New approaches to delay the progression of chronic renal failure

Background. The molecular cloning of many bone morphogenetic proteins (BMP)-encoding genes and their identification as transforming growth factor-β (TGF-β) relatives enhanced the interest in these molecules and allowed expression and functional studies to be performed. Methods. Rats with ureteral obstruction were distributed into four groups. Group 1 received vehicle, group 2 received enalapril 12.5 mg/kg body wt/day, group 3 received 50 or 300 μg/kg body wt BMP-7, and group 4 received both enalapril and the high dose of BMP-7. We also studied the effects of BMP-7 administration in a model streptozocin-induced diabetes. Results. Treatment with BMP-7 in rats with ureteral obstruction of 3 days duration and subsequent release indicated that this compound decreases interstitial volume and accelerates the return of renal function. After 16 weeks of diabetes, the rats were treated with BMP-7. The administration of BMP-7 partially reversed renal hypertrophy, restored GFR to normal, and decreased proteinuria. Conclusions. These studies indicate that administration of BMP-7 maintains and restores renal function and structure in animals with ureteral obstruction and diabetic nephropathy.