This study examined the effects of two new selective metalloprotease (MMP) inhibitors, XL081 and XL784, on the development of renal injury in rat models of hypertension- (Dahl S) and diabetic- (T2DN) nephropathy. Protein excretion rose from 20 to 120 mg/day in Dahl S rats fed a high salt diet (8.0% NaCl) for 4 weeks to induce hypertension. Chronic treatment with XL081 markedly reduced proteinuria and glomerulosclerosis but it also attenuated the development of hypertension. To determine if a MMP inhibitor could oppose the progression of renal damage in the absence of changes in blood pressure, Dahl S rats were fed a high salt diet (4.0% NaCl) for 5 weeks to induce renal injury and then were treated with the more potent and bioavailable MMP inhibitor, XL784, either given alone or in combination with lisinopril and losartan. Treatment with XL784 or the angiotensin II (AII) blockers reduced proteinuria and glomerulosclerosis by about 30% and had no effect on blood pressure. Proteinuria fell from 150 to 30 mg/day in the rats receiving both, XL784 and the AII blockers, and the degree of renal injury fell to levels seen in normotensive Dahl S rats maintained from birth on a low salt diet. In other studies, albumin excretion rose from 125 to >200 mg/day over a 4 month period in 12 month old, uninephrectomized, type II diabetic (T2DN) rats. In contrast, albumin excretion fell by >50% in T2DN rats treated with XL784, lisinopril or combined therapy. XL784 reduced the degree of glomerulosclerosis in the T2DN rats to a greater extent than lisinopril, and combined therapy was more effective than either drug alone. These results indicate that chronic administration of a selective MMP inhibitor delays the progression, and may even reverse hypertension- and diabetic- nephropathy.
- MMP inhibitor
- renal fibrosis
- renal disease
- Copyright © 2010, American Journal of Physiology - Renal Physiology