Reversing glomerular hypertension stabilizes established glomerular injury in renal ablation

Male Munich-Wistar rats were studied 18 weeks after 1 2/3 nephrectomy. One group received no therapy. A second group received the angiotensin converting enzyme (ACE) inhibitor enalapril, starting 1 week after ablation. Two additional groups received no therapy during the first 8 weeks, and then received ACE inhibitor or a low (12%) protein diet. Early ACE inhibitor therapy resulted in control of systemic and glomerular hypertension (HTN), and a striking limitation of proteinuria and glomerular sclerosis. During the first 8 weeks untreated rats developed severe systemic HTN and increasing proteinuria. After 8 weeks proteinuria increased further in untreated rats, and widespread sclerosis resulted. Late ACE inhibition reversed systemic HTN. Both late ACE inhibition and late protein restriction reversed glomerular HTN and prevented further increases in proteinuria and sclerosis. Thus, control of glomerular HTN can stabilize renal injury even when therapy is delayed until hypertension and glomerular injury are established.