Expression Of Bcl-2 And Caspase-3 In Spinal Cord Neuron After Ischemia-reperfusion Of Hind Limb In Rats And The Interventional Effects Of PGE₁

Background Ischemia-reperfusion injury of limb is very common in surgery, to investigate the ischemia-reperfusion injury of limb is very significant. Ischemia-reperfusion of limb not only caused local injury ,but also caused systemic inflammatory response syndrome by nerve,endocrine and immunologic mechanism, caused multiple organ dysfunction syndrome , even threat to life. Peripheral nerve had changes of construction and function after ischemia-reperfusion of limb, which had important effect of central nervous system.Object To investigate effects of PGE1 and the changes in cell apoptosis ,expression of Bcl-2 and Caspase-3 in spinal cord neuron after ischemia-reperfusion of hind limbs in rats.Method Seventy-two healthy SD rats were randomly divided into 3 groups:①sham group (n=24), the rats received the operation without other treatment.②ischemia-reperfusion group (n=24).③ischemia-reperfusion +PGE1 group(n=24), the rats were received intravenous injection of PGE1 5μg·ml-1·kg-1 before ischemia 10min. Every group was divided into 4 groups(4h,12h,24h,48h)according to reperfusion time .At the end of the experiment, all rats were killed by heart perfusion to get spinal cord lumbar segments (1-5);The pathologic changes of spinal cord were assessed by HE staining. The expression of Bcl-2 and Caspase-3 was assessed by immunohistochemical method(SP). The cell apoptosis was measured by TUNEL method.Result①Compared with the sham group, the expression of Bcl-2, Caspase-3 increased obviously in IR group and PGE1 group. Compared with IR group , the expression of Bcl-2 increased , while Caspase-3 was lower in PGE1 group. The expression of Bcl-2 reach the peak at 12h,while Caspase-3 reach the peak at 24h in IR,PGE1 group.②The TUNEL results: There were no significant apoptosis cells in sham group. Ischemia-reperfusion significant increased apoptosis index of spinal cord, while PGE1 significantly attenuated these changes. The expression of Caspase-3 positively correlated to apoptosis index.Conclusion①Apoptosis of spinal cord neuron participated in the injury induced by ischemia-reperfusion of hind limbs. Ischemia-reperfusion can increase Bcl-2 and Caspase-3.②PGE1 injecting 10min before ischemia has inhibitive effect on spinal cord apoptosis following ischemia-reperfusion of hind limbs in rats. PGE1 may protect spinal cord by increasing Bcl-2 and decreasing Caspase-3.