Systemic administration of beta-endorphin: potent hypotensive effect involving a serotonergic pathway.

摘要: In normal adult rats anesthetized with urethane, intravenous injections of beta-endorphin (30--150 micrograms kg-1) induced a transient fall blood pressure followed by small hypertension and prolonged hypotension. Prior administration naloxone completely blocked these effects, whereas naloxone, given 1 hr after beta-endorphin, did not reverse the depressor phase opioid peptide. The effects on arterial were greatly reduced in animals pretreated p-chlorophenylalanine, specific depletor serotonin. Moreover, potent serotonin antagonists such as cyproheptadine, mianserin, metergoline, produce significant Furthermore, effect was potentiated fluoxetine, uptake inhibitor. These observations suggest participation serotonergic pathway action pressure.