脉冲磁场抑制缺血再灌注大鼠神经细胞凋亡与Ca^(2+)分布的关系

Relationship between the inhibition of pulse magnetic field in nerve cell apoptosis of rats following cerebral ischemia reperfusion and Ca^(2+)

目的:研究磁场对急性脑缺血再灌注的大鼠神经细胞凋亡和Ca2+分布的关系。方法:SD大鼠32只,采用线栓法制备左侧大脑中动脉栓塞2h后再灌注模型,磁疗组在再灌注的同时给予脉冲磁场处理15min,磁场强度0.4T,频率40次/min。24h后取材。用免疫组化法检测凋亡、c-fos,Bcl-2;草酸—焦锑酸钾电镜细胞化学技术观察细胞超微结构变化及细胞内Ca2+分布情况。结果:磁疗组的神经细胞凋亡数比缺血组少犤分别为(14.5±7.1)及(18.1±8.3)个/视野犦,c-fos阳性细胞数磁疗组比缺血组少犤分别为(12.3±7.1)及(16.0±7.9)个/视野犦,皆有统计学差异(t=2.10,2.18,P<0.05)。Bcl-2两组皆为阴性。缺血组神经细胞超微结构有损伤现象,磁疗组损伤轻于缺血组,但两组细胞内都有大量Ca2+沉积。结论:脉冲磁场能抑制缺血再灌注神经细胞的凋亡和c-fos的表达,减轻细胞损伤,但其途径可能与Ca2+分布无关。

AIM:To study the relationship of magnetic field in inhibition of nerve cell apoptosis in rats with acute cerebral ischemia reperfusion to the Ca2+distribution.METHODS:Left middle cerebral arteries of 32 SD rats were blocked by thread for 2 h followed by reperfusion. The rats in the magnetic group were exposed to pulse magnetic field at the intensity of 0.4 T and the frequency of 40 times per minute for 15 minutes. Twenty-four hours after treatment, the specimens were taken to inspect cell apoptosis,c-fos and Bcl-2 with immunohistochemical method,and to inspect cell ultrastructure and Ca2+distribution with oxalate-pyroantimonate electronmicroscopic cytochemical technique. RESULTS:The amounts of apoptotic cells were(14.5±7.1) per visual field in the magnetic group, less than in the ischemic group[(18.1±8.3) per visual field],and the amounts of c-fos positive cells were (12.3±7.1) per visual field, also less than in the ischemic group[(16.0±7.9) per visual field](t=2.10,2.18,P< 0.05).Bcl-2 showed negative in the two groups.The ultrastructure of nerve cells in the ischemic group was damaged more seriously than that in the magnetic group,but mass Ca2+depositions were found in the two groups.CONCLUSION:Pulse magnetic field can inhibit the cell apoptosis after cerebral ischemia reperfusion and c-fos expression,and alleviate cell damage,which may be not related with the distribution of Ca2+.