RELATION OF RENAL PRESSOR SUBSTANCE TO HYPERTENSION OF HYDRONEPHROTIC RATS

Abstract

In the course of investigations concerning the renal pressor substance (Tigerstedt's renin) we have encountered a number of rats with spontaneous hydronephrosis. Such animals are usually found to have an elevation of blood pressure. The following investigations were undertaken to obtain information concerning the mechanism of the rise in blood pressure displayed by these animals: METHODS After anesthesia had been induced by the intraperitoneal injection of pentobarbital sodium, the blood pressure was measured by cannulation of the abdominal aorta with a needle attached to a small bore manometer, heparin being used to prevent clotting. The renal pressor substance was prepared from pig kidneys by precipitation with alcohol and extraction with dilute solution of sodium bicarbonate according to the technic described by Grossman.¹ Observations of two different types were made. In one series of experiments the sensitivity of hydronephrotic rats to renal pressor substance was compared with that of normal