Urotensin II acts centrally to increase epinephrine and ACTH release and cause potent inotropic and chronotropic actions

Abstract

Urotensin II is a small peptide whose receptor was recently identified in mammals as the orphan G protein-coupled receptor-14. The reported cardiovascular responses to systemic urotensin II administration are variable, and there is little detailed information on its central cardiovascular actions. We examined the cardiovascular and humoral actions of intracerebroventricular urotensin II (0.02 and 0.2 nmol/kg and vehicle) and intravenous urotensin II (2, 20, and 40 nmol/kg and vehicle) in conscious ewes previously surgically implanted with flow probes and intracerebroventricular guide tubes. Two hours after intracerebroventricular infusion of urotensin II (0.2 nmol/kg over 1 hour; n=5), heart..