硫酸镁对大鼠脑缺血-再灌注损伤的脑保护研究

目的：观察ＭｇＳＯ４作为非竞争性ＮＭＤＡ－Ｒ拮抗剂对大鼠脑缺血－再灌注的保护作用。方法：用线栓法制作７２只Ｗｉｓｔａｒ大鼠的大脑中动脉栓塞模型，在术后２小时给予再灌注，分别在再灌注同时及其２小时后给予不同剂量ＭｇＳＯ４治疗，术后进行皮层脑电图描记，测定血Ｍｇ＾２＋浓度，进行运动功能评估，测定脑组织含水量，观察病理组织学变化，并计算凋亡细胞数。结果：ＭｇＳＯ４能减少扩展性抑制波产生数目（Ｐ〈０．０５）；１０％，ＭｇＳＯ４组疗效优于５％ＭｇＳＯ４组，并明显改善大鼠运动功能，且早期给药效果更佳（Ｐ〈０．０５）；ＭｇＳＯ４能减轻脑组织含水量；但在短期内不能减少凋亡细胞数。结论：通过电生理、病理研究和临床评估证明ＭｇＳＯ４对大鼠脑缺血－再灌注损伤确有保护作用。

The effects of cerebral protection of MgSO_4 on rats with cerebral isckemia-reperfusion injury

Objective:To observe the protective effects of MgSO4 on cerebral ischemia-reperfusion injury in rats. Methods: The animal model of reformed middle cerebral artery occlusion was made in 72 Wistar rats, which were treated by MgSO4 in different doses at distinct stages. In all the rats, the changes of cortical spreading depressions (SDs) and Mg2 concentration in serum 24 hours after operation were found and the motive function was evaluated according to 0-5 grades. Then the rats were killed to determine contents of water in cerebral tissue, the pathological changes were observed and the numbers of apoptosis cells were measured. Results: The motive function in rats was obviously improved after using higher dose of MgSO4 in earlier stage; MgSO4 can significantly reduce the numbers of SDs; 10% MgSO4 has better neuroprotective effects than 5%MgSO4 and the much better effects were found in MgSO4 group used in the earlier stage. MgSO4 can also ameliorate brain edema; and MgSO4 has no role in reducing apoptosis cells in earlier stage. Conclusion: MgSO4, as a non-competitive antagonist of NMDA-R, can reduce the numbers of SDs significantly and exhibit protective effects during cerebral ischemia-reperfusion injury.