Central nervous system effects of corticotropin releasing factor in the dog

Corticotropin releasing factor (CRF) given intracerebroventricularly (i.c.v.) increases mean arterial pressure (MAP) and heart rate (HR), while CRF given intravenously decreases MAP and increases HR. CRF given i.c.v. elevates plasma concentrations of vasopressin and catecholamines. Ganglionic blockade with chlorisondamine prevents CRF-induced increases in MAP; the vasopressin antagonist, [1-deaminopenicillamine,2-(O-methyl)tyrosine]-vasopressin does not alter CRF-induced increases in MAP. In contrast to CRF, angiotensin II (A-II) given i.c.v. increases MAP but decreases HR.

(1) CRF elevation of MAP and HR in dogs is dependent on an intact sympathetic nervous system, and (2) CRF and A-II have different CNS effects on cardiovascular function.