Effect Of Different Abdominal Incision On The Expression Of HSP70and HMGB1in Myocardium

Objective:To study the effect of different abdominal incision stimulation on the stress induced myocardial injury and the expression of HSP70and HMGB1in the myocardial tissues in the SD rats, and to investigate the role of HSP70and HMGB1in the pathogenesis of the stress induced myocardial injury.Method:48adult male SD rats were randomly divided into8groups(6animals each) and the different abdominal operations were made respectively. Group C(control group):no incision was made; group S2:a2cm skin incision was made; group S4:a4cm skin incision was made; group Mu a1cm skin incision and a1cm muscle incision were made; group M2:a2cm skin incision and a2cm muscle incision were made; group M4:a4cm skin incision and a4cm muscle incision were made; group P2:a2cm skin incision and a2cm muscle incision and a2cm peritoneum incision were made; group E2:a2cm skin incision and a2cm muscle incision and a2cm peritoneum incision and2min abdominal cavity exploration were made and the intestin was pulled out.7days after operation the rats were sacrificed and the myocardial tissues were prepared. To observe the morphology change of the myocardial tissues by HE staining method, and immunohistochemical method was employed to detect the expression of HSP70and HMGB1in the myocardial tissues of the rats in each group. Acquired the IOD of the HSP70and HMGB1by ImagePro-Plus6.0(IPP6.0), and then compared the scores of the myocardial injury and the IOD of the HSP70and HMGB1between groups with SPSS13.0. Results:1.The data of age, gender, weight, duration of anesthesia, recovery time, and the dosage of propofol between the rats in each group were not statistically significant (P>0.05). Except group C, the operation time of group M2to E2were longer than group S2to M1(P<0.05). The operation increased MAP, PR in operation groups(Group S2-E2)(P<0.05)2.The morphology of the myocardial tissues of the rats in group C was normal and the myocardial tissues were damaged in the rats from group S2to group E2. The scores of myocardial injury showed an increasing trend, and the difference between groups was statistically signicant (F=16.546, P=0.000)3. The expression of HSP70was mainly in the cytoplasm of all the myocardial tissues, and the expression in the nucleus was weaken. The expression of HSP70in the myocardial tissues showed an increasing trend from group S2to group E2, but the difference between groups was not statistically significant (F=1.006, P=0.441)4. The expression of HMGB1was mainly in the nucleus of all the myocardial tissues, and the expression in the cytoplasm was weaken. The expression of HMGB1in the myocardial tissues gradually increased from group S2to group E2, and the difference between groups was statistically significant (F=31.180, P=0.000)Conclusions:1. The different abdominal incision could result in the stress induced myocardial injury with different levels, and the pathological change was still existed obviously in the7days after operation.2. The expression of HSP70in the myocardial tissues were not increased obviously in the later stage after operation. 3. The expression of HMGB1in the myocardial tissues was increased obviously in the later stage after operation, and increased accompanied with the increasing of the stress intensity. As a late inflammatory mediator, HMGB1may be related with the stress induced myocardial injury by its proinflammatory effect.