The Protective Effect Of Nano-Se On Myocardium Of Experimental Diabetes Mice And Its Possible Mechanism

Objective As an indispensible micro-element of human beings, selenium is a major active content of GSH-Px. The most important bio-effect of selenium is its antioxidant, On the other hand, selenium itself has some effect on reducing sugar like para-insulin. Diabetic cardiomyopathy, which could be shortened as DC, is a serious syndrome of diabetes patient, the occurrence mechanism has not been clear until now, which may have a relationship with free radical abnormity, oxidation stress, decreasing ability of antioxidant induced by falling expression of GSH-Px and so on.To illuminate whether Nano-Se has some effects on antioxidant to diabetic cardiomyopathy , we use STZ on mice to set up a diabetic model(DM) and investigate the protective effect and possible mechanism of Nano-Se on myocardium of experimental mice in order to supply experimental and theoretical accordance to treat diabetic cardiomyopathy.Methods Sixty healthy male KM mice, weight rangs from 30g to 40g were chosen,ten of which were selected randomly as the control group . After being fasted for 24 hours ,The 50 mice were injected streptozotocin(STZ)50mg/kgBW in left lower intraperitoneal for 5 days. After 7 days , the blood glucose were measured from vena caudalis.40 mice with blood glucose exceeded 16.65mmol/L were randomized into four groups: the positive control group, low dose (25ug/kg bw) Nano-Se group, mid dose (50ug/kg bw) Nano-Se group, and high dose (100ug/kg bw) Nano-Se group. Each group of mice were intragastric administrated with the total dose of 0.2ml normal saline and corresponding dose of Nano-Se. The weight of each mice were measured every week, and the dose of Nano-Se given was adjusted by the weight changing. 8 weeks later, the mice was killed from eyeball.Part of cardiac muscle of the left ventricle were taken to make 10% homogenate to measure SOD, GSH-Px activity and MDA content; the rest were used in two ways: using TUNEL to measure the myocardial cell apoptosis, and using immunohistochemistry to measure the expression of bc1-2 and bax protein .Results Compared to normal group, the SOD and GSH-Px activity of positive control group decreased, MDA level increased, the myocardial cell apoptosis rate increased significantly(P<0.05), bc1-2 protein deceased and bax protein increased (P<0.05); when compared to positive control group, the SOD and GSH-Px activity of low and mid dose Nano-Se groups increased, MDA level decreased, myocardial cell apoptosis rate decreased, bc1-2 protein increased and bax protein decreased; more over, the SOD and GSH-Px activity of high dose Nano-Se group decreased obviously comparing to mid dose Nano-Se group, MDA level and myocardial cell apoptosis rate increased, bc1-2 protein decreased and bax protein increased, there were no significant difference with positive control group on SOD, GSH- Px activity, MDA level and myocardial cell apoptosis rate.Conclusion The myocardial cell apoptosis rate was alleviated when supplied appropriate Nano-Se to diabetes mice , which demonstrate the protective effect of Nano-Se on myocardium of experimental diabetes mice. The protective mechanism may be related to antioxidation, blood-sugar adjustment and the increase of bc1-2 expressing.