role of body dimensions, BP, and family history, as well as the association between cIMT and distensibility, was investigated. cIMT increased and distensibility decreased with age, height, body mass index, and BP. A significant sex difference was apparent from the age of 15 years. Age- and height-normalized cIMT and distensibility values differed in children who are short or tall for their age. By stepwise multivariate analysis, standardized systolic BP and body mass index were independently positively associated with cIMT SD scores (SDS). Systolic BP SDS independently predicted all distensibility measures. Distensibility coefficient SDS was negatively and β SDS positively associated with cIMT SDS, whereas incremental modulus of elasticity was independent of cIMT. Morphological and functional aspects of the common carotid artery are particularly influenced by age, body dimensions, and BP. The reference charts established in this study allow to accurately compare vascular phenotypes of children with chronic conditions with those of healthy children. PMID:23817494

  2. Extracellular potassium and chemosensitivity in the rat carotid body, in vitro.

    PubMed Central

    Pepper, D R; Landauer, R C; Kumar, P

    1996-01-01

    1. The effects of raising extracellular potassium concentration ([K+]o) from 3.0 to 5.3, 9.5 or 16.8 mM on chemoreceptor responses to hypoxia, hypercapnia and asphyxia were examined in a superfused in vitro rat carotid body preparation. 2. Single-exponential functions with offset were fitted to the chemoreceptor discharge responses to ramp decreases in Po2. Increasing [K+]o was without effect upon the rate constants of the fitted exponential functions (P > 0.20). Increasing [K+]o, significantly increased the horizontal asymptote (chemoreceptor discharge in hyperoxia) in a non-linear fashion when all levels of [K+]o were included in the analysis (P < 0.001) but not when a comparison was made only between 3.0 and 5.3 mM Ko+ (P > 0.40). The rightward position of the response curves, as quantified by the Po2 at 50% maximum discharge, was linearly related to [K+]o but only when all levels of [K+]o were included in the analysis (P < 0.03). Chemoreceptor sensitivity to [K+]o increased non-linearly as [K+]o was increased but this effect was not dependent upon the Po2 (P > 0.90). 4. Increasing PCO2 in hyperoxia increased chemoreceptor discharge linearly at all levels of [K+]o. Whilst discharge at any level of PCO2 was elevated by increased levels of [K+]o, raising [K+]o did not increase CO2 sensitivity (P > 0.20). Similarly, increasing PCO2 did not increase chemosensitivity to [K+]o. The lack of effect of [K+]o upon CO2 chemosensitivity was also observed as Po2 was decreased to hypoxic levels (P > 0.10). 5. Our data demonstrate that an elevation of [K+]o can increase chemoreceptor discharge in the in vitro carotid body in a PO2- and PCO2-independent manner, suggesting that the PO2-dependent effects of [K+]o, previously reported in vivo may be due to other indirect effects of [K+]o or hypoxia. PMID:8799903

  3. Almitrine has no effect on gas exchange after bilateral carotid body resection in severe chronic airflow obstruction.

    PubMed

    De Backer, W; Vermeire, P; Bogaert, E; Janssens, E; Van Maele, R

    1985-01-01

    Using a double-blind cross-over design, a single dose of 100 mg almitrine bismesylate and placebo were administered orally to eight patients with chronic airflow obstruction having undergone bilateral carotid body resection (BCBR) up to two years earlier to alleviate their extreme dyspnoea. In an open study, two other patients have been given almitrine before and three weeks after BCBR. In all patients, arterial blood gases, ventilation and breathing patterns, neuromuscular drive and hypoxic responsiveness have been studied before and three hours after drug administration. Almitrine failed to improve gas exchange in the patients with BCBR, nor did it affect ventilation, ventilatory or hypoxic drive. In the patients studied before and after BCBR, almitrine only improved gas exchange significantly before BCBR. It is concluded that in man almitrine acts solely as a peripheral chemoreceptor agonist and that the well-documented improvement in V/Q relationship is mediated through carotid body stimulation. PMID:3904873

  4. Multidisciplinary Management of Carotid Body Tumors in a Tertiary Urban Institution

    PubMed Central

    Galyfos, George; Stamatatos, Ioannis; Kerasidis, Stavros; Stefanidis, Ioannis; Giannakakis, Sotirios; Kastrisios, Georgios; Geropapas, Georgios; Papacharalampous, Gerasimos; Maltezos, Chrisostomos

    2015-01-01

    Objective. Aim of this study is to present the experience of our institution in carotid body tumors (CBTs) treatment. Methods. All cases treated in a Vascular Surgery Department within 2.5 years (03/2013–09/2015) were retrospectively evaluated. Demographics, diagnostic, and treatment strategy were recorded. All patients with known CBT underwent ultrasound and magnetic resonance imaging preoperatively. All cases were classified according to the Shamblin type and evaluated by a radiologist, otolaryngologist, and anesthesiologist before and after surgery. Major outcomes included mortality, stroke, cranial nerve injury, and recurrence. Results. Overall, nine patients (mean age: 59.5 ± 16.3 years) with a total of ten CBTs were treated. There was no gender prevalence and most of the cases (55%) were asymptomatic. There were no functional or familial cases. There was only one bilateral case treated in a staged manner. No preoperative embolization of CBTs was performed. Mortality and stroke rates were null. No severe complication was observed in the early and late setting. No malignancy was recorded. Mean follow-up was 15.6 ± 7.8 months. Conclusions. Multidisciplinary management of patients with CBTs is imperative for optimal results, especially in type III tumors, bilateral or functional cases. After careful treatment planning and intraoperative manipulations, complications could be avoided even without preoperative embolization. PMID:26783464

  5. The neurogenic niche in the carotid body and its applicability to antiparkinsonian cell therapy.

    PubMed

    López-Barneo, José; Pardal, Ricardo; Ortega-Sáenz, Patricia; Durán, Rocío; Villadiego, Javier; Toledo-Aral, Juan José

    2009-08-01

    The carotid body (CB) is a neural crest-derived organ whose major function is to sense changes in arterial O(2) tension to elicit hyperventilation during hypoxia. The CB is composed of clusters of neuron-like glomus, or type I, cells that are highly dopaminergic and contain large amounts of the glial cell line-derived neurotrophic factor (GDNF). Glomus cells are enveloped by glia-like sustentacular, or type II, cells. In chronic hypoxia the CB grows with increase in glomus cell number. This adaptive response depends on a collection of neural progenitors that can be isolated and induced to form clonal neurospheres in vitro. CB neurospheres contain numerous newly differentiated glomus cells, which maintain their functional properties and the ability to synthesize dopamine and GDNF. Intrastriatal CB transplants have been assayed in animal models of Parkinson's disease (PD) to test whether they increase the striatal dopamine levels and/or exert a neuroprotective action on the nigrostriatal pathway. Two pilot safety studies performed on PD patients subjected to CB autotransplantation have suggested that a major limitation of this technique is the small size of the organ. This could, however, be overcome by the in vitro formation of new CB tissue derived from adult CB stem cells. PMID:19263191

  6. Neuroprotective and reparative effects of carotid body grafts in a chronic MPTP model of Parkinson's disease.

    PubMed

    Muñoz-Manchado, Ana B; Villadiego, Javier; Suárez-Luna, Nela; Bermejo-Navas, Alfonso; Garrido-Gil, Pablo; Labandeira-García, José L; Echevarría, Miriam; López-Barneo, José; Toledo-Aral, Juan J

    2013-03-01

    Intrastriatal transplantation of dopaminergic carotid body (CB) cells ameliorates parkinsonism in animal models and, with less efficacy, in Parkinson's disease patients. CB-based cell therapy was initially proposed because of its high dopamine content. However, later studies suggested that its beneficial effect might be due to a trophic action exerted on nigrostriatal neurons. Compatible with this concept are the high levels of neurotrophic factors encountered in CB cells. To test experimentally this idea, unilateral striatal transplants were performed with a sham graft in the contralateral striatum, as a robust internal control. Thereafter, the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6, -tetrahydropyridine was injected during 3 months. CB grafts protected from degeneration ipsilateral nigral dopaminergic neurons projecting to the transplant in a dose-dependent manner regarding size and glial cell line-derived neurotrophic factor expression. Grafts performed at different times after the onset of the neurotoxic treatment demonstrated with histological and behavioral methods protection and repair of the nigrostriatal pathway by CB transplants. This study provides a mechanistic explanation for the action of CB transplants on parkinsonian models. It should also help to improve cell therapy approaches to Parkinson's disease. PMID:22743091

  7. Histochemical demonstration of tripeptidyl aminopeptidase I in the rat carotid body.

    PubMed

    Atanasova, Dimitrinka; Lazarov, Nikolai

    2015-03-01

    Tripeptidyl aminopeptidase I (TPP I) is a lysosomal exopeptidase that is widely distributed throughout the central nervous system (CNS) and internal organs in many mammalian species. The enzyme is involved in the breakdown of collagen and different peptides. The carotid body (CB) is the main peripheral arterial chemoreceptor playing an important role in the control of breathing and the autonomic control of cardiovascular function. In response to hypoxia its neuron-like glomus cells release a variety of peptide transmitters that trigger an action potential through the afferent fibers, thus conveying the chemosensory information to the CNS. In the present study we investigated the histochemical localization of TPP I in the CB of rats. Enzyme histochemistry showed high activity of TPP I in CB glomeruli. In particular, the glomus cells contained many TPP I-positive granules, while the glial-like sustentacular cells displayed a slightly fainter reaction. The interglomerular connective tissue was also weakly stained. The results show that both the parenchymal cells of the rat CB express, albeit with different intensity, TPP I. Taken together with our previous enzyme histochemical investigations on the rat CB, it seems likely that the glomus cells possess enzymatic equipment necessary for the neuropeptide intracellular and collagen extracellular initial degradation. These findings also suggest that TPP I is involved in the general turnover of chemotransmitters between glomus cells and sensory nerve endings which emphasizes its importance for chemoreception under hypoxic conditions. PMID:25636608

  8. Central role of carotid body chemoreceptors in disordered breathing and cardiorenal dysfunction in chronic heart failure

    PubMed Central

    Marcus, Noah J.; Del Rio, Rodrigo; Schultz, Harold D.

    2014-01-01

    Oscillatory breathing (OB) patterns are observed in pre-term infants, patients with cardio-renal impairment, and in otherwise healthy humans exposed to high altitude. Enhanced carotid body (CB) chemoreflex sensitivity is common to all of these populations and is thought to contribute to these abnormal patterns by destabilizing the respiratory control system. OB patterns in chronic heart failure (CHF) patients are associated with greater levels of tonic and chemoreflex-evoked sympathetic nerve activity (SNA), which is associated with greater morbidity and poor prognosis. Enhanced chemoreflex drive may contribute to tonic elevations in SNA by strengthening the relationship between respiratory and sympathetic neural outflow. Elimination of CB afferents in experimental models of CHF has been shown to reduce OB, respiratory-sympathetic coupling, and renal SNA, and to improve autonomic balance in the heart. The CB chemoreceptors may play an important role in progression of CHF by contributing to respiratory instability and OB, which in turn further exacerbates tonic and chemoreflex-evoked increases in SNA to the heart and kidney. PMID:25505417

  9. Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

    PubMed

    Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

    2015-01-01

    Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB. PMID:26742253

  10. Carotid intima media thickness is associated with body fat abnormalities in HIV-infected patients

    PubMed Central

    2014-01-01

    Background HIV-infected patients may be at increased risk of cardiovascular (CV) events, and lipodystrophy is generally associated with proatherogenic metabolic disturbances. Carotid intima-media thickness (cIMT) has been used as a surrogate marker for atherosclerosis and it has been shown to be an independent risk factor for CV disease. Our objective was to evaluate cIMT in HIV-infected patients on combined anti-retroviral therapy (cART) with and without lipodystrophy defined by fat mass ratio (L-FMR), and to determine the association of lipodystrophy and visceral obesity [(visceral (VAT), subcutaneous adipose tissue (SAT) volume and VAT/SAT ratio, objectively evaluated by CT scan] with cIMT. Methods Cross-sectional study of 199 HIV-infected patients. Body composition by DXA and abdominal CT, lipids, blood pressure, inflammatory markers, and cIMT by ultrasonography were performed. L-FMR was defined as the ratio of the percentage of trunk fat mass to the percentage of lower limb fat mass by DXA. Categorical variables were compared using the chi-square or Fisher’s exact test. Spearman correlation coefficients were estimated to study the association between cIMT and clinical and metabolic characteristics. Means of cIMT, adjusted for age, were calculated, using generalized linear models. Results L-FMR was present in 41.2% of patients and cIMT was higher in these patients [0.81 (0.24) vs. 0.76 (0.25); p = 0.037)]. Lipodystrophic patients had higher VAT and VAT/SAT ratio and lower SAT. cIMT was associated with lipodystrophy evaluated by FMR, trunk fat, total abdominal fat, VAT and VAT/SAT ratio. No association was observed between cIMT and leg fat mass. Using generalized linear models, cIMT means were adjusted for age and no significant differences remained after this adjustment. The adjusted mean of cIMT was 0.787 (95% CI: 0.751-0.823) in patients without lipodystrophy, and 0.775 (95% CI: 0.732-0.817) in those with lipodystrophy (p = 0.671). Conclusions

  11. Contractile responses in bladder body, bladder neck and prostate from rat, guinea pig and cat.

    PubMed

    Cohen, M L; Drey, K

    1989-03-01

    Lower urinary tract smooth muscle displays marked heterogeneity in pharmacologic responsiveness to contractile agents. The present study details differences among species with regard to muscarinic, adrenergic, histaminergic and serotonergic agonists in the bladder body, bladder neck and prostate from guinea pig, rat and cat. Under in vitro conditions, all smooth muscle preparations contracted to potassium chloride. The muscarinic agonist, carbamylcholine, produced maximal contraction, whereas alpha receptor agonists exerted only minimal, if any, effect in bladder body preparations from all three species. In contrast, alpha receptor-mediated responses predominated relative to muscarinic responses in bladder neck preparations from all three species. Prostatic contractility was examined in tissue from guinea pig and rat and contraction occurred to both alpha and muscarinic receptor agonists. Contractile response to norepinephrine in bladder neck and prostate was potentiated by neuronal uptake inhibition but not by beta receptor blockade. Serotonin and histamine exhibited more diverse effects among species and tissues. In general, histamine contracted all three tissues from guinea pig with minimal contraction occurring in tissues from rat or cat. On the other hand, serotonin markedly contracted the cat bladder body and rat prostate, but exerted no effect on tissues from the guinea pig. These data reinforce and detail the heterogeneity of pharmacologic contractile responses in lower urinary tract smooth muscle. Furthermore, the studies document the relative similarity among species in cholinergic and adrenergic responsiveness and the dissimilarity among species in serotonergic and histaminergic responsiveness of lower urinary tract smooth muscle. PMID:2539454

  12. Acute hypoxia modifies cAMP levels induced by inhibitors of phosphodiesterase-4 in rat carotid bodies, carotid arteries and superior cervical ganglia

    PubMed Central

    Nunes, Ana R; Batuca, Joana R; Monteiro, Emília C

    2010-01-01

    Background and purpose: Phosphodiesterase (PDE) inhibitors are useful to treat hypoxia-related diseases and are used in experiments studying the effects of oxygen on 3′-5′-cyclic adenosine monophosphate (cAMP) production. We studied the effects of acute hypoxia on cAMP accumulation induced by PDE inhibitors in oxygen-specific chemosensors, the carotid bodies (CBs) and in non-chemosensitive CB-related structures: carotid arteries (CAs) and superior cervical ganglia (SCG). Experimental approach: Concentration–response curves for the effects of a non-specific PDE inhibitor [isobutylmethylxanthine (IBMX) ], PDE4 selective inhibitors (rolipram, Ro 20-1724) and a PDE2 selective inhibitor (erythro-9-(2-hydroxy-3-nonyl)adenine) on cAMP levels were obtained in normoxic (20% O2/5% CO2) or hypoxic (5% O2/5% CO2) conditions. Key results: Responses to the PDE inhibitors were compatible with the presence of PDE4 in rat CBs, CAs and SCG but in the absence of PDE2 in CAs and CBs. Acute hypoxia enhanced the effects of IBMX and PDE4 inhibitors on cAMP accumulation in CAs and CBs. In SCG, acute hypoxia reduced cAMP accumulation induced by all the four PDE inhibitors tested. Differences between the effects of Ro 20-1724 and rolipram on cAMP were found in CAs and CBs during hypoxia. Conclusions and implications: The effects of PDE4 inhibitors could be potentiated or inhibited by acute hypoxia depending on the PDE isoforms of the tissue. The similarities between the characterization of PDE4 inhibitors at the CBs and CAs, under normoxia and hypoxia, did not support a specific role for cAMP in the oxygen-sensing machinery at the CB and suggested that no direct CB-mediated, hyperventilatory, adverse effects would be expected with administration of PDE4 inhibitors. PMID:20082613

  13. Intermittent Hypoxia-Induced Carotid Body Chemosensory Potentiation and Hypertension Are Critically Dependent on Peroxynitrite Formation

    PubMed Central

    Moya, Esteban A.; Arias, Paulina; Varela, Carlos; Oyarce, María P.; Del Rio, Rodrigo; Iturriaga, Rodrigo

    2016-01-01

    Oxidative stress is involved in the development of carotid body (CB) chemosensory potentiation and systemic hypertension induced by chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea. We tested whether peroxynitrite (ONOO−), a highly reactive nitrogen species, is involved in the enhanced CB oxygen chemosensitivity and the hypertension during CIH. Accordingly, we studied effects of Ebselen, an ONOO− scavenger, on 3-nitrotyrosine immunoreactivity (3-NT-ir) in the CB, the CB chemosensory discharge, and arterial blood pressure (BP) in rats exposed to CIH. Male Sprague-Dawley rats were exposed to CIH (5% O2, 12 times/h, 8 h/day) for 7 days. Ebselen (10 mg/kg/day) was administrated using osmotic minipumps and BP measured with radiotelemetry. Compared to the sham animals, CIH-treated rats showed increased 3-NT-ir within the CB, enhanced CB chemosensory responses to hypoxia, increased BP response to acute hypoxia, and hypertension. Rats treated with Ebselen and exposed to CIH displayed a significant reduction in 3-NT-ir levels (60.8 ± 14.9 versus 22.9 ± 4.2 a.u.), reduced CB chemosensory response to 5% O2 (266.5 ± 13.4 versus 168.6 ± 16.8 Hz), and decreased mean BP (116.9 ± 13.2 versus 82.1 ± 5.1 mmHg). Our results suggest that CIH-induced CB chemosensory potentiation and hypertension are critically dependent on ONOO− formation. PMID:26798430

  14. An evaluation on management of carotid body tumour (CBT). A twelve years experience*

    PubMed Central

    BOSCARINO, G.; PARENTE, E.; MINELLI, F.; FERRANTE, A.; SNIDER, F.

    2014-01-01

    Summary Objectives Carotid Body Tumor (CBT) is a rare lesion of the neuroendocrine system but it is the most common form of head and neck paraganglioma (PGL). Our objective is to discuss the optimal management of these lesions to provide the best outcome of patients treated by surgical resection. Patients and Methods A retrospective evaluation was obtained by review of the records of 20 patients with 26 CBT treated at our institution between 2000 and 2012. Primary tumor characteristics, diagnostic protocols, surgical treatment, short and long-term outcomes were collected and analyzed. Results A total of 26 CBTs resections were performed on 20 patients; the age range was 21–89 years. There was a female prevalence (14 women-80% and 6 men-20%). Familial cases occurred in 6 patients (30%); of these, 3 patients had bilateral lesions and 1 patient multiple paragangliomas. In all cases no lymph node metastasis was found. All lesions were grouped into three groups according to the latero-lateral diameter: Group I < 3 cm; Group II 3<>5cm; Group III >5cm. All patients were managed by surgical resection of the CBT. There were no operative deaths. Overall we found transitory neurological impairment in 15,3% and permanent neurological deficit in 7,6% of cases. No complications occurred in all resections of Group I tumors. In Group II only 1 resection was followed by dysphonia by recurrent nerve palsy (after vagal nerve en-bloc resection). In Group III only 1 resection was followed by permanent vagus nerve palsy. Conclusions Surgical removal of the tumor is the only treatment that can ensure a complete eradication of the disease. Family screening is of great importance in patients with hereditary forms. Careful preoperative planning of surgical procedure by integrated diagnostic imaging and a full mastery of the surgical technique can minimize the risk of the most common postoperative complications. Lifelong follow-up is mandatory to make early diagnosis of recurrent disease

  15. Comparative gene expression profile of mouse carotid body and adrenal medulla under physiological hypoxia

    PubMed Central

    Ganfornina, MD; Pérez-García, MT; Gutiérrez, G; Miguel-Velado, E; López-López, JR; Marín, A; Sánchez, D; González, C

    2005-01-01

    The carotid body (CB) is an arterial chemoreceptor, bearing specialized type I cells that respond to hypoxia by closing specific K+ channels and releasing neurotransmitters to activate sensory axons. Despite having detailed information on the electrical and neurochemical changes triggered by hypoxia in CB, the knowledge of the molecular components involved in the signalling cascade of the hypoxic response is fragmentary. This study analyses the mouse CB transcriptional changes in response to low PO2 by hybridization to oligonucleotide microarrays. The transcripts were obtained from whole CBs after mice were exposed to either normoxia (21% O2), or physiological hypoxia (10% O2) for 24 h. The CB transcriptional profiles obtained under these environmental conditions were subtracted from the profile of control non-chemoreceptor adrenal medulla extracted from the same animals. Given the common developmental origin of these two organs, they share many properties but differ specifically in their response to O2. Our analysis revealed 751 probe sets regulated specifically in CB under hypoxia (388 up-regulated and 363 down-regulated). These results were corroborated by assessing the transcriptional changes of selected genes under physiological hypoxia with quantitative RT-PCR. Our microarray experiments revealed a number of CB-expressed genes (e.g. TH, ferritin and triosephosphate isomerase) that were known to change their expression under hypoxia. However, we also found novel genes that consistently changed their expression under physiological hypoxia. Among them, a group of ion channels show specific regulation in CB: the potassium channels Kir6.1 and Kcnn4 are up-regulated, while the modulatory subunit Kcnab1 is down-regulated by low PO2 levels. PMID:15890701

  16. Carotid Body Ablation Abrogates Hypertension and Autonomic Alterations Induced by Intermittent Hypoxia in Rats.

    PubMed

    Del Rio, Rodrigo; Andrade, David C; Lucero, Claudia; Arias, Paulina; Iturriaga, Rodrigo

    2016-08-01

    Chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea, enhances carotid body (CB) chemosensory responses to hypoxia and produces autonomic dysfunction, cardiac arrhythmias, and hypertension. We tested whether autonomic alterations, arrhythmogenesis, and the progression of hypertension induced by CIH depend on the enhanced CB chemosensory drive, by ablation of the CB chemoreceptors. Male Sprague-Dawley rats were exposed to control (Sham) conditions for 7 days and then to CIH (5% O2, 12/h 8 h/d) for a total of 28 days. At 21 days of CIH exposure, rats underwent bilateral CB ablation and then exposed to CIH for 7 additional days. Arterial blood pressure and ventilatory chemoreflex response to hypoxia were measured in conscious rats. In addition, cardiac autonomic imbalance, cardiac baroreflex gain, and arrhythmia score were assessed during the length of the experiments. In separate experimental series, we measured extracellular matrix remodeling content in cardiac atrial tissue and systemic oxidative stress. CIH induced hypertension, enhanced ventilatory response to hypoxia, induced autonomic imbalance toward sympathetic preponderance, reduced baroreflex gain, and increased arrhythmias and atrial fibrosis. CB ablation normalized blood pressure, reduced ventilatory response to hypoxia, and restored cardiac autonomic and baroreflex function. In addition, CB ablation reduced the number of arrhythmias, but not extracellular matrix remodeling or systemic oxidative stress, suggesting that reductions in arrhythmia incidence during CIH were related to normalization of cardiac autonomic balance. Present results show that autonomic alterations induced by CIH are critically dependent on the CB and support a main role for the CB in the CIH-induced hypertension. PMID:27381902

  17. Study of the effects of age and body mass index on the carotid wall vibration: extraction methodology and analysis.

    PubMed

    Yousefi Rizi, Fereshteh; Setarehdan, Seyed Kamaledin; Behnam, Hamid; Alizadeh Sani, Zahra

    2014-07-01

    This study aims to non-invasively extract the vibrations of the carotid wall and evaluate the changes in the carotid artery wall caused by age and obesity. Such evaluation can increase the possibility of detecting wall stiffness and atherosclerosis in its early stage. In this study, a novel method that uses a phase-tracking method based on the continuous wavelet transform calculates the carotid wall motion from the ultrasound radio frequency signals. To extract the high-frequency components of the wall motion, wall vibration, the empirical mode decomposition was then used. The posterior wall (intima-media) motion and vibration were extracted for 54 healthy volunteers (mean age: 33.87 ± 14.73 years), including 13 overweight subjects (body mass index > 25) and 14 female participants using their radio frequency signals. The results showed that the dominant frequency of the wall vibration correlates with age (r = -0.5887, p < 0.001) and body mass index (r = -0.4838, p < 0.001). The quantitative analysis further demonstrated that the dominant frequency of the vibration in the radial direction of the carotid wall decreases by age and is lower in overweight subjects. Besides, the peak-to-peak amplitude of the wall vibration showed significant correlations with age (r = -0.5456, p < 0.001) and body mass index (r = -0.5821, p < 0.001). The peak-to-peak amplitude also decreases by age and is lower in overweight subjects. However, there were no significant correlations between these features of the wall vibrations and systolic/diastolic blood pressure and sex. Our proposed measures were certified using the calculated arterial stiffness indices. The average power spectrum of the elderly subjects'wall motion in the frequency range of the wall vibration (>100 Hz) is decreased more in comparison with the young subjects. Our results revealed that the proposed method may be useful for detecting the stiffness and distortion in the carotid wall that occur prior to wall thickening

  18. Peripheral chemoreceptors determine the respiratory sensitivity of central chemoreceptors to CO2 : role of carotid body CO2.

