The Effect of Hypotensive Agents on Renal Hemodynamics in Hypertensive Patients

1. The glomerular filtration rate, renal plasma flow, renal blood flow, filtration fraction and calculated renal vascular resistance were estimated in 5 normotensive, 20 benign and malignant hypertensive and 5 renal hypertensive subjects. 2. The acute effect on renal hemodynamics of hexamethonium, veratrum alkaloids or apresoline, parenterally administered, were investigat-ed in 28 hypertensive patients including 23 benign and malignant hyper-tension and 5 renal hypertension. In benign hypertension, there were in general an increase in renal plasma flow, renal blood flow, and a reduction in filtration fraction or renal vascular resistance following the administration of each hypotensive agent, but glomerular filtration rate shows a slight increase after hexa-methonium and no change or slight decrease after veratrum or apresoline. In malignant hypertension and in renal hypertension, though in the latter to a less degree, the glomerular filtration rate, renal plasma flow, renal blood flow and filtration fraction are reduced, common to all three drugs, but renal vascular resistance shows a depression after veratrum and an increase after hexamethonium or apresoline. Differences between the responses to each agent are not significant. 3. It is discussed whether or not artificially lowering blood pressure using hypotensive agents is advantageous in hypertensive patients; further, the indication for the blood pressure reduction is argued. Part of this paper was presented at the 18th Annual Meeting of the Japanese Circulation Society at Nagoya, April 1954. The expense of this study was in part defrayed by a grant in Aid for Medical Research from the Medical Affairs Bureau, Welfare Ministry.