甲基强的松龙与地塞米松对C6胶质瘤大鼠放射性脑水肿的治疗效果差异

The difference in efficacy between methylprednisolone and dexamethasone to treat radioactive cerebral edema of cell line C6 brain glioma in rats

目的观察甲基强的松龙与地塞米松对C6胶质瘤大鼠放射性脑损伤后脑水肿程度的影响以及对血液中性粒细胞CD18 mRNA表达水平的改变。方法雄性Wistar大鼠100只，体质量250～300g，随机分成5组，每组20只，分别为接受照射同时30mg／kg体重甲基强的松龙或10mg／kg体重甲基强的松龙或5mg／kg体重地塞米松治疗组（A、B、C组），接受照射但未接受激素治疗的实验对照组（D），未接受照射和激素治疗的正常对照组（E）。各组均颅内种植肿瘤，ABCD组于种植15d后予^60Co照射，同时自照射前3d开始静脉注射激素或生理盐水，直至照射后6d，照射后第7天取大鼠脑组织测含水量，颈总动脉取血，离心取中性粒细胞层，逆转录-聚合酶链反应（RT—PCR）分析测定血液中性粒细胞CD18 mRNA表达水平。结果脑组织含水量与血液中性粒细胞CD18 mRNA表达水平：D组、E组分别与ABC组比较差异均有统计学意义（P〈0．05）；DE组两组间比较，差异有统计学意义（P〈0．05）；C组分别与AB组比较，差异均有统计学意义（P〈0．05）；A、B两组间比较，差异无统计学意义（P〉0．05）。结论甲基强的松龙与地塞米松均可通过抑制CD18表达的方式减轻放射性脑水肿，但甲基强的松龙效果较好。

Objective To study the effect of methylprednisolone or Dexamethasone on radioactive cerebral edema and the expression of CD18 in the rat neutrophilic granulocytes. Methods One hundred male Wistar rats were divided into 5 groups at random （n = 20 in each group）. Group A was irradiated and treated with 30 mg/kg methylprednisolone, group B was irradiated and treated with 10 mg/kg methylprednisolone, group C was irradiated and treated with 5 mg/kg Dexamethasone, group D was irradiated and treated without glucocorticoid, and group E served as normal controls. Glioma cells were implanted into brains of rats in groups A, B, C, D and E. The rats in groups A, B, C and D were subjected to 60 Co radiation 15 days after tumor implantation. All groups were administered with glucocorticoids or normal saline at 3rd day before and at 14th day after radiation. The water content of the brain tissue in rats was measured at 7th day after radiation. The expression of CD18 in the neutrophils of rats was detected. Results There was significant difference in the water content of the brain tissues and the level of CD18 mRNA expression between groups D, E and groups A, B, C （ P 〈 0.05 ） , group D and group E （ P 〈 0.05 ） , group C and group A （ P 〈 0.05 ） , but there was no significant difference between groups A and B （ P 〉 0.05 ）. Conclusion Both methylprednisolone and Dexamethasone can protect the radiation-induced injury and brain edema changes by inhibiting the expression of CD18 in rats, and the methylprednisolone is superior to Dexamethasone.