[Effect of losartan on the expressions of TGF-beta1, p-Smad2/3, and Smad7 in the remnant renal tissues of 5/6 nephrectomized rats].

Objective: To investigate the mechanism of losartan treating glomerulosclerosis and to observe the effect of losartan on the expressions of TGF-beta1, p-Smad2/3, and Smad7 in the renal tissues of 5/6 nephrectomized rats.

Methods: Male Wistar rats were randomly divided into a sham-operated group, a 5/6 nephrectomized model group, and a losartan treated group. The rats in the model group and the losartan treated group were performed 5/6 nephrectomy by the method with 2 procedures. Twelve weeks after of the operation, all rats were killed. The 24-hour urinary protein, serum creatinine, and urea nitrogen were detected. Pathological changes of the renal tissues were observed by HE and Masson staining, and the expressions of TGF-beta1, p-Smad2/3, and Smad7 were detected by immunohistochemical staining.

Results: The 24-hour urinary protein, serum creatinine, urea nitrogen, and the relative area of collagen in the renal tissues of the rats in the model group significantly increased (P<0.01), and losartan could reduce these indexes. The expressions of TGF-beta1 and p-Smad2/3 were just at a low level in the renal tissues of the rats in the sham-operated group, and were strongly positive in the model group; but losartan could decrease the expressions of TGF-beta1 and p-Smad2/3 (P<0.01). The expression of Smad7 in the model group was fewer than that in the sham-operated group (P<0.01), but losartan could improve the expression of Smad7 (P<0.01).

Conclusion: Losartan may implement its anti-glomerulosclerosis by affecting TGF-beta1, p-Smad2/3, and Smad7 of TGF-beta/Smads pathway of the renal tissues of 5/6 nephrectomized rats.