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Influence of urocortin and corticotropin releasing factor on venous tone in conscious rats.

Research paper by Aly M AM Abdelrahman, Su S Lin Lim, Catherine C Y CC Pang

Indexed on: 03 Mar '05Published on: 03 Mar '05Published in: European Journal of Pharmacology



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.