Effects of Losartan on Expression of TNF-α in Myocardium in Renovascular Hypertensive Rats

Objective To investigate the effect of angiotensin Ⅱ-1 receptor antagonist losartan on expression of tumor necrosis factor-alpha (TNF-α) in the ventricular myocardium in the renovascular hypertension rats. Methods Renovascular hypertension model was obtained by clip left renal artery in Sprague-Dawley(SD) rats. After operation the rats were divided into 3 groups: sham group, two-kidney one clip (2K1C) group, and losartan treatment group(2K1C and losartan 20 mg/kg·d by drinking). Tail blood pressure was determined every week. Animals were euthanized after treatment with losartan for four weeks. Cardiac index(CI)was calculated by HW/BW, and TNF-α protein of ventricle myocardium was determined by ELISA and immunohistochemistry. Results Losartan significantly decreased blood pressure(P0.01), CI(sham group:2.86±0.37 vs 2K1C group:4.12±0.27 vs losartan group:3.35±0.62,P0.05) and the expression of TNF-α in the myocardium (ELISA:sham group:1.1±0.1 vs 2K1C group:31.3±3.0 vs losartan:2.3±0.2 ng/mg, P0.05). Conclusion Losartan reverse ventricles remodeling in renovascular hypertension rats which was associated with the decreases in TNF-α expression.