Abstract:

bstract:Objective To investigate the relationships between angiotensin-converting enzyme 2(ACE2) and essential hypertension (EH) and heart function,and to clarify the function of ACE2 in the development of hypertension. Methods 113 EH patients were selected as  experiment group(EH group),there were two parts in  EH group: the group of patients who had non-left ventricular systolic dysfunction (non-HF group,65 cases),and the group of patients who had  left ventricular systolic dysfunction (HF group,48 cases).60 cases of healthy people were selected as control group.The levels of ACE2,angiotensin Ⅱ(Ang Ⅱ),atrial natriuretic peptide(ANP) and brain natruretic peptide(BNP) in the serum of 113 EH patients and 60 normal persons were detected by ELISA method. And the Chisquare test,independent-samples t test,ANOVA and stepwise regression analysis were used to analyze those clinic results. Results The levels of ACE2 in non-HF group was significantly lower than those in control group (P<0.05),and the levels of AngⅡ,ANP and BNP were significantly higher than that in control group (P<0.05). In addition,when EH came along with heart failure,the levels of ACE2,AngⅡ,ANP and BNP in HF group were statistically higher than those in non-HF group. The multiple stepwise regression analysis showed that the evels of ACE2,AngⅡ,ANP and BNP were positively correlated with the courses of hypertension and the left ventricular end-diastolic diameter(LVDD)(r=0.034,r=8.466,r=1.300,r=2.004,P<0.01;r=0.265,r=5.019,r=4.303,r=2.099,P<0.01);and negatively correlated with the ejection fraction(EF)(r=－0.815，r=－4.077，r=－10.137，r=－13.116，P<0.01). Conclusion During the occurrence of hypertension and heart failure,the activation of renin-angiotensin system(RAS)  together with the expansion of ventricle lead to the rise of the release of AngⅡ,ANP and BNP. As a novel cardiovascular protective factor,the level of release of ACE2 increases in the process of hypertension and heart failure,and counteracts the cardiovascular damage caused by the excessive release of AngⅡ,thus protecting the cardiac vessel.

Key words: hypertension；angiotensin-converting enzyme 2；angiotensinⅡ；atrial natriuretic peptide；brain natriuretic peptide