Influences of percutaneous pulse current stimulation at hepatic region to Bcl-2 and Bax expression in and ultrastructure of hepatocytes in exercise-induced fatigue rats

Objective To explore the influence of percutaneous pulse current stimulation at hepatic region to Bcl-2 and Bax expression in and ultrastructure of hepatocytes in exercise-induced fatigue rats.Methods Seventy-two male Wistar rats were randomly divided into three groups:control group,exercise training group and stimulating group(24 each).Animals of the latter two groups were treated with swimming training to establish exercise-induced fatigue model,and rats of stimulating group received percutaneous pulse current stimulation(1024Hz,10mA) after training.At the last day of 1st,3rd and 5th week,8 rats of each group were randomly chosen and sacrificed,the Bcl-2 and Bax protein expression and distribution were determined by immunohistochemical method,and ultrastructural changes of the hepatic tissues were observed by transmission electron microscopy.Results At the end of 1st week,no remarkable difference of Bcl-2 expression was found among the 3 groups(P0.05).At the 3rd week,the Bcl-2 expression was lower in exercise training group than in stimulating group and control group(P0.05),while no significant difference existed between the latter two groups.At the 5th week,the Bcl-2 expression was higher in stimulating group than in exercise training group,but was lower than in control group(P0.05).The Bax expression was higher in stimulating group than in control group at 3rd and 5th week(P0.05),but was lower than in exercise training group at 1st,3rd and 5th week(P0.05).The Bcl-2/Bax was lower in exercise training group than in control group and stimulating group at the 1st,3rd and 5th week(P0.05).Observation by electron microscopy revealed a large number of chondriosome,rough endoplasmic reticulum(RER) and hepatic glycogenosome in cytoplasm of hepatocytes of control group.At the 5th week,the number of chondriosome and glycogenosome decreased,cell cavitation occurred,membrane structure and RER broke,and lots of cell content in sinusoid appeared in exercise training group.The degree of damage of both chondriosome and RER was obviously milder in stimulating group than in exercise training group.Conclusion Exercise-induced fatigue may obviously increase the Bax expression and reduce the Bcl-2 expression in hepatocytes,induce apoptosis of hepatocyte and damage of liver tissues,while percutaneous pulse current stimulation may reduce the Bax expression and increase the Bcl-2 expression,so protect the normal construction of liver tissues.