Background: In treatment of hypertension, care should be taken for preventing hypertensive organ injuries as well as lowering blood pressure to the adequate level in order to decrease the risk of cardiovascular and renal diseases. Objectives: To assess and compare the possible protective effect of various angiotensin receptor blockers namely candesartan, olmesartan, telmisartan ,and valsaratn on cardiovascular and renal tissues in renal hypertensive rats Methods: In this study 72 adult male albino rats were used and divided into six equal groups (each of 12 rats): Group 1,
control normal received the vehicle; Group 2, control renal hypertensive induced by left renal artery ligation received the vehicle and Group 3 treated renal hypertensive rats which is divided into four subgroups: subgroup (A) received candesartan ( 0.1 mg/kg/day); subgroup (B) received olmesartan ( 3mg/kg/day ); subgroup (C) received telmisartan ( 0.5 mg/kg/day),and subgroup (D) received valsartan (0.5 mg/kg/day). Rats received drugs orally by gavage once daily for 2 weeks. Results: The present study revealed that left renal artery ligation induced significant increases in mean arterial blood pressure (MABP), heart rate (HR), heart weight, cardiac fibrosis and glomerulosclerosis. Also, there were significant increases in serum level of tumor necrosis factor alpha (TNF-α), cardiac level of inteleukin1β (IL1β), and cardiac and renal levels of malondialdehyde (MDA) concomitant with significant reduction in cardiac and renal level of reduced glutathione (GSH). MABP was similarly reduced in candesartan, olmesartan, telmisartan and valsartan groups compared to control renal hypertensive group. Heart rate, cardiac weight, and cardiac fibrosis were significantly reduced in telmisartan and candesartan group. Telmisartan and candesartan suppressed serum level of TNFα and the cardiac level of IL-1β. Meanwhile, olmesartan and valsartan significantly decreased glomerulosclerosis index and renal level of MDA with significant increase in renal level of GSH. Conclusion: Telmisartan and candesartan exerted better cardioprotective effect via prevention of inflammatory cascade, and olmesartan and valsartan exerted better renoprotective effect via enhancement of antioxidant capacity.