    PubMed

    Smith, Curtis A; Blain, Grégory M; Henderson, Kathleen S; Dempsey, Jerome A

    2015-09-15

    We asked if the type of carotid body (CB) chemoreceptor stimulus influenced the ventilatory gain of the central chemoreceptors to CO2 . The effect of CB normoxic hypocapnia, normocapnia and hypercapnia (carotid body PCO2 ≈ 22, 41 and 68 mmHg, respectively) on the ventilatory CO2 sensitivity of central chemoreceptors was studied in seven awake dogs with vascularly-isolated and extracorporeally-perfused CBs. Chemosensitivity with one CB was similar to that in intact dogs. In four CB-denervated dogs, absence of hyper-/hypoventilatory responses to CB perfusion with PCO2 of 19-75 mmHg confirmed separation of the perfused CB circulation from the brain. The group mean central CO2 response slopes were increased 303% for minute ventilation (V̇I)(P ≤ 0.01) and 251% for mean inspiratory flow rate (VT /TI ) (P ≤ 0.05) when the CB was hypercapnic vs. hypocapnic; central CO2 response slopes for tidal volume (VT ), breathing frequency (fb ) and rate of rise of the diaphragm EMG increased in 6 of 7 animals but the group mean changes did not reach statistical significance. Group mean central CO2 response slopes were also increased 237% for V̇I(P ≤ 0.01) and 249% for VT /TI (P ≤ 0.05) when the CB was normocapnic vs. hypocapnic, but no significant differences in any of the central ventilatory response indices were found between CB normocapnia and hypercapnia. These hyperadditive effects of CB hyper-/hypocapnia agree with previous findings using CB hyper-/hypoxia.We propose that hyperaddition is the dominant form of chemoreceptor interaction in quiet wakefulness when the chemosensory control system is intact, response gains physiological, and carotid body chemoreceptors are driven by a wide range of O2 and/or CO2 . PMID:26171601

  19. Properties of a transient K+ current in chemoreceptor cells of rabbit carotid body.

    PubMed Central

    López-López, J R; De Luis, D A; Gonzalez, C

    1993-01-01

    1. Adult rabbit carotid body chemoreceptor cells, enzymatically dispersed and short-term cultured, exhibit an inactivating outward K+ current that is reversibly inhibited by low PO2. In the present work we have characterized the biophysical and pharmacological properties of this current using the whole-cell voltage clamp recording technique. 2. Inactivating current was recorded after blockage of Ca2+ currents with extracellular Co2+, Cd2+, or after complete washing out of Ca2+ channels. 3. The threshold of activation of this inactivating current was about -40 mV. Current activated very quickly (mean rise time 4.8 +/- 0.42 ms at +60 mV) but inactivated more slowly. Inactivation was well fitted by two exponentials with time constants of 79.7 +/- 6.6 and 824 +/- 42.8 ms (at +40 mV). The inactivation process showed a little voltage dependence. 4. The steady-state inactivation was well fitted by a Boltzman function. Inactivation was fully removed at potentials negative to -80 mV and was complete at voltages near -10 mV; 50% inactivation occurred at -41 mV. 5. Recovery from inactivation had several components and was voltage dependent. Initial recovery was fast, but full recovery, even at -100 mV, required more than 30 s. 6. Inactivating current was selectively blocked by 4-aminopyridine (4-AP), in a dose-dependent manner (IC50, 0.2 mM). The duration of chemoreceptor cells action potentials was augmented by 1 mM 4-AP from 2.3 +/- 0.36 to 7.0 +/- 0.25 ms at 0 mV. Tetraethylamonium (TEA), at concentrations above 5 mM, blocked inactivating and non-inactivating components of the whole K+ current. 7. Inactivating current was modulated by cyclic AMP (cAMP). Bath application of 2 mM dibutyryl cAMP reduced peak amplitude by 18.7 +/- 2.9% (at +30 mV) and slowed down the rise time of the current. The effect was not voltage dependent. Forskolin (10-20 microM) also affected inactivating current, by accelerating the inactivation process. In the same preparations neither dibutyryl c

  20. Properties of ionic currents from isolated adult rat carotid body chemoreceptor cells: effect of hypoxia.

    PubMed Central

    López-López, J R; González, C; Pérez-García, M T

    1997-01-01

    1. The electrical properties of chemoreceptor cells from neonatal rat and adult rabbit carotid bodies (CBs) are strikingly different. These differences have been suggested to be developmental and/or species related. To distinguish between the two possibilities, the whole-cell configuration of the patch-clamp technique was used to characterize the ionic currents present in isolated chemoreceptor cells from adult rat CBs. Since hypoxia-induced inhibition of O2-sensitive K+ currents is considered a crucial step in O2 chemoreception, the effect of hypoxia on the adult rat chemoreceptor cell currents was also studied. 2. Outward currents were carried mainly by K+, and two different components could be distinguished: a Ca(2+)-dependent K+ current (IK(Ca)) sensitive to Cd2+ and charybdotoxin (CTX), and a Ca(2+)-insensitive, voltage-dependent K+ current (IK(V)). IK(V) showed a slow voltage-dependent activation (time constant (tau) of 87.4 ms at -20 mV and 8.8 ms at +60 mV) and a very slow inactivation, described by the sum of two exponentials (tau 1 = 684 +/- 150 ms and tau 2 = 4.96 +/- 0.76 s at + 30 mV), that was almost voltage insensitive. The kinetic and pharmacological properties of IK(V) are typical of a delayed rectifier K+ channel. 3. Voltage-dependent Ca2+ currents (ICa) were present in nineteen of twenty-seven cells. TTX-sensitive Na+ currents were also observed in about 10% of the cells. 4. Low PO2 (< 10 mmHg) reduced the whole outward current amplitude by 22.17 +/- 1.96% (n = 27) at +20 mV. This effect was absent in the presence of Cd2+. Since low PO2 did not affect ICa, we conclude that hypoxia selectively blocks IK(Ca). 5. The properties of the currents recorded in adult rat chemoreceptor cells, including the specific inhibition of IK(Ca) by hypoxia, are similar to those reported in neonatal rat CB cells, implying that the differences between rat and rabbit chemoreceptor cells are species related. PMID:9080372

  1. Effects of mitochondrial uncouplers on intracellular calcium, pH and membrane potential in rat carotid body type I cells

    PubMed Central

    Buckler, K J; Vaughan-Jones, R D

    1998-01-01

    Mitochondrial uncouplers are potent stimulants of the carotid body. We have therefore investigated their effects upon isolated type I cells. Both 2,4-dinitrophenol (DNP) and carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP) caused an increase in [Ca2+]i which was largely inhibited by removal of extracellular Ca2+ or Na+, or by the addition of 2 mm Ni2+. Methoxyverapamil (D600) also partially inhibited the [Ca2+]i response. In perforated-patch recordings, the rise in [Ca2+]i coincided with membrane depolarization and was greatly reduced by voltage clamping the cell to −70 mV. Uncouplers also inhibited a background K+ current and induced a small inward current. Uncouplers reduced pHi by 0.1 unit. Alkaline media diminished this acidification but had no effect on the [Ca2+]i response. FCCP and DNP also depolarized type I cell mitochondria. The onset of mitochondrial depolarization preceded changes in cell membrane conductance by 3–4 s. We conclude that uncouplers excite the carotid body by inhibiting a background K+ conductance and inducing a small inward current, both of which lead to membrane depolarization and voltage-gated Ca2+ entry. These effects are unlikely to be caused by cell acidification. The inhibition of background K+ current may be related to the uncoupling of oxidative phosphorylation. PMID:9824720

  2. Effects of mitochondrial uncouplers on intracellular calcium, pH and membrane potential in rat carotid body type I cells.

    PubMed

    Buckler, K J; Vaughan-Jones, R D

    1998-12-15

    1. Mitochondrial uncouplers are potent stimulants of the carotid body. We have therefore investigated their effects upon isolated type I cells. Both 2,4-dinitrophenol (DNP) and carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP) caused an increase in [Ca2+]i which was largely inhibited by removal of extracellular Ca2+ or Na+, or by the addition of 2 mM Ni2+. Methoxyverapamil (D600) also partially inhibited the [Ca2+]i response. 2. In perforated-patch recordings, the rise in [Ca2+]i coincided with membrane depolarization and was greatly reduced by voltage clamping the cell to -70 mV. Uncouplers also inhibited a background K+ current and induced a small inward current. 3. Uncouplers reduced pHi by 0.1 unit. Alkaline media diminished this acidification but had no effect on the [Ca2+]i response. 4. FCCP and DNP also depolarized type I cell mitochondria. The onset of mitochondrial depolarization preceded changes in cell membrane conductance by 3-4 s. 5. We conclude that uncouplers excite the carotid body by inhibiting a background K+ conductance and inducing a small inward current, both of which lead to membrane depolarization and voltage-gated Ca2+ entry. These effects are unlikely to be caused by cell acidification. The inhibition of background K+ current may be related to the uncoupling of oxidative phosphorylation. PMID:9824720

  3. Long-term influence of neonatal hypoxia on catecholamine activity in carotid bodies and brainstem cell groups of the rat.

    PubMed Central

    Soulier, V; Dalmaz, Y; Cottet-Emard, J M; Lagercrantz, H; Pequignot, J M

    1997-01-01

    1. In order to determine the long-term influence of neonatal hypoxia on catecholaminergic activity in peripheral arterial chemoreceptors and brainstem noradrenergic cell groups (A1, A2, A5 and A6), 1-day-old male rat pups were subjected to hypoxia (10% oxygen) for 6 days and then supplied with normal air. Control animals were kept at normoxia from birth. Rats were killed at either 3 or 8 weeks of age. 2. The content of dopamine and noradrenaline in carotid bodies of neonatally hypoxic rats was increased at both 3 and 8 weeks of age. 3. Noradrenaline turnover was selectively decreased in the caudal portion of A2 (located in the area of chemosensory afferent projection) at 8 weeks of age (-76 +/- 2%), while this turnover was unaffected in rostral A2 cells. Noradrenergic activity in A1, A5 and A6 was altered by neonatal hypoxia in an age-dependent fashion. 4. The data suggest that neonatal hypoxia induces long-term changes in the basal activity of the carotid body and brainstem noradrenergic cell groups. Such changes might contribute to neuronal regulation of the delayed respiratory, arousal and neural sequelae associated with neonatal hypoxia. These changes could also be involved in the early programming of respiratory and blood pressure control. PMID:9032699

  4. An unusual presentation of foreign body in the common carotid artery.

    PubMed

    Lahiri, Somdatta; Ghosh, Shibajyoti; Sengupta, Goutam; Bakshi, Udayan

    2011-12-01

    Penetrating trauma to neck resulting in arteriovenous (AV) fistula and aneurysms involving the carotid system are uncommon injuries with life-threatening consequences. We report here a case of a young factory worker who developed a traumatic AV fistula with false aneurysm, with however, no other complications. He was successfully operated when he presented to us two months after the injury and is doing well in follow-up. PMID:23204711

  5. Lower body positive pressure application with an antigravity suit in acute carotid occlusion.

    PubMed

    Berthet, Karine; Lukaszewicz, Anne Claire; Bousser, Marie-Germaine; Payen, Didier

    2010-01-01

    The challenge in acute stroke is still to reperfuse as early as possible the ischemic territory. Since fibrinolytic therapies have a limited window with potential risk of bleeding, having a nonpharmacologic mean to recruit vessels in area surrounding necrosis might be useful. We propose here to use antigravity suit inflated at "venous" pressure levels to shift blood towards thoracic and brain territories. We report two cases of spectacular clinical recovery after acute carotid occlusion. PMID:20798842

  6. A computational model of the cat medial geniculate body ventral division

    SciTech Connect

    Travis, B.J.

    1992-08-01

    The medial geniculate body of the thalamus receives input from a variety of sources, both auditory and non-auditory. The ventral division (MGv), however, appears to be a purely auditory center, that is, it receives from lower (and higher) centers which are primarily involved in encoding auditory stimuli. It has some of the characteristics of auditory cortex, e.g., layering of neurons and EE/EI bands, but has a much simpler architecture. The MGv plays a central role in analyzing auditory stimuli. A wealth of data is available now on its anatomy, connectivity and responses. A detailed computational model of the ventral division of the cat medial geniculate body has been constructed. This model is being compared to physiological recordings for validation purposes, and should prove useful tool for testing theories of auditory sensory representation and functioning.

  7. A computational model of the cat medial geniculate body ventral division

    SciTech Connect

    Travis, B.J.

    1992-01-01

    The medial geniculate body of the thalamus receives input from a variety of sources, both auditory and non-auditory. The ventral division (MGv), however, appears to be a purely auditory center, that is, it receives from lower (and higher) centers which are primarily involved in encoding auditory stimuli. It has some of the characteristics of auditory cortex, e.g., layering of neurons and EE/EI bands, but has a much simpler architecture. The MGv plays a central role in analyzing auditory stimuli. A wealth of data is available now on its anatomy, connectivity and responses. A detailed computational model of the ventral division of the cat medial geniculate body has been constructed. This model is being compared to physiological recordings for validation purposes, and should prove useful tool for testing theories of auditory sensory representation and functioning.

  8. Effects of hypercapnia on membrane potential and intracellular calcium in rat carotid body type I cells.

    PubMed Central

    Buckler, K J; Vaughan-Jones, R D

    1994-01-01

    1. An acid-induced rise in the intracellular calcium concentration ([Ca2+]i) of type I cells is thought to play a vital role in pH/PCO2 chemoreception by the carotid body. In this present study we have investigated the cause of this rise in [Ca2+]i in enzymatically isolated, neonatal rat type I cells. 2. The rise in [Ca2+]i induced by a hypercapnic acidosis was inhibited in Ca(2+)-free media, and by 2 mM Ni2+. Acidosis also increased Mn2+ permeability. The rise in [Ca2+]i is dependent, therefore, upon a Ca2+ influx from the external medium. 3. The acid-induced rise in [Ca2+]i was attenuated by both nicardipine and methoxyverapamil (D600), suggesting a role for L-type Ca2+ channels. 4. Acidosis depolarized type I cells and often (approximately 50% of cells) induced action potentials. These effects coincided with a rise in [Ca2+]i. When membrane depolarization was prevented by a voltage clamp, acidosis failed to evoke a rise in [Ca2+]i. The acid-induced rise in [Ca2+]i is a consequence, therefore, of membrane depolarization. 5. Acidosis decreased the resting membrane conductance of type I cells. The reversal potential of the acid-sensitive current was about -75 mV. 6. A depolarization (30 mM [K+]o)-induced rise in [Ca2+]i was blocked by either the removal of extracellular Ca2+ or the presence of 2 mM Ni2+, and was also substantially inhibited by nicardipine. Under voltage-clamp conditions, [Ca2+]i displayed a bell-shaped dependence on membrane potential. Depolarization raises [Ca2+]i, therefore, through voltage-operated Ca2+ channels. 7. Caffeine (10 mM) induced only a small rise in [Ca2+]i (< 10% of that induced by 30 mM extracellular K+). Ca(2+)-induced Ca2+ release is unlikely, therefore, to contribute greatly to the rise in [Ca2+]i induced by depolarization. 8. Although the replacement of extracellular Na+ with N-methyl-D-glucamine (NMG), but not Li+, inhibited the acid-induced rise in [Ca2+]i, this was due to membrane hyperpolarization and not to the inhibition

  9. Tetrodotoxin as a tool to elucidate sensory transduction mechanisms: the case for the arterial chemoreceptors of the carotid body.

    PubMed

    Rocher, Asuncion; Caceres, Ana Isabel; Obeso, Ana; Gonzalez, Constancio

    2011-12-01

    Carotid bodies (CBs) are secondary sensory receptors in which the sensing elements, chemoreceptor cells, are activated by decreases in arterial PO(2) (hypoxic hypoxia). Upon activation, chemoreceptor cells (also known as Type I and glomus cells) increase their rate of release of neurotransmitters that drive the sensory activity in the carotid sinus nerve (CSN) which ends in the brain stem where reflex responses are coordinated. When challenged with hypoxic hypoxia, the physiopathologically most relevant stimulus to the CBs, they are activated and initiate ventilatory and cardiocirculatory reflexes. Reflex increase in minute volume ventilation promotes CO(2) removal from alveoli and a decrease in alveolar PCO(2) ensues. Reduced alveolar PCO(2) makes possible alveolar and arterial PO(2) to increase minimizing the intensity of hypoxia. The ventilatory effect, in conjunction the cardiocirculatory components of the CB chemoreflex, tend to maintain an adequate supply of oxygen to the tissues. The CB has been the focus of attention since the discovery of its nature as a sensory organ by de Castro (1928) and the discovery of its function as the origin of ventilatory reflexes by Heymans' group (1930). A great deal of effort has been focused on the study of the mechanisms involved in O(2) detection. This review is devoted to this topic, mechanisms of oxygen sensing. Starting from a summary of the main theories evolving through the years, we will emphasize the nature and significance of the findings obtained with veratridine and tetrodotoxin (TTX) in the genesis of current models of O(2)-sensing. PMID:22363245

  10. Tetrodotoxin as a Tool to Elucidate Sensory Transduction Mechanisms: The Case for the Arterial Chemoreceptors of the Carotid Body

    PubMed Central

    Rocher, Asuncion; Caceres, Ana Isabel; Obeso, Ana; Gonzalez, Constancio

    2011-01-01

    Carotid bodies (CBs) are secondary sensory receptors in which the sensing elements, chemoreceptor cells, are activated by decreases in arterial PO2 (hypoxic hypoxia). Upon activation, chemoreceptor cells (also known as Type I and glomus cells) increase their rate of release of neurotransmitters that drive the sensory activity in the carotid sinus nerve (CSN) which ends in the brain stem where reflex responses are coordinated. When challenged with hypoxic hypoxia, the physiopathologically most relevant stimulus to the CBs, they are activated and initiate ventilatory and cardiocirculatory reflexes. Reflex increase in minute volume ventilation promotes CO2 removal from alveoli and a decrease in alveolar PCO2 ensues. Reduced alveolar PCO2 makes possible alveolar and arterial PO2 to increase minimizing the intensity of hypoxia. The ventilatory effect, in conjunction the cardiocirculatory components of the CB chemoreflex, tend to maintain an adequate supply of oxygen to the tissues. The CB has been the focus of attention since the discovery of its nature as a sensory organ by de Castro (1928) and the discovery of its function as the origin of ventilatory reflexes by Heymans group (1930). A great deal of effort has been focused on the study of the mechanisms involved in O2 detection. This review is devoted to this topic, mechanisms of oxygen sensing. Starting from a summary of the main theories evolving through the years, we will emphasize the nature and significance of the findings obtained with veratridine and tetrodotoxin (TTX) in the genesis of current models of O2-sensing. PMID:22363245

  11. Subcutaneous hemangiosarcoma induced by a foreign body (steel staple) in a cat

    PubMed Central

    Tan, Rommel Max; Singh, Kuldeep; Sandman, Kristi

    2013-01-01

    An 8-year-old, female domestic shorthair cat was presented with a ventral abdominal subcutaneous mass. A radiograph showed that the center of the mass contained what appeared to be steel sutures, presumed to be from an ovariohysterectomy performed 7 years earlier. The excised mass was irregular and contained numerous pockets filled with friable necrotic material and hemorrhages that were dissected by fibrous connective tissue bands. Multiple tangled and fragmented pieces of steel staples were deeply embedded within the mass. Histologically, the mass was non-encapsulated, densely cellular, and infiltrative. Neoplastic cells lined caverns and channels and were factor VIII-positive by immunohistochemistry. The neoplastic cells were oval to round with granular cytoplasm and vesicular nucleus and exhibited moderate cellular and nuclear pleomorphism. A diagnosis of subcutaneous hemangiosarcoma was made. To our knowledge, this is the first report of foreign body associated hemangiosarcoma and the first case of steel staple associated neoplasm in domestic animals. PMID:24082166

  12. Carotid Endarterectomy

    MedlinePlus

    ... the carotid arteries. This limits or blocks the flow of oxygen-rich blood to your brain, which can lead to a stroke. Carotid Arteries Figure A shows ... normal carotid artery that has normal blood flow. Figure C show the inside of a carotid ...

  13. Detection of feline coronavirus RNA in feces, tissues, and body fluids of naturally infected cats by reverse transcriptase PCR.

    PubMed Central

    Herrewegh, A A; de Groot, R J; Cepica, A; Egberink, H F; Horzinek, M C; Rottier, P J

    1995-01-01

    A nested reverse transcriptase PCR (RT-nPCR) was developed for the detection of feline coronavirus (FCoV) RNA in the feces, tissues, and body fluids of infected cats. The RT-nPCR was targeted to the highly conserved 3'-untranslated region of the viral genome and will detect most, if not all, feline coronaviruses in the field. With the RT-nPCR, FCoV RNA was detected in plasma samples from experimentally infected cats as early as 2 days postinoculation. FCoV RNA was also detected in serum, plasma, or ascitic fluid samples from 14 of 18 cats (78%) with naturally occurring feline infectious peritonitis (FIP). The use of RT-PCR for FIP diagnosis is limited because of the occurrence of apparently healthy FCoV carriers. These asymptomatic cats shed the virus in the feces and, in a number of cases, also had detectable virus in the plasma. Because of the nature of FCoV infections, our RT-PCR assay with plasma or serum cannot be used to establish a definite diagnosis of FIP. However, this assay does provide a new means to identify asymptomatic FCoV carriers. As such, RT-nPCR will be of use to screen cats before their introduction into FCoV-free catteries. Moreover, this assay provides an important tool to study the epidemiology of FCoV. PMID:7751377

  14. Carotid artery surgery

    MedlinePlus

    Carotid endarterectomy; CAS surgery; Carotid artery stenosis - surgery; Endarterectomy - carotid artery ... through the catheter around the blocked area during surgery. Your carotid artery is opened. The surgeon removes ...

  15. Interleukin-1β promotes the neurogenesis of carotid bodies by stimulating the activation of ERK1/2.

    PubMed

    Xue, Fen; Liu, Ling; Fan, Juan; He, ShanShan; Li, Rui; Peng, Zheng-Wu; Wang, Bai-Ren

    2015-12-01

    The carotid body (CB) is a complex sensory organ that functions to sense homeostatic O2 in the blood. Previous studies have shown that CBs express interleukin (IL)-1 receptor type I and that the chemosensitivity of CBs is increased following stimulation with pro-inflammatory cytokines. However, the effects of pro-inflammatory cytokines, such as IL-1β, on the neurogenesis of CB are unclear. Thus, in this study, we aimed to assess the effects of IL-1β and intermittent hypobaric hypoxia (IHH) plus IL-1β on the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, tyrosine hydroxylase (TH) and the expression of nestin, a well-established stem cell marker in the nervous system. The results showed that TH, nestin expression and ERK1/2 phosphorylation were increased in the rat CB following intraperitoneal injection of IL-1β. Moreover, IL-1β had additive effects on IHH. These results suggested that the plasticity of CB was increased following treatment with IL-1β and that ERK1/2 may be involved in neurogenic signaling in CBs. PMID:26327233

  16. Hyperbaric Oxygen Therapy Improves Glucose Homeostasis in Type 2 Diabetes Patients: A Likely Involvement of the Carotid Bodies.

