Effects of intermittent hypoxic preconditioning on apoptosis-related Bcl-2 and Bax protein expression in rat liver after partial hepatectomy under ischemia-reperfusion / 国际外科学杂志

ABSTRACT

Objective To observe the effects of intermittent hypoxic preconditioning on the expression of apoptosis-related Bcl-2 and Bax protein after 70％ hepatectomy combined with ischemia-reperfusion injury.Methods A total of fifty-four SD rats were randomly divided into three groups (n =18).Partial hepatectomy hroup (PH Group)Rats underwent the left and middle lobectomy of liver(70％ hepatectomy).Ischemia reperfusion group (IR group)The left and middle lobes of liver were resected during the occlusion of the hepatoduodenal ligament for 20 minutes.Residual liver underwent the process of ischemia-reperfusion.Intermittent hypoxia preconditioning group (IHP group)rats were exposed to hypoxic environment of 10％ oxygen for 1 h/d.After 7 consecutive days,the left and middle lobes of liver were resected under the portal triad clamping.At 12,24 and 48 hours after the operation,the rats were killed and detected.The serum levels of ALT and AST were determined by automatic biochemical analyzer.The expression of Bcl-2 and Bax protein in liver tissue were measured by immunohistochemistry.Results At each time point after surgery,the serum levels of ALT and AST in IR group and IHP group were higher than that of PH group,and IHP group were lower than in IR group.Compared with IR group,the expression of Bcl2 protein significantly increased and Bax protein expression significantly decreased in IHP group.All these differences were statistically significant (P ＜ 0.05).Conclusions Intermittent hypoxic preconditioning might protect residual liver against ischemia reperfusion injury,through increasing the expression of Bcl-2 protein and reducing the expression of Bcl-2 protein to decrease liver cell apoptosis.