硫酸镁对大鼠急性放射性脑损伤后脂质过氧化的抑制作用

目的探讨硫酸镁对电离辐射诱发的脑组织损伤的保护作用。方法将成熟的SD大鼠60只随机分为空白对照组、实验对照组和硫酸镁实验用药组，用6MeV电子线对实验大鼠进行20Gy全脑单次垂直照射，分别于1d、7d、14d和30d处死，取其脑组织，用考马斯亮蓝法测定总蛋白相对浓度，黄嘌呤氧化法测定超氧化物歧化酶（SOD）活性，硫代巴比妥酸法测定丙二醛（MDA）浓度，并与空白对照组进行比较。结果与空白对照组相比，实验对照组大鼠脑组织中SOD活性显著下降（P〈0．05），MDA浓度显著升高（P〈0．05）；与实验对照组相比，硫酸镁实验用药组大鼠脑组织中SOD活力在照射后7d呈逐渐上升趋势，MDA浓度明显降低（P〈0．05）。结论早期使用硫酸镁可抑制辐射引起的脑组织中脂质过氧化的程度，减轻自由基对脑组织的损伤程度。

Inhibitory effect of magnesium sulfate on reaction of lipid hyperoxidation after radiation-induced acute brain injuries

Objective To explore the protection of magnesium sulfate(MgSO4) on radiation-induced acute brain injuries. Methods 60 maturity Sprague-Dawley(SD)rats were randomly divided into 3 groups: blank control group,experimental control group and experimental-therapeutic group. The whole brain of SD rats of experimental control group and experimental-therapeutic group was irradiated to a dose of 20Gy using 6 MeV electron. MgSO4 was injected intraperitoneally into the rats of experimental-therapeutic group before and after irradiation for five times. At different time points ranging from the 1 d,7 d,14 d,30 d after irradiation,the brain tissue were taken. The xanthine oxidase and colorimetric examination were used to measure the superoxide dismurtase(SOD) and malonyldialdehyde(MDA) respectively in the rat brain respectively. Results Compared with blank control group,the SOD in brain of experimental control group decreased significantly(P<0.05),and the MDA in brain in experimental control group increased markedly(P<0.05). Compared with that of the experimental control group,the SOD in brain in experimental-therapeutic group were climbing since 7 d later after irradiation,the MDA in brain significantly lower than those experimental control group(P<0.05). Conclusions MgSO4 used in early stage can inhibit the lipid peroxidation after radiation-induced acute brain injuries and alleviate the damage induced by free radicals to brain tissue.