Behavioral and neuroendocrine actions of endomorphin-2.
The effects of intracerebroventricularly administered endomorphin-2 (EM2) on open-field activity and the hypothalamo-pituitary-adrenal (HPA) system were investigated. EM2 (0.25-1 microg) significantly increased both the locomotor and the rearing activity, resulting in a bell-shaped dose-response curve. EM2 also enhanced corticosterone release, with an even more profound downturn phase at higher concentrations. The corticotropin-releasing hormone (CRH) antagonist alpha-helical CRH9-41 completely abolished the EM2-evoked endocrine and behavioral responses. These findings reinforce the hypothesis that the endomorphins may play a significant role in the regulation of locomotion, rearing activity and the HPA system through the release of CRH.
Bujdosó
E
E
Department of Pathophysiology, University of Szeged, Neurohumoral Research Group, Hungarian Academy of Sciences, Szeged, Hungary.
Jászberényi
M
M
Tömböly
C
C
Tóth
G
G
Telegdy
G
G
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects*; D009842:Oligopeptides / Q000008:administration & dosage / Q000138:chemical synthesis / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D017450:Receptors, Opioid, mu / Q000819:agonists; D013997:Time Factors
D000701:Analgesics, Opioid; D009842:Oligopeptides; D010446:Peptide Fragments; D017450:Receptors, Opioid, mu; C105294:endomorphin 2; D003346:Corticotropin-Releasing Hormone; C045089:corticotropin releasing hormone (9-41); D003345:Corticosterone