Published online Jul 21, 2008. doi: 10.3748/wjg.14.4332
Revised: June 17, 2008
Accepted: June 24, 2008
Published online: July 21, 2008
AIM: To investigate the effects of prednisolone on cell membrane bleb formation, calpain &mgr; activation and talin degradation during hepatic ischemia-reperfusion injury in rats.
METHODS: The hilar area of the left lateral and median lobes of rat liver (68%) was clamped for 60 min and followed by 120 min reperfusion. Prednisolone was administered at 1.0, 3.0, or 10 mg/kg at 30 min before ischemia. In addition to biochemical and microscopic analyses, activation of calpain &mgr; was determined using specific antibodies against the intermediate (activated) form of calpain &mgr;. Degradation of talin was also studied by Western blotting.
RESULTS: In the control and prednisolone (1.0 mg/kg) groups, serum aspartate transaminase (AST) and alanine transaminase (ALT) level were elevated, and cell membrane bleb formation was observed after 120 min of reperfusion. Moreover, calpain &mgr; activation and talin degradation were detected. Infusion of prednisolone at 3.0 or 10 mg/kg significantly suppressed serum AST and ALT, and prevented cell membrane bleb formation. At 10 mg/kg, prednisolone markedly suppressed calpain &mgr; activation and talin degradation.
CONCLUSION: Prednisolone can suppress ischemia-reperfusion injury of the rat liver. Its cytoprotective effect is closely associated with the suppression of calpain &mgr; activation and talin degradation.