Effect of antihypertensive therapy in experimental chronic renal failure

In this study, the effect of the antihypertensive agents nifedipine (4.5 mg/day) and hydralazine (50-200 mg/l of drinking water) on the progression of chronic renal failure and scarring was evaluated in rats submitted to subtotal (5/6) nephrectomy (SNx). The effect of blood pressure reduction was studied in groups of rats fed either a medium-protein diet (24%) or high-protein diet (50%). SNx rats fed a high-protein diet had significantly higher levels of proteinuria and severer renal scarring at sacrifice (120 days after SNx). Nifedipine reduced proteinuria in SNx rats fed a high-protein diet. Both drugs significantly reduced systemic hypertension in SNx rats. Hydralazine and nifedipine also reduced hypertriglyceridaemia but had no effect on blood cholesterol levels. However, in spite of adequate control of systemic hypertension with the agents studied, the severity of renal scarring (glomerular sclerosis or tubulo-interstitial scarring) was not affected by treatment. We confirm that the control of systemic hypertension is not sufficient to prevent renal scarring in rats submitted to extensive renal ablation.