丙酸睾酮对HIBD新生大鼠海马、皮层GFAP表达的影响及其意义

Effect of testosterone propionate on the expressions of GFAP in hippocampus and cortex of neonatal rats with HIBD and the significance

目的:观察新生大鼠缺氧缺血性脑损伤(HIBD)后不同时间点皮层与海马胶质原纤维酸性蛋白(gial fibrillaryacidic protein,GFAP)表达情况,以及不同剂量丙酸睾酮(T)预处理后对其表达的影响,揭示丙酸睾酮对HIBD新生大鼠脑保护作用及其时间、量效关系。方法:200只3日龄SD大鼠随机分为3组,T预处理组80只、HIBD对照组80只和假手术组40只;T组和HIBD对照组再各自分为30 mg/kg组、120 mg/kg组。T组中每剂量组每只大鼠均给丙酸睾酮,HIBD对照组中每剂量组每只大鼠均给相应ml数花生油,方法同T组。7日龄时T组和HIBD对照组制作HIBD模型,对比观察HI后不同组别及各剂量组在24、48、72 h、7天和14天海马和大脑皮层GFAP表达的动态变化。结果:HIBD对照组脑组织30、120 mg/kg组GFAP的平均光密度数值均显著高于相同时间点的假手术组,其差异具有统计学意义(P<0.01)。T干预后,海马、皮层30、120 mg/kg两个剂量组GFAP的平均光密度较HIBD对照组各相同剂量组在相同时点GFAP平均光密度量显著减少,且差异有统计学意义(P<0.01)。HIBD对照组以及T组内的两个剂量组之间比较,在海马、皮层相同时间点GFAP的表达量的差异无统计学意义(P>0.05)。结论:新生大鼠HIBD后,脑组织GFAP的表达增加。T干预可抑制脑组织因HIBD所致的GFAP的过度表达,有抑制脑损伤区星形胶质细胞的过度增殖分裂,减少胶质瘢痕形成对神经轴突修复的不利影响的脑保护作用。

Objective：To observe the expressions of glial fibrillary acidic protein（GFAP） in cortex and hippocampus of neonatal rats with hypoxic-ischemic brain damage（HIBD） at different time points and the effects of pretreatment with testosterone propionate of different doses on the expressions,reveal the protective effect of testosterone propionate for brain of neonatal rats with HIBD and the time-response relationship and dose-effect relationship.Methods：200 3-day-old SD rats were randomly divided into testosterone propionate pretreatment group（n=80）,HIBD control group（n=80） and sham operation group（n=40）;then the rats in testosterone propionate pretreatment group and HIBD control group were divided into 30mg/kg subgroup and 120mg/kg subgroup,respectively.Every rat in testosterone propionate pretreatment group was treated with testosterone propionate,and every rat in HIBD control group was treated with testosterone propionate of the same dose.7-day-old rats in testosterone propionate pretreatment group and HIBD control group were used to establish HIBD model,the dynamic changes of GFAP expressions in hippocampus and cortex of the rats at 24 hours,48 hours,72 hours,7 days and 14 days were compared and observed in different groups.Results：The average optical density values of GFAP in 30mg/kg subgroup and 120mg/kg subgroup of HIBD control group were significantly higher than those in 30mg/kg subgroup and 120mg/kg subgroup of sham operation group（P0.01）.The average optical density values of GFAP in 30mg/kg subgroup and 120mg/kg subgroup of testosterone propionate pretreatment group were significantly lower than those in 30mg/kg subgroup and 120mg/kg subgroup of HIBD control group（P0.01）.In HIBD control group and testosterone propionate pretreatment group,there was no significant difference in the expression level of GFAP in hippocampus and cortex between 30mg/kg subgroup and 120mg/kg subgroup（P0.05）.Conclusion：The expression of GFAP increases in brain tissue of neonatal rats with HIBD.Testosterone propionate pretreatment can inhibit GFAP overexpression induced by HIBD in brain tissue,which plays a protective role on the brain tissue of neonates rats with HIBD by inhibiting the excessive muitiplefission of astrocytes in brain damaged areas and reducing the adverse effect of glial scar formation on the recovery of nerve axon.