| Objective:1、To observe the difference of blood pressure, cardiovascular remodeling in spontaneously hypertensive rats(SHR) and wistar-kyotorats (WKY)2、To search the effects of valsartan on blood pressure, cardiovascular remodeling in SHR.3、To investigate the expression of angiotensin converting enzyme2(ACE2) in the heart and thoracic aorta of SHR, to explore the protective effect on the cardiovascular.4、To observe the effect of valsartan on ACE2in the heart and thoracic aorta of SHR, to explore the new mechanism of pressing down the blood and reversing cardiovascular remodeling.Methods:Twenty-four12week-old male SHR were randomly divided to SHR group(n=12)and valsartan group(n=12). Twelve12week-old male WKY rats were served as control group. Valsartan group was given daily dose of30mg/kg valsartan for10weeks and the other two groups were given equal saline. After10weeks, abdominal anesthesia to death for the following index test:1、determine the left ventricular weight index. 2、HE dying to observe the changs of morphology and to determine the rate of intima media thickness and lumen diameter of the aorta (M/L)3、determine the hydroxyproline content in myocardium and ventricular by buck solution.4、detect the expression of mRNA in myocardium and ventricula by RT-PCR.5、detect the expression of ACE2protein in myocardium and ventricular by immunohistochemistry.6、determine the concentration of Ang II in serum by ELISA.Results:1、The systolic blood pressure(SBP) of SHR was significantly hihger than the control group. After10weeks, the SBP of valsartan group was markedly decreased, but higher than the control group.2、LVWI and M/L of SHR were markedly hihger than the control group. Compared with SHR group, the above indexes were decreased.3、The hydroxyproline content of SHR was markedly hihger than the control group. Compared with SHR group, the hydroxyproline content was decreased.4、The resault of RT-PCR indicated the ACE2mRNA expression in SHR group was decreased compared with the control group, the valsartan group was increased.5、The resault of immunohistochemistry indicated the ACE2protein expressed in the cytoplasm myocardial cell and vascular smooth muscle cell.The ACE2protein expression of SHR group and valsartan group were lower than the control group, but the valsartan group was higher than the SHR group. 6、The concentration of Ang Ⅱ was significantly increased in the SHR group, the concentration of Ang Ⅱ of the valsartan group was higher than the SHR group.Conclusions:1、The blood pressure of the SHR was significantly hihger than the WKY rats, and the SHR developed to the cardiovascular remodeling.2、Valsartan was able to significantly decreased the SBP, and reversed the cardiovascular remodeling.3、The ACE2mRNA and ACE2protein expression of SHR were markedly lower than WKY rats.4、Valsartan was able to strengthen ACE2expression by flocked Ang Ⅱ, which maybe the new mechanism of reversing cardiovascular remodeling of valsartan. |
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