LONG-LASTING VASOCONSTRICTION AND EFFICIENT REGIONAL EXTRACTION OF ENDOTHELIN-1 IN HUMAN SPLANCHNIC AND RENAL TISSUES

Six healthy subjects were given endothelin-1, intravenously in a dose of 4 pmol • kg-1 • min-1 for 20 min. Blood samples were drawn from arterial, hepatic and renal vein catheters for determinations of splanchnic and renal blood flows and the extraction of endothelin-1 in these vascular beds. Intravenous infusion of endothelin-1 increased the mean arterial blood pressure by 6.8 ± 2.0 mm Hg (p<0.05) and reduced splanchnic and renal blood flows by 34% (p<0.005) and 26% (p<0.001) respectively. Return to basal flow values occurred after about 1 hr for the splanchnic and 3 hrs for the renal blood flow. The fractional extractions of endothelin-1-like immunoreactivity corresponded to 75 ± 2% and 60 ± 2% in the splanchnic and renal vascular beds, respectively. The disappearance curve in plasma had two half-lives of 1.4 ± 0.1 min and 35 ± 2.8 min respectively. © 1991 Academic Press, Inc.