Central nervous system actions of corticotropin-releasing factor on cardiovascular function in the absence of locomotor activity.
Studies were performed in conscious and anesthetized Sprague-Dawley rats to examine whether the cardiovascular responses to intracerebroventricular (i.c.v.) administration of corticotropin-releasing factor (CRF) required concomitant locomotor activation. I.c.v. administration of CRF to conscious animals elicited significant increases in arterial pressure, heart rate, mesenteric resistance, and iliac blood flow, as well as intermittent locomotor, grooming and chewing activity. Intravenous infusion of the anesthetic agent, Saffan, at the minimal dose required to abolish locomotor activity caused slight but significant elevations of heart rate and mesenteric vascular resistance. I.c.v. administration of CRF to anesthetized animals produced delayed, yet significant and sustained increases in the heart rate and arterial pressure, without altering regional blood flow. These results demonstrate that locomotor activation is not requisite for the expression of CRF-induced pressor and tachycardic responses. It is concluded that CRF acts within the central nervous system to influence cardiovascular function in the absence of locomotor activity.
Overton
J M
JM
Department of Pharmacology, College of Medicine, University of Arizona, Tucson 85724.
Fisher
L A
LA
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects*; D001921:Brain / Q000187:drug effects*; D003346:Corticotropin-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D007083:Iliac Artery / Q000187:drug effects; D007276:Injections, Intraventricular; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D009043:Motor Activity; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects
D003346:Corticotropin-Releasing Hormone