Effects of endothelin-1 on arterial pressure and myocardial contractility in the conscious normotensive rabbit.

SUMMARY 1. We studied the effects of an intravenous bolus of endothelin-1 on arterial pressure and myocardial contractility in the conscious rabbit. 2. Endothelin produced an initial fall in arterial pressure accompanied by an increase in heart rate. This was followed by a dose-dependent increase in arterial pressure, peaking about 7 min after injection, accompanied by a reciprocal fall in heart rate. 3. Left ventricular rate of change of pressure (LV dP/dt) increased with endothelin except at higher doses (0.8 and 1.6 nmol/kg), where in some animals it decreased.