Protective effect and the possible mechanism of Nano-Se on myocardium of experimental diabetes mice / 中国病理生理杂志

ABSTRACT

AIM:To observe the protective effect of Nano-Se on myocardium of experimental diabetes mice.METHODS:Sixty healthy male KM mice were chosen,ten of which were selected randomly as the normal control group.After fasted for 24 h,the rest 50 mice were injected with streptozotocin(STZ,50 mg/kg)intraperitoneally for 5 d.At 7th d,the blood-sugar was measured from vena caudalis,40 mice,of which blood-sugar exceeded 16.65mmol/L,were selected and randomized into 4 groups:the positive control group,low dose(25 ?g/kg)Nano-Se group,mid dose(50 ?g/kg)Nano-Se group,high dose(50 ?g/kg)Nano-Se group.All mice were given intragastric administration of 0.2 mL normal saline and corresponding dose of Nano-Se.The body weights were measured every week,and the dose of which was adjusted according to the change of the body weights.8 weeks later,the mice were killed and cardiac muscle of the left ventricle was taken.The myocardium was prepared to 10% homogenate for measuring SOD,GSH-Px activity and MDA content.The myocardial cell apoptosis was measured by TUNEL.The expressions of Bc1-2 and Bax proteins were determined by immunohistochemistry.RESULTS:Compared to normal group,the SOD and GSH-Px activities in positive control group decreased,MDA level increased,the rate of myocardial cell apoptosis increased significantly,Bc1-2 protein expression deceased and Bax protein expression increased.Compared to positive control group,the SOD and GSH-Px activities in low and mid dose Nano-Se groups expression increased,MDA level decreased,myocardial cell apoptosis rate decreased,Bc1-2 protein expression increased and Bax protein expression decreased.Moreover,the SOD and GSH-Px activities in high dose Nano-Se group decreased obviously compared to those in mid dose Nano-Se group.MDA level and myocardial cell apoptosis rate increased,Bc1-2 protein expression decreased and Bax protein expression increased,no significant difference in SOD,GSH-Px activity,MDA level and myocardial cell apoptosis rate was observed compared with positive control group.CONCLUSION:The damage of cardiac muscle is alleviated when a certain dose of Nano-Se is supplied to diabetes mice.The protective mechanism may be related to antioxidation,blood-sugar adjustment and the increase of Bc1-2 expressing.