The Influence Of Mild Hypothermia Associated With Propofol On Bcl-2 And Bax Induced By Hepatic Ischemia-reperfusion In Rats

Objective To observe and compare the contents of Bcl-2 and Bax protein expressed in hepatic ischemia-reperfusion in rats under different influences of mild hypothermia,propofol and mild hypothermia associated with propofol. To investigate the possible mechanism of them.Methods Sixty healthy SD rats not discriminated female and male,weighting 200-250g were randomly divided into five groups:sham operation group(sham group, n=12);ischemia-reperfusion group(IR group,n=12); mild hypothermia group(H group, n=12); propofol group(P group,n=12)and mild hypothermia associated with propofol group(HP group,n=12).A rat model of hepatic ischemia-reperfusion was established.The left hepatic lobes were sampled at the end of reperfusion. Light microscope was performed to verify the morphologic changes of apoptosis. Contents of Bcl-2 and Bax protein in liver tissues was assessed by immunohistochemical method and MIAS-2000.The apoptosis index(AI)of hepatic cells was measured by terminal deoxynucleotidy transferase mediated dUTPnick and labeling (TUNEL) method.Results1.The result of Light microscopy:To compare with IR group,the pathological lesion were lighter in H group,P group and HP group.2.The results of Bcl-2 and Bax protein in different groups:The expression of Bcl-2 and Bax protein were significantly higher in IR group,H group,P group and HP group than in sham group,the difference between groups has statistical significance (P<0.01).Bcl-2 protein expression was significantly higher in H group,P group and HP group than in IR group,while Bax protein expression were significantly lower than in IR group, the difference between groups has statistical significance (P＜0.01).Compared with HP group, the expression of Bcl-2 protein in H group and in P group were lower,while Bax protein expression were higher, the difference between groups has statistical significance (P<0.01).The difference between H group and P group is not statistically significant(P>0.05).3.The results of AI in different groups:AI was significantly higher in IR group,H group,P group and HP group than in sham group,the difference between groups has statistical significance (P<0.01).To compare with IR group,AI was lower in H group,P group and HP group,the difference between groups has statistical significance(P<0.01).AI was significantly lower in HP group than in H group and in P group,the differece between groups has statistical significance(P<0.01).The difference between H group and P group is not statistically significant(P>0.05). Conclusion1.Both mild hypothermia and propofol can relieve the liver cellular apoptosis by up-regulating Bcl-2 protein and down-regulating Bax protein.2.the protective effect of mild hypothermia associated with propofol is more than respectively themselves.