    PubMed

    Vera-Cruz, P; Guerreiro, F; Ribeiro, M J; Guarino, M P; Conde, S V

    2015-01-01

    The carotid bodies (CBs) are peripheral chemoreceptors that respond to hypoxia increasing minute ventilation and activating the sympathetic nervous system. Besides its role in ventilation we recently described that CB regulate peripheral insulin sensitivity. Knowing that the CB is functionally blocked by hyperoxia and that hyperbaric oxygen therapy (HBOT) improves fasting blood glucose in diabetes patients, we have investigated the effect of HBOT on glucose tolerance in type 2 diabetes patients. Volunteers with indication for HBOT were recruited at the Subaquatic and Hyperbaric Medicine Center of Portuguese Navy and divided into two groups: type 2 diabetes patients and controls. Groups were submitted to 20 sessions of HBOT. OGTT were done before the first and after the last HBOT session. Sixteen diabetic patients and 16 control individual were included. Fasting glycemia was143.5 ± 12.62 mg/dl in diabetic patients and 92.06 ± 2.99 mg/dl in controls. In diabetic patients glycemia post-OGTT was 280.25 ± 22.29 mg/dl before the first HBOT session. After 20 sessions, fasting and 2 h post-OGTT glycemia decreased significantly. In control group HBOT did not modify fasting glycemia and post-OGTT glycemia. Our results showed that HBOT ameliorates glucose tolerance in diabetic patients and suggest that HBOT could be used as a therapeutic intervention for type 2 diabetes. PMID:26303484

  17. Regulation of hypoxia-inducible factor-α isoforms and redox state by carotid body neural activity in rats

    PubMed Central

    Peng, Ying-Jie; Yuan, Guoxiang; Khan, Shakil; Nanduri, Jayasri; Makarenko, Vladislav V; Reddy, Vaddi Damodara; Vasavda, Chirag; Kumar, Ganesh K; Semenza, Gregg L; Prabhakar, Nanduri R

    2014-01-01

    Previous studies reported that chronic intermittent hypoxia (CIH) results in an imbalanced expression of hypoxia-inducible factor-α (HIF-α) isoforms and oxidative stress in rodents, which may be due either to the direct effect of CIH or indirectly via hitherto uncharacterized mechanism(s). As neural activity is a potent regulator of gene transcription, we hypothesized that carotid body (CB) neural activity contributes to CIH-induced HIF-α isoform expression and oxidative stress in the chemoreflex pathway. Experiments were performed on adult rats exposed to CIH for 10 days. Rats exposed to CIH exhibited: increased HIF-1α and decreased HIF-2α expression; increased NADPH oxidase 2 and decreased superoxide dismutase 2 expression; and oxidative stress in the nucleus tractus solitarius and rostral ventrolateral medulla as well as in the adrenal medulla (AM), a major end organ of the sympathetic nervous system. Selective ablation of the CB abolished these effects. In the AM, sympathetic activation by the CB chemoreflex mediates CIH-induced HIF-α isoform imbalance via muscarinic acetylcholine receptor-mediated Ca2+ influx, and the resultant activation of mammalian target of rapamycin pathway and calpain proteases. Rats exposed to CIH presented with hypertension, elevated sympathetic activity and increased circulating catecholamines. Selective ablation of either the CB (afferent pathway) or sympathetic innervation to the AM (efferent pathway) abolished these effects. These observations uncover CB neural activity-dependent regulation of HIF-α isoforms and the redox state by CIH in the central and peripheral nervous systems associated with the chemoreflex. PMID:24973414

  18. Type I cell ROS kinetics under hypoxia in the intact mouse carotid body ex vivo: a FRET-based study.

    PubMed

    Bernardini, A; Brockmeier, U; Metzen, E; Berchner-Pfannschmidt, U; Harde, E; Acker-Palmer, A; Papkovsky, D; Acker, H; Fandrey, J

    2015-01-01

    Reactive oxygen species (ROS) mainly originating from NADPH oxidases have been shown to be involved in the carotid body (CB) oxygen-sensing cascade. For measuring ROS kinetics, type I cells of the mouse CB in an ex vivo preparation were transfected with the ROS sensor construct FRET-HSP33. After 2 days of tissue culture, type I cells expressed FRET-HSP33 as shown by immunohistochemistry. In one population of CBs, 5 min of hypoxia induced a significant and reversible decrease of type I cell ROS levels (n = 9 CBs; P < 0.015), which could be inhibited by 4-(2-aminoethyl)benzensulfonylfluorid (AEBSF), a highly specific inhibitor of the NADPH oxidase subunits p47(phox) and p67(phox). In another population of CBs, however, 5 min of hypoxia induced a significant and reversible increase of ROS levels in type I cells (n = 8 CBs; P < 0.05), which was slightly enhanced by administration of 3 mM AEBSF. These different ROS kinetics seemed to coincide with different mice breeding conditions. Type I cells of both populations showed a typical hypoxia-induced membrane potential (MP) depolarization, which could be inhibited by 3 mM AEBSF. ROS and MP closely followed the hypoxic decrease in CB tissue oxygen as measured with an O2-sensitive dye. We conclude that attenuated p47(phox) subunit activity of the NADPH oxidase under hypoxia is the physiological trigger for type I cell MP depolarization probably due to ROS decrease, whereas the observed ROS increase has no influence on type I cell MP kinetics under hypoxia. PMID:25318107

  19. Dissociation between blood pressure and heart rate response to hypoxia after bilateral carotid body removal in men with systolic heart failure.

    PubMed

    Niewinski, Piotr; Janczak, Dariusz; Rucinski, Artur; Tubek, Stanislaw; Engelman, Zoar J; Jazwiec, Przemyslaw; Banasiak, Waldemar; Sobotka, Paul A; Hart, Emma C J; Paton, Julian F R; Ponikowski, Piotr

    2014-03-01

    While the ventilatory response to hypoxia is known to be mediated by the carotid bodies, the origin of the haemodynamic alterations evoked by hypoxia is less certain. Bilateral carotid body removal (CBR) performed to treat congestive heart failure may serve as a model to improve our understanding of haemodynamic responses to hypoxia in humans. We studied six congestive heart failure patients before and 1 month after CBR [median (interquartile range): age, 58.5 (56-61) years old; and ejection fraction, 32 (25-34)%]. Peripheral chemosensitivity (hypoxic ventilatory response) was equated to the slope relating lowest oxygen saturation to highest minute ventilation following exposures to hypoxia. Likewise, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) slopes were calculated as slopes relating the lowest oxygen saturations to the highest SBP, DBP and HR responses. We found that CBR reduces the hypoxic ventilatory response (91%, P < 0.05), SBP (71%, P < 0.05) and DBP slopes (59%, P = 0.07). In contrast, the HR slope remained unchanged. The dissociation between the blood pressure and HR responses after CBR shows involvement of a different chemoreceptive site(s) maintaining the response to acute hypoxia. We conclude that carotid bodies are responsible for ventilatory and blood pressure responses, while the HR response might be mediated by the aortic bodies. The significant reduction of the blood pressure response to hypoxia after CBR suggests a decrease in sympathetic tone, which is of particular clinical relevance in congestive heart failure. PMID:24243836

  20. Impact of ovariohysterectomy and food intake on body composition, physical activity, and adipose gene expression in cats.

    PubMed

    Belsito, K R; Vester, B M; Keel, T; Graves, T K; Swanson, K S

    2009-02-01

    The mechanisms contributing to BW gain following ovariohysterectomy in domestic cats are poorly understood. Moreover, the effects of food restriction to maintain BW following spaying have been poorly studied. Thus, our primary objective was to determine the effects of spaying and food restriction to maintain BW on adipose and skeletal muscle mRNA abundance and activity levels in cats. After a 4-wk baseline period (wk 0), 8 adult (approximately 1.5 yr old) domestic shorthair cats were spayed and fed to maintain BW for 12 wk. After 12 wk, cats were fed ad libitum for an additional 12 wk. Body composition was determined, activity levels were measured, and adipose and muscle biopsies were collected at wk 0, 12, and 24. Fasting blood samples were collected at wk 0, 6, 12, 18, and 24. To maintain BW post-spay, food intake was decreased (P < 0.05) by 30%. During this phase, mRNA abundance of adipose tissue lipoprotein lipase and leptin was decreased (P < 0.05), representing only 52 and 23% of baseline expression, respectively. Interleukin-6 mRNA, however, was increased (P < 0.05) 2-fold. Physical activity was decreased (P < 0.05) by wk 12, most dramatically during the dark period (approximately 20% of baseline activity). During ad libitum feeding (wk 12 to 24), food intake, BW, body fat percentage, and total fat mass were greatly increased (P < 0.05). Compared with wk 0, circulating leptin concentrations tended to increase (P < 0.10) by wk 18 and 24 (4.45 vs. 10.02 and 9.14 ng/mL, respectively), whereas glucose (91 vs. 162 mg/dL) and triacylglyceride (30 vs. 48 mg/dL) concentrations were increased (P < 0.05) by wk 24. Adipose tissue lipoprotein lipase, hormone sensitive lipase, and adiponectin mRNA were decreased (P < 0.05) at wk 24. Adipose interleukin-6 mRNA was increased (P < 0.05) at 24 wk. Physical activity was further decreased (P < 0.05) by wk 24, during the light (60% of baseline) and dark (33% of baseline) periods. In summary, spaying and food restriction affect

  1. CaV3.2 T-type Ca2+ channels mediate the augmented calcium influx in carotid body glomus cells by chronic intermittent hypoxia.

    PubMed

    Makarenko, Vladislav V; Ahmmed, Gias U; Peng, Ying-Jie; Khan, Shakil A; Nanduri, Jayasri; Kumar, Ganesh K; Fox, Aaron P; Prabhakar, Nanduri R

    2016-01-01

    Chronic intermittent hypoxia (CIH) is a hallmark manifestation of sleep apnea. A heightened carotid body activity and the resulting chemosensory reflex mediate increased sympathetic nerve activity by CIH. However, the mechanisms underlying heightened carotid body activity by CIH are not known. An elevation of intracellular calcium ion concentration ([Ca(2+)]i) in glomus cells, the primary oxygen-sensing cells, is an essential step for carotid body activation by hypoxia. In the present study, we examined the effects of CIH on the glomus cell [Ca(2+)]i response to hypoxia and assessed the underlying mechanisms. Glomus cells were harvested from adult rats or wild-type mice treated with 10 days of either room air (control) or CIH (alternating cycles of 15 s of hypoxia and 5 min of room air; 9 episodes/h; 8 h/day). CIH-treated glomus cells exhibited an enhanced [Ca(2+)]i response to hypoxia, and this effect was absent in the presence of 2-(4-cyclopropylphenyl)-N-((1R)-1-[5-[(2,2,2-trifluoroethyl)oxo]-pyridin-2-yl]ethyl)acetamide (TTA-A2), a specific inhibitor of T-type Ca(2+) channels, and in voltage-gated calcium channel, type 3.2 (CaV3.2), null glomus cells. CaV3.2 knockout mice exhibited an absence of CIH-induced hypersensitivity of the carotid body. CIH increased reactive oxygen species (ROS) levels in glomus cells. A ROS scavenger prevented the exaggerated TTA-A2-sensitive [Ca(2+)]i response to hypoxia. CIH had no effect on CaV3.2 mRNA levels. CIH augmented Ca(2+) currents and increased CaV3.2 protein in plasma membrane fractions of human embryonic kidney-293 cells stably expressing CaV3.2, and either a ROS scavenger or brefeldin-A, an inhibitor of protein trafficking, prevented these effects. These findings suggest that CIH leads to an augmented Ca(2+) influx via ROS-dependent facilitation of CaV3.2 protein trafficking to the plasma membrane. PMID:26561606

  2. A method for recording effects of anti-epileptic drugs on interictal discharge in the cat's cerebral cortex. Factors determining the distribution of external carotid artery infusions.

    PubMed

    Landgren, S; Selstam, G; Aasly, J; Danielsson, E

    1986-11-01

    The method utilizes infusion via the external carotid (ECA), the internal maxillary arteries and their anastomoses to the cerebral circulation. It takes into account the ipsilateral distribution of the carotid blood supply. A regular interictal epileptiform spiking from foci on both hemispheres was provided by local application to the cortical surface of small pieces of filter paper soaked in sodium benzylpenicillin, 100,000 IE ml-1. The infused drug affects the ipsilateral foci, and the contralateral one functions as a simultaneous untreated control. The stability of the interictal frequency and the effect of non-oxygen carrying solvents are described. The effect of changes in blood pressure, temperature and PCO2 are considered as well as the coupling between activity in ipsi- and contralateral foci. Experiments with infused radioactive microspheres were performed to determine the strictness of the ipsilateral distribution and the conditions under which it was upheld. With mean arterial blood pressures between 70 mm Hg and 170 mm Hg and infusion speeds between 1.0 ml min-1 and 6.3 ml min-1 the distribution to the contralateral cerebral hemisphere was 0.3% (SD 0.2, SEM 0.1). Infusions of [125I]albumin were used to determine the blood flow in ECA. The flow varied between 20 ml min-1 and 68 ml min-1. The higher values were seen when the extracerebral shunting was high. Conditions influencing the dilution of the infusion and its distribution within the brain were investigated. Important factors were carotid and cerebral blood flow, arterial blood pressure, speed and duration of the infusion, recirculation and cerebral temperature. Arterial PCO2, pH and PO2 should be carefully controlled. Computer-supported treatment of interictal spike frequency and amplitude, as well as of circulatory and respiratory parameters, was utilized. The method was tested in experiments with infusions of 5 alpha-pregnanolone. It was shown that infusions, shorter than the estimated

  3. Bilateral carotid artery injury response in side impact using a vessel model integrated with a human body model.

    PubMed

    Danelson, Kerry A; Gayzik, F Scott; Yu, Mao M; Martin, R Shayn; Duma, Stefan M; Stitzel, Joel D

    2009-10-01

    In a far-side crash configuration, the occupant can experience severe excursion from the seat space. Given this challenge, there are research efforts focused on alternate restraints, such as four-point belts. A potential implication of this geometry would be interaction of the belt with the occupant's neck. This study examines the response of the carotid arteries using a Finite Element Model (FEM) in a far-side crash configuration with a reversed three-point restraint. A FEM of the carotid artery and neck fascia was developed and integrated with the Total Human Model for Safety (THUMS) version 1.44. This model was subjected to four test conditions simulating far-side crashes. Load conditions included a low velocity impact of approximately 4 m/s and a higher velocity impact of approximately 10 m/s. For each velocity, the model was restrained with a belt placed low on the neck and a belt placed higher on the neck. Strain data in each element of the carotid arteries was analyzed. The overall response of the vessel was examined to determine locations of high strain values. Low belt placement resulted in more head excursion, stretching the carotid on the non-struck side. High belt placement resulted in compression of the artery on the struck side due to direct loading of the vessel from the belt. Strain values in the carotid artery elements increased with increasing speed of impact. The lower and higher speed tests with a low belt configuration resulted in a maximum principal strains, at maximal belt engagement, of 0.223 and 0.459, respectively. Corresponding values for the high belt configuration were 0.222 and 0.563. In both belt configurations, the non-struck side vessel stretched more than the struck side vessel; however, the non-struck side vessel experienced higher compressive forces. Strain values measured during the simulations can be compared to a value of 0.31 to intimal failure in previous experimental tests. These results quantitatively illustrate the two

  4. Bilateral Carotid Artery Injury Response in Side Impact Using a Vessel Model Integrated with a Human Body Model

    PubMed Central

    Danelson, Kerry A.; Gayzik, F. Scott; Yu, Mao M.; Martin, R. Shayn; Duma, Stefan M.; Stitzel, Joel D.

    2009-01-01

    In a far-side crash configuration, the occupant can experience severe excursion from the seat space. Given this challenge, there are research efforts focused on alternate restraints, such as four-point belts. A potential implication of this geometry would be interaction of the belt with the occupant’s neck. This study examines the response of the carotid arteries using a Finite Element Model (FEM) in a far-side crash configuration with a reversed three-point restraint. A FEM of the carotid artery and neck fascia was developed and integrated with the Total Human Model for Safety (THUMS) version 1.44. This model was subjected to four test conditions simulating far-side crashes. Load conditions included a low velocity impact of approximately 4 m/s and a higher velocity impact of approximately 10 m/s. For each velocity, the model was restrained with a belt placed low on the neck and a belt placed higher on the neck. Strain data in each element of the carotid arteries was analyzed. The overall response of the vessel was examined to determine locations of high strain values. Low belt placement resulted in more head excursion, stretching the carotid on the non-struck side. High belt placement resulted in compression of the artery on the struck side due to direct loading of the vessel from the belt. Strain values in the carotid artery elements increased with increasing speed of impact. The lower and higher speed tests with a low belt configuration resulted in a maximum principal strains, at maximal belt engagement, of 0.223 and 0.459, respectively. Corresponding values for the high belt configuration were 0.222 and 0.563. In both belt configurations, the non-struck side vessel stretched more than the struck side vessel; however, the non-struck side vessel experienced higher compressive forces. Strain values measured during the simulations can be compared to a value of 0.31 to intimal failure in previous experimental tests. These results quantitatively illustrate the two

  5. Carotid Ultrasound

    MedlinePlus

    ... plaque narrows the carotid arteries and reduces the flow of oxygen-rich blood to the brain. If the plaque ruptures, a blood clot can form on its surface. A clot can mostly or completely block blood flow through a carotid artery, which can cause a ...

  6. Heteromeric TASK-1/TASK-3 is the major oxygen-sensitive background K+ channel in rat carotid body glomus cells.

    PubMed

    Kim, Donghee; Cavanaugh, Eric J; Kim, Insook; Carroll, John L

    2009-06-15

    Carotid body (CB) glomus cells from rat express a TASK-like background K+ channel that is believed to play a critical role in the regulation of excitability and hypoxia-induced increase in respiration. Here we studied the kinetic behaviour of single channel openings from rat CB cells to determine the molecular identity of the 'TASK-like' K+ channels. In outside-out patches, the TASK-like background K+ channel in CB cells was inhibited >90% by a reduction of pH(o) from 7.3 to 5.8. In cell-attached patches with 140 mM KCl and 1 mM Mg2+ in the bath and pipette solutions, two main open levels with conductance levels of approximately 14 pS and approximately 32 pS were recorded at a membrane potential of -60 mV. The K+ channels showed kinetic properties similar to TASK-1 (approximately 14 pS), TASK-3 (approximately 32 pS) and TASK-1/3 heteromer (approximately 32 pS). The presence of three TASK isoforms was tested by reducing [Mg2+](o) to approximately 0 mM, which had no effect on the conductance of TASK-1, but increased those of TASK-1/3 and TASK-3 to 42 pS and 74 pS, respectively. In CB cells, the reduction of [Mg2+](o) to approximately 0 mM also caused the appearance of approximately 42 pS (TASK-1/3-like) and approximately 74 pS (TASK-3-like) channels, in addition to the approximately 14 pS (TASK-1-like) channel. The 42 pS channel was the most abundant, contributing approximately 75% of the current produced by TASK-like channels. Ruthenium red (5 microM) had no effect on TASK-1 and TASK-1/3, but inhibited TASK-3 by 87%. In CB cells, ruthenium red caused approximately 12% inhibition of TASK-like activity. Methanandamide reduced the activity of all three TASKs by 80-90%, and that of TASK-like channels in CB cell also by approximately 80%. In CB cells, hypoxia caused inhibition of TASK-like channels, including TASK-1/3-like channels. These results show that TASK-1, TASK-1/3 and TASK-3 are all functionally expressed in isolated CB cells, and that the TASK-1/3 heteromer

  7. Role of voltage-dependent calcium channels in stimulus–secretion coupling in rabbit carotid body chemoreceptor cells

    PubMed Central

    Rocher, Asunción; Geijo-Barrientos, Emilio; Cáceres, Ana Isabel; Rigual, Ricardo; González, Constancio; Almaraz, Laura

    2005-01-01

    We have defined Ca2+ channel subtypes expressed in rabbit carotid body (CB) chemoreceptor cells and their participation in the stimulus-evoked catecholamine (CA) release. Ca2+ currents (ICa) activated at –30 mV, peaked at +10 mV and were fully blocked by 200 μm Cd2+. L-type channels (sensitive to 2 μm nisoldipine) activated at –30 mV and carried 21 ± 2% of total ICa. Non-L-type channels activated at potentials positive to –10 mV and carried: N channels (sensitive to 1 μm ω-conotoxin-GVIA) 16 ± 1% of total ICa, P/Q channels (sensitive to 3 μm ω-conotoxin-MVIIC after nisoldipine plus GVIA) 23 ± 3% of total ICa and R channels (resistant to all blockers combined) 40 ± 3% of total ICa. CA release induced by hypoxia, hypercapnic acidosis, dinitrophenol (DNP) and high K+o in the intact CB was inhibited by 79–98% by 200 μm Cd2+. Hypoxia, hypercapnic acidosis and DNP, depolarized chemoreceptor cells and eventually generated repetitive action potential discharge. Nisoldipine plus MVIIC nearly abolished the release of CAs induced by hypoxia and hypercapnic acidosis and reduced by 74% that induced by DNP. All these secretory responses were insensitive to GVIA. 30 and 100 mm K+o brought resting membrane potential (Em) of chemoreceptor cells (–48.1 ± 1.2 mV) to –22.5 and +7.2 mV, respectively. Thirty millimolar K+o-evoked release was abolished by nisoldipine but that induced by 100 mm K+o was mediated by activation of L, N, and P/Q channels. Data show that tested stimuli depolarize rabbit CB chemoreceptor cells and elicit CA release through Ca2+ entry via voltage-activated channels. Only L and P/Q channels are tightly coupled to the secretion of CA. PMID:15528240

  8. Responses of neurons in the rostral ventrolateral medulla to whole body rotations: comparisons in decerebrate and conscious cats.

    PubMed

    Destefino, V J; Reighard, D A; Sugiyama, Y; Suzuki, T; Cotter, L A; Larson, M G; Gandhi, N J; Barman, S M; Yates, B J

    2011-06-01

    The responses to vestibular stimulation of brain stem neurons that regulate sympathetic outflow and blood flow have been studied extensively in decerebrate preparations, but not in conscious animals. In the present study, we compared the responses of neurons in the rostral ventrolateral medulla (RVLM), a principal region of the brain stem involved in the regulation of blood pressure, to whole body rotations of conscious and decerebrate cats. In both preparations, RVLM neurons exhibited similar levels of spontaneous activity (median of ∼17 spikes/s). The firing of about half of the RVLM neurons recorded in decerebrate cats was modulated by rotations; these cells were activated by vertical tilts in a variety of directions, with response characteristics suggesting that their labyrinthine inputs originated in otolith organs. The activity of over one-third of RVLM neurons in decerebrate animals was altered by stimulation of baroreceptors; RVLM units with and without baroreceptor signals had similar responses to rotations. In contrast, only 6% of RVLM neurons studied in conscious cats exhibited cardiac-related activity, and the firing of just 1% of the cells was modulated by rotations. These data suggest that the brain stem circuitry mediating vestibulosympathetic reflexes is highly sensitive to changes in body position in space but that the responses to vestibular stimuli of neurons in the pathway are suppressed by higher brain centers in conscious animals. The findings also raise the possibility that autonomic responses to a variety of inputs, including those from the inner ear, could be gated according to behavioral context and attenuated when they are not necessary. PMID:21493724

  9. Pneumomediastinum, pneumothorax and pneumoretroperitoneum following endoscopic retrieval of a tracheal foreign body from a cat.

    PubMed

    Zambelli, A B

    2006-03-01

    A 6-year-old entire male cat was presented with a 1-week history of severe dyspnoea without coughing. Upon auscultation, an inspiratory and particularly pronounced expiratory wheeze was noted, with severe dyspnoea. The minimum database was normal. Plain thoracic radiographs showed signs of a mural or intraluminal intrathoracic (T1-T4) tracheal narrowing. A dynamic collapsing trachea was ruled out using fluoroscopy. Bronchoscopy was performed and a dark green and brown spiculated foreign object was found just cranial to the carina. Following removal, the cat rapidly developed extensive truncal subcutaneous emphysema and oxygen-responsive dyspnoea and cyanosis. Follow-up radiographs demonstrated unilateral pneumothorax and lung collapse, marked pneumomediastinum and dissection of air through the tracheal wall. A thoracic drain was placed and the pneumothorax resolved rapidly. Follow-up radiographs demonstrated resolution of pneumothorax and development of extensive retroperitoneal air. The cat made an uneventful recovery. The foreign object was the calyx and stem of a flower. This article emphasises the importance of diagnostic imaging in the dyspnoeic patient, both for confirming initial suspicions of respiratory tract disease, and in managing and charting post-therapy resolution or complications. PMID:16700477

  10. The Influence of Body Position on Cerebrospinal Fluid Pressure Gradient and Movement in Cats with Normal and Impaired Craniospinal Communication

    PubMed Central

    Radoš, Milan; Erceg, Gorislav; Petošić, Antonio; Jurjević, Ivana

    2014-01-01

    Intracranial hypertension is a severe therapeutic problem, as there is insufficient knowledge about the physiology of cerebrospinal fluid (CSF) pressure. In this paper a new CSF pressure regulation hypothesis is proposed. According to this hypothesis, the CSF pressure depends on the laws of fluid mechanics and on the anatomical characteristics inside the cranial and spinal space, and not, as is today generally believed, on CSF secretion, circulation and absorption. The volume and pressure changes in the newly developed CSF model, which by its anatomical dimensions and basic biophysical features imitates the craniospinal system in cats, are compared to those obtained on cats with and without the blockade of craniospinal communication in different body positions. During verticalization, a long-lasting occurrence of negative CSF pressure inside the cranium in animals with normal cranio-spinal communication was observed. CSF pressure gradients change depending on the body position, but those gradients do not enable unidirectional CSF circulation from the hypothetical site of secretion to the site of absorption in any of them. Thus, our results indicate the existence of new physiological/pathophysiological correlations between intracranial fluids, which opens up the possibility of new therapeutic approaches to intracranial hypertension. PMID:24748150

  11. Body composition and amino acid concentrations of select birds and mammals consumed by cats in northern and central California.

