Expression Of Cx43 And Effects Of Leonurus Heterophyllus Sweet In Experimental Diabetic Cardiomyopathy

Backgroud & Objective Diabetic cardiomyopathy (DCM) as a distinct entity is different from coronary heart disease and hypertensive cardiopathy. It is one of the fatal chronic complications of diabetic patients. So many etiological factors involved in diabetic cardiomyopathy made the pathogenesis still uncertain now, and the assuredly operative prevention and cure of diabetic cardiomyopathy is not fined either at present. The cardiac gap junction (GJ) is a special intercellular channel connecting the adjacent cardiomyocytes. The principal function of GJ is to mediate the intercellular communication. Connexin 43 (Cx43) is the predominant protein of gap junction in ventricular. Previous studies have showed that changes of expression and alternation of distribution pattern of Cx43 correlated with many cardiovascular diseases. Leonurus heterophyllus sweet (LHS) is an ancient Chinese traditional herb. The pharmacological effects of LHS have been shown on uterus, vascular system, microcirculation, platelets and hemodynamics. In this study, we investigated the changes of expression and distribution pattern of Cx43 and the effects of LHS in experimental diabetic cardiomyopathy rat models, with an aim to find out the relationship between Cx43 and diabetic cardiomyopathy, and the effects of LHS in experimental diabetic cardiomyopathy.Methods The diabetic cardiomyopathy rat models were developed by injecting streptozotocin(STZ). The expression and distribution of Cx43 was detected by the SP immunohistochemical staining in different period rats. The heart ultrastructure was observed and the Cx43 was detected to evaluate the effects of LHS.Results (1) Compared with normal groups, the expression of Cx43 was evidently decreased and the distribution of Cx43 was disorganized in diabetic cardiomyopathy groups, the changes were showed as time-dependent. The pixel density of Cx43 in normal groups of 10 , 12 , 14 and 16 weeks old were 206.8 + 5.89, 205.2 + 6.14, 204.6 + 5.64 and 207.4 + 6.34 respectively; in diabetic cardiomyopathy groups of 10 , 12 , 14 and 16 weeks old were 186.3 + 4.19, 164.8+4.08, 143.5 + 3.65 and 131.2 + 5.62 respectively. Statistical analysis showed that there were no difference of Cx43 in different periods of normal rats (P>0.05), and Cx43 in different periods of diabetic cardiomyopathy were time-dependently decreased (P0.001) and lower than that in normal groups (PO.001).(2) Compared with the untreated diabetic cardiomyopathy group, the changes of heart ultrastucture and Cx43 in LHS-treated group ameliorated greatly, but couldn't recover to normal state. The pixel density of Cx43 in LHS-treated group (16 weeks old) was 196.3 + 4.16, higher than that of untreated DCM rats (P0.001), but lower than that ofnormal rats in the same period (P<0.001).Cone I us i ons The expression of Cx43 was evidently decreased and the distribution pattern was disturbed in diabetic cardiomyopathy rats , this changes were time-dependent. LHS could ameliorate the pathological changes of diabetic cardiomyopathy, the ultrastructure of heart and expression of Cx43 in treated group were approach to normal group.