The Expression And Significance Of Cx43 On Cardiac Of Newborn Rats Of Gestational Diabetes

Objective:To observe abnormal heart rate of fetal rats by creating a model of gestation diabetes mellitus(GDM) S-D rats, to observe the expression of Cx43 on cardiac of newborn rats of gestational diabetes.investigate the mechanisms of the heart developmental defect in infant of diabetic mother.Methods:80 female SD rats were randomized into experimental group and control group.One was injected streptozotocin(STZ) at abdominal cavity.and the other was injected phosphate buffered solution (PBS) in the same position.Observe blood glucose every day after 72h when tats were given drugs,all rats were uterine-incision delivery to draw the materials from embryo heart tissues at gestation 12th,15th,19th day randomly,heart tissue for pathological change by H.E stain,The expression of Cx43 protein in heart tissues of all groups were analyzed with immunohistochemical techniques;The expression of Cx43 mRNA in heart tissues of all groups were analyzed with Real time quantitative-polymerase chain reaction.Results (1):In gestational diabetes mellitus group,there are obvious difference(p<0.01)at the number of liquefactive embryos,dead ones,huge ones and hypoevolutism ones between two groups,There are more at embryo heart development defect numbers at diabetes group than that of the control group,there exists obvious statistics difference(p<0.01),major including caul-conus development malformation ventricular septal defect(VSD),ventricular septal cleft(VSC) and myocardial hypertrophy and so on.(2) The expression of Cx43. Immunohistochemical reveals the Cx43 protein expressed in the 12,15,19 days of myocardial cells in fetal rats both in the control group and the experimental group, The Cx43 immuno - labelling present punctate distribution in cytoplasm and cytomembrane on embryonic day (ED) 12, along with the increase of the embryonic day,Its distribution scope expands gradually.To ED 19, the Cx43 protein in cardiac form dispersion distribution.Compared with control groups,the expression of Cx43 was evidently decreased and the distribution of Cx43 disorganized in experimental group.The result of Real time quantitative-polymerase chain reaction. The Cx43mRNA have expressed on myocardial tissue both in control group and in experimental group from ED13, with the increase of the embryonic day,the Cx43mRNA expression gradually decrease.At the same time,compared with the control group,the expression of the Cx43mRNA have clear differences(p<0.05), The expression of Cx43mRNA in the experimental group were obviously reduced than in control group.Conclusions:The incidence of abnormal heart development in Gestational diabetes groups was significantly higher than that in control group. At the same time point,Compared with control group, the expression of Cx43 protein and mRNA on fetal heart in GDM groups were significantly lower than in control group. Maternal gestational diabetes may cause cardiovascular abnormalty of fetal rats by down-regulation of Cx43.