The Changes Of Connexin43 And The Effects Of Captopril And Candesartan In Juvenile Rats With Right Heart Failure Caused By Monocrotaline

Object:To observe the alterations of Cx43 in the serum and its expression in right ventricular myocardium of juvenile rats with right heart failure (RHF) induced by Monocrotaline(MCT) and the effects of Captopril and Candesartan on them.Methods:50 juvenile rats were injected in belly cavity with Monocrotaline to induce PAH, and were randomly divided into 5 groups:heart failure group I (E1),heart failure groupâ…¡(E2),Captopril group (C1),Candesartan group (C2), Combination group(C3).Other 20 rats taken as controls were injected with saline in the belly cavity and were divided into normal control groupâ… (N,) and normal control groupâ…¡(N2).The blood dynamics,myocardial weight analysis of survival rats in each group were measured and the myocardial morphology was also observed. Cx43 in serum was measured by ELISA, Cx43 and Cx43mRNA in right ventricular myocardium were measured by immunohistochemistry and RT-PCR methods respectivelyResults:At 4 weeks,right ventricular hypertrophy index, central venous pressure(CVP)and right ventricular systolic pressure(RVSP)increased and right ventricular pressure maximum upstroke velocity(dp/dt)decreased significantly in the E1 compared with those in the N1. The indiscriminate arrangement of right ventricular cadiocyte,solution of myoplasm and vacuolar degeneration were observed and the model of right heart failure was successfully formed. Cx43 in serum, Cx43 and Cx43 mRNA in right ventricular myocardium decreased in the E1 compared with those in the N1.Compared with N2, RV/(LV+S),CVP,RVSP increased and RVdp/dt decreased significantly, Cx43 in serum, Cx43 and Cx43 mRNA in right ventricular myocardium decreased in the E2.Compared with E1,RV/(LV+S),CVP,RVSP increased and RVdp/dt decreased, Cx43 in serum, Cx43 and Cx43 mRNA in right ventricular myocardium decreased in the E2. C1 and C2 groups showed rise in the levels of Cx43 in serum, Cx43 and Cx43 mRNA in right ventricular myocardium and right ventricular hypertrophy was relieved compared with E2. There were no remarkable differences in the levels of the Cx43 in serum, Cx43 and Cx43mRNA in right ventricular myocardium among the groups C1,C2 or C3Conclusion:In juvenile rats with right heart failure caused by pulmonary artery hypertension,Cx43 in serum, Cx43 and Cx43 mRNA in myocardium decrease and coincide with the development of RHF. Both Captopril and Candesartan when used individually are effective in the management of RHF through increase the level of Cx43.The simultaneous use of the two drugs did not show any marked curative effect.