The influence of dietary protein on the synthesis of vasoactive substances in subtotally nephrectomized spontaneously hypertensive rats

The effects of dietary protein alterations on the synthesis of prostaglandins and kallikrein were examined in subtotally nephrectomized spontaneously hypertensive rats. Three diets containing 40, 24 and 8% protein were prepared. After subtotal nephrectomy, rats were given one of the three diets for the next 12 weeks. During the study, systolic blood pressure, urinary excretions of protein, 6-keto-prostaglandin F1α, thromboxane B₂ and kallikrein were measured every 2 weeks. Although the diets did not prevent the further elevation of systolic blood pressure, the rats on the low protein diet displayed lower serum creatinine levels and urinary protein levels. The urinary excretion of thromboxane B₂ was unaffected by the amount of dietary protein, but the urinary excretion of 6-keto-prostaglandin F1α was lower in the low protein diet group. Furthermore, the urinary excretion of kallikrein increased significantly in rats on high protein diet. These results suggest that manipulation of dietary protein may alter the natural course of renal failure induced by subtotal nephrectomy in spontaneously hypertensive rats.