The Correlation Between Adiponectin, T-cadherin And STZ-induced Diabetic Cardiomyopathy

Objective To observe the expression of adiponectin(ADPN)in blood samples and the expression of ADPN and its receptor T-cadherin(T-cad)in myocardial tissue of streptozotocin(STZ)-induced diabetic rats,and the changes of myocardium structure.To study the role of ADPN and T-cad in diabetic cardiomyopathy.Methods 64 Wistar rats were divided randomly into two groups.There were 32 in diabetic group and 32 in normal control group.The subjects in diabetic group were injected intraperitoneally with STZ citrate buffer(STZ 50mg/kg),while the ones in normal control group were injected intraperitoneally with the similar dose of citrate buffer.After 1 week,4 weeks,8 weeks and 12 weeks,the level of ADPN and C peptide in blood samples were measured by ELISA.The expression of T-cadherin in myocardial tissue was measured by immunohistochemistry.The changes of myocardium structure were observed by microscope and electronmicroscope.Meanwhile,the changes of myocardium structure and immunohistochemistry were used to analyze morphologically.We compare these data between two groups and among the different stages with analysis of variance,and analyze the correlation between ADPN and T-cad.Results 1.There was a difference in the increase of body weight between diabetic group and normal control group(P＜0.01).The body weight of normal control group increased significantly but diabetic group not.There was a significantly difference in the level of fast blood glucose between two groups(P＜0.01).The fast blood glucose of diabetic group sustained at high level and the C peptide maintained at low level after lweek while the control group was normal.2.Compared with normal control group,myocardial cells swelling was observed by microscope and myofilament rarefaction,chondriosome swelling and escaping by electronmicroscope in diabetic groups.In normal control group,myofilament and chondriosome were tidy.With the progression of the course of disease,the affection was gradually seriously.3.The blood level of ADPN in diabetic group was higher than that in normal control group after 4weeks(4weeks P＜0.05,8weeks,12weeksP＜0.01),and increased gradually during the whole experiment.4.Compared with normal control group,the expression of T-cad in myocardial tissue was strongly in diabetic group,and increased gradually.There was a significantly difference of IDP between two groups after 4weeks(P＜0.01).5.There was a significant positive correlation between ADPN and T-cad in diabetic group (r=0.794,P＜0.01).Conclusion 1.The model of STZ-induced diabetic rats was succeeding.The pathological changes in myocardial cell were consistent with diabetic cardiomyopathy.2.The blood level of ADPN in diabetic group was more than that in normal control group,and increased gradually with the development of cardiomyopathy.This is similar to the reports of document.This result suggested that ADPN was possibly a protective factor in the course of diabetic cardiomyopathy.3.The expression of T-cad in diabetic group was higher than that in normal control group. There was a significant positive correlation between ADPN and T-cad in diabetic group.With the increase of ADPN level,the expression of T-cad was strongly in myocardial tissue.4.From these results,we could suggest that ADPN bind T-cad to protect against apoptosis of myocardial cell and neointima hyperplasy.They could protect myocardial cell from damage in type 1 diabetes.