The Study On The Relationship Of Some Vasoactive Substances To The Heredity Of Essential Hypertension

Objective To investigate the relationship between some vasoactive substances and the heredity of essential hypertension and the role of the vasoactive substances in the pathogenesis of essential hypertension by determining the plasma level of nitric oxide (NO), plasma renin activity(PRA) and angiotensin II (AT II) in healthy offsping with family history of essential hypertension.Methods 60 healthy offsping with family history of essential hypertension were randomly recruited as the study group and divided into 2 subgroups:30 offsping of both parents with essential hypertension(study group 1),30 offsping of a parent with essential hypertension (study group 2).20 healthy offsping of parents without essential hypertension were assigned as the control group.The level of plasma NO was determined by electrophotometer and the levels of PRA,AT II were determined by radioimmnnoassay.Results (1)The levels of NO,PRA,AT II increased significantly in offsping with family history of essential hypertension compared to those in the control group (t= 2.782,2.841,3.418,P<0.01).(2)There were statistical differences in the levels of NO,PRA between the study group 1 and the control group (t= 2.163,2.721, P<0.05),and significantly statistical differences in the level of AT II between the former two groups(t= 3.433,P<0.01).There were statistical differences in the levels of NO,PRA,ATII between the study group 2 and the control group (t=2.206,2.268,2.734,P<0.05);There were no differences in the levels of NO, PRA,ATII between the study group 1 and study group 2(t= 0.374,0.18l,1.07,P>0.05).(3)There were positive correlations between the levels of plasma NO and AT II (r=0.378 , P<0.05),and positive correlations between the levels of plasma AT II and PRA (r=0. 544, P<0.05).Conclusions (1)Before blood pressure is raised ,the activity of renin-angiotensin system increases in the offsping with family history of essential hypertension ,which is related to the heredity of essential hypertension . (2) Activity of renin-angiotensin system may play an important role in the development of essential hypertension . (3)Because NO and RAS can antagonise the effect of each other, the vasodilative substances and the vasocontractive substances can maintainbalance at a high level to keep blood pressure normal.(4)The levels of vasoactive substances change in the offsping with family history because of the heredity of essential hypertension before blood pressure is raised .The altered vasoactive factors can result in the development of essential hypertension.