Changes Of Fetal Rat Heart And Mechanism Of Fetal Rat Sudden Death In Intrahepatic Cholestasis Of Pregnancy

PartⅠ : Cardiomyocytes changes of pregnant rats and fetus in intrahepatic cholestasis of pregnancy Objective To investigate the cardiomyocytes changes of pregnant rats and fetus in intrahepatic cholestasis of pregnancy. Methods The animal model of intrahepatic cholestasis of pregnancy was induced by 17-α-Ethinylestradiol and Progesterone. Pathohistological examinations of the hearts of the pregnant rats and fetus were done under light microscope and electronic microscope. Results ① The levels of serum ALT, AST, and TBA were significantly higher in group ICP than the control (P<0.01). ② Pathohistological examinations under light and electronic microscope showed granular and vacuolational changes in some hepatocytes and dilation of bile canaliculi with some high electronic density materials aggraded in maternal rats of group ICP. ③ Granular and vacuolational changes were also found in some syncytiotrophoblast of placenta of group ICP. ④ Regional granular changes were found in some cardiomyocytes in maternal rats of group ICP. ⑤ Under light and electronic microscope, it showed abroad vacuolational changes occurred, high electronic density materials aggraded, fibrin ruptured, texture blurred, and mitochondrion swelled with demyelination in fetal rat cardiomyocytes of group ICP. Conclusins It showed that obvious pathologic cardiomyocytes changes of maternal and fetal rat,especially severe to fetal rat, occured in ICP. Part Ⅱ : Bcl-2 and bax expression and apoptosis in fetal rat myocardial cells of intrahepatic cholestasis of pregnancy. Objective To investigate bcl-2 and bax expression and apoptosis in fetal rat myocardial cells (FRMCs).of intrahepatic cholestasis of pregnancy (ICP).. Methods The rat model of ICP was induced by 17-α-Ethinylestradiol and Progesterone. Pathohistological examinations of FRMCs were done under light microscope. TdT-mediated dUTP nick end labeling (TUNEL) and immuno-histochemistry methods were used to detect apoptosis and bcl-2 and bax expression in FRMCs of pregenancy 21st day. Results ① Under light microscope, it showed vacuolational changes and edema in FRMCs of group ICP. ② The apoptosis index (39.79±2.3421)% in FRMCs of group ICP was significantly higher than that (19.29±2.4624)% in control group, P<0.01. ③ The expression of bcl-2 protein in FRMCs of group ICP was significantly lower than that in control group, P<0.01;Compared to the control,there was no significant difference in the expression of bax protein in FRMCs of group ICP, P>0.05. Conclusins It demonstrated that apoptosis appeared in FRMCs.of ICP. Low expression of bcl-2 protein in FRMCs may contribute to apoptosis in FRMCs.of ICP. Part Ⅲ: Chaotic analysis for cardiac systems of normal pregnant rats and fetus Objective To investigate the chaotic characteristics of cardiac system and differences of autonomic nervous system development of normal pregnant rats and fetuses. Methods The electrocardiograms, chaotic graphics and digital characteristics of heart period signal(HPS) of normal pregnant rats and fetuses by day 21st were evaluated by biologicalsignal extracting and analyzing system Powerlab Chart 5 Software. Results ①The mean values of frequency and voltage of fetal rats electrocardiograms were lower than pregnant rats significantly(P<0.01). ② Similar to the human, it showed three-peaks spectral features in both normal pregnant rats and fetuses.However, the second and third peak in fetal rats were lower than pregnant rats.③ The Relative Dispersion, Lyapunov Index and Fractional Dimension were significantly lower in fetal rats than pregnant rats(P<0.01). Conclusins It demonstrated that the autonomic nervous system development of fetal rat was still unmature with lower complexity of HPS and chaotic degree than pregnant rat. Part Ⅳ: Changes of Heart Rate Power Spectrum and Its Association with Sudden Death in Fetal Rats of Intrahepatic Cholestasis of Pregnancy Objective To investigate the relationship between cardiac autonomic nervous system imbalance and sudden death in fetal rats of intrahepati...