Vasodilators,Intrarenal Distribution of Blood Flow,and Renal Function in Isolated Perfused Canine Kidneys 1

Abstract

Summary

Each of the seven different vasodilators (acetylcholine, histamine, PGE₂, bradykinin, saralasin, SQ 20881, and eledoisin) infused into isolated blood-perfused canine kidneys at constant systolic perfusion pressure (130 mm Hg) at rates to cause 20-40% increases in RBF caused increases of fractional blood flow to the inner renal cortex and medulla as measured by radioactive microspheres. Despite similar hemodynamic effects of the different vasodilators on RBF, perfusion pressure and intrarenal distribution of blood flow, their effects on GFR, U_NaV, and V were dissimilar. In particular, eledoisin and PGE₂ reduced GFR and acetylcholine produced the greatest di-uresis and natriuresis by its effect to interfere with the tubular reabsorption of salt and water.

We wish to acknowledge the expert technical assistance of J. Meller, B. MacMillan, and B. Rood. We also wish to thank M. Brock for help in preparing this manuscript. Saralasin was generously provided by Norwich Pharmacal Company and SQ 20881 was provided by E. R. Squibb Company.