THE RENAL BLOOD FLOW IN NORMAL AND 

 HYPERTENSIVE SUBJECTS 



It is appropriate to apply the methods which have been 

 described in the previous lecture in a few experiments that 

 throw light upon the physiological control of the renal blood 

 flow. 



The first experiment which I would like to discuss con- 

 cerns the effects of oil of juniper on renal function (Figure 

 1 ) . Many years ago oil of juniper enjoyed a vogue as a di- 

 uretic, which fact led us to suspect that it might have some 

 action on the renal circulation. (The experiment serves 

 chiefly to illustrate the method of examination.) The sub- 

 ject was prepared for the determination of renal clearances 

 in the usual manner. He was well hydrated by the copious 

 administration of water, both the night before and early in 

 the morning of the examination, in order to establish good 

 urine flows. Suitable plasma concentrations of diodrast and 

 inulin were maintained by continuous intravenous infusion, 

 and urine was collected by catheter, the bladder being rinsed 

 out with saline at the end of each urine collection period. The 

 data recorded in the figure are the cc. of plasma cleared per 

 minute of diodrast (D) and inulin (IN), the filtration frac- 

 tion (FF), the brachial blood pressure, and, at the bottom 

 the urine flow in cc. per minute ( V) . The diodrast clear- 

 ance indicates the renal plasma flow, the inulin clearance the 

 rate of glomerular filtration, the filtration fraction the per 

 cent of plasma filtered through the glomeruli. 



As shown by the three control periods at the left of the 

 chart, he had a basal renal plasma flow averaging 782 cc. per 

 minute. The administration of 1 cc. oil of juniper had no 

 effect on either the renal plasma flow or the filtration rate. 



