THE ROLE OF CENTRAL CORTICOLIBERIN IN THE ETHER STRESS-INDUCED SECRETION OF NEUROHYPOPHYSEAL HORMONES AND CORTICOSTERONE IN THE RAT

As corticotropin-releasing factor (CRF) and oxytocin (OXT) are release d in response to various stressors and a role of CRF in stress-induced OXT secretion has been proposed by previous authors, the present expe riments were scheduled to investigate the participation of the brain C RF system in the stress-evoked release of OXT, arginine-8-vasopressin (AVP) and corticosterone. CRF-antiserum (AS) was given into the latera l ventricle of the brain of Wistar male rats, and 24 h later, the inje ction was repeated 30 min prior to ether stress followed by decapitati on in 5 min. Plasma OXT and AVP were measured by radioimmunoassay and corticosterone by fluorimetry. Ether stress increased the levels of co rticosterone and OXT, but not that of AVP. CRF-AS alone did not change the secretion of these hormones. CRF-AS pretreatment blocked the cort icosterone-releasing action of ether stress, whereas it exerted no inf luence on the stress-induced OXT secretion into the circulation. There was no effect of a combined application of CRF-AS and stress on the p lasma AVP level. These results suggest that the central CRF system is involved in the ether stress-elicited corticosterone response, however CRF is unlikely to be connected with the regulation of OXT secretion under these experimental conditions.