Involvement of CRH receptors in urocortin-induced hyperthermia

• Published in: Peptides (New York, N.Y. : 1980) N.Y. : 1980), 2008-11, Vol.29 (11), p.1937-1942
• Main Authors: Telegdy, G., Adamik, A.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Body Temperature - drug effects; Colon - drug effects; Corticotropin-Releasing Hormone - pharmacology; CRH receptors; Fever; Fundamental and applied biological sciences. Psychology; Hyperthermia; Hyperthermia, Induced; Injections, Intraventricular; Male; Peptide Fragments - pharmacology; Peptides, Cyclic - pharmacology; Pyrimidines - pharmacology; Pyrroles - pharmacology; Rats; Rats, Wistar; Receptors, Corticotropin-Releasing Hormone - physiology; Urocortins; Urocortins - pharmacology; Vertebrates: endocrinology
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/j.peptides.2008.07.028

The actions of individual corticotropin-releasing hormone (CRH) receptor (CRHR1 and CRHR2) were studied on the hyperthermia caused by urocortin 1, urocortin 2 and urocortin 3 in rats. Urocortin 1, urocortin 2 or urocortin 3 was injected into the lateral brain ventricle in conscious rats and the colon temperature was measured at different times following injection, up to 6 h. In order to study the possible role of CRH receptors, the animals were treated with a urocortins together with the urocortin receptor inhibitors CRF 9–41, antalarmin and astressin 2B to influence the action of urocortins in initiating hyperthermia. Urocortin 1 at a dose of 2 μg caused an increase in colon temperature, maximal action being observed in body temperature at 3 h. CRH 9–41 and antalarmin, CRHR1 receptor antagonists, prevented the urocortin-induced increase in colon temperature while astressin 2B (CRHR2 receptor antagonist) was ineffective. Urocortin 2 at a dose of 2 μg showed a byphasic action in increase in colon temperature having the first peak between 30 min and 1 h and the second peak at 4 h following treatment. CRF (9–41) and antalarmin was ineffective while astressin 2B fully blocked the action of urocortin 2. Urocortin 3 in a dose of l μg increased colon temperature; the maximal effect was observed at 2 h. CRF (9–41) and antalarmin was ineffective while astressin 2B fully blocked the action of urocortin 3. The results demonstrated that urocortin 1, 2 or 3 when injected into the lateral brain ventricle caused increases in body temperature is mediated by urocortin receptors. The action of urocortin 1 is mediated by CRHR1 receptor, while in the action of urocortin 2 and urocortin 3 CRHR2 receptor is involved.