Effects of endothelin on regional hemodynamics in conscious rats.

Endothelin is a potent vasoactive peptide in anesthetized rats and isolated vascular smooth muscle. This study was performed to describe the hemodynamic effects of endothelin in conscious, freely moving rats. Endothelin (0.067-2 nmol/kg i.v.) produced long-lasting, dose-dependent increases in arterial pressure, mesenteric and, to a lesser degree, hindquarters vascular resistances and decreases in heart rate. We suggest that endothelin may play an important role in regulation of arterial pressure by modulating peripheral vasomotor tone.