The Effect of High Protein Diets on Experimental Renal Hypertension*

Although the belief is widely held that a high protein diet is deleterious to the hypertensive patient, a careful survey of the literature discloses that this is not a generally substantiated point of view. Some clinicians (1-4) in particular Newburgh (5), have insisted that the withdrawal of protein from the diet of patients with hypertension results in the reduction of their blood pressure and the elimination of the concomitant symptoms. Others have maintained that the amount of protein in the diet generally has little or no relation to the blood pressure (6, 7). I t has even been suggested that a continued low protein diet may be pathogenic (8, 9). The relationships between renal excretory insufficiency and diet have been studied experimentally by numerous investigators (10), but the recent development of a satisfactory method for the experimental production of persistent renal hypertension (11) has made possible studies on the relationship between the factors of diet, renal excretory insufficiency and hypertension of renal origin in animals (12, 13). Although the processes which result in relative renal excretory insufficiency and those factors which lead to hypertension are frequently seen together, we have shown that they are fundamentally distinct (14, 15). Nevertheless there still remains the possibility that an augmented load on the kidney might cause an increased amount of work and thus lead to a relative renal ischemia and the induction of those processes which lead to hypertension. We have therefore undertaken a study of the effect of high and low protein diets upon dogs with: (a) normotension and unimpaired renal function; (b) normotension and embarrassed renal function due to temporary complete occlusion of the renal arteries; (c) normotension and relative renal excretory insufficiency due to chronic partial occlusion of the renal arteries; (d) moderate hypertension with slight evidence of renal excretory insufficiency; (e) severe hypertension with frank renal excretory insufficiency.