    PubMed

    Kremen, N A; Calvert, C C; Larsen, J A; Baldwin, R A; Hahn, T P; Fascetti, A J

    2013-03-01

    The diet of the feral domestic cat consists of primarily birds and small mammals, but the nutritional composition is relatively unknown. Because of the increasing popularity of natural diets for cats and other wild captive carnivores, the purpose of this study was to describe the body composition and AA concentrations of select birds and small mammals in northern and central California: wild-caught mice (n = 7), Norway rats (n = 2), roof rats (n = 2), voles (n = 4), moles (n = 2), gophers (n = 3), and birds (n = 4). Body water, crude fat (CFa), CP, ash, and AA composition for each specimen were determined. Results are reported as mean ± SD. All results are reported on a DM basis except body water (as-is basis) and AA (g/16 g N). Combined, carcasses had this mean composition: 67.35 ± 3.19% water, 11.72 ± 6.17% CFa, 62.19 ± 7.28% CP, and 14.83 ± 2.66% ash. Concentrations of Arg, Tau, Cys, and Met were 5.63 ± 0.46, 0.92 ± 0.33, 1.91 ± 0.89, and 1.82 ± 0.19 g/16 g N, respectively. Using NRC physiologic fuel values for CP, CFa, and carbohydrate by difference, the combined average energy content of the carcasses was 3,929 kcal/kg DM, but the fiber content was not determined. With the exception of mice and rats, little historical data exist regarding the body and AA composition of many of the species analyzed in this study. Wild-caught mice and rats were composed of less fat but more ash compared with previously reported data in their purpose-bred counterparts. The CP content of mice in this study was similar to previous reports in purpose-bred mice. The CP content of rats was similar or slightly greater compared with historical findings in purpose-bred rats. The N content of rats and AA concentrations on a per-N basis for both rats and mice were similar to previously published data on purpose-bred rodents. The discrepancies in nutrient composition, especially fat concentration, indicate that using purpose-bred animals to represent the diet of the feral domestic

  12. Association between adjunctive metformin therapy in young type 1 diabetes patients with excess body fat and reduction of carotid intima-media thickness.

    PubMed

    Burchardt, Paweł; Zawada, Agnieszka; Kaczmarek, Jolanta; Marcinkaniec, Justyna; Wysocki, Henryk; Wierusz-Wysocka, Bogna; Grzymisławski, Marian; Rzeźniczak, Janusz; Zozulińska-Ziółkiewicz, Dorota; Naskręt, Dariusz

    2016-08-25

    INTRODUCTION    Lipoprotein-associated phospholipase A2 (Lp-PLA2) and cholesteryl ester lipase (CEL) may oxidize low-density lipoproteins (oxLDL). OBJECTIVES    The aim of the study was to determine the influence of metformin on the metabolism of atherogenic lipid fractions in relation to Lp-PLA2 and CEL levels, as well as assess consequent improvement in the intima-media thickness (IMT) of the common carotid artery in young type 1 diabetes patients with excess body fat. PATIENTS AND METHODS    It was an open-label randomized clinical trial that lasted 6 months. It included a total of 84 people with metabolic decompensation (glycated hemoglobin >7.5%, >58.5 mmol/mol) of diabetes. Adjunctive metformin therapy (in addition to insulin) was administered in 42 patients, and the remaining 42 patients received insulin alone. Glycated low-density lipoproteins (LDLs), oxLDL, Lp-PLA2, and CEL were assessed by commercially available enzyme-linked immunosorbent assay kits. Cartoid IMT was measured using the Carotid Analyser for Research tool. Biochemical analyses were performed using routine laboratory techniques. RESULTS    The reduction of mean carotid IMT was observed in young type 1 diabetic adults treated additionally with metformin (0.6 ±0.1 cm vs 0.53 ±0.1 cm; P = 0.002). This effect was probably due to weight reduction (90 ±16 kg vs 87 ±15 kg, P = 0.054) and the decrease in atherogenic glycated LDL levels (1.5 ±0.5 mg/dl vs 1.6 ±1.046 mg/dl, P = 0.006). No such correlations were observed in patients treated with insulin alone. Additionally, in patients receiving metformin, glycated LDL levels were inversely correlated with Lp-PLA2 levels (r = -0.31, P <0.05). CONCLUSIONS    Additional use of metformin in young type 1 diabetic patients with excess body fat leads to a significant reduction of mean IMT in the common carotid artery. Concentrations of CEL and Lp-PLA2 were significantly increased in both study arms despite improved glucose metabolism

  13. Tasting arterial blood: what do the carotid chemoreceptors sense?

    PubMed Central

    Prabhakhar, Nanduri R.; Joyner, Michael J.

    2015-01-01

    The carotid bodies are sensory organs that detect the chemical composition of the arterial blood. The carotid body sensory activity increases in response to arterial hypoxemia and the ensuing chemoreflex regulates vital homeostatic functions. Recent studies suggest that the carotid bodies might also sense arterial blood glucose and circulating insulin levels. This review focuses on how the carotid bodies sense O2, glucose, and insulin and some potential implications of these sensory functions on physiological regulation and in pathophysiological conditions. Emerging evidence suggests that carbon monoxide (CO)-regulated hydrogen sulfide (H2S), stemming from hypoxia, depolarizes type I cells by inhibiting certain K+ channels, facilitates voltage-gated Ca2+ influx leading to sensory excitation of the carotid body. Elevated CO and decreased H2S renders the carotid bodies insensitive to hypoxia resulting in attenuated ventilatory adaptations to high altitude hypoxia, whereas reduced CO and high H2S result in hypersensitivity of the carotid bodies to hypoxia and hypertension. Acute hypoglycemia augments the carotid body responses to hypoxia but that a prolonged lack of glucose in the carotid bodies can lead to a failure to sense hypoxia. Emerging evidence also indicates that carotid bodies might sense insulin directly independent of its effect on glucose, linking the carotid bodies to the pathophysiological consequences of the metabolic syndrome. How glucose and insulin interact with the CO-H2S signaling is an area of ongoing study. PMID:25642193

  14. Microsurgical anatomy of the human carotid body (glomus caroticum): Features of its detailed topography, syntopy and morphology.

    PubMed

    Schulz, Sissy-Amelie; Wöhler, Aliona; Beutner, Dirk; Angelov, Doychin N

    2016-03-01

    The human glomus caroticum (GC) is not readily accessible during ordinary anatomical teaching courses because of insufficient time and difficulties encountered in the preparation. Accordingly, most anatomical descriptions of its location, relationship to neighboring structures, size and shape are supported only by drawings, but not by photographs. The aim of this study is to present the GC with all associated roots and branches. Following microscope-assisted dissection and precise photo-documentation, a detailed analysis of location, syntopy and morphology was performed. We carried out this study on 46 bifurcations of the common carotid artery (CCA) into the external (ECA) and internal (ICA) carotid arteries and identified the GC in 40 (91%) of them. We found significant variations regarding the location of the GC and its syntopy: GC was associated with CCA (42%), ECA (28%) and ICA (30%) lying on the medial or lateral surface (82% or 13%, respectively) or exactly in the middle (5%) of the bifurcation. The short and long diameter of its oval form varied from 1.0×2.0 to 5.0×5.0mm. Connections with the sympathetic trunk (100%), glossopharyngeal (93%), vagus (79%) and hypoglossal nerve (90%) could be established in 29 cadavers. We conclude that precise knowledge of this enormous variety might be very helpful not only to students in medicine and dentistry during anatomical dissection courses, but also to surgeons working in this field. PMID:26704358

  15. The role of the solitary and paramedian reticular nuclei in mediating cardiovascular reflex responses from carotid baro- and chemoreceptors

    PubMed Central

    Miura, Mitsuhiko; Reis, Donald J.

    1972-01-01

    1. With dye-filled micro-electrodes single neurones in the medulla of anaesthetized paralysed cats were identified which: (a) fired rhythmically in synchrony with or were modulated by the cardiac cycle, and which ceased firing with occlusion of the ipsilateral common carotid artery (carotid sinus baroreceptor neurones); (b) were excited by stimulation of carotid body chemoreceptors by close intra-arterial injection of lobeline into the thyroid artery (carotid body chemoreceptor neurones). 2. Twelve carotid baroreceptor neurones were identified, in thirty-three cats, nine of which were localized in the intermediate area of the nucleus of the solitary tract (NTS) within 1 mm ahead of or behind the obex; three units were located either in the parahypoglossal area or the dorsal portion of the paramedian reticular nucleus (PRN). 3. Of the twenty-one carotid chemoreceptor neurones which were identified, thirteen were localized in the NTS, three in the parahypoglossal area and four in the dorsal PRN. 4. Bilateral lesions of the paramedian reticular area of medulla destroying the PRN, abolished or reversed the depressor response to electrical stimulation of myelinated fibres of the carotid sinus nerve (CSN), attenuated the depressor response to carotid sinus stretch and augmented the pressor response to chemoreceptor stimulation by lobeline. Such lesions did not significantly alter the reflex heart rate responses. 5. Small lesions of the NTS within an area 1 mm rostral to the obex abolished all reflex blood pressure and heart rate responses to electrical stimulation of the CSN or natural stimulation of carotid baro- or chemoreceptors. 6. Baroreceptors and chemoreceptors of the CSN project both to the intermediate zone of the NTS and to more medial areas of the medulla, particularly the dorsal PRN and parahypoglossal area. 7. The PRN serves to mediate the reflex depressor, but not cardio-vagal, response from myelinated baroreceptors and buffers the pressor responses from

  16. Carotid Artery Disease

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Carotid Artery Disease? Carotid artery disease is a disease in ... blood to your face, scalp, and neck. Carotid Arteries Figure A shows the location of the right ...

  17. Non-invasive assessment of growth, gender and time of day related changes of respiratory pattern in healthy cats by use of barometric whole body plethysmography.

    PubMed

    Kirschvink, Nathalie; Leemans, Jérôme; Delvaux, François; Snaps, Frédéric; Marlin, David; Sparkes, Andrew; Clercx, Cécile; Gustin, Pascal

    2006-11-01

    The objective of this study was to establish a reference base for respiratory variables (respiratory rate [R(R)], inspiratory and expiratory time [T(i) and T(e)], peak inspiratory and expiratory pseudoflow [PIF and PEF], tidal volume [V(T)], minute ventilation [V(E)] and enhanced pause [Penh]) of healthy cats by use of barometric whole body plethysmography (BWBP). Eighteen healthy European cats (10 male, 8 female) were studied from the age of 3 to 13 months in order to assess growth- and gender-related changes of BWBP variables. Chest radiographs and bronchoalveolar lavage cytology were performed to confirm pulmonary health status. Diurnal changes were investigated every 2 h over a period of 24 h when the cats were adult. V(T), V(E), PIF and PEF significantly increased during somatic growth and were higher in males than in females, whereas R(R), T(i), T(e), T(e)/T(i) ratio, PEF/PIF ratio and Penh remained unchanged and were not affected by gender. When measured over 24 h, Penh, T(e) and T(i) were significantly increased in the early morning hours (04:00 h), whereas R(R), PIF and PEF were decreased at that time. This study provides reference values of BWBP variables for healthy male and female cats and indicates when circadian changes might be observed. PMID:16051506

  18. Anomalous course of the external carotid artery.

    PubMed

    Kawai, Katsushi

    2016-09-01

    The course and the branching patterns of the external carotid artery were investigated macroscopically in a total of 550 bodies or 1100 head sides of Japanese subjects, donated for student dissection at Kumamoto University from 1994 to 2014. With the exception of 14 head sides, the external carotid arteries running between the posterior belly of the digastric and stylohyoid muscles were found in 42 (3.87 %) out of 1086 head sides. Strictly speaking, they passed between the stylohyoid muscle and the stylohyoid branch of the facial nerve in 23 out of these 42 head sides. In the remaining 19 instances, the stylohyoid branch of the facial nerve was cut and its relationship to the external carotid artery was not clear. The external carotid artery running lateral to the intact stylohyoid branch of the facial nerve, medial to the digastric muscle was not found. The external carotid arteries running lateral to the digastric muscle were found in 4 (0.37 %) out of 1086 head sides. As a result, it is proposed that plural, potential courses of the external carotid artery originally exist and that some parts of such potential courses remain as branches of the external carotid artery in the usual instance, while the anomalous courses of the external carotid artery are induced mainly by anastomosis between the muscular branches supplying the wall of the head and neck in contrast to the usual external carotid artery induced mainly by the branches originally supplying the pharynx. PMID:26439732

  19. Gene Expression Profiling Supports the Neural Crest Origin of Adult Rodent Carotid Body Stem Cells and Identifies CD10 as a Marker for Mesectoderm-Committed Progenitors.

    PubMed

    Navarro-Guerrero, Elena; Platero-Luengo, Aida; Linares-Clemente, Pedro; Cases, Ildefonso; López-Barneo, José; Pardal, Ricardo

    2016-06-01

    Neural stem cells (NSCs) are promising tools for understanding nervous system plasticity and repair, but their use is hampered by the lack of markers suitable for their prospective isolation and characterization. The carotid body (CB) contains a population of peripheral NSCs, which support organ growth during acclimatization to hypoxia. We have set up CB neurosphere (NS) cultures enriched in differentiated neuronal (glomus) cells versus undifferentiated progenitors to investigate molecular hallmarks of cell classes within the CB stem cell (CBSC) niche. Microarray gene expression analysis in NS is compatible with CBSCs being neural crest derived-multipotent progenitor cells able to sustain CB growth upon exposure to hypoxia. Moreover, we have identified CD10 as a marker suitable for isolation of a population of CB mesectoderm-committed progenitor cells. CD10 + cells are resting in normoxia, and during hypoxia they are activated to proliferate and to eventually complete maturation into mesectodermal cells, thus participating in the angiogenesis necessary for CB growth. Our results shed light into the molecular and cellular mechanisms involved in CBSC fate choice, favoring a potential use of these cells for cell therapy. Stem Cells 2016;34:1637-1650. PMID:26866353

  20. Carotid artery anatomy (image)

    MedlinePlus

    There are four carotid arteries, two on each side of the neck: right and left internal carotid arteries, and right and left external carotid arteries. The carotid arteries deliver oxygen-rich blood from the heart to the head and brain.

  1. Carotid baroreflex responsiveness in heat-stressed humans

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.

    2000-01-01

    The effects of whole body heating on human baroreflex function are relatively unknown. The purpose of this project was to identify whether whole body heating reduces the maximal slope of the carotid baroreflex. In 12 subjects, carotid-vasomotor and carotid-cardiac baroreflex responsiveness were assessed in normothermia and during whole body heating. Whole body heating increased sublingual temperature (from 36.4 +/- 0.1 to 37.4 +/- 0.1 degrees C, P < 0.01) and increased heart rate (from 59 +/- 3 to 83 +/- 3 beats/min, P < 0. 01), whereas mean arterial blood pressure (MAP) was slightly decreased (from 88 +/- 2 to 83 +/- 2 mmHg, P < 0.01). Carotid-vasomotor and carotid-cardiac responsiveness were assessed by identifying the maximal gain of MAP and heart rate to R wave-triggered changes in carotid sinus transmural pressure. Whole body heating significantly decreased the responsiveness of the carotid-vasomotor baroreflex (from -0.20 +/- 0.02 to -0.13 +/- 0.02 mmHg/mmHg, P < 0.01) without altering the responsiveness of the carotid-cardiac baroreflex (from -0.40 +/- 0.05 to -0.36 +/- 0.02 beats x min(-1) x mmHg(-1), P = 0.21). Carotid-vasomotor and carotid-cardiac baroreflex curves were shifted downward and upward, respectively, to accommodate the decrease in blood pressure and increase in heart rate that accompanied the heat stress. Moreover, the operating point of the carotid-cardiac baroreflex was shifted closer to threshold (P = 0.02) by the heat stress. Reduced carotid-vasomotor baroreflex responsiveness, coupled with a reduction in the functional reserve for the carotid baroreflex to increase heart rate during a hypotensive challenge, may contribute to increased susceptibility to orthostatic intolerance during a heat stress.

  2. Inhibition of [3H]catecholamine release and Ca2+ currents by prostaglandin E2 in rabbit carotid body chemoreceptor cells.

    PubMed Central

    Gómez-Niño, A; López-López, J R; Almaraz, L; González, C

    1994-01-01

    Basal release of [3H]catecholamine ([3H]CA) from rabbit carotid bodies (CBs), previously incubated in the presence of [3H]tyrosine, was not significantly modified by prostaglandin E2 (PGE2). On the contrary, PGE2 (3-300 nM) produced a dose-dependent inhibition of the low PO2-evoked release of [3H]CA. The inhibition was greatest (55%) at a low intensity of hypoxic stimulation (incubating solution PO2 approximately 66 mmHg) and decreased with increasing intensities of hypoxia. Chronic denervation of the CB did not modify the response to PGE2. The release of [3H]CA induced by incubating the CBs in a hypercapnic-acidic solution (PCO2 approximately 132 mmHg; pH = 6.60) and by dinitrophenol (100 microM) was not significantly modified by 300 nM PGE2. PGE2 (300 nM) inhibited the release of [3H]CA elicited by incubating the CBs in a high K+ (35 mM)-containing solution. The release response elicited by high K+ (25 mM) was strongly augmented by a dihydropyridine agonist of Ca2+ channels, Bay K 8644, at a concentration of 1 microM. The Bay K 8644 effect was partly inhibited by PGE2 (300 nM). Using whole-cell recordings in freshly dispersed or short-term cultured chemoreceptor cells from adult rabbits it was found that Ca2+ currents (ICa) were reversibly inhibited by bath application of PGE2. A good parallelism exits between the dose-response curves for PGE2 inhibition of ICa in isolated chemoreceptor cells and high extracellular [K+]- or hypoxia-evoked release of [3H]CA from the whole CB.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7519263

  3. Increase in cytosolic Ca2+ produced by hypoxia and other depolarizing stimuli activates a non-selective cation channel in chemoreceptor cells of rat carotid body

    PubMed Central

    Kang, Dawon; Wang, Jiaju; Hogan, James O; Vennekens, Rudi; Freichel, Marc; White, Carl; Kim, Donghee

    2014-01-01

    The current model of O2 sensing by carotid body chemoreceptor (glomus) cells is that hypoxia inhibits the outward K+ current and causes cell depolarization, Ca2+ influx via voltage-dependent Ca2+ channels and a rise in intracellular [Ca2+] ([Ca2+]i). Here we show that hypoxia (<5% O2), in addition to inhibiting the two-pore domain K+ channels TASK-1/3 (TASK), indirectly activates an ∼20 pS channel in isolated glomus cells. The 20 pS channel was permeable to K+, Na+ and Cs+ but not to Cl− or Ca2+. The 20 pS channel was not sensitive to voltage. Inhibition of TASK by external acid, depolarization of glomus cells with high external KCl (20 mm) or opening of the Ca2+ channel with FPL64176 activated the 20 pS channel when 1 mm Ca2+ was present in the external solution. Ca2+ (10 μm) applied to the cytosolic side of inside-out patches activated the 20 pS channel. The threshold [Ca2+]i for activation of the 20 pS channel in cell-attached patches was ∼200 nm. The reversal potential of the 20 pS channel was estimated to be −28 mV. Our results reveal a sequential mechanism in which hypoxia (<5% O2) first inhibits the K+ conductance and then activates a Na+-permeable, non-selective cation channel via depolarization-induced rise in [Ca2+]i. Our results suggest that inhibition of K+ efflux and stimulation of Na+ influx both contribute to the depolarization of glomus cells during moderate to severe hypoxia. PMID:24591572

  4. A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats.

    PubMed

    Hoelmkjaer, Kirsten M; Wewer Albrechtsen, Nicolai J; Holst, Jens J; Cronin, Anna M; Nielsen, Dorte H; Mandrup-Poulsen, Thomas; Bjornvad, Charlotte R

    2016-01-01

    Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks) treatment with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg) or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose homeostasis, body weight, body composition as measured by dual-energy x-ray absorptiometry and overall safety. An intravenous glucose tolerance test (1 g/kg body weight) was conducted at week 0 and week 12. Exenatide did not change the insulin concentration, plasma glucose concentration or glucose tolerance (P>0.05 for all). Exenatide tended to reduce body weight on continued normal feeding. Median relative weight loss after 12 weeks was 5.1% (range 1.7 to 8.4%) in the exenatide group versus 3.2% (range -5.3 to 5.7%) in the placebo group (P = 0.10). Body composition and adipokine levels were unaffected by exenatide (P>0.05). Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean cats. Further investigations are required to fully elucidate the effect on insulin secretion, glucose tolerance and body weight in obese cats. PMID:27136422

  5. A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats

    PubMed Central

    Hoelmkjaer, Kirsten M.; Wewer Albrechtsen, Nicolai J.; Holst, Jens J.; Cronin, Anna M.; Nielsen, Dorte H.; Mandrup-Poulsen, Thomas; Bjornvad, Charlotte R.

    2016-01-01

    Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks) treatment with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg) or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose homeostasis, body weight, body composition as measured by dual-energy x-ray absorptiometry and overall safety. An intravenous glucose tolerance test (1 g/kg body weight) was conducted at week 0 and week 12. Exenatide did not change the insulin concentration, plasma glucose concentration or glucose tolerance (P>0.05 for all). Exenatide tended to reduce body weight on continued normal feeding. Median relative weight loss after 12 weeks was 5.1% (range 1.7 to 8.4%) in the exenatide group versus 3.2% (range -5.3 to 5.7%) in the placebo group (P = 0.10). Body composition and adipokine levels were unaffected by exenatide (P>0.05). Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean cats. Further investigations are required to fully elucidate the effect on insulin secretion, glucose tolerance and body weight in obese cats. PMID:27136422

  6. Metabolic determinants of body weight after cats were fed a low-carbohydrate high-protein diet or a high-carbohydrate low-protein diet ad libitum for 8 wk.

    PubMed

    Coradini, M; Rand, J S; Morton, J M; Rawlings, J M

    2014-10-01

    Overweight and obese conditions are common in cats and are associated with the development of a number of diseases. Knowledge of metabolic determinants and predictors of weight gain may enable better preventative strategies for obesity in cats. Lean, healthy cats were fed either a low-carbohydrate high-protein diet (n 16) or a high-carbohydrate low-protein (n 16) diet ad libitum for 8 wk. Potential determinants and predictors of final body weight assessed were body fat and lean masses, energy required for maintenance, energy requirements above maintenance for each kilogram of weight gain, insulin sensitivity index, fasting, mean 24-h and peak plasma glucose, insulin, and leptin concentrations, and fasting and mean 24-h serum adiponectin concentrations. In cats fed the low-carbohydrate high-protein diet, after adjusting for initial body weight, those with higher energy requirements for weight gain and higher fasting glucose concentration had higher final body weights (P ≤ 0.01). Predicted final body weights using initial body weight, fasting glucose and mean 24-h insulin concentrations (partial R(2) 37.3%) were imprecise. An equation using just initial body weight and fasting glucose concentration would be of more practical value, but was marginally less precise. In cats fed the high-carbohydrate low-protein diet, those with lower fasting leptin concentration initially had higher final body weights (P = 0.01). Predicted final body weights using initial body weight, energy requirements for maintenance, total body fat percentage and fasting leptin concentration (partial R(2) 39.2%) were reasonably precise. Further studies are warranted to confirm these findings and to improve the precision of predicted final body weights. PMID:25084314

  7. A moderate fat, low-energy dry expanded diet reduces gain in body condition score when fed as part of a post neutering weight-control regimen in growing pet cats.

    PubMed

    Spofford, Nathaniel; Mougeot, Isabelle; Elliott, Denise A; Addleman, Ashlee; Lefebvre, Sandra L; Wang, Mansen; Yang, Mingyin; Feugier, Alexandre; Biourge, Vincent; Lund, Elizabeth M

    2014-01-01

    Neutering of cats has been associated with significant weight gain in the weeks following surgery. The present study aimed to evaluate the effectiveness of a moderate fat, low-energy dry expanded diet in reducing weight gain in growing pet cats when fed as part of a weight-control regimen over the 6 months post-neutering. Cats in participating primary care veterinary hospitals were enrolled at neutering and assigned to receive one of the two dietary treatments based on the hospital of origin. Owners of cats in the treatment group were instructed to feed the trial diet at maintenance (324·7 kJ/kg BW(0·711) per d). Instructions for the control group were to feed the cat's regular diet according to the manufacturer's recommendations. Body weight and condition were evaluated by veterinarians at enrolment, 2-weeks, and 1-4 and 6 months after surgery. Body condition score (five-point scale) was compared between enrolment and each subsequent visit, controlling for enrolment age and sex. Percentage change in body weight was evaluated via multivariate mixed modelling to account for repeated measures. A total of 187 cats (eighty-seven females and 100 males) with a mean age of 5·2 (sd 0·8) months and mean weight of 2·8 (sd 0·6) kg from fifty-one hospitals completed the trial. The odds of being scored as overweight were 4·1 times as great for cats in the control v. treatment groups (95 % CI 2·1, 8·2). Percentage change in body weight differed significantly with enrolment age (P = 0·007) and approached significance between diet groups (P = 0·08). Cats fed the trial diet had a significantly reduced incidence of overweight in the 6 months following neutering. PMID:26101609

  8. Carotid Artery Disease

    MedlinePlus

    ... brain with blood. If you have carotid artery disease, the arteries become narrow, usually because of atherosclerosis. ... one of the causes of stroke. Carotid artery disease often does not cause symptoms, but there are ...

