Control of renal function during intrarenal infusion of endothelin.
It has been demonstrated that bolus injections of a vasoconstrictor derived from endothelial cells, endothelin 1 (ET-1), constricts isolated arteries and increases blood pressure in animals when infused intravenously. The purpose of this study was to examine the direct effects of intrarenal infusions of ET-1 on renal function at doses that do not alter systemic arterial pressure. The effects of ET-1 on renal hemodynamics and electrolyte excretion were examined during 40 min of intrarenal infusions of ET-1 at rates of 1.15 and 5 ng.kg-1.min-1. Infusion of ET-1 (1.15 ng.kg-1.min-1) resulted in a transient increase in renal blood flow (RBF) followed by a progressive vasoconstriction, which reduced RBF by 23%. ET-1 decreased glomerular filtration rate (GFR) and had no significant effect on filtration fraction. Intrarenal infusion of ET-1 (1.15 ng.kg-1.min-1) had no effect on fractional excretion of sodium (FENa) or potassium. Infusion of ET-1 at a higher dose (5 ng.kg-1.min-1) produced further reductions in RBF, GFR, and FENa. These data indicate that ET-1 is a potent renal vasoconstrictor that could play a role in controlling renal hemodynamics.
Stacy
D L
DL
Department of Physiology, Eastern Virginia Medical School, Norfolk 23501.
Scott
J W
JW
Granger
J P
JP
D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004573:Electrolytes / Q000652:urine; D016232:Endothelins; D004730:Endothelium, Vascular / Q000378:metabolism; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006439:Hemodynamics; D007267:Injections; D007668:Kidney / Q000187:drug effects* / Q000502:physiology; D010455:Peptides / Q000494:pharmacology*; D012079:Renal Circulation / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D004573:Electrolytes; D016232:Endothelins; D010455:Peptides