AN EFFECT OF ANTIDIURETIC HORMONE ON THE FLOW OF BLOOD THROUGH THE VASA RECTA OF THE RAT KIDNEY

Abstract

SUMMARY The injection of a fluorescent dye which stained the vessel walls showed the pathway taken by the blood in the renal medulla in rats. The vasa recta stained in normal rats given water; they did not stain in dehydrated rats nor did they stain in rats given an antidiuretic dose of vasopressin in addition to water. The vasa recta stained in all rats with diabetes insipidus whether they were given water or dehydrated. These results suggest that antidiuretic hormone increases water conservation in the medulla by reducing blood flow through the countercurrent system as well as by increasing the permeability of the collecting ducts to water.