  9. Carotid artery disease

    MedlinePlus

    ... you have had a stroke or TIA, a nervous system (neurological) exam will show other problems. You may also have the following tests: Blood cholesterol and triglycerides test Blood sugar (glucose) test Ultrasound of the carotid arteries ( carotid ...

  10. Carotid artery surgery - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000238.htm Carotid artery surgery - discharge To use the sharing features on this page, please enable JavaScript. You had carotid artery surgery to restore proper blood flow to your ...

  11. Carotid artery surgery - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100124.htm Carotid artery surgery - series To use the sharing features on ... 4 Normal anatomy Overview There are four carotid arteries, with a pair located on each side of ...

  12. Carotid endarterectomy or stenting?

    PubMed Central

    Ng, P Y

    2009-01-01

    The relative role of surgical or endovascular treatment in carotid stenosis remains controversial. Results of recent studies add even more confusion to the debate. Major clinical trials so far have shown a wide range of complication rates for carotid endarterectomy and carotid stenting. Only surgeons or interventionists who can maintain a complication rate of 3% or below should consider treating patients with asymptomatic disease.

  13. Carotid sinus syndrome.

    PubMed

    Mallet, Mark

    2003-02-01

    This article reviews the recent literature about carotid sinus syndrome. It looks principally at the various ways in which it may present, the limited knowledge of its pathophysiology, and the role of carotid sinus massage in the investigation of carotid sinus syndrome. PMID:12619336

  14. Molecular identification of Kvα subunits that contribute to the oxygen-sensitive K+ current of chemoreceptor cells of the rabbit carotid body

    PubMed Central

    Sanchez, Diego; López-López, Jose R; Pérez-García, M Teresa; Sanz-Alfayate, Gloria; Obeso, Ana; Ganfornina, Maria D; Gonzalez, Constancio

    2002-01-01

    Rabbit carotid body (CB) chemoreceptor cells possess a fast-inactivating K+ current that is specifically inhibited by hypoxia. We have studied the expression of Kvα subunits, which might be responsible for this current. RT-PCR experiments identified the expression of Kv1.4, Kv3.4, Kv4.1 and Kv4.3 mRNAs in the rabbit CB. There was no expression of Kv3.3 or Kv4.2 transcripts. Immunocytochemistry with antibodies to tyrosine hydroxylase (anti-TH) and to specific Kv subunits revealed the expression of Kv3.4 and Kv4.3 in chemoreceptor cells, while Kv1.4 was only found in nerve fibres. Kv4.1 mRNA was also found in chemoreceptor cells following in situ hybridization combined with anti-TH antibody labelling. Kv4.1 and Kv4.3 appeared to be present in all chemoreceptor cells, but Kv3.4 was only expressed in a population of them. Electrophysiological experiments applying specific toxins or antibodies demonstrated that both Kv3.4 and Kv4.3 participate in the oxygen-sensitive K+ current of chemoreceptor cells. However, toxin application experiments confirmed a larger contribution of members of the Kv4 subfamily. [Ca2+]i measurements under hypoxic conditions and immunocytochemistry experiments in dispersed CB cells demonstrated the expression of Kv3.4 and Kv4.3 in oxygen-sensitive cells; the presence of Kv3.4 in the chemoreceptor cell membrane was not required for the response to low PO2. In summary, three Kv subunits (Kv3.4, Kv4.1 and Kv4.3) may be involved in the fast-inactivating outward K+ current of rabbit CB chemoreceptor cells. The homogeneous distribution of the Kv4 subunits in chemoreceptor cells, along with their electrophysiological properties, suggest that Kv4.1, Kv4.3, or their heteromultimers, are the molecular correlate of the oxygen-sensitive K+ channel. PMID:12122138

  15. Stimulation of raphe (obscurus) nucleus causes long-term potentiation of phrenic nerve activity in cat.

    PubMed

    Millhorn, D E

    1986-12-01

    1. The respiratory response, measured as integrated phrenic nerve activity, during and for up to an hour following 10 min of continuous electrical stimulation of raphe obscurus was quantitated in anaesthetized, artificially ventilated cats whose carotid sinus nerves and vagus nerves had been cut. End-tidal PCO2 and body temperature were kept constant with servocontrollers. 2. Stimulation of raphe obscurus caused a significant increase in both phrenic tidal activity and respiratory frequency that persisted following cessation of the stimulus. This persistent facilitation is referred to as 'long-term potentiation' of respiration. 3. Control stimulations in the parenchyma of the medulla oblongata failed to stimulate respiration and cause the long-term potentiation. 4. Both the direct facilitatory effects of raphe obscurus stimulation on phrenic nerve activity and the long-term potentiation of respiration following the stimulus were prevented by pre-treating cats with methysergide, a serotonin receptor antagonist. 5. The results are discussed in terms of the raphe obscurus being the potential source of the long-term potentiation of respiration that occurs following stimulation of carotid body afferents (Millhorn, Eldridge & Waldrop, 1980a, b). PMID:3114470

  16. In vitro activation of cyclo-oxygenase in the rabbit carotid body: effect of its blockade on [3H]catecholamine release.

    PubMed Central

    Gómez-Niño, A; Almaraz, L; González, C

    1994-01-01

    The release of prostaglandin E2 (PGE2) from rabbit carotid bodies (CBs) incubated in basal conditions (PO2 approximately 132 mmHg; PCO2 approximately 33 mmHg; pH = 7.42) amounts to 94.4 +/- 10.1 pg (mg protein)-1 (10 min)-1 (mean +/- S.E.M.). Incubation of the CB in a hypoxic solution (PO2 approximately 46 mmHg) produced a significant 40% increase (P < 0.05) in the release of PGE2. Indomethacin (2 microM) prevented the hypoxia-induced release of PGE2. Sensory plus sympathetic denervation of the CB 4 days prior to the experiments did not modify either basal or low PO2-induced PGE2 release, indicating that intraglomic nerve endings are not significant sources for the PGE2 released. Incubation of the CB in an acidic-hypercapnic solution (PO2 approximately 132 mmHg; PCO2 approximately 132 mmHg; pH = 6.60) or in a high K(+)-containing solution (35 mM) was also effective in promoting an increase in the outflow of PGE2 from the organs. The release of [3H]catecholamines ([3H]CA) from the CB elicited by incubating the organs in low PO2 solutions (PO2 ranged between 66 and 13 mmHg) was potentiated by two inhibitors of cyclo-oxygenase, acetylsalicylic acid (ASA, 100 microM) and indomethacin (2 microM). The effect persisted after chronic denervation of the organ. The secretory response elicited by acidic stimuli was also augmented by cyclo-oxygenase inhibitors. Thus, [3H]CA release elicited by incubating the CBs in the acidic-hypercapnic solution increased by 300% in the presence of indomethacin (2 microM), and ASA (100 microM) more than doubled the release induced by dinitrophenol (100 microM), a protonophore that mimics an acidic stimulus. Indomethacin, but not ASA, moderately increased the high K(+)-evoked [3H]CA release. The effect of indomethacin on the release of [3H]CA elicited by acidic and hypoxic stimuli was reversed by PGE2 in a dose-dependent manner (0.3-300 nM). These results show that low PO2 and high PCO2-low pH, the natural stimuli to the CB, as well as high

  17. Living with Carotid Artery Disease

    MedlinePlus

    ... from the NHLBI on Twitter. Living With Carotid Artery Disease If you have carotid artery disease, you can take steps to manage the ... treatment plan, and getting ongoing care. Having carotid artery disease raises your risk of having a stroke . ...

  18. Cat Batiks.

    ERIC Educational Resources Information Center

    Buban, Marcia H.

    1998-01-01

    Discusses an art activity where fourth-grade students created backgrounds using melted paraffin and a variety of paints for their cat batik/collage. Explains that after the students created their backgrounds, they assembled their paper cats for the collage using smaller shapes glued together and wax to add texture for fur. (CMK)

  19. [Carotid atherosclerosis and dementia].

    PubMed

    Harlé, Louise-Marine; Plichart, Matthieu

    2015-09-01

    Over the past decade a growing interest has been devoted to exploring the role of atherosclerosis in the development of dementia. Despite a well-known association between atherosclerosis risk factors in middle-life with later cognitive decline, the pathophysiological pathways underlying this association remain unclear. The current hypothesis is that neurodegenerative and vascular lesions coexist and have a synergistic role in the development of cognitive impairment and dementia. Carotid atherosclerosis (e.g. carotid plaques and intima-media thickness as measured by carotid ultrasonography) has been associated with cognitive decline and dementia and may help to better understand the complex interaction between the vascular and neurodegenerative processes. Furthermore, carotid atherosclerosis has been used in the recent field for dementia risk prediction. In this review, we discuss the physiopathological implications from the current available data on the relationship between carotid atherosclerosis and dementia as well as the interest of carotid biomarkers for individual dementia risk prediction. PMID:26395304

  20. Muscle spindle responses to horizontal support surface perturbation in the anesthetized cat: insights into the role of autogenic feedback in whole body postural control.

    PubMed

    Honeycutt, Claire F; Nardelli, Paul; Cope, Timothy C; Nichols, T Richard

    2012-09-01

    Intact cats and humans respond to support surface perturbations with broadly tuned, directionally sensitive muscle activation. These muscle responses are further sensitive to initial stance widths (distance between feet) and perturbation velocity. The sensory origins driving these responses are not known, and conflicting hypotheses are prevalent in the literature. We hypothesize that the direction-, stance-width-, and velocity-sensitive muscle response during support surface perturbations is driven largely by rapid autogenic proprioceptive pathways. The primary objective of this study was to obtain direct evidence for our hypothesis by establishing that muscle spindle receptors in the intact limb can provide appropriate information to drive the muscle response to whole body postural perturbations. Our second objective was to determine if spindle recordings from the intact limb generate the heightened sensitivity to small perturbations that has been reported in isolated muscle experiments. Maintenance of this heightened sensitivity would indicate that muscle spindles are highly proficient at detecting even small disturbances, suggesting they can provide efficient feedback about changing postural conditions. We performed intraaxonal recordings from muscle spindles in anesthetized cats during horizontal, hindlimb perturbations. We indeed found that muscle spindle afferents in the intact limb generate broadly tuned but directionally sensitive activation patterns. These afferents were also sensitive to initial stance widths and perturbation velocities. Finally, we found that afferents in the intact limb have heightened sensitivity to small perturbations. We conclude that muscle spindle afferents provide an array of important information about biomechanics and perturbation characteristics highlighting their potential importance in generating appropriate muscular response during a postural disturbance. PMID:22673334

  1. Mercury induced time-dependent alterations in lipid profiles and lipid peroxidation in different body organs of cat-fish Heteropneustes fossilis

    SciTech Connect

    Bano, Y.; Hasan, M.

    1989-04-01

    The effects of mercuric chloride (HgCl/sub 2/) on lipid profiles and lipid peroxidation in different body organs of fresh water cat-fish Heteropneustes fossilis were studied. The daily exposure of HgCl/sub 2/ 0.2 mg/L for 10, 20 and 30 days depleted the total lipids in brain. But the content of phospholipids enhanced significantly at 30 days. Significant diminution in C/P ratio was discernible with 30 days of exposure following mercury toxicosis. Liver exhibited elevated levels of total lipids, phospholipids, cholesterol and C/P ratio. Interestingly kidney showed marked decrease in the concentration of total lipids, cholesterol and C/P ratio at higher exposure. However, the phospholipid values increased during the longer exposure. The content of total lipids and phospholipids was high in muscle but the level of cholesterol and C/P ratio were depleted. Significant increment in lipid peroxidation was discernible in brain, liver and muscle. In kidney the rate of lipid peroxidation was significantly reduced. The results suggest that exposure of HgCl/sub 2/ enhances the peroxidation of endogenous lipids in brain, liver and muscle. Interestingly the lipid contents are affected differently in different body organs.

  2. Carotid Artery Disease

    MedlinePlus

    ... small balloon on its tip. They inflate the balloon at the blockage site in the carotid artery to flatten or compress the plaque against the artery wall. Carotid angioplasty is often combined with the placement of a small, metal, mesh-like device called a stent. When a stent is placed inside of a ...

  3. The effect of low-dose acetazolamide on the ventilatory CO2 response curve in the anaesthetized cat.

    PubMed Central

    Wagenaar, M; Teppema, L; Berkenbosch, A; Olievier, C; Folgering, H

    1996-01-01

    1. The effect of 4 mg kg-1 acetazolamide (I.V.) on the slope (S) and intercept on the Pa,CO2 axis (B) of the ventilatory CO2 response curve of anaesthetized cats with intact or denervated carotid bodies was studied using the technique of dynamic end-tidal forcing. 2. This dose did not induce an arterial-to-end-tidal PCO2 (P(a-ET),CO2) gradient, indicating that erythrocytic carbonic anhydrase was not completely inhibited. Within the first 2 h after administration, this small dose caused only a slight decrease in mean standard bicarbonate of 1.8 and 1.7 mmol l-1 in intact (n = 7) and denervated animals (n = 7), respectively. Doses of acetazolamide larger than 4 mg kg-1 (up to 32 mg kg-1) caused a significant increase in the P(a-ET),CO2 gradient. 3. In carotid body-denervated cats, 4 mg kg-1 acetazolamide caused a decrease in the CO2 sensitivity of the central chemoreflex loop (Sc) from 1.52 +/- 0.42 to 0.96 +/- 0.32 l min-1 kPa-1 (mean +/- S.D.) while the intercept on the Pa,CO2 axis (B) decreased from 4.5 +/- 0.5 to 4.2 +/- 0.7 kPa. 4. In carotid body-intact animals, 4 mg kg-1 acetazolamide caused a decrease in the CO2 sensitivity of the peripheral chemoreflex loop (Sp) from 0.28 +/- 0.18 to 0.19 +/- 0.12 l min-1 kPa-1. Se and B decreased from 1.52 +/- 0.55 to 0.84 +/- 0.21 l min-1 kPa-1, and from 4.0 +/- 0.5 to 3.0 +/- 0.6 kPa, respectively, not significantly different from the changes encountered in the denervated animals. 5. It is argued that the effect of acetazolamide on the CO2 sensitivity of the peripheral chemoreflex loop in intact cats may be caused by a direct effect on the carotid bodies. Both in intact and in denervated animals the effects of the drug on Sc and B may not be due to a direct action on the central nervous system, but rather to an effect on cerebral vessels resulting in an altered relationship between brain blood flow and brain tissue PCO2. PMID:8866365

  4. Carotid stenting and endarterectomy.

    PubMed

    Yip, Hon-Kan; Sung, Pei-Hsun; Wu, Chiung-Jen; Yu, Cheuk-Man

    2016-07-01

    Stroke, either ischemic or hemorrhagic, remains the second commonest cause of death worldwide in the last decade. Etiologies for ischemic stroke (IS) vary widely. Atherothrombotic occlusion is an essential cause to which carotid artery stenosis (CAS) is a major contributor. Administration of anti-platelet agent to patients with CAS has been shown to reduce incidence of long-term IS. In additional, in patients with symptomatic CAS, clinical trials have demonstrated that carotid endarterectomy (CEA) is superior to medical therapy for prevention of future CAS-related IS. However, CEA is not suitable for CAS post-radiotherapy or those located at higher level of the internal carotid artery; and major complications of this procedure including cranial nerve injuries have stimulated the interest of using percutaneous transfemoral carotid stenting as an alternative approach. Although transfemoral arterial approach of carotid stenting is not inferior to CEA in improving clinical outcomes, it has been reported to be associated with vascular complication and has its limitations in patients with athero-occlusive disease of abdominal aorta or bilateral iliac arteries, level II or III aortic arch, or bovine type carotid arterial anatomy. Therefore, transradial/transbrachial arterial approach has emerged as a novel method for carotid stenting. This article provides a critical review on interventional approaches for the treatment of CAS. PMID:27061654

  5. Photoacoustic imaging of carotid artery atherosclerosis

    NASA Astrophysics Data System (ADS)

    Kruizinga, Pieter; van der Steen, Antonius F. W.; de Jong, Nico; Springeling, Geert; Robertus, Jan Lukas; van der Lugt, Aad; van Soest, Gijs

    2014-11-01

    We introduce a method for photoacoustic imaging of the carotid artery, tailored toward detection of lipid-rich atherosclerotic lesions. A common human carotid artery was obtained at autopsy, embedded in a neck mimicking phantom and imaged with a multimodality imaging system using interstitial illumination. Light was delivered through a 1.25-mm-diameter optical probe that can be placed in the pharynx, allowing the carotid artery to be illuminated from within the body. Ultrasound imaging and photoacoustic signal detection is achieved by an external 8-MHz linear array coupled to an ultrasound imaging system. Spectroscopic analysis of photoacoustic images obtained in the wavelength range from 1130 to 1250 nm revealed plaque-specific lipid accumulation in the collagen structure of the artery wall. These spectroscopic findings were confirmed by histology.

  6. Albendazole therapy for experimentally induced Paragonimus kellicotti infection in cats.

    PubMed

    Dubey, J P; Hoover, E A; Stromberg, P C; Toussant, M J

    1978-06-01

    The effect of albendazole therapy was studied in 6 cats with pulmonary paragonimiasis induced by experimental inoculation of metacercariae (25/cat) of Paragonimus kellicotti. At 76 to 101 days after they were inoculated, 5 cats were administered an oral aqueous suspension of albendazole in 2 divided doses totaling 20 mg (2 cats), 50 mg (1 cat), or 100 mg (2 cats)/kg of body weight each day for 14 to 21 days. The 6th cat (control) was not administered albendazole. Nine days after cats were given the 50- and 100-mg/kg dosages, Paragonimus ova were not seen in the feces of 3 cats. There was marked reduction in ova production in the feces of the 2 cats administered 20 mg/kg of albendazole. Live flukes were not recovered from the lungs of 3 cats necropsied 4 or 5 weeks after dosing with 50 or 100 mg/kg, but the lungs of the 2 cats administered 20 mg of albendazole/kg yielded 9 and 7 apparently viable flukes. Seventeen live flukes were recovered from the control cat not treated with albendazole. In 4 noninoculated normal cats administered 20 mg (1 cat), 100 mg (1 cat), and 200 mg (2 cats) of albendazole/kg of body weight each day for 14 days, there were no gross or microscopic lesions attributable to the drug. PMID:666077

  7. Cat scratch disease (image)

    MedlinePlus

    Cat scratch disease is an infectious illness associated with cat scratches, bites, or exposure to cat saliva, causing chronic swelling of the lymph nodes. Cat scratch disease is possibly the most common cause of ...

  8. Cat Scratch Disease

    MedlinePlus

    Cat scratch disease (CSD) is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry ... infection does not make cats sick. However, the scratch or bite of an infected cat can cause ...

  9. Cat scratch disease (image)

    MedlinePlus

    Cat scratch disease is an infectious illness associated with cat scratches, bites, or exposure to cat saliva, causing chronic swelling of the lymph nodes. Cat scratch disease is possibly the most common cause of chronic ...

  10. Carotid artery surgery

    MedlinePlus

    ... Aspirin and heart disease Butter, margarine, and cooking oils Carotid artery surgery - discharge Cholesterol and ... by: Daniel Kantor, MD, Kantor Neurology, Coconut Creek, FL and Immediate Past President of the ...

  11. Angioplasty and stent placement - carotid artery

    MedlinePlus

    Carotid angioplasty and stenting; CAS; Angioplasty - carotid artery; Carotid artery stenosis - angioplasty; ... Carotid angioplasty and stenting (CAS) is done using a small surgical cut. Your surgeon will make a surgical cut in your groin after using some ...

  12. P2 purinergic receptor activation of neuronal nitric oxide synthase and guanylyl cyclase in the dorsal facial area of the medulla increases blood flow in the common carotid arteries of cats.

    PubMed

    Hung, Y-W; Leung, Y-M; Lin, N-N; Lee, T J-F; Kuo, J-S; Tung, K-C; Gong, C-L

    2015-02-12

    In the dorsal facial area (DFA) of the medulla, an activation of either P2 purinergic receptor or nitric oxide synthase (NOS) results in the release of glutamate, leading to an increase in blood flow of the common carotid artery (CCA). It is not known whether activation of the P2 receptor by ATP may mediate activation of NOS/guanylyl cyclase to cause glutamate release and/or whether L-Arg (nitric oxide (NO) precursor) may also cause ATP release from any other neuron, to cause an increase in CCA flow. We demonstrated that microinjections of P2 receptor agonists (ATP, α,β-methylene ATP) or NO precursor (L-arginine) into the DFA increased CCA blood flow. The P2-induced CCA blood flow increase was dose-dependently reduced by pretreatment with NG-nitro-arginine methyl ester (L-NAME, a non-specific NOS inhibitor), 7-nitroindazole (7-NI, a relatively selective neuronal NOS inhibitor) or methylene blue (MB, a guanylyl cyclase inhibitor) but not by that with D-NAME (an isomer of L-NAME) or N5-(1-iminoethyl)-L-ornithine (L-NIO, a potent endothelial NOS inhibitor). Involvement of glutamate release in these responses were substantiated by microdialysis studies, in which perfusions of ATP into the DFA increased the glutamate concentration in dialysates, but co-perfusion of ATP with L-NAME or 7-NI did not. Nevertheless, the arginine-induced CCA blood flow increase was abolished by combined pretreatment of L-NAME and MB, but not affected by pretreatment with a selective P2 receptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS). In conclusion, ATP activation of the P2 receptor in the DFA induced activation of neuronal NOS/guanylyl cyclase, which causes glutamate release leading to an increase in CCA blood flow. However, arginine activation of neuronal NOS/guanylyl cyclase, which also caused glutamate release and CCA blood flow increase, did not induce activation of P2 receptors. These findings provide important information for drug design and

  13. [Evaluation of carotid stenosis by using carotid ultrasonography].

    PubMed

    Seike, Nahoko; Ito, Michiko; Yasaka, Masahiro

    2010-12-01

    Carotid stenosis is observed in several diseases such as atherosclerosis, moyamoya disease, and aortitis. Carotid stenosis can be assessed using computed tomography (CT), magnetic resonance angiography (MRA), ultrasonography, or cerebral angiography. Carotid ultrasonography is superior to other modalities because it is a noninvasive, repeatable, and easy method that does not involve much cost. The intima-media complex thickness (IMT) can be easily measured using carotid ultrasonography. The incidence of cerebral and cardiovascular events increases with increase in the thickness of the IMT. The percentage of stenosis was expressed using the NASCET, ECST, or area methods. The NASCET criterion of 70% stenosis for performing carotid endarterectomy for symptomatic carotid stenosis corresponded to 85% ECST stenosis, 90% area stenosis, and 200 cm/sec of peak systolic velocity. Carotid ultrasonography provides information on not only carotid stenosis but also unstable plaques such as ulcer, hypoechoic plaque, thin fibrous cap, and mobile plaque. In patients with moyamoya disease, carotid ultrasonography often reveals that the diameter of the internal carotid artery (ICA) is greatly reduced at the proximal portion above the bulbus (resembling a champagne bottle neck) and is less than 50% that of the common carotid artery (champagne bottle neck sign); the diameter of the ICA is smaller than that of the external carotid artery (diameter reversal sign). In patients with aortitis, IMT thickness is frequently observed at the common carotid artery (Macaroni sign) but not at the ICA. PMID:21139180

  14. Drugs and PGO waves in the lateral geniculate body of the curarized cat. V. Miscellaneous compounds. Synopsis of the role of central neurotransmitters on PGO wave activity.

    PubMed

    Ruch-Monachon, M A; Jalfre, M; Haefely, W

    1976-02-01

    In the last part of this series we have studied the effects of various drugs on ponto-geniculo-occipital (PGO) waves induced by the benzoquinolizine derivative, Ro 4-1284 (PGO(1284)), and by the inhibitor of trypotophan hydroxylase, p-chlorophenylalanine (PGO(PCPA)), and continuously recorder and counted in the lateral geniculate bodies (LGB) of unanaesthetized and immobilizedcats. The major aim of this study was to test the specificity of drug-induced alterations of the PGO wave activity suggested by the previous investigations. Hypnotics-sedatives of different classes had no significant effects in doses that did not markedly alter the electrical background activity in the LGB. A notable exception was gamma-hydroxybutyric acid which increased the density of PGO(1284) and PGO(PCPA). A number of neuroleptics were found inactive; sulpiride surprisingly decreased the density of PGO(1284). Bulbocapnine had a similar effect. Convulsants in subconvulsive doses did not uniformly affect PGO waves; while pentetrazole had no consistent effect, strychnine decreased and picrotoxin increased the density of PGO(1284). High doses of morphine, methadone and meperidine decreased the PGO(1284). Ethanol was inactive even in high doses. Caffeine and mefexamide reduced the density of PGO(1284). Mepiprazol was the most potent depressant of PGO(1284, probably by inhibiting the uptake of 5-HT. Mescaline was a weak depressor of PGO(1284). p-Chloromethamphetamine induced PGO waves in untreated cats less consitently than did PCPA. Amantadine reduced the amplitude of PGO waves due to a central antinicotinic action. The results of this study and of the whole series suggested a tentative scheme of the generation and modulation of PGO waves, in which the hypothetical roles and sites of action of four central neurotransmitters are included. PMID:5977

  15. Screening for Carotid Artery Stenosis

    MedlinePlus

    ... Task Force learned about the potential benefits and harms of screening for carotid artery stenosis: Health professionals ... blood flow through the arteries. Potential Benefits and Harms of Carotid Artery Stenosis Screening and Treatment The ...

