ET-3 is extracted by and induces potent vasoconstriction in human splanchnic and renal vasculatures.
To investigate splanchnic and renal vascular effects and elimination of endothelin-3 (ET-3), ET-3 (10 pmol.kg-1.min-1 iv for 20 min) was given to six healthy male volunteers. Arterial plasma ET-3-like immunoreactivity (ET-3-Li) increased 10-fold to 111 +/- 31 pmol/l (P < 0.01). The initial half-life of plasma ET-3-Li determined in three subjects was 1.7 +/- 0.2 min. The fractional extraction of ET-3-Li was 68 +/- 7% in the splanchnic and 63 +/- 4% in the renal vascular beds. Mean arterial blood pressure fell from 86 +/- 4 to 94 +/- 4 mmHg (10%) (P < 0.05). Splanchnic and renal blood flows fell by 43 +/- 3% (P < 0.05) and 29 +/- 4% (P < 0.05), respectively, during the infusion. Splanchnic and renal vascular resistances rose by 92 +/- 22% (P < 0.05) and 58 +/- 7% (P < 0.05). In conclusion, ET-3 infusion in humans induces splanchnic and renal vasoconstriction of similar magnitude as previously shown during endothelin-1 infusion, presumably by ETB receptor activation. Plasma ET-3 is efficiently extracted in the splanchnic and renal vascular regions.
Weitzberg
E
E
Department of Anesthesiology and Intensive Care, Karolinska Hospital, Stockholm, Sweden.
Hemsén
A
A
Lundberg
J M
JM
Ahlborg
G
G
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D001808:Blood Vessels / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D016232:Endothelins / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D006207:Half-Life; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008297:Male; D011863:Radioimmunoassay; D012079:Renal Circulation / Q000187:drug effects / Q000502:physiology*; D017595:Renal Plasma Flow / Q000502:physiology; D013152:Splanchnic Circulation / Q000187:drug effects / Q000502:physiology*; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*
D016232:Endothelins; D014662:Vasoconstrictor Agents