Chronic pathophysiologic circulating endothelin levels produce hypertension in conscious dogs.

Although recent studies have reported endogenous plasma endothelin (ET) levels to be elevated two-to fivefold in chronic pathophysiologic states, whether such an increase in circulating ET levels alone can lead to significant long-term alterations in cardiovascular function is not known. The purpose of this study was to examine the long-term systemic hemodynamic effects of a pathophysiologic increase in circulating ET concentration in chronically instrumented, conscious dogs (n=4). Infusion of endothelin (2.5 ng/kg/min) for 8 days increased plasma concentration of endothelin two- to threefold. ET increased mean arterial pressure from 85±3 to 103±3 mm Hg, which was sustained throughout the period of infusion