title: Influence of urocortin and corticotropin releasing factor on venous tone in conscious rats.
abstract: The corticotropin releasing factor (CRF) family includes CRF and urocortin. The effects of urocortin and CRF (0.3, 1, 3 and 10 nmol/kg, i.v.) relative to those of vehicle (0.9% NaCl) on mean arterial pressure and mean circulatory filling pressure (index of venous tone) were examined in conscious, unrestrained rats that were either intact (unblocked) or ganglion-blocked by treatment with mecamylamine (10 mg/kg, i.v.) followed by noradrenaline (4 microg/kg/min, i.v.) to increase vasomotor tone. Both urocortin and CRF dose-dependently decreased mean arterial pressure in intact rats and ganglion-blocked rats. The depressor action of urocortin was greater than that of CRF at all doses. In intact rats, neither compound reduced mean circulatory filling pressure. In ganglion-blocked rats, urocortin and the highest dose of CRF decreased mean circulatory filling pressure. In conclusion, both urocortin and CRF are vasodepressor agents with venodilator action.
authors.affiliation: Department of Pharmacology and Therapeutics, Faculty of Medicine, The University of British Columbia, 2176 Health Sciences Mall, Vancouver, B.C., Canada V6T 1Z3.
authors.forename: Aly M
authors.initials: AM
authors.lastname: Abdelrahman
authors.forename: Su
authors.initials: S
authors.lastname: Lin Lim
authors.forename: Catherine C Y
authors.initials: CC
authors.lastname: Pang
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003243:Consciousness; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005730:Ganglionic Blockers / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D054832:Urocortins; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014690:Venous Pressure / Q000187:drug effects*
chemical_list: D005730:Ganglionic Blockers; D054832:Urocortins; D014662:Vasoconstrictor Agents; D008464:Mecamylamine; D003346:Corticotropin-Releasing Hormone; D009638:Norepinephrine