Aim: To investigate the effects of prednisolone on cell membrane bleb formation, calpain mu 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 micro was determined using specific antibodies against the intermediate (activated) form of calpain mu. 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 mu 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 mu 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 mu activation and talin degradation.