Effect of corticotropin releasing hormone on the pituitary-adrenocortical activity under basal and social stress conditions.
The effect of social crowding stress on the CRH-induced hypothalamic-pituitary-adrenocortical (HPA) responsiveness was assessed in rats crowded for 3 days, when the HPA response to neurotransmitter receptors stimulation was powerfully reduced. CRH given systemically dose-dependently increased the secretion of corticosterone. The increase was not affected by pretreatment with prazosin or propranolol, an alpha 1- or beta-adrenergic receptor antagonist, indicating the lack of involvement of adrenergic receptors in that stimulation. In the corticosterone response to CRH administered icv, a moderate involvement of hypothalamic alpha 1-adrenergic receptors and neuronal noradrenaline seems possible. The corticosterone responses to CRH given by either route to rats exposed to social crowding stress were identical with the responses of unstressed controls. Our results for the first have time shown that social crowding stress does not impair the HPA responsiveness to CRH stimulation.
Bugajski
J
J
Institute of Pharmacology, Polish Academy of Sciences, Kraków.
Gadek-Michalska
A
A
Ołowska
A
A
Borycz
J
J
Bugajski
A J
AJ
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D003441:Crowding; D004305:Dose-Response Relationship, Drug; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects*; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D011224:Prazosin / Q000008:administration & dosage / Q000494:pharmacology; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000503:physiopathology*
D003346:Corticotropin-Releasing Hormone; D011433:Propranolol; D003345:Corticosterone; D011224:Prazosin