The Effects Of Intrauterine Chronic Hypoxia On NO Concentration And ENOS Acetylation Of Cardiomyocytes Of Adult Male Rats

ObjectiveIntrauterine chronic hypoxia will affect fetal development and promote the development cardiovascular disease in adulthood.The effects of intrauterine chronic hypoxia on male body weight,blood pressure,blood lipid,cardiomyocyte morphology,NO concentration in myocardial tissue and eNOS acetylation level were studied.To explore the possible mechanism of intrauterine chronic hypoxia to promote male cardiovascular disease in adulthood.MethodTake 10 healthy SD pregnant rats,and randomly divide them into two groups on the seventh day of pregnancy,namely,hypoxia group(group H)and control group(group C).Place the hypoxia group in the low-oxygen cabin in the every day(8 hours),and control the oxygen concentration in low-oxygen cabin at(10.0±0.5)%.Place the control group in the low-oxygen cabin too,but inject air and maintain the oxygen concentration same as that of atmosphere outside.Repeat the process above until maternal rat delivery(21st day of pregnancy).After maternal rat delivery,select 6 offspring male rats from each group with the random number table,and normally feed them to 4 months of age.The body weight,blood pressure and TC?TG level were measured;the the diameter of cardiomyocytes were observed and measured by hematoxylin-eosin staining method(HE);concentration of NO in adult male rat cardiomyocytes was detected by microplate(Microwell Plate);The expression of eNOS proximal promoter histone H3 and H4 in adult male rat cardiomyocytes was detected by Western blot method.Results(1)Intrauterine chronic hypoxia does not affect the body weight of 4-monthold adult male rats(F=2.473,P=0.154,P>0.05);does not affect Systolic blood pressure(F=1.181,P=0.309,P>0.05)?Diastolic pressure(F=0.240,P=0.637,P>0.05)?Mean arterial pressure(F=0.001,P=0.979,P>0.05);does not affect the level of TC(F=0.910,P=0.368,P>0.05)?TG(F=2.815,P=0.132,P>0.05);(2)Intrauterine chronic hypoxia can change the diameter of cardiomyocytes in 4-month-old adult male rats(F=1.335,P<0.05);(3)Intrauterine chronic hypoxia can decrease the concentration of NO in cardiomyocytes of 4-month-old adult male rats(F=1.626,P<0.001),and decrease the degree of acetylation of eNOS histone H3(F=1.501,P<0.001),increase the degree of acetylation of eNOS histone H4(F=1.428,P<0.001).Conclusions(1)Intrauterine chronic hypoxia does not affect the body weight,blood pressure and blood lipid level of 4-month-old adult male rats;(2)Intrauterine chronic hypoxia can affect the diameter of cardiomyocytes in 4-month-old adult male rats;(3)Intrauterine chronic hypoxia could down-regulate the acetylation expression of eNOS histone H3 in 4-month-old adult male rat cardiomyocytes,Up-regulation of eNOS histone H4 acetylation,H3/H4 ratio decline and the production of NO is reduced.