  16. The square cat

    NASA Astrophysics Data System (ADS)

    Putterman, E.; Raz, O.

    2008-11-01

    We present a simple two-dimensional model of a "cat"—a body with zero angular momentum that can rotate itself with no external forces. The model is used to explain the nature of a gauge theory and to illustrate the importance of noncommutative operators. We compare the free-space cat in Newtonian mechanics and the same problem in Aristotelian mechanics at low Reynolds numbers (with the velocity proportional to the force rather than to the acceleration). This example shows the analogy between (angular) momentum in Newtonian mechanics and (torque) force in Aristotelian mechanics. We discuss a topological invariant common to the model in free space and at low Reynolds number.

  17. Cat scratch disease.

    PubMed

    Bozhkov, V; Madjov, R; Plachkov, I; Arnaudov, P; Chernopolsky, P; Krasnaliev, I

    2014-01-01

    Approximately 24,000 people are infected with cat scratch disease (CSD) every year. CSD is caused by the bacteria Bartonella henselae, a gram-negative bacteria most often transmitted to humans through a bite or scratch from an infected cat or kitten. Although CSD is often a benign and self-limiting condition, it can affect any major organ system in the body, manifesting in different ways and sometimes leading to lifelong sequelae. It is a disease that is often overlooked in primary care because of the wide range of symptom presentation and relative rarity of serious complications. It is important for health care providers to recognize patients at risk for CSD, know what laboratory testing and treatments are available, and be aware of complications that may arise from this disease in the future. PMID:25199244

  18. CT -- Body

    MedlinePlus

    ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Body Computed tomography (CT) of the body uses special x-ray ... Body? What is CT Scanning of the Body? Computed tomography, more commonly known as a CT or CAT ...

  19. Common Carotid Intima Media Thickness and Ankle-Brachial Pressure Index Correlate with Local but Not Global Atheroma Burden: A Cross Sectional Study Using Whole Body Magnetic Resonance Angiography

    PubMed Central

    Weir-McCall, Jonathan R.; Khan, Faisel; Lambert, Matthew A.; Adamson, Carly L.; Gardner, Michael; Gandy, Stephen J.; Ramkumar, Prasad Guntur; Belch, Jill J. F.; Struthers, Allan D.; Rauchhaus, Petra; Morris, Andrew D.; Houston, J. Graeme

    2014-01-01

    Background Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA). Methods 50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50–70%, 3 = 70–99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated. Results The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β −0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β −0.45 p = 0.005). Conclusion ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral

  20. Cool Cats: Feline Fun with Abstract Art.

    ERIC Educational Resources Information Center

    Lambert, Phyllis Gilchrist

    2002-01-01

    Presents a lesson that teaches students about abstract art in a fun way. Explains that students draw cats, learn about the work of Pablo Picasso, and, in the style of Picasso, combine the parts of the cats (tail, legs, head, body) together in unconventional ways. (CMK)

  1. Urgent Intracranial Carotid Artery Decompression after Penetrating Head Injury

    PubMed Central

    Kim, Seong Joon

    2013-01-01

    We describe a case of intracranial carotid artery occlusion due to penetrating craniofacial injury by high velocity foreign body that was relieved by decompressive surgery. A 46-year-old man presented with a penetrating wound to his face. A piece of an electric angular grinder disc became lodged in the anterior skull base. Computed tomography revealed that the disc had penetrated the unilateral paraclinoid and suprasellar areas without flow of the intracranial carotid artery on the lesion side. The cavernous sinus was also compromised. Removal of the anterior clinoid process reopened the carotid blood flow, and the injection of glue into the cavernous sinus restored complete hemostasis during extraction of the fragment from the face. Digital subtraction angiography revealed complete recanalization of the carotid artery without any evidence of dissection. Accurate diagnosis regarding the extent of the compromised structures and urgent decompressive surgery with adequate hemostasis minimized the severity of penetrating damage in our patient. PMID:23634269

  2. Effects on body temperature of prostaglandins of the A, E and F series on injection into the third ventricle of unanaesthetized cats and rabbits.

    PubMed

    Milton, A S; Wendlandt, S

    1971-10-01

    1. Prostaglandins were injected into the third ventricle of unanaesthetized cats and rabbits whilst rectal temperature was recorded.2. In cats prostaglandin E(1) and E(2) (PGE(1) and PGE(2)) produced hyperthermia which mostly began within a minute of injection and lasted 1 or more hours. With PGE(1) the hyperthermia was shown to be dose dependent between 10 ng and 10 mug (2.8 x 10(-11) and 2.8 x 10(-8)M). The hyperthermia was associated with vigorous shivering, skin vasoconstriction and piloerection. In several experiments a secondary rise in temperature occurred a few hours after the injection but such an effect was sometimes observed with control injections of 0.9% NaCl solution as well.3. None of the other prostaglandins (A(1), F(1alpha), F(2alpha)) examined in cats had an immediate or strong effect on temperature comparable to the hyperthermia produced by PGE(1) and PGE(2).4. In rabbits PGE(1) (2 mug) also caused hyperthermia which began shortly after the injection and lasted for hours. PGF(2alpha) and PGA(1), did not affect temperature.5. In cats it was seen that an intraperitoneal injection of 4-acetamidophenol (paracetamol 50 mg/kg) did not affect the initial strong hyperthermia produced by PGE(1) and PGE(2) but abolished the secondary rise.6. The possibility is discussed that PGE(1) plays a role as a central transmitter or modulator in temperature regulation. PMID:4330929

  3. Carotid Artery Disease

    MedlinePlus

    ... and efficacy continues to be studied in several medical centers. This procedure involves the placement of a small flexible tube (catheter) into an artery from the groin. The catheter is then directed to the neck to reach the carotid artery blockage. A balloon pushes open the artery wall and a stent ( ...

  4. Carotid Artery Screening

    MedlinePlus

    ... or radiologist then places the transducer on the skin in various locations, sweeping over the area of interest or angling the sound beam from a different location to better see an area of concern. Doppler sonography and Carotid IMT US are performed using the ...

  5. Carotid-cardiac baroreflex influence on forearm vascular resistance during low level LBNP

    NASA Technical Reports Server (NTRS)

    Ludwig, David

    1990-01-01

    Twelve healthy males were tested at low levels of lower body negative pressure (LBNP) with and without artificial stimulation of the carotid-cardiac baroreceptors. The carotid-cardiac baroreceptors were stimulated by applying a pressure of 10 mmHg to the carotid artery via a pressurized neck chamber. During the procedure, forearm blood flow (FBF) and forearm vascular resistance (FVR) were measured using a Whitney mercury silastic strain gauge technique. FBF decreased while FVR increased with increased intensity of LBNP. Both FBF and FVR were unaffected by carotid-cardiac baroreceptor stimulation.

  6. How Can Carotid Artery Disease Be Prevented?

    MedlinePlus

    ... from the NHLBI on Twitter. How Can Carotid Artery Disease Be Prevented? Taking action to control your risk factors can help prevent or delay carotid artery disease and stroke . Your risk for carotid artery ...

  7. Management of Carotid Artery Trauma

    PubMed Central

    Lee, Thomas S.; Ducic, Yadranko; Gordin, Eli; Stroman, David

    2014-01-01

    With increased awareness and liberal screening of trauma patients with identified risk factors, recent case series demonstrate improved early diagnosis of carotid artery trauma before they become problematio. There remains a need for unified screening criteria for both intracranial and extracranial carotid trauma. In the absence of contraindications, antithrombotic agents should be considered in blunt carotid artery injuries, as there is a significant risk of progression of vessel injury with observation alone. Despite CTA being used as a common screening modality, it appears to lack sufficient sensitivity. DSA remains to be the gold standard in screening. Endovascular techniques are becoming more widely accepted as the primary surgical modality in the treatment of blunt extracranial carotid injuries and penetrating/blunt intracranial carotid lessions. Nonetheless, open surgical approaches are still needed for the treatment of penetrating extracranial carotid injuries and in patients with unfavorable lesions for endovascular intervention. PMID:25136406

  8. Obesity and carotid artery remodeling

    PubMed Central

    Kozakova, M; Palombo, C; Morizzo, C; Højlund, K; Hatunic, M; Balkau, B; Nilsson, P M; Ferrannini, E

    2015-01-01

    Background/Objective: The present study tested the hypothesis that obesity-related changes in carotid intima-media thickness (IMT) might represent not only preclinical atherosclerosis but an adaptive remodeling meant to preserve circumferential wall stress (CWS) in altered hemodynamic conditions characterized by body size-dependent increase in stroke volume (SV) and blood pressure (BP). Subjects/Methods: Common carotid artery (CCA) luminal diameter (LD), IMT and CWS were measured in three different populations in order to study: (A) cross-sectional associations between SV, BP, anthropometric parameters and CCA LD (266 healthy subjects with wide range of body weight (24–159 kg)); (B) longitudinal associations between CCA LD and 3-year IMT progression rate (ΔIMT; 571 healthy non-obese subjects without increased cardiovascular (CV) risk); (C) the impact of obesity on CCA geometry and CWS (88 obese subjects without CV complications and 88 non-obese subjects matched for gender and age). Results: CCA LD was independently associated with SV that was determined by body size. In the longitudinal study, baseline LD was an independent determinant of ΔIMT, and ΔIMT of subjects in the highest LD quartile was significantly higher (28±3 μm) as compared with those in the lower quartiles (8±3, 16±4 and 16±3 μm, P=0.001, P<0.05 and P=0.01, respectively). In addition, CCA CWS decreased during the observational period in the highest LD quartile (from 54.2±8.6 to 51.6±7.4 kPa, P<0.0001). As compared with gender- and age-matched lean individuals, obese subjects had highly increased CCA LD and BP (P<0.0001 for both), but only slightly higher CWS (P=0.05) due to a significant increase in IMT (P=0.005 after adjustment for confounders). Conclusions: Our findings suggest that in obese subjects, the CCA wall thickens to compensate the luminal enlargement caused by body size-induced increase in SV, and therefore, to normalize the wall stress. CCA diameter in obesity could

  9. Cat and Dog Bites

    MedlinePlus

    MENU Return to Web version Cat and Dog Bites Cat and Dog Bites How should I take care of a bite from a cat or a dog? Whether from a family pet or a neighborhood stray, cat and dog bites are common. Here are some ...

  10. Cat-Scratch Disease

    MedlinePlus

    ... and how do people get it? Cat-scratch disease is an infection caused by a type of bacteria (germs) carried in cat saliva. This bacteria is called Bartonella henselae and can be passed from a cat to a human. Doctors and ... from fleas. Cat-scratch disease is not a severe illness in people who ...

  11. Management of carotid artery stenosis

    PubMed Central

    Louridas, George; Junaid, Asad

    2005-01-01

    OBJECTIVE To clarify the definition of carotid artery diseases, the appropriateness of screening for disease, investigation and management of patients presenting with transient ischemic attacks, and management of asymptomatic carotid bruits. SOURCES OF INFORMATION MEDLINE was searched using the terms carotid endarterectomy, carotid disease, and carotid stenosis. Most studies offer level II or III evidence. Consensus statements and guidelines from various neurovascular societies were also consulted. MAIN MESSAGE Patients with symptoms of hemispheric transient ischemic attacks associated with >70% stenosis of the internal carotid artery are at highest risk of major stroke or death. Risk is greatest within 48 hours of symptom onset; patients should have urgent evaluation by a vascular surgeon for consideration of carotid endarterectomy (CEA). Patients with 50% to 69% stenosis might benefit from urgent surgical intervention depending on clinical features and associated comorbidity. Patients with <50% stenosis do not benefit from surgery. Asymptomatic patients with >60% stenosis should be considered for elective CEA. CONCLUSION Symptomatic carotid artery syndromes need urgent carotid duplex evaluation to determine the need for urgent surgery. Those with the greatest degree of stenosis derive the greatest benefit from timely CEA. PMID:16060177

  12. Carotid Artery Stenting versus Endarterectomy

    PubMed Central

    Gahremanpour, Amir; Perin, Emerson C.; Silva, Guilherme

    2012-01-01

    For about 2 decades, investigators have been comparing carotid endarterectomy with carotid artery stenting in regard to their effectiveness and safety in treating carotid artery stenosis. We conducted a systematic review to summarize and appraise the available evidence provided by randomized trials, meta-analyses, and registries comparing the clinical outcomes of the 2 procedures. We searched the MEDLINE, SciVerse Scopus, and Cochrane databases and the bibliographies of pertinent textbooks and articles to identify these studies. The results of clinical trials and, consequently, the meta-analyses of those trials produced conflicting results regarding the comparative effectiveness and safety of carotid endarterectomy and carotid stenting. These conflicting results arose because of differences in patient population, trial design, outcome measures, and variability among centers in the endovascular devices used and in operator skills. Careful appraisal of the trials and meta-analyses, particularly the most recent and largest National Institutes of Healthsponsored trial (the Carotid Revascularization Endarterectomy vs Stenting Trial [CREST]), showed that carotid stenting and endarterectomy were associated with similar rates of death and disabling stroke. Within the 30-day periprocedural period, carotid stenting was associated with higher risks of stroke, especially for patients aged >70 years, whereas carotid endarterectomy was associated with a higher risk of myocardial infarction. The slightly higher cost of stenting compared with endarterectomy was within an acceptable range by cost-effectiveness standards. We conclude that carotid artery stenting is an equivalent alternative to carotid endarterectomy when patient age and anatomy, surgical risk, and operator experience are considered in the choice of treatment approach. PMID:22949763

  13. Cervical carotid pseudoaneurysm: A carotid artery stenting complication

    PubMed Central

    Raso, Jair; Darwich, Rogerio; Ornellas, Carlos; Cariri, Gustavo

    2011-01-01

    Background: As carotid artery stenting becomes increasingly used, more complications are likely to occur. We present a case of Staphylococcus septicemia and pseudoaneurysm arising in the neck portion of the carotid artery after stenting. Case Description: A 51-year-old man was admitted with mild left hemiparesis. CT and MRI showed right hemisphere ischemia. Duplex Scan and MRA showed bilateral severe stenosis of the carotid arteries in the neck. A percutaneous angioplasty with stenting of the left carotid artery was performed. Two weeks after the procedure, he developed fever and swelling in the right leg and shoulder. An abscess, near where the groin had been punctured for the angioplasty was surgically drained. Blood samples were positive for S. aureus. After treatment the patient complained of a painful bulky pulsatile left cervical mass. Duplex scan and MRA showed a pseudoaneurysm of the left carotid artery. We excised the pseudoaneurysm and rebuilt the carotid artery with a saphenous vein graft. The postoperative period was uneventful, and the MRA revealed a patent saphenous graft. Conclusion: Mycotic pseudoaneurysm of the carotid artery is a rare complication of percutaneous angioplasty and stenting. Surgical treatment with saphenous vein graft is the treatment of choice. PMID:21748038

  14. Cat Scratch Disease

    MedlinePlus

    Cat scratch disease (CSD) is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry the infection ... symptoms of CSD, call your doctor. Centers for Disease Control and Prevention

  15. Cat-Scratch Disease

    MedlinePlus

    ... Patients Infants and Young Children Publications & Materials Announcements Cat-Scratch Disease Recommend on Facebook Tweet Share Compartir ( ... play and learn how to attack prey. How cats and people become infected Kitten playing with a ...

  16. Getting a CAT Scan

    MedlinePlus

    ... Here's Help White House Lunch Recipes Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  17. Pulmonary thromboembolism in cats.

    PubMed

    Schermerhorn, Thomas; Pembleton-Corbett, Julie R; Kornreich, Bruce

    2004-01-01

    Pulmonary thromboembolism (PTE) is rarely diagnosed in cats, and the clinical features of the disease are not well known. PTE was diagnosed at postmortem examination in 17 cats, a prevalence of 0.06% over a 24-year period. The age of affected cats ranged from 10 months to 18 years, although young (<4 years) and old (>10 years) cats were more commonly affected than were middle-aged cats. Males and females were equally affected. The majority of cats with PTE (n = 16) had concurrent disease, which was often severe. The most common diseases identified in association with PTE were neoplasia, anemia of unidentified cause, and pancreatitis. Cats with glomerulonephritis, encephalitis, pneumonia, heart disease, and hepatic lipidosis were also represented in this study. Most cats with PTE demonstrated dyspnea and respiratory distress before death or euthanasia, but PTE was not recognized ante mortem in any cat studied. In conclusion, PTE can affect cats of any age and is associated with a variety of systemic and inflammatory disorders. It is recommended that the same clinical criteria used to increase the suspicion of PTE in dogs should also be applied to cats. PMID:15320593

  18. The reflex release of adrenaline and noradrenaline from the adrenal glands of cats and dogs.

    PubMed Central

    Critchley, J A; Ellis, P; Ungar, A

    1980-01-01

    1. We have studied the release of noradrenaline and adrenaline from the adrenal glands of dogs and cats in response to the lowering of carotid sinus pressure (baroreceptor tests) and to the perfusion of the vascularly isolated carotid bifurcations with hypoxic blood (chemoreceptor tests). 2. In cats, the resting output of catecholamines had a ratio of noradrenaline to adrenaline of 1:1. The ratio in the incremental release during baroreceptor tests rose to 3:1, and during chemoreceptor tests it fell to 1:6. 3. In dogs, the ratio of noradrenaline to adrenaline at rest was 1:4. The ratio did not change over a wide range of outputs during baroreceptor tests, chemoreceptor tests and splanchnic nerve stimulation. 4. The release of catecholamines in response to baroreceptor tests in the cat was abolished by hexamethomium bromide at doses that did not diminish the response to chemoreceptor tests. PMID:7359443

  19. Lessons learnt from carotid artery trials.

    PubMed

    Van Damme, H; Limet, R

    2006-01-01

    The objective of the authors is to assess the natural history of carotid artery disease and the role of carotid intervention in preventing ipsilateral stroke. The development of endovascular techniques for correction of carotid artery stenoses made this less invasive technique very popular, with an inherent risk of unregulated overuse by a variety of medical specialists, who are not always well informed on the natural history of carotid artery disease. It re-opened the discussion on the value of carotid endarterectomy for stroke prophylaxis. This ongoing debate offers the opportunity to distil evidence-based guidelines for the management of extracranial carotid artery stenoses. In recent papers, some authors expressed doubts on the validity and general applicability of the results of the pivotal randomised trials of carotid endarterectomy. The excellent results in terms of operative outcome and long term stroke prevention would, according to certain comments, not be attainable in routine practice. Another criticism of carotid endarterectomy is its higher operative morbidity in terms of cranial nerve lesions and myocardial infarctions, compared to endovascular procedures. This consideration is, for some authors, the main reason to espouse carotid artery stenting as a better alternative to carotid endarterectomy. Any evidence supporting this point of view is missing. The supposed equivalence or non-inferiority of carotid artery stenting is purely speculative. The aim of this review paper is to summarize the crude data of carotid surgery trials. The authors aim to answer four questions. For which lesions is carotid endarterectomy most beneficial ? Are the results of randomised carotid surgery trials biased by the selection of patients ? Is operative morbidity, other than stroke, under-estimated ? Is carotid artery stenting safe and efficacious ? An in-depth review with a critical analysis is made of recently published and on-going trials, comparing carotid surgery

  20. Chronic Interactions Between Carotid Baroreceptors and Chemoreceptors in Obesity Hypertension.

    PubMed

    Lohmeier, Thomas E; Iliescu, Radu; Tudorancea, Ionut; Cazan, Radu; Cates, Adam W; Georgakopoulos, Dimitrios; Irwin, Eric D

    2016-07-01

    Carotid bodies play a critical role in protecting against hypoxemia, and their activation increases sympathetic activity, arterial pressure, and ventilation, responses opposed by acute stimulation of the baroreflex. Although chemoreceptor hypersensitivity is associated with sympathetically mediated hypertension, the mechanisms involved and their significance in the pathogenesis of hypertension remain unclear. We investigated the chronic interactions of these reflexes in dogs with sympathetically mediated, obesity-induced hypertension based on the hypothesis that hypoxemia and tonic activation of carotid chemoreceptors may be associated with obesity. After 5 weeks on a high-fat diet, the animals experienced a 35% to 40% weight gain and increases in arterial pressure from 106±3 to 123±3 mm Hg and respiratory rate from 8±1 to 12±1 breaths/min along with hypoxemia (arterial partial pressure of oxygen=81±3 mm Hg) but eucapnia. During 7 days of carotid baroreflex activation by electric stimulation of the carotid sinus, tachypnea was attenuated, and hypertension was abolished before these variables returned to prestimulation values during a recovery period. After subsequent denervation of the carotid sinus region, respiratory rate decreased transiently in association with further sustained reductions in arterial partial pressure of oxygen (to 65±2 mm Hg) and substantial hypercapnia. Moreover, the severity of hypertension was attenuated from 125±2 to 116±3 mm Hg (45%-50% reduction). These findings suggest that hypoxemia may account for sustained stimulation of peripheral chemoreceptors in obesity and that this activation leads to compensatory increases in ventilation and central sympathetic outflow that contributes to neurogenically mediated hypertension. Furthermore, the excitatory effects of chemoreceptor hyperactivity are abolished by chronic activation of the carotid baroreflex. PMID:27160198

  1. Exocrine Pancreas in Cats With Diabetes Mellitus.

    PubMed

    Zini, E; Ferro, S; Lunardi, F; Zanetti, R; Heller, R S; Coppola, L M; Guscetti, F; Osto, M; Lutz, T A; Cavicchioli, L; Reusch, C E

    2016-01-01

    Pancreatitis has been described in cats with diabetes mellitus, although the number of studies currently available is very limited. In addition, ketoacidosis has been hypothesized to be associated with pancreatitis in diabetic cats. The aims of the present study were to investigate whether diabetic cats have pancreatitis and to determine if pancreatitis is more frequent with ketoacidosis. Samples of pancreas were collected postmortem from 37 diabetic cats, including 15 with ketoacidosis, and 20 control cats matched for age, sex, breed, and body weight. Sections were stained with hematoxylin and eosin, double-labeled for insulin/CD3, insulin/CD20, insulin/myeloperoxidase, insulin/PCNA, and glucagon/Ki67, and single-labeled for Iba1. A previously proposed semiquantitative score was used to characterize pancreatitis, along with counts of inflammatory cells. Scores of pancreatitis and the number of neutrophils, macrophages, and lymphocytes in the exocrine pancreas did not differ between diabetic and control cats or between diabetic cats with and without ketoacidosis. Of note, PCNA-positive acinar cells were increased (P = .002) in diabetic cats, particularly near islets (P < .001). Ki67-positive acinar cells were increased only near islets (P = .038). Ketoacidosis was not linked to proliferation. The results suggest that histopathologic evidence of pancreatitis may not be more frequent in diabetic cats and that ketoacidosis may not be associated with it at the time of death. Augmented PCNA-positive acinar cells might indicate increased proliferation due to chronic pancreatitis. The reason behind the prevalent proliferation of acinar cells surrounding pancreatic islets deserves further investigation. PMID:26319779

  2. Endocrine Pancreas in Cats With Diabetes Mellitus.

    PubMed

    Zini, E; Lunardi, F; Zanetti, R; Heller, R S; Coppola, L M; Ferro, S; Guscetti, F; Osto, M; Lutz, T A; Reusch, C E; Cavicchioli, L

    2016-01-01

    Pancreatic amyloidosis and loss of α and β cells have been shown to occur in cats with diabetes mellitus, although the number of studies currently available is very limited. Furthermore, it is not known whether pancreatic islet inflammation is a common feature. The aims of the present study were to characterize islet lesions and to investigate whether diabetic cats have inflammation of the pancreatic islets. Samples of pancreas were collected postmortem from 37 diabetic and 20 control cats matched for age, sex, breed, and body weight. Histologic sections were stained with hematoxylin and eosin and Congo red; double labeled for insulin/CD3, insulin/CD20, insulin/myeloperoxidase, insulin/proliferating cell nuclear antigen, and glucagon/Ki67; and single labeled for amylin and Iba1. Mean insulin-positive cross-sectional area was approximately 65% lower in diabetic than control cats (P = .009), while that of amylin and glucagon was similar. Surprisingly, amyloid deposition was similar between groups (P = .408). Proliferation of insulin- and glucagon-positive cells and the number of neutrophils, macrophages, and T (CD3) and B (CD20) lymphocytes in the islets did not differ. The presence of T and B lymphocytes combined tended to be more frequent in diabetic cats (n = 8 of 37; 21.6%) than control cats (n = 1 of 20; 5.0%). The results confirm previous observations that loss of β cells but not α cells occurs in diabetic cats. Islet amyloidosis was present in diabetic cats but was not greater than in controls. A subset of diabetic cats had lymphocytic infiltration of the islets, which might be associated with β-cell loss. PMID:26113611

  3. Sympathoinhibition and hypotension in carotid sinus hypersensitivity.

    PubMed

    Smith, M L; Ellenbogen, K A; Eckberg, D L

    1992-12-01

    Carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position. PMID:1290922

  4. Sympathoinhibition and hypotension in carotid sinus hypersensitivity

    NASA Technical Reports Server (NTRS)

    Smith, M. L.; Ellenbogen, K. A.; Eckberg, D. L.

