Methylprednisolone On Cerebral Ischemia Reperfusion Injury In Rats

Objective To investigate the protection of methylprednisolone(MP) on neuronal apoptosis during focal cerebral ischemia-reperfusion injury in rats and to study the possible role of MP in neural apoptosis.Method Sixty-three male Sprague-Dawley rats were randomly divided into three groups: sham operation group(Sh group), ischemia/reperfusion group(I/R group),and methylprednisolone group(MP group).The model of focal cerebral ischemia- reperfusion injury was induced by suture method (ischemia for 2 hours and reperfusion for 3,6,24 hours respectively).In MP group, MP(30mg/kg) was intra- peritoneally injected when it was reperfusioned.The apoptosis in nerve cell was detected by TUNEL while the expression of Caspase-3 and HO-1 were measured by immunohistochemical stain and the mean optical density (OD) values of positive fields were examined quantitively by image analysis system.The pathological and ultra structure changes of cerebral tissue were also observed.Results The number of apoptosis cells and the expression of Caspase-3 and HO-1 were significantly higher in IR group than in Sh group(P<0.01), MP group had more significant change in apoptosis number(P<0.01), the expression of Caspase-3 was lower than I/R group(P<0.01) while HO-1 was obviously higher (P<0.01). The pathological and ultra structure change of cerebral tissue was better in MP group than in I/R group.Conclusion Methylprednisolone has a protective effect on cerebral ischemia reperfu- sion injury, the mechanism may be related to the higher expression of HO-1 by reducing oxidative damage, and inhibiting the neuronal apoptosis.