Attenuation of reperfusion-induced hepatocyte apoptosis is associated with reversed bcl-2/bax ratio in hemi-hepatic artery-preserved portal occlusion.

BACKGROUND

This study aimed to examine the hepatocyte apoptosis in a hepatic blood inflow occlusion rat model without hemi-hepatic arterial control and its association with the expressions of the apoptosis-regulating genes bcl-2 and bax.

MATERIALS AND METHODS

Wistar rats were equally and randomly assigned to undergo sham operation (control group, n = 8), Pringle's maneuver (group PR, n = 32), hemi-hepatic occlusion (group HH, n = 32), or hemi-hepatic artery-preserved portal occlusion (group HP, n = 32). The hepatic blood inflow was interrupted for 30 min using a microvascular clip in the three experimental groups. The clips were removed to achieve hepatic reperfusion for up to 24 h. Blood samples and liver specimens were collected following reperfusion to perform pathologic examination, serum transferase assay, apoptosis analysis, and determination of bcl-2 and bax mRNA and protein expressions.

RESULTS

The reperfusion-related hepatocytic injuries were more severe in the PR group than in the HH and HP groups, both pathologically and biochemically. More reperfused hepatocytes became apoptotic in the PR group than in the HH and HP groups. However, the values of the HH and HP groups were comparable in cellularity, levels of serum transferases, and apoptosis rate following reperfusion. The ratios of bcl-2/bax were reversed, which was more evident in the HH and HP groups than in the PR group.

CONCLUSION

Hemi-hepatic artery-preserved portal occlusion had little effect on hepatocyte apoptosis compared with Pringle's maneuver and caused minor ischemia-reperfusion injury as shown by the reversed bcl-2/bax ratio.