Effect of nitrendipine and nisoldipine on renal structure and function in long-term experimental diabetes in rats

This study investigates the efficacy of late intervention with the calcium channel blockers (CCBs) nitrendipine and nisoldipine in preventing development of albuminuria and glomerular hypertrophy in experimental diabetes. Streptozotocin (STZ)-induced diabetic rats were treated with nitrendipine or nisoldipine for 6 weeks after 3 or 6 months of untreated diabetes. The CCBs were administered in the fodder in a concentration of 250 mg/kg. After 3 months of untreated diabetes, nitrendipine treatment for 6 weeks significantly reduced urinary albumin excretion (UAE; P < 0.05) and glomerular hypertrophy. Nitrendipine also prevented an increase in systemic blood pressure compared with untreated diabetes. Nisoldipine showed no significant effect on UAE or glomerular hypertrophy despite systemic blood pressures similar to those of the diabetic nitrendipine-treated group. After 6 months of untreated diabetes, treatment with nitrendipine or nisoldipine for 6 weeks did not show effects on UAE, glomerular hypertrophy, or systemic blood pressure. No effect was found on renal growth in the treatment groups, and neither nitrendipine nor nisoldipine had any effect on body weight, blood glucose level, or food intake.