    1992-01-01

    Carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position.

  5. How Is Carotid Artery Disease Treated?

    MedlinePlus

    ... Links Related Topics Atherosclerosis Carotid Endarterectomy Carotid Ultrasound Stents Stroke Send a link to NHLBI to someone ... outward against the wall of the artery. A stent (a small mesh tube) is then put in ...

  6. Glenoid dysplasia and osteochondritis dissecans in a cat

    PubMed Central

    Schwarze, Rebecca A.; Tano, Cheryl A.; Carroll, Vincent W.

    2015-01-01

    A 2-year-old Maine coon cat was presented for a right forelimb lameness. Computed tomography of the shoulder revealed a shallow glenoid, osteophyte deposition at the caudal humeral head and medial glenoid, and an intra-articular osseous body. This cat had glenoid dysplasia and osteochondritis dissecans of the glenoid. PMID:26130839

  7. Multimodality Imaging of Carotid Stenosis

    PubMed Central

    Adla, Theodor; Adlova, Radka

    2015-01-01

    Four diagnostic modalities are used to image the following internal carotid artery: digital subtraction angiography (DSA), duplex ultrasound (DUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA). The aim of this article is to describe the potentials of these techniques and to discuss their advantages and disadvantages. Invasive DSA is still considered the gold standard and is an indivisible part of the carotid stenting procedure. DUS is an inexpensive but operator-dependent tool with limited visibility of the carotid artery course. Conversely, CTA and MRA allow assessment of the carotid artery from the aortic arch to intracranial parts. The disadvantages of CTA are radiation and iodine contrast medium administration. MRA is without radiation but contrast-enhanced MRA is more accurate than noncontrast MRA. The choice of methods depends on the clinical indications and the availability of methods in individual centers. However, the general approach to patient with suspected carotid artery stenosis is to first perform DUS and then other noninvasive methods such as CTA, MRA, or transcranial Doppler US. PMID:26417185

  8. Carotid bruits as predictor for carotid stenoses detected by ultrasonography: an observational study

    PubMed Central

    Johansson, Elias P; Wester, Per

    2008-01-01

    Background Carotid surgery in asymptomatic subjects with carotid stenosis is effective to prevent ischemic stroke. There is, however, uncertainty how to find such persons at risk, because mass screening with carotid artery ultrasonography (US) is not cost-effective. Signs of carotid bruits corresponding to the carotid arteries may serve as a tool to select subjects for further investigation. This study is thus aimed at determining the usefulness of carotid bruits in the screening of carotid stenoses. Methods 1555 consecutive carotid ultrasonography investigations from 1486 cases done between January 2004 and March 2006 at Norrlands University Hospital, Sweden, were examined. 356 subjects, medium age 69 (27–88) years, had a significant (≥ 50%) US-verified carotid stenosis uni- or bilaterally, 291 had been examined for signs of carotid bruits. The likelihood ratios for carotid bruits to predict US-verified carotid stenoses were calculated and expressed as likelihood percentages. Results Thirty-one out of 100 persons (31%) with carotid bruit as an indication to perform carotid US had a significant (≥ 50%) carotid stenosis. 281 of the 356 (79%) cases with significant carotid stenoses were found among patients with cerebrovascular disease (CVD). 145 of 226 (64%) CVD patients with a significant carotid stenosis had a carotid bruit. In patients with 50–99% carotid stenoses carotid bruits had an accuracy of 75% (436/582), a sensitivity of 71% (236/334), a specificity of 81% (200/248), a positive likelihood ratio at 3.65 and a negative likelihood at 0.36. Patients with 70–99% stenoses had the highest sensitivity at 77% (183/238). In patients with 100% carotid stenoses, carotid bruits had a sensitivity of 26% (15/57) and a specificity of 49% (256/525). Conclusion Although carotid bruits are not accurate to confirm or to exclude significant carotid stenoses, these signs are appropriate for directed screening for further investigation with carotid US if the patient

  9. Metabolizable energy intake of client-owned adult cats.

    PubMed

    Thes, M; Koeber, N; Fritz, J; Wendel, F; Dobenecker, B; Kienzle, E

    2015-12-01

    A retrospective analysis of the metabolizable energy (ME) intake of privately owned pet cats from the authors' nutrition consultation practice (years 2007-2011) was carried out to test whether current recommendations are suitable for pet cats. Data of 80 adult cats (median age: 9.0 years, median deviation from ideal weight: +22.5%, majority neutered) at maintenance were available. Six percentage of the cats were healthy and the others were affected by various chronic diseases. A standardized questionnaire was used, cat owners weighed cat and food. For ration calculation, the software Diet Check Munich(™) was used (ME prediction according to National Research Council, 2006: Nutrient Requirements of Dogs and Cats. National Academy Press, Washington, DC). Data were analysed for the factors deviation from ideal weight, breed, age, gender, disease and type of feeding [prepared food (dry, wet) vs. home-made]. Over- or underweight were defined as ≥15% deviation from ideal body weight (BW) according to Kienzle and Moik (British Journal of Nutrition 2011, 106, Suppl 1: S113). Cat owner's estimation of ideal BW was higher than literature data from Kienzle and Moik (2011). Based on literature data, 26.3% of the pet cats were normal weight, 63.7% overweight and 10% underweight. The mean ME intake of all adult cats amounted to 0.40 ± 0.14 MJ/kg actual BW(0.67) (n = 80). When the data were analysed according to normal, over- and underweight, there was a significant effect with normal weight cats eating 0.46 MJ/kg BW(0.67) . Underweight cats ate even more (0.49 MJ/kg BW(0.67) ), whereas overweight cats ate considerably less (0.36 MJ/kg BW(0.67) ). The other factors had no influence on ME intake of adult cats. PMID:26456847

  10. Carotid chemoreceptor “resetting” revisited

    PubMed Central

    Carroll, John L.; Kim, Insook

    2012-01-01

    Carotid body (CB) chemoreceptors transduce low arterial O2 tension into increased action potential activity on the carotid sinus nerves, which contributes to resting ventilatory drive, increased ventilatory drive in response to hypoxia, arousal responses to hypoxia during sleep, upper airway muscle activity, blood pressure control and sympathetic tone. Their sensitivity to O2 is low in the newborn and increases during the days or weeks after birth to reach adult levels. This postnatal functional maturation of the CB O2 response has been termed “resetting” and it occurs in every mammalian species studied to date. The O2 environment appears to play a key role; the fetus develops in a low O2 environment throughout gestation and initiation of CB “resetting” after birth is modulated by the large increase in arterial oxygen tension occurring at birth. Although numerous studies have reported age-related changes in various components of the O2 transduction cascade, how the O2 environment shapes normal CB prenatal development and postnatal “resetting” remains unknown. Viewing CB “resetting” as environment-driven (developmental) phenotypic plasticity raises important mechanistic questions that have received little attention. This review examines what is known (and not known) about mechanisms of CB functional maturation, with a focus on the role of the O2 environment. PMID:22982216

  11. That Fat Cat

    ERIC Educational Resources Information Center

    Lambert, Phyllis Gilchrist

    2012-01-01

    This activity began with a picture book, Nurit Karlin's "Fat Cat On a Mat" (HarperCollins; 1998). The author and her students started their project with a 5-inch circular template for the head of their cats. They reviewed shapes as they drew the head and then added the ears and nose, which were triangles. Details to the face were added when…

  12. Diseases Transmitted by Cats.

    PubMed

    Goldstein, Ellie J C; Abrahamian, Fredrick M

    2015-10-01

    Humans and cats have shared a close relationship since ancient times. Millions of cats are kept as household pets, and 34% of households have cats. There are numerous diseases that may be transmitted from cats to humans. General modes of transmission, with some overlapping features, can occur through inhalation (e.g., bordetellosis); vector-borne spread (e.g., ehrlichiosis); fecal-oral route (e.g., campylobacteriosis); bite, scratch, or puncture (e.g., rabies); soil-borne spread (e.g., histoplasmosis); and direct contact (e.g., scabies). It is also likely that the domestic cat can potentially act as a reservoir for many other zoonoses that are not yet recognized. The microbiology of cat bite wound infections in humans is often polymicrobial with a broad mixture of aerobic (e.g., Pasteurella, Streptococcus, Staphylococcus) and anaerobic (e.g., Fusobacterium, Porphyromonas, Bacteroides) microorganisms. Bacteria recovered from infected cat bite wounds are most often reflective of the oral flora of the cat, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. PMID:26542039

  13. Carotid Plaques Correlates in Patients With Familial Hypercholesterolemia.

    PubMed

    Waluś-Miarka, Małgorzata; Czarnecka, D; Wojciechowska, W; Kloch-Badełek, M; Kapusta, M; Sanak, M; Wójcik, M; Małecki, M T; Starzyk, J; Idzior-Waluś, B

    2016-05-01

    Patients with familial hypercholesterolemia (FH) are at increased risk of premature cardiovascular disease. We compared factors associated with the presence of carotid plaques and carotid intima-media thickness (cIMT), markers of subclinical atherosclerosis, in 241 patients with FH (98, 40.7% men; mean age 41 ± 18.4 years). Patients with FH having carotid plaques (36.5%) had mean age, apolipoprotein (apo) B, glucose, apoA1, systolic blood pressure (SBP) and diastolic BP, waist/hip ratio (WHR), and body mass index higher than patients without plaques. Logistic regression revealed that apoB (odds ratio [OR] per 1 unit change 1.03,P= .005), high-density lipoprotein cholesterol (HDL-C; OR per 1 standard deviation [SD] change 0.59,P= .015), and non-HDL-C (OR per 1SD change 1.53,P= .04) were significantly associated with the presence of plaques. The cIMT correlated with obesity parameters, BP, apoB, glucose, high-sensitivity C-reactive protein, creatinine, γ-glutamyl transpeptidase, and alanine transaminase (P< .001). Regression analysis revealed that cIMT was significantly associated with apoB, SBP, and WHR. These results confirm the role of apoB-containing lipoproteins and low HDL-C with the presence of carotid plaques and apoB, BP, and WHR with cIMT. PMID:26198473

  14. Distribution of transient receptor potential channels in the rat carotid chemosensory pathway.

    PubMed

    Buniel, Maria C F; Schilling, William P; Kunze, Diana L

    2003-09-22

    Glomus cells in the carotid body respond to decreases in oxygen tension of the blood and transmit this sensory information in the carotid sinus nerve to the brain via neurons in the petrosal ganglion. G-protein-coupled membrane receptors linked to phospholipase C may play an important role in this response through the activation of the cation channels formed by the transient receptor potential (TRP) proteins. In the present study, expression of TRPC proteins in the rat carotid body and petrosal ganglion was examined using immunohistochemical techniques. TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7 were present in neurons throughout the ganglion. TRPC1 was expressed in only 28% of petrosal neurons, and of this population, 45% were tyrosine hydroxylase (TH)-positive, accounting for essentially all the TH-expressing neurons in the ganglion. Because TH-positive neurons project to the carotid body, this result suggests that TRPC1 is selectively associated with the chemosensory pathway. Confocal images through the carotid body showed that TRPC1/3/4/5/6 proteins localize to the carotid sinus nerve fibers, some of which were immunoreactive to an anti-neurofilament (NF) antibody cocktail. TRPC1 and TRPC3 were present in both NF-positive and NF-negative fibers, whereas TPRC4, TRPC5, and TRPC6 expression was primarily localized to NF-negative fibers. Only TRPC1 and TRPC4 were localized in the afferent nerve terminals that encircle individual glomus cells. TRPC7 was not expressed in sensory fibers. All the TRPC proteins studied were present in type I glomus cells. Although their role as receptor-activated cation channels in the chemosensory pathway is yet to be established, the presence of TRPC channels in glomus cells and sensory nerves of the carotid body suggests a role in facilitating and/or sustaining the hypoxic response. PMID:12900933

  15. Minimal nocturnal oxygen saturation predicts future subclinical carotid atherosclerosis: the Wisconsin sleep cohort.

    PubMed

    Gunnarsson, Sverrir I; Peppard, Paul E; Korcarz, Claudia E; Barnet, Jodi H; Hagen, Erika W; Hla, K Mae; Palta, Mari; Young, Terry; Stein, James H

    2015-12-01

    Previous data on the associations between nocturnal oxygen saturation parameters and carotid atherosclerosis are conflicting. We examined the prospective associations of nocturnal oxygen saturation (SaO2 ) and cardiovascular disease (CVD) risk factors with carotid intima-media thickness (IMT) and plaques. We used data on 689 Wisconsin sleep cohort participants who had baseline overnight polysomnography followed by carotid ultrasonography a mean (SD) of 7.8 (2.5) years later. Far wall common carotid IMT was measured using B-mode ultrasound. Bilateral common, bifurcation and internal carotid artery segments were evaluated for plaque score. Participants (8) were aged 56 years (55% male); 32% had hypertension and mean body mass index (BMI) was 31 (7) kg m(2). Mean and minimum nocturnal SaO2 were 95% (2) and 86% (7), respectively. Mean percentage sleep time with SaO2 < 90% was 2% (8). Both mean (odds ratio [OR]: 0.60 lower plaque count per 5% higher mean SaO2, 95% confidence interval [CI]: 0.38-0.96, P = 0.033) and minimum SaO2 (OR: 0.88 lower plaque count per 5% higher minimum SaO2, 95% CI: 0.80-0.97, P = 0.013) predicted carotid plaque score after adjusting for age, sex and BMI. Minimum SaO2 predicted future plaque score after adding adjustment for traditional CVD risk factors (OR: 0.90 lower plaque count per 5% higher minimum SaO2, 95% CI: 0.81-0.99, P = 0.038). Mean SaO2 was not associated with carotid IMT after CVD risk factor adjustment. We conclude that minimum nocturnal SaO2 is an independent predictor of future carotid plaque burden. Other nocturnal SaO2 parameters are not associated with future carotid IMT or plaques after adjusting for traditional CVD risk factors. PMID:26096939

  16. Taking your carotid pulse (image)

    MedlinePlus

    ... take oxygenated blood from the heart to the brain. The pulse from the carotids may be felt on either side of the front of the neck just below the angle of the jaw. This rhythmic "beat" is caused by varying volumes of blood being pushed out of the heart ...

  17. Parasitic infections of domestic cats, Felis catus, in western Hungary.

    PubMed

    Capári, B; Hamel, D; Visser, M; Winter, R; Pfister, K; Rehbein, S

    2013-02-18

    During 2011, faeces from 235 owned domestic cats from a rural area in western Hungary were examined using standard coproscopical techniques. The overall prevalence of cats with endoparasites was 39.6% (95% CI 33.3-46.1). The most frequently identified faecal forms were those of ascarids (Toxocara, 17.4%; Toxascaris 7.2%), followed by those of Aelurostrongylus lungworms (14.5%), hookworms (11.1%), taeniid cestodes (4.7%), Cystoisospora coccidians (4.3%), and capillarids (3.8%). Single and multiple infections with up to five parasites concurrently were founded in 24.7% and 14.9% of the cats, respectively. Mixed endoparasite infections were recorded more frequently (p=0.0245) in cats greater than one year old compared to younger cats. Young cats (≤ 1 year) were parasitized more frequently (p<0.05) with ascarids and Cystoisospora spp. but demonstrated infections of hookworms, lungworms and taeniid cestodes less often than the older cats. Cats with taeniid infection were more likely (p<0.05) to harbour Toxocara, hookworm, Aelurostrongylus, and capillarid infections than cats without taeniid cestodes. Cats of owners who claimed the use of wormers were less frequently helminth-positive compared to cats whose owners did not use anthelmintics (21.2% vs. 44.4%; p=0.001). A subset of 115 faecal samples screened by a coproantigen ELISA revealed Giardia-specific antigen in 37.4% samples. Giardia cysts were found by immunofluorescent staining in 30 of the 43 samples tested positive for Giardia by ELISA. In addition, ectoparasites collected from 82 cats by body search and combing were identified. Fleas (1-30 per cat), biting lice (Felicola subrostratus), and ticks (1-5 per cat) were isolated from 58, 1 and 43 cats, respectively. Ctenocephalides felis was identified on all flea infested cats while single specimens of C. canis and Pulex irritans were recovered from three and two cats, respectively. All but one tick collected were adult Ixodes ricinus; the single other tick was a

  18. The prevalence of carotid plaque with different stability and its association with metabolic syndrome in China: The Asymptomatic Polyvascular Abnormalities Community study.

    PubMed

    Wang, Anxin; Wu, Lingyun; Liu, Xiaoxue; Su, Zhaoping; Luo, Yanxia; Chen, Shuohua; Li, Haibin; Liu, Xiangtong; Tao, Lixin; Guo, Jin; Zhang, Feng; Cao, Yibin; Zhao, Xingquan; Wu, Shouling; Guo, Xiuhua

    2016-08-01

    Few studies have investigated the prevalence of carotid plaque with different stability in Chinese. As is well known, carotid atherosclerosis is tightly associated with metabolic syndrome (MetS); however, the data about the association between the presence of carotid plaque with different stability and MetS was limited. The aim of our study was to investigate the prevalence of carotid plaque with different stability and its potential association with MetS in general Chinese population.The Asymptomatic Polyvascular Abnormalities Community study is a community-based study to investigate the epidemiology of asymptomatic polyvascular abnormalities in Chinese adults. A total of 5393 participants were finally eligible and included in this study. The carotid plaque and its stability were assessed using ultrasonography. The MetS was defined using the criteria from US National Cholesterol Education Program-Adult Treatment Panel III. Data were analyzed with multivariate logistic regression models.Of the 5393 subjects, 1397 (25.9%) participants had stable carotid plaque, 1518 (28.1%) had unstable carotid plaque in participants, and 1456 (27.0%) had a MetS. MetS was, respectively, significantly associated with the prevalence of carotid plaque (odds ratio [OR]: 1.25; 95% confidence interval [CI]: 1.07, 1.47), stable carotid plaque (OR: 1.23; 95% CI: 1.02,1.48), and unstable carotid plaque (OR: 1.27; 95% CI: 1.03,1.56) after adjusting for age, gender, level of education, income, smoking, drinking, physical activity, body mass index, low-density lipoprotein, and high-sensitivity C-reactive protein. With the number of MetS components, the prevalence of carotid plaque, stable carotid plaque, and unstable carotid plaque significantly increased (P for trend <0.0001), respectively.In summary, the prevalence of carotid plaque was 54.1%, stable carotid plaque was 25.9%, and unstable carotid plaque was 28.1%. Our study revealed that the prevalence of carotid plaque, stable carotid plaque

  19. Increased Vessel Depiction of the Carotid Bifurcation with a Specialized 16-Channel Phased Array Coil at 3T

    PubMed Central

    Tate, Quinn; Kim, Seong-Eun; Treiman, Gerald; Parker, Dennis L.; Hadley, J. Rock

    2012-01-01

    The purpose of this work was to design and construct a multi-channel receive-only RF coil for 3 Tesla magnetic resonance imaging of the human carotid artery and bifurcation with optimized signal to noise ratio in the carotid vessels along the full extent of the neck. A neck phantom designed to match the anatomy of a subject with a neck representing the body habitus often seen in subjects with carotid arterial disease, was constructed. Sixteen circular coil elements were arranged on a semi-rigid fiberglass former that closely fit the shape of the phantom, resulting in a 16-channel bilateral phased array coil. Comparisons were made between this coil and a typical 4-channel carotid coil in a study of 10 carotid vessels in 5 healthy volunteers. The 16-channel carotid coil showed a 73% average improvement in signal to noise ratio (SNR) at the carotid bifurcation. This coil also maintained an SNR greater than the peak SNR of the 4-channel coil over a vessel length of 10 cm. The resulting increase in SNR improved vessel depiction of the carotid arteries over an extended field of view, and demonstrated better image quality for higher parallel imaging reduction factors compared to the 4-channel coil. PMID:22777692

  20. Carotid blood flow measured by an ultrasonic volume flowmeter in carotid stenosis and patients with dementia.

    PubMed Central

    Uematsu, S; Folstein, M F

    1985-01-01

    The volume flowmeter is a simple, noninvasive Doppler ultrasound technique that provides accurate measurement of carotid artery diameter and flow. The device provides a useful laboratory test that can aid significantly in diagnosis of carotid stenosis and dementia. PMID:2935592

  1. What Are the Signs and Symptoms of Carotid Artery Disease?

    MedlinePlus

    ... What Are the Signs and Symptoms of Carotid Artery Disease? Carotid artery disease may not cause signs or symptoms until it severely narrows or blocks a carotid artery. Signs and symptoms may include a bruit, a ...

  2. Aseptic polyurethane carotid patch rejection: complication, allergy or miraculous healing?

    PubMed

    Tshomba, Y; De Dominicis, D; Marone, E M; Mascia, D; Sanvito, F; Chiesa, R

    2011-12-01

    Carotid endarterectomy plays an important role in the prevention of ischemic stroke; patching could reduce the risk of intra- and postoperative complications and late restenosis among primary closure. Materials actually available for the patch tailoring are synthetic or biological: which is the best is still debated. We present the case of a polyurethane (PU) carotid patch rejection three years after its implant, with no evident arterial discontinuity and no sign of infection. Histopathological analysis on hematoxylin-eosin stained sections of the regenerated arterial wall tissue removed revealed plasma cell infiltration and clusters of foreign body giant cells. PU patch rejection has been seldom described in literature. This is an unusual late complication that should be considered at long-term follow-up evaluation of these patients. PMID:21750481

  3. Left carotid steal. A new observation.

    PubMed

    Shumacker, H B; Isch, J H

    1975-04-01

    A patient had an occlusion of the left subclavian artery just proximal to the takeoff of a previously placed subclavian-carotid graft. This caused reversal of flow in the graft and a symptomatic steal of blood via to the intracranial arteries. An axilloaxillary graft restored forward flow. In a second patient, a steal occurred from the right carotid and vertebral systems into the distal carotid system of the left side that has been isolated by a proximal carotide artery occlusion from arteriosclerosis. A saphenous vein, used as a bypass from the subclavian to the carotid artery, restored normal flow. Thus, the carotide system may be the low-pressure area responsible for the steal, although this is rarer than the subclavian. PMID:1147756

  4. Atherosclerotic carotid stenosis and cognitive function.

    PubMed

    Wang, Tao; Mei, Bin; Zhang, Junjian

    2016-07-01

    Atherosclerosis carotid stenosis is associated with stroke and cognitive impairment. Progressive cognitive decline may be an even greater problem than stroke, but it has not been widely recognized and therefore must be adequately addressed. Although both Carotid Endarterectomy (CEA) and Carotid Artery Stenting (CAS) have been proven can prevent future stroke in patients with atherosclerotic carotid stenosis, the influence of CEA and CAS on cognitive function is not clear. In the first part of this review, we evaluated the literature concerning carotid stenosis and the risk of cognitive impairment. Studies have suggested that both symptomatic and asymptomatic carotid stenosis are associated with cognitive impairment. In the second part, we reviewed the impact of CEA and CAS on cognitive function, some studies have shown benefits, but others have not. PMID:27152468

  5. [Carotid endarterectomy and carotid stenting: a vascular surgeon's point of view].

    PubMed

    Beloyartsev, D F

    2016-01-01

    Presented in the article is a review of the literature related to comparing the outcomes of carotid endarterectomy and carotid stenting in treatment of atherosclerotic stenosis of the internal carotid artery. Special attention is paid to carefully considering the clinical situations wherein preference should be given to either method of intervention. PMID:27159933

  6. Carotid Stump Syndrome: Pathophysiology and Endovascular Treatment Options

    SciTech Connect

    Lakshminarayan, Raghuram; Scott, Paul M.; Robinson, Graham J.; Ettles, Duncan F.

    2011-02-15

    Carotid stump syndrome is one of the recognised causes of recurrent ipsilateral cerebrovascular events after occlusion of the internal carotid artery. It is believed that microemboli arising from the stump of the occluded internal carotid artery or the ipsilateral external carotid artery can pass into the middle cerebral artery circulation as a result of patent external carotid-internal carotid anastomotic channels. Different pathophysiologic causes of this syndrome and endovascular options for treatment are discussed.

