恒定磁场对大鼠脑缺血再灌注损伤保护作用的研究

目的：研究恒定磁场对大鼠脑缺血再灌注损伤的保护作用。方法：40只动物被随机分成3组，假手术组、模型组及磁疗组，其中后2组参考Longa法制成大鼠大脑中动脉缺血再灌注模型，磁疗组在脑缺血模型完成后立即将其头颈部置于40mT的恒磁场中，持续30min，每天1次，7d后眼球取血、断头取脑，测量血液流变学、红细胞膜流动性、抗氧化酶活性以及NO、NOS等各项指标的变化，假手术组及模型组均未给予相应治疗措施，并与磁疗组对照。结果：模型组大鼠血液流变学、红细胞膜流动性等各项指标以及一氧化氮、一氧化氮合成酶含量均显著高于假手术组，抗氧化酶活性显著低于假手术组；经过磁场治疗后，大鼠血液流变学、红细胞膜流动性、一氧化氮及一氧化氮合成酶等含量均有所下降，抗氧化酶活性有所升高，差异均有显著性。结论：恒定磁场能显著改善大鼠的血液流变学特性，提高红细胞膜流动性及机体的抗氧化酶活性、降低MDA、NO及NOS含量，提高机体的抗氧化能力，从而有效阻止自由基、一氧化氮等对神经组织的损伤，从而阻断了脑缺血的病理生理过程，对脑缺血再灌注损伤起到一定的保护作用。

The protective effect of constant magnetic field on ischemia-reperfusion injury of the brain in rats

Objective To study the beneficial effect of constant magnetic field (CMF) on brain tissue injury of rats caused by cerebral ischemia and reperfusion. Methods Forty rats were divided into three groups: control group (n=10), reperfusion group (n=15) and CMF group (n=15). In the reperfusion and CMF groups, cerebral ischemia-reperfusion was caused by using the Longa's surgical procedure, while the sham operation was performed on the rats in the control group. The rats in the CMF group were immediately exposed to 40mT constant magnetic field on bilateral carotid areas for 30 minutes once daily after the operation, and seven days later, the hemorrheologic parameters, erythrocyte membrane fluidity, anti-oxidase activity and the level of NO and NOS in these rats were determined. The animals in the control and CMF groups underwent the same procedure except exposure to CMF. Results The parameters inclusing hemorrheologic ones, erythrocyte membrane fluidity and the levels of NO and NOS of the reperfusion group were higher than those of the control group (P<0.05, or P< 0.01), but the levels of anti-oxidase activity were significantly lower (P<0.05, or P<0.01). After the CMF treatment, all the parameters except anti-oxidase activity were significantly increased (P<0.05, or P<0.01). Conclusion The constant magnetic field could effectively improve cerebral microcirculation, and inhibit the injurious effects of free radicals, NO and NOS, indicating that CMF might protect the cerebral tissue from injury caused by ischemia-reperfusion.