白藜芦醇对脑创伤后小胶质细胞激活的影响

目的检测白藜芦醇治疗后大鼠脑损伤区激活小胶质细胞的形态及数量改变,以探讨白藜芦醇的脑保护机制。方法健康雄性SD大鼠75只,随机分为创伤组、对照组和治疗组,每组分伤后3、12、24、48和72h共5个时间点,各时间点每组5只动物,用改良Feeney自由落体法致伤动物。治疗组予以白藜芦醇(50mg/kg体重)腹腔注射,对照组给予等量生理盐水,创伤组未给予药物处理。分别于伤后各时间点麻醉动物,取伤区脑组织,用抗OX-42免疫组化法检测小胶质细胞变化。结果伤后早期小胶质细胞即被激活,在不同时间点小胶质细胞形态不同:正常大鼠脑内小胶质细胞处于静息状态,细胞形态不清晰;伤后3h,OX-42浅染,小胶质细胞形态可见;伤后12h,小胶质细胞反应明显,OX-42深染,细胞形态清楚;伤后24h,小胶质细胞反应达高峰,细胞形态清晰,突起上可见到小棘;48h以后,反应减弱,OX-42浅染,细胞数量减少。治疗组小胶质细胞数量明显减少(P<0.05),创伤组与对照组无明显差异(P>0.05)。结论伤后不同时间点激活小胶质细胞的形态和数目不同,白藜芦醇能抑制小胶质细胞的激活,具有脑保护作用。

The effects of resveratrol on the activation of microglias after cerebral trauma

Objective To detect the morphologic and quantitive changes of the activated microglias in rats with cerebral trauma and to investigate the possible cerebral protection mechanism of resveratrol.Methods The craniocerebral injury model was created by modified Feeney's method. Seventy-five healthy male SD rats were randomly divided into three groups: trauma group, control group and treatment group. There were five rats at each time point in each group. The rats were sacrificed at 3 h, 12 h, 24 h, 48 h and 72 h after injury. The immunohistochemical method was used to detect the positive expression of OX-42 in local injured brain tissues.Results The morphologic and quantitative changes of the activated microglias differed at the different time courses after brain injury. In normal rats, the microglias kept in a quiescent condition, OX-42 staining was negative or weak. At 3 h after injury, the microglias presented light response, OX-42 staining was weak, and OX-42-positive cells were found but their features were unclear. At 12 h after injury, the response of microglias was obvious and OX-42 staining kept strong. At 24 h after injury, the response of microglias reached peak and OX-42 staining became intense. At 48 h and 72 h after injury, the response of microglias decreased, and OX-42 staining became weak again. The quantity of activated microglias decreased significantly in treatment group than that in control group (P<0.05), there was no significant difference between the trauma group and the control group (P>0.05).Conclusion The morphologic and quantitative changes of the activated microglias in rats differ at the different time courses after brain injury. Resveratrol can inhibit the activation of microglias after cerebral trauma and there is a good protective effect of resveratrol on craniocerebral injury.