The central serotonergic system was manipulated using a serotonin receptor antagonist (cyproheptadine), electrolytic lesioning of the raphe nuclei and neurochemical destruction of the serotonergic terminals in the hypothalamus. The effects of these interventions on ether-induced ACTH secretion were studied in adrenalectomized rats. Serotonin, norepinephrine and dopamine concentrations were measured in the medial basal hypothalamus (MBH) or in individual nuclei of the hypothalamus and of certain midbrain regions. Cyproheptadine pretreatment inhibited ether-induced ACTH hypersecretion in adrenalectomized animals. Neither the electrolytic lesions of the midbrain raphe nuclei, nor the neurotoxic destruction of the hypothalamic serotonergic terminals (by intraventricular administration of 5,6-dihydroxytryptamine) caused any alteration of stimulated ACTH secretion after ether inhalation and/or long-term corticoid deficiency. These results suggest a lack of correlation between the activity of the central serotonergic system and the ACTH releasing effect of ether-stress in adrenalectomized rats.
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http://dx.doi.org/10.1159/000123121 | DOI Listing |
Lab Anim
April 2002
Solvay Pharmaceuticals, Weesp, The Netherlands.
The main objective of this study was to assess the endocrine stress response to multiple anaesthesia followed by sham anaesthesia in order to detect any memory effects. For this purpose, jugular-vein cannulated rats were subjected to either sham, diethyl-ether or halothane/O2/N2O anaesthesia, and their plasma ACTH, corticosterone, glucose, adrenaline and noradrenaline levels measured. The study had three separate experiments, each consisting of a control and treatment group.
View Article and Find Full Text PDFEndocrinology
November 2001
McGill University, Department of Psychiatry, Douglas Hospital Research Center, Montreal, Québec, Canada H4H 1R3.
Leptin modifies the activity of the hypothalamic-pituitary-adrenal axis in adult rodents and inhibits the production of glucocorticoids from human and rat adrenals in vitro. During development, high levels of circulating leptin and low levels of corticosterone secretion are observed together with adrenal hyporesponsiveness to stress. As chronic neonatal leptin administration reduced stress-induced corticotropin-releasing factor mRNA expression and ACTH secretion in pups, we determined whether elevated leptin levels enhanced the feedback effect of glucocorticoids on the hypothalamic-pituitary-adrenal axis.
View Article and Find Full Text PDFPsychopharmacology (Berl)
March 2000
Neuroendocrinologie du Dévelopement, UPRES-EA 2701, Université de Lille, Villeneuve d'Ascq, France.
Rationale: Gabolysat PC60 is a fish protein hydrolysate with anxiolytic properties commonly used as a nutritional supplement.
Objective: The diazepam-like effects of PC60 on stress responsiveness of the rat pituitary-adrenal system and on sympathoadrenal activity were studied.
Methods: The activity of the pituitary-adrenal axis, measured by plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone (B) of the sympathoadrenal complex, measured by circulating levels of noradrenaline (NA) and adrenaline (A), and the gamma aminobutyric acid (GABA) content in the hippocampus and the hypothalamus were investigated in male rats which received daily, by an intragastric feeding tube, for 5 days running either diazepam (1 mg/kg) or PC60 (300 or 1,200 mg/kg).
Psychoneuroendocrinology
April 1999
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
The effect of different alpha 2-adrenoreceptor subtype agonists and antagonists on adrenocorticotrop hormone (ACTH) and beta-endorphin release induced by ether stress was examined. Ether inhalation-induced ACTH and beta-endorphin increase was inhibited by i.c.
View Article and Find Full Text PDFNeurobiology (Bp)
April 1998
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest.
Stress mediators, CRF-41 and vasopressin known to be synthesized in, and released from the parvocellular neurosecretory neurons of the hypothalamic paraventricular nucleus (PVN) are essential to release adrenocorticotropin (ACTH) in response to stress. In addition, suckling-induced prolactin (PRL) release also depends on the integrity of the PVN. In the present study, ether stress-induced adrenocorticotrop hormone (ACTH) and prolactin (PRL) release was studied 2, 5 and 42 days after placing lesions in the hypothalamic paraventricular nucleus (PVN) of male rats.
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