  7. Carotid artery stenting: current and emerging options

    PubMed Central

    Morr, Simon; Lin, Ning; Siddiqui, Adnan H

    2014-01-01

    Carotid artery stenting technologies are rapidly evolving. Options for endovascular surgeons and interventionists who treat occlusive carotid disease continue to expand. We here present an update and overview of carotid stenting devices. Evidence supporting carotid stenting includes randomized controlled trials that compare endovascular stenting to open surgical endarterectomy. Carotid technologies addressed include the carotid stents themselves as well as adjunct neuroprotective devices. Aspects of stent technology include bare-metal versus covered stents, stent tapering, and free-cell area. Drug-eluting and cutting balloon indications are described. Embolization protection options and new direct carotid access strategies are reviewed. Adjunct technologies, such as intravascular ultrasound imaging and risk stratification algorithms, are discussed. Bare-metal and covered stents provide unique advantages and disadvantages. Stent tapering may allow for a more fitted contour to the caliber decrement between the common carotid and internal carotid arteries but also introduces new technical challenges. Studies regarding free-cell area are conflicting with respect to benefits and associated risk; clinical relevance of associated adverse effects associated with either type is unclear. Embolization protection strategies include distal filter protection and flow reversal. Though flow reversal was initially met with some skepticism, it has gained wider acceptance and may provide the advantage of not crossing the carotid lesion before protection is established. New direct carotid access techniques address difficult anatomy and incorporate sophisticated flow-reversal embolization protection techniques. Carotid stenting is a new and exciting field with rapidly advancing technologies. Embolization protection, low-risk deployment, and lesion assessment and stratification are active areas of research. Ample room remains for further innovations and developments. PMID:25349483

  8. Quantification of carotid vessel atherosclerosis

    NASA Astrophysics Data System (ADS)

    Chiu, Bernard; Egger, Micaela; Spence, J. D.; Parraga, Grace; Fenster, Aaron

    2006-03-01

    Atherosclerosis is characterized by the development of plaques in the arterial wall, which ultimately leads to heart attacks and stroke. 3D ultrasound (US) has been used to screen patients' carotid arteries. Plaque measurements obtained from these images may aid in the management and monitoring of patients, and in evaluating the effect of new treatment options. Different types of measures for ultrasound phenotypes of atherosclerosis have been proposed. Here, we report on the development and application of a method used to analyze changes in carotid plaque morphology from 3D US images obtained at two different time points. We evaluated our technique using manual segmentations of the wall and lumen of the carotid artery from images acquired in two US scanning sessions. To incorporate the effect of intraobserver variability in our evaluation, manual segmentation was performed five times each for the arterial wall and lumen. From this set of five segmentations, the mean wall and lumen surfaces were reconstructed, with the standard deviation at each point mapped onto the surfaces. A correspondence map between the mean wall and lumen surfaces was then established, and the thickness of the atherosclerotic plaque at each point in the vessel was estimated to be the distance between each correspondence pairs. The two-sample Student's t-test was used to judge whether the difference between the thickness values at each pair corresponding points of the arteries in the two 3D US images was statistically significant.

  9. Cats protecting birds revisited.

    PubMed

    Fan, Meng; Kuang, Yang; Feng, Zhilan

    2005-09-01

    In this paper, we revisit the dynamical interaction among prey (bird), mesopredator (rat), and superpredator (cat) discussed in [Courchamp, F., Langlais, M., Sugihara, G., 1999. Cats protecting birds: modelling the mesopredator release effect. Journal of Animal Ecology 68, 282-292]. First, we develop a prey-mesopredator-superpredator (i.e., bird-rat-cat, briefly, BRC) model, where the predator's functional responses are derived based on the classical Holling's time budget arguments. Our BRC model overcomes several model construction problems in Courchamp et al. (1999), and admits richer, reasonable and realistic dynamics. We explore the possible control strategies to save or restore the bird by controlling or eliminating the rat or the cat when the bird is endangered. We establish the existence of two types of mesopredator release phenomena: severe mesopredator release, where once superpredators are suppressed, a burst of mesopredators follows which leads their shared prey to extinction; and mild mesopredator release, where the mesopredator release could assert more negative impact on the endemic prey but does not lead the endemic prey to extinction. A sharp sufficient criterion is established for the occurrence of severe mesopredator release. We also show that, in a prey-mesopredator-superpredator trophic food web, eradication of introduced superpredators such as feral domestic cats in the BRC model, is not always the best solution to protect endemic insular prey. The presence of a superpredator may have a beneficial effect in such systems. PMID:15998496

  10. Haemorrhage in seven cats with suspected anticoagulant rodenticide intoxication.

    PubMed

    Kohn, B; Weingart, C; Giger, U

    2003-10-01

    Clinical features were evaluated in seven adult cats (six males, one female) with haemorrhage and presumptive anticoagulant rodenticide intoxication. Haemorrhage appeared as thoracic haemorrhage, otic bleeding, haematoma, melena, haematochezia, and petechiation. The most common other presenting signs were lethargy, anorexia, and tachypnoea or dyspnoea. Six cats were anaemic, four cats were mildly thrombocytopenic (58000-161000/ microL), and three had slightly decreased plasma protein or albumin values. The prothrombin time (30.3->100 s, reference range: 16.5-27.5 s) and activated partial thromboplastin time values (32.6->100 s; reference range: 14-25 s) were markedly prolonged in all cats. All cats received vitamin K(1)subcutaneously or orally (3.7-5 mg/kg body weight initially) and depending on severity of signs five cats were transfused with fresh whole blood. Plasma coagulation times improved in all cats and returned to normal in 1-5 days. Rodenticide poisons represent an important but relatively rare cause of haemorrhage in cats and can be effectively treated. PMID:12948505

  11. Use of Absorbable Sutures in Canine Carotid Arteries

    PubMed Central

    Rey, Alejandro R.; Carrillo-Farga, Joaquin; Velasco, Carlos O.; Valencia, Martin O.V.

    1990-01-01

    To study the functional and microstructural characteristics of polydioxanone sutures in vascular surgery, we created 48 vascular anastomoses in the right and left common carotid arteries of 24 mongrel dogs. In each animal, polydioxanone sutures were used in 1 carotid artery, and polypropylene sutures were used in the contralateral carotid artery. Twelve groups of 2 animals each were then formed. The 1st group was observed for 1 month, the 2nd for 2 months, the 3rd for 3 months, and so on until the 12th group, which was observed for 12 months. At the end of each observation period, reoperation was undertaken to evaluate the vascular anastomoses by means of angiography and microscopy. The polypropylene anastomoses showed a marked deformity, with tissue retraction and a foreign body reaction. In contrast, the polydioxanone anastomoses exhibited satisfactory healing, without deformity, and were well tolerated histologically. We believe that polydioxanone may be a useful, alternative vascular suture material. (Texas Heart Institute Journal 1990;17:99-102) Images PMID:15227391

  12. What to Expect After Carotid Endarterectomy

    MedlinePlus

    ... getting larger. As part of your long-term treatment, you can take steps to keep your carotid arteries healthy. One important step is to not smoke. Smoking increases the risk of carotid artery disease and stroke. If you smoke, ask your doctor about programs and products that can help you ...

  13. What's inside your cat's head? A review of cat (Felis silvestris catus) cognition research past, present and future.

    PubMed

    Vitale Shreve, Kristyn R; Udell, Monique A R

    2015-11-01

    The domestic cat (Felis silvestris catus) has shared an intertwined existence with humans for thousands of years, living on our city streets and in our homes. Yet, little scientific research has focused on the cognition of the domestic cat, especially in comparison with human's other companion, the domestic dog (Canis lupus familiaris). This review surveys the current status of several areas of cat cognition research including perception, object permanence, memory, physical causality, quantity and time discrimination, cats' sensitivity to human cues, vocal recognition and communication, attachment bonds, personality, and cognitive health. Although interest in cat cognition is growing, we still have a long way to go until we have an inclusive body of research on the subject. Therefore, this review also identifies areas where future research must be conducted. In addition to the scientific value of future work in this area, future research on cat cognition could have an important influence on the management and welfare of pet and free-roaming cats, leading to improved human-cat interactions. PMID:26154131

  14. Membranous nephropathy in sibling cats.

    PubMed

    Nash, A S; Wright, N G

    1983-08-20

    Membranous nephropathy was diagnosed in two sibling cats from the same household. Both cases presented with the nephrotic syndrome but 33 months elapsed before the second cat became ill, by which time the first cat had been in full clinical remission for over a year. PMID:6623883

  15. Cat Scratch Disease (For Parents)

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Cat Scratch Disease KidsHealth > For Parents > Cat Scratch Disease Print A A A Text Size ... Doctor en español Enfermedad por arañazo de gato Cat scratch disease is a bacterial infection that a ...

  16. Blood volume of nonsplenectomized and splenectomized cats before and after acute hemorrhage

    SciTech Connect

    Breznock, E.M.; Strack, D.

    1982-10-01

    Blood volume (BV) was determined in awake, nonsplenectomized (NSPX) and splenectomized (SPX) cats before and after hemorrhage (6 ml/kg). Each NSPX cat had a determined BV at least 10 ml/kg greater than the same cat after splenectomy. The mean BV of SPX cats was 43.4 +/- 8.94. ml kg (4.3% of body weight). The calculated RBC masses of NSPX and SPX cats were 17.0 +/- 4.07 and 12.2 +/- 1.12 ml/kg, respectively. Each NSPX cat had apparent RBC masses of 5 ml/kg greater than that of the same cat after splenectomy was done. At 1 hour after a hemorrhage, the BV and RBC masses determined in SPX cats were 46.7 +/- 12.1 and 9.7 +/- 1.90 ml/kg, respectively. Extravascular-to-intravascular fluid flux (calculated from RBC masses and plasma protein dilution) was approximately 0.80% of body weight. The indirect method with /sup 51/Cr-labeled RBC for BV determination was accurate and precise in awake, SPX cats; in awake, NSPX cats, the /sup 51/Cr-labeled RBC dilution method was precise, but not accurate. The spleen in the cat resulted in marked overestimations of BV and RBC masses.

  17. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  18. Vibrational Schroedinger Cats

    NASA Technical Reports Server (NTRS)

    Kis, Z.; Janszky, J.; Vinogradov, An. V.; Kobayashi, T.

    1996-01-01

    The optical Schroedinger cat states are simple realizations of quantum states having nonclassical features. It is shown that vibrational analogues of such states can be realized in an experiment of double pulse excitation of vibrionic transitions. To track the evolution of the vibrational wave packet we derive a non-unitary time evolution operator so that calculations are made in a quasi Heisenberg picture.

  19. Maintenance energy requirement determination of cats after spaying.

    PubMed

    Mitsuhashi, Yuka; Chamberlin, Amy J; Bigley, Karen E; Bauer, John E

    2011-10-01

    Neutering is often associated with obesity in companion animals. However, the maintenance energy requirement (MER) for these animals has not been clearly defined. The present study investigated the MER for spayed cats whose body weights (BW) began to increase shortly after ovariohysterectomy. A total of twenty-two shorthair adult female cats were fed complete and balanced diets in amounts to maintain their BW and body condition score (BCS) before the present study. All cats were spayed and the diet was fed for 11 weeks using the same MER as previously. During these weeks, all cats gained weight. Beginning with week 12, a weight-loss regimen was initiated until each cat achieved a BCS of 5 out of 9. After each cat obtained a BCS of 5, an appropriate amount of diet was fed to maintain its BW for at least 4 weeks to determine a modified MER. Daily food consumption, weekly BW and BCS were monitored. Blood was collected before and after weight loss for plasma biochemistry profiles. BW and BCS increased by 16 % and one point (P < 0.01), respectively, during the first 11 weeks after surgery, although food consumption was constant both pre- and post-surgery. The mean MER after obtaining a BCS of 5 was 313.6 (SEM 23.6) kJ/BW(0.67), which is 25 % lower than the current National Research Council recommendation and lower than the cat's requirement before surgery (P < 0.05). In conclusion, spaying significantly increased BW when using MER values for intact cats. Thus, 313.6 × ideal BW(0.67) kJ is proposed for the MER of spayed adult cats. PMID:22005410

  20. Future Management of Carotid Stenosis: Role of Urgent Carotid Interventions in the Acutely Symptomatic Carotid Patient and Best Medical Therapy for Asymptomatic Carotid Disease

    PubMed Central

    Bazan, Hernan A.; Smith, Taylor A.; Donovan, Melissa J.; Sternbergh, W. Charles

    2014-01-01

    Background Stroke is the fourth leading cause of death in the United States, leading to devastating disability. Most strokes are ischemic, and nearly one-third of these are caused by carotid disease. The primary mechanism of carotid-related stroke is an atheroembolic event from an unstable atherosclerotic plaque rupture. In the 1990s, randomized trials demonstrated the benefit of carotid endarterectomy (CEA) in reducing the risk of stroke in both symptomatic and asymptomatic carotid disease. Methods We review best medical therapy (BMT) for asymptomatic carotid disease and recent randomized trials comparing CEA and carotid angioplasty stenting (CAS), and we discuss the role of urgent carotid interventions in patients with acute neurologic symptoms. Results In 2010, 2 large trials demonstrated the efficacy of CAS in select patients, although CAS was associated with an increased procedural stroke risk compared to CEA. An age effect was observed; patients >75 years do worse with CAS compared to CEA. As BMT has evolved in the past decade, a future trial (CREST-2) will address whether BMT is equal to intervention (CEA or CAS) in asymptomatic carotid disease. In a subgroup of patients with asymptomatic carotid disease, CEA plus BMT will likely remain the mainstay therapy for carotid disease compared to BMT alone. CEA and CAS will continue to play complementary roles in the future, as CAS will be done in select patients in whom CEA cannot be undertaken because of high-risk anatomical or medical conditions. Finally, a role for urgent carotid interventions in a select group of patients who present with acute neurologic symptoms is developing as a way to prevent recurrent stroke after an initial carotid plaque rupture event. Conclusion CAS has an increasingly higher risk of stroke with advancing age. Patients treated with CAS have a 1.76-fold increased risk of stroke (95% CI, 1.35-2.31) with each 10-year increase in age. No such age effect is seen in patients treated with CEA

  1. Carotid Baroreflex Function During Prolonged Exercise

    NASA Technical Reports Server (NTRS)

    Raven, P. B.

    1999-01-01

    Astronauts are often required to work (exercise) at moderate to high intensities for extended periods while performing extra-vehicular activities (EVA). Although the physiologic responses associated with prolonged exercise have been documented, the mechanisms involved in blood pressure regulation under these conditions have not yet been fully elucidated. An understanding of this issue is pertinent to the ability of humans to perform work in microgravity and complies with the emphasis of NASA's Space Physiology and Countermeasures Program. Prolonged exercise at a constant workload is know to result in a progressive decrease in mean arterial pressure (MAP) concomitant with a decrease in stroke volume and a compensatory increase in heart rate. The continuous decrease in MAP during the exercise, which is related to the thermoregulatory redistribution of circulating blood volume to the cutaneous circulation, raises the question as to whether there is a loss of baroreflex regulation of arterial blood pressure. We propose that with prolongation of the exercise to 60 minutes, progressive increases on central command reflect a progressive upward resetting of the carotid baroreflex (CBR) such that the operating point of the CBR is shifted to a pressure below the threshold of the reflex rendering it ineffectual in correcting the downward drift in MAP. In order to test this hypothesis, experiments have been designed to uncouple the global hemodynamic response to prolonged exercise from the central command mediated response via: (1) continuous maintenance of cardiac filling volume by intravenous infusion of a dextran solution; and (2) whole body surface cooling to counteract thermoregulatory cutaneous vasodialation. As the type of work (exercise) performed by astronauts is inherently arm and upper body dependent, we will also examine the physiologic responses to prolonged leg cycling and arm ergometry exercise in the supine positions with and without level lower body negative

  2. Carotid Sheath Abscess Caused by a Tooth Decay Infection on the Opposite Side

    PubMed Central

    Tuncturk, F. Ruya; Uzun, Lokman; Kalcioglu, M. Tayyar; Egilmez, Oguz Kadir; Timurlenk, Emine; Erguven, Muferet

    2015-01-01

    Deep neck infections are mortal diseases that need emergency treatment. It can occur at any age but usually in pediatric ages. In this report, a left cervical carotid space abscess of a pediatric patient was discussed. It was interesting that the only origin of the left carotid sheath abscess was right inferior first molar tooth decay. Right neck spaces were all clean. Patient had no immunosupression and also there were no congenital masses such as branchial cleft cysts, foreign bodies, or masses suspicious for malignancies in cervical ultrasound and MRI. We discussed this rare condition under the light of the literature. PMID:25878916

  3. [Pharmacological preconditioning in carotid endarterectomy].

    PubMed

    Kuznetsov, M R; Karalkin, A V; Fedin, A I; Virganskii, A O; Kunitsyn, N V; Kholopova, E A; Yumin, S M

    2015-01-01

    The study was aimed at examining efficacy of preoperative preparation (pharmacological preconditioning) for carotid endarterectomy in patients with chronic cerebrovascular insufficiency. For this purpose, we analysed the outcomes of surgical treatment in a total of 80 patients presenting with haemodynamically significant unilateral and bilateral lesions of carotid arteries. Of these, 40 patients were operated on immediately and a further 40 patients underwent surgery after pharmacological preconditioning with Actovegin taken at a daily dose of 1,200 mg for 1.5 months. It was demonstrated that preoperative preparation prior to surgery increases cerebral perfusion which is determined by means of single-photon emission computed tomography, thus substantially improving the outcomes of surgical treatment. Statistically significant differences in cognitive function of these groups of patients were revealed 7 days and 6 months after the operation. Improvement of cognitive functions was associated with fewer symptom-free postoperative cerebral ischaemic foci in various regions of the brain. A conclusion was made on a positive role of pharmacological preconditioning with Actovegin in surgical management of cerebrovascular insufficiency, first of all in relation to more complete restoration of cognitive functions. PMID:26355920

  4. [A Case of Carotid Free-Floating Thrombus Treated by Carotid Ultrasonography-Guided Endovascular Approach].

    PubMed

    Otawa, Masato; Kinkori, Takeshi; Watanabe, Kenichi; Ando, Ryo; Tambara, Masao; Arima, Toru

    2016-06-01

    We experienced a case of carotid free-floating thrombus treated by carotid ultrasonography-guided endovascular approach. A 63-year-old man was brought to our hospital with the chief complaint of sudden onset left hemiplegia. MRI revealed acute infarction of the right MCA territory due to the right M1 occlusion. Carotid ultrasonography showed a pedunculated, polypoid mobile plaque floating with the cardiac beat. We attempted ultrasonography-guided endovascular treatment. Under proximal balloon protection, the floating plaque was successfully aspirated into the Penumbra aspiration catheter. Carotid stent was also placed to stabilize the residual pedicle of the plaque. Aspirated plaque was identified as fresh thrombus by pathological examination. Carotid ultrasonography-guided endovascular approach was effective for getting the picture of real-time dynamics of the carotid FFT. PMID:27270147

  5. Carotid stent infection: a rare but potentially fatal complication of carotid artery stenting.

    PubMed

    Son, Seungnam; Choi, Nack-Cheon; Choi, Dae Seob; Cho, Oh Hyun

    2015-04-01

    Infections involving endovascular devices are rare and, to our knowledge, only three cases of infection with an inserted carotid stent have ever been reported. A 68-year-old man underwent carotid artery stenting (CAS) of the left proximal internal carotid artery. Two days after CAS the patient developed a high fever and investigation showed that the inserted carotid stent was infected. The infection could not be controlled despite adequate antibiotic therapy. Eventually a rupture of the carotid artery occurred and the patient underwent emergency resection of the left carotid bifurcation in addition to stent removal and reconstruction with a saphenous vein interposition graft. The patient recovered fully without any neurological sequelae. PMID:24688061

  6. Skin Temperature Over the Carotid Artery, an Accurate Non-invasive Estimation of Near Core Temperature

    PubMed Central

    Imani, Farsad; Karimi Rouzbahani, Hamid Reza; Goudarzi, Mehrdad; Tarrahi, Mohammad Javad; Ebrahim Soltani, Alireza

    2016-01-01

    Background: During anesthesia, continuous body temperature monitoring is essential, especially in children. Anesthesia can increase the risk of loss of body temperature by three to four times. Hypothermia in children results in increased morbidity and mortality. Since the measurement points of the core body temperature are not easily accessible, near core sites, like rectum, are used. Objectives: The purpose of this study was to measure skin temperature over the carotid artery and compare it with the rectum temperature, in order to propose a model for accurate estimation of near core body temperature. Patients and Methods: Totally, 124 patients within the age range of 2 - 6 years, undergoing elective surgery, were selected. Temperature of rectum and skin over the carotid artery was measured. Then, the patients were randomly divided into two groups (each including 62 subjects), namely modeling (MG) and validation groups (VG). First, in the modeling group, the average temperature of the rectum and skin over the carotid artery were measured separately. The appropriate model was determined, according to the significance of the model’s coefficients. The obtained model was used to predict the rectum temperature in the second group (VG group). Correlation of the predicted values with the real values (the measured rectum temperature) in the second group was investigated. Also, the difference in the average values of these two groups was examined in terms of significance. Results: In the modeling group, the average rectum and carotid temperatures were 36.47 ± 0.54°C and 35.45 ± 0.62°C, respectively. The final model was obtained, as follows: Carotid temperature × 0.561 + 16.583 = Rectum temperature. The predicted value was calculated based on the regression model and then compared with the measured rectum value, which showed no significant difference (P = 0.361). Conclusions: The present study was the first research, in which rectum temperature was compared with that

  7. Progression of carotid-artery disease in type 2 diabetic patients: a cohort prospective study.

    PubMed

    Bosevski, Marijan; Stojanovska, Lily

    2015-01-01

    In order to assess the progression of carotid-artery disease in type 2 diabetic cohort (n=207 patients), the dynamic change in carotid intima-media thickness (CIMT) and the occurrence of plaques were followed for a period of 31.35±10.59 months. The mean CIMT at the beginning of the study was 0.9178±0.1447 mm, with a maximal value of 1.1210±0.2366 mm. The maximal value of CIMT changed by 0.07 mm/year. Progression of CIMT was noted in 86.8% and its regression in 7.8% of patients. The occurrence of carotid plaques was detected in 41.8% of patients. Multiple regression analysis revealed the maximal value of CIMT to be associated with diastolic blood pressure, despite mean CIMT being predicted by body mass index. The presence of peripheral arterial disease and hypo-high-density lipoproteinemia were found to be predictors for the occurrence of carotid plaques. Our data have clinical implications in predicting risk factors for the progression of carotid-artery disease in type 2 diabetic patients for their appropriate management. PMID:26527880

  8. Associations between bicycling and carotid arterial stiffness in adolescents: The European Youth Hearts Study.

    PubMed

    Ried-Larsen, M; Grøntved, A; Østergaard, L; Cooper, A R; Froberg, K; Andersen, L B; Møller, N C

    2015-10-01

    The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate-and-vigorous physical activity. This cross-sectional study included 375 adolescents (age 15.7 ± 0.4 years) from the Danish site of the European Youth Heart Study. Total frequency of bicycle usage was assessed by self-report, and carotid arterial stiffness was assessed using B-mode ultrasound. After adjusting for pubertal status, body height, and objectively measured physical activity and other personal lifestyle and demographic factors, boys using their bicycle every day of the week displayed a higher carotid arterial compliance {standard beta 0.47 [95% confidence interval (CI) 0.07-0.87]} and distension [standard beta 0.38 (95% CI -0.04 to 0.81)]. Boys using their bicycle every day of the week furthermore displayed a lower Young's elastic modulus [standard beta -0.48 (95% CI -0.91 to -0.06)]. Similar trends were observed when investigating the association between commuter bicycling and carotid arterial stiffness. These associations were not observed in girls. Our observations suggest that increasing bicycling in adolescence may be beneficial to carotid arterial health among boys. PMID:25156494

  9. Progression of carotid-artery disease in type 2 diabetic patients: a cohort prospective study

    PubMed Central

    Bosevski, Marijan; Stojanovska, Lily

    2015-01-01

    In order to assess the progression of carotid-artery disease in type 2 diabetic cohort (n=207 patients), the dynamic change in carotid intima-media thickness (CIMT) and the occurrence of plaques were followed for a period of 31.35±10.59 months. The mean CIMT at the beginning of the study was 0.9178±0.1447 mm, with a maximal value of 1.1210±0.2366 mm. The maximal value of CIMT changed by 0.07 mm/year. Progression of CIMT was noted in 86.8% and its regression in 7.8% of patients. The occurrence of carotid plaques was detected in 41.8% of patients. Multiple regression analysis revealed the maximal value of CIMT to be associated with diastolic blood pressure, despite mean CIMT being predicted by body mass index. The presence of peripheral arterial disease and hypo-high-density lipoproteinemia were found to be predictors for the occurrence of carotid plaques. Our data have clinical implications in predicting risk factors for the progression of carotid-artery disease in type 2 diabetic patients for their appropriate management. PMID:26527880

  10. Big cat genomics.

    PubMed

    O'Brien, Stephen J; Johnson, Warren E

    2005-01-01

    Advances in population and quantitative genomics, aided by the computational algorithms that employ genetic theory and practice, are now being applied to biological questions that surround free-ranging species not traditionally suitable for genetic enquiry. Here we review how applications of molecular genetic tools have been used to describe the natural history, present status, and future disposition of wild cat species. Insight into phylogenetic hierarchy, demographic contractions, geographic population substructure, behavioral ecology, and infectious diseases have revealed strategies for survival and adaptation of these fascinating predators. Conservation, stabilization, and management of the big cats are important areas that derive benefit from the genome resources expanded and applied to highly successful species, imperiled by an expanding human population. PMID:16124868