Abstract: AIM : To investigate The protect effect of olmesartan medoxomil on chronic heart failure mice METHODS: C57 mice were divided into sham operation group (SHAM group), chronic heart failure group (CHF group) and olmesartan medoxomil treatment group (OLM group). Experimental CHF models were established by coronary artery ligation, in which OLM group fed with a daily dose of 10mg/kg. The heart rate, blood pressure, plasma and cardiac angiotensin Ⅱ levels; Real-time PCR detection of cardiac AT1R, type Ⅰ, Ⅲ collagen expression,and AZAN staining of cardiac pathological changes were determined after 4 weeks,．RESULTS: Compared with SHAM group, systolic blood pressure, plasma and cardiac angiotensin Ⅱ levels, AT1R and Ⅰ, Ⅲ type collagen expression were increased in CHF group (P <0.05), while in OLM Group ,they were significantly lower than that in CHF group except for the plasma angiotensin Ⅱ levels (P <0.05). AZAN staining of myocardial infarction in the CHF group were blue-stained , the myocardial fibers were disappear and replaced by fibrous connective tissue, OLM Group also can see the blue-stained fibrous connective tissue, but the area is reduced compared with the CHF group. CONCLUSION: Chronic heart failure can activate the intracardiac renin-angiotensin system and leading to heart damage,olmesartan medoxomil can protect heart by inhibiting the effects of angiotensin Ⅱ.

Key words: olmesartan medoxomi, chronic heart failure, heart damage