Study On The Relationship Between Homocysteinemia, Congential Heart Disease And PAX-8 Gene

Objective To create a mode of congenital abnormal heart of fetal rats by intervening pregnant S-D rats with homocysteine(Hcy),and to investigate the relationship between congenital heart disease(CHD) and homocysteine(Hcy),PAX-8 gene,Folic Acid(FA),VitB₁₂.And to explore the etiology of CHD from molecular genetics of heart development.Methods The 40 pregnant rats were randomly divided into four groups:high dose group of 2%Hcy(Group-A),low dose group of 1%Hcy(Group-B),intervention group of FA(FA,VitB₁₂+2%Hcy,Group-C) and control group(Group-D).Each group had 10 pregnant rats and the rats were injected intraperitoneally with Hcy on the seventh day of pregnancy.The dosage in each group was as follows:A-2%Hcy 2mg/10g/d,B-1%Hcy 1mg/10g/d,C-2%Hcy 2mg/10g/d,D- the same amount of saline.Rats in Group-C were administrated with FA 0.05mg/10g/d and VitB₁₂ 1mg/10g/d from the first pregnant day to the day of fetal rats borne naturally.The heart of fetal rats of each group were observed by stereoscope on the day when they are borne naturally.RNA extraction was performed from one part of heart in fetal rats of each group,mRNA expression of PAX-8 in hearts of these fetal rats of each group were detected by Real-time quantitative PCR.Expression of PAX-8 protein in heart of these fetal rats of each group were assessed by immunohistochemistryResults1,The difference of the average number of births among the 4 groups is significant(p＜0.01),and the average number of births of each group was 9.04,12.1,11.56 and 13.56 respectively.The average number of births of Group-D was significantly higher than that of Group-A, Group-B and Group-C respectively,p＜0.01.The differences of average number of births between A,B and C are significant(P＜0.01).2,The difference of the abnormal heart incidence of fetal rats among the 4 groups is significant(p＜0.01),and the abnormal heart incidence of each group was 13.5%,9.17%,8.77%and 0.74%respectively.The differences of abnormal heart incidence of fetal rats between A,B and C are not significant(P＞0.05).The abnormal heart rate of fetal rats of Group-D was significantly lower than that of Group-A,Group-B and Group-C respectively,p＜0.013,The difference of mRNA expression of PAX-8 in heart of fetal rats among the 4 groups is significant(p＜0.01).The mRNA expression of PAX-8 in heart of fetal rats with VSD was significantly lower than that of fetal rats without CHD.The difference of mRNA expression of PAX-8 in heart of fetal rats between A and B,A and C are significant(p＜0.01). There was no deference between B and C(p＞0.05).The difference of mRNA expression of PAX-8 in heart of fetal rats without CHD among the 4 groups is not significant(P＞0.05).The mRNA expression of PAX-8 in hearts of fetal rats was correlated with the levels of Hcy injected negatively.The low expression of PAX-8 mRNA may cause cardiovascular abnormality of fetal rats.4,The difference of expression of PAX-8 protein in heart of fetal rats among the 4 groups is significant(p＜0.01).The expression of PAX-8 protein in heart of fetal rats with VSD was significantly lower than that of fetal rats without CHD.The difference of expression of PAX-8 protein in heart of fetal rats between A,B,and C are not significant(p＞0.05).The difference of expression of PAX-8 protein in heart of fetal rats without CHD among the 4 groups is not significant(P＞0.05).Conclusion1,The mRNA expression of PAX-8 in fetal rats with VSD is lower than that of normal heart,and correlates with the levels of Hcy injected negatively.The low expression of PAX-8 mRNA may be related to the formation of VSD.2,FA and VitB 12 intervention during pregnancy may increase the average number of births,and reduce the embryo toxicity of Hcy.