孕酮在脑缺血大鼠TNF-α和IL-6引起脑损伤中的作用

The role of progesterone in brain ischemic damage with ischemia rat caused by TNF-α and IL-6 in rats

目的观察孕酮在炎症因子TNF-α和IL-6引起新生鼠缺氧缺血性脑损伤中的作用,进一步探讨孕酮神经保护作用的分子机制。方法 96只7日龄新生Wistar大鼠随机分成4组,正常对照组、假手术组、缺氧缺血组、药物预防组。缺氧缺血组和药物预防组动物先行左侧颈总动脉结扎术,然后将动物置于37℃恒温的密闭容器中,以1.5L/min的速度吸入80ml/L氧气和920ml/L氮气混合气体2.5h建立缺氧缺血脑病动物模型。药物预防组动物于建立模型前30min按8mg/kg腹腔注射0.5g/L孕酮溶液。采用ELISA法检测脑组织中TNF-α和IL-6含量的变化,RT-PCR检测TNF-α和IL-6 mRNA的表达。结果缺氧缺血组脑组织中炎症因子TNF-α和IL-6含量在缺氧缺血后6h、24h、48h、72h明显高于对照组和假手术组大鼠(P<0.05),且在缺氧后24h升到最高点,以后逐渐下降,至7d两者差异不显著,药物预防组在缺氧缺血后各时间点均低于缺氧缺血组(P<0.05)。且缺氧24h后缺氧缺血组脑组织TNF-α、IL-6 mRNA的表达明显高于正常对照组和假手术组,药物预防组mRNA的表达明显低于缺氧缺血组(P<0.05)。结论孕酮可以保护新生鼠缺氧缺血后引起的脑损伤,其作用机制与抑制炎症因子TNF-α和IL-6 mRNA的表达以及抑制TNF-α和IL-6的生成有关。

Objective To study the role of progesterone in brain damage with ischemia rat caused by TNF-α and IL- 6, and discuss the protective molecular mechanism of progesterone. Methods 96 7-day-old neonatal rats were randomly divided into four groups：normal group, sham-operated group, hypoxic-ischemie group and pretreatment groups. Rats in bypoxic-ischemic group and pretreatment groups were subjected to left common carotid artery ligation, then were exposed to 80ml/L oxygen and 920ml/L nitrogen gas in 37℃ closed container for up to 2.5h to establish HIE model. Progesterone was injected intraperitoneally into the rats of pretreatment groups rats at 30 minutes before hypoxia,The contents of TNF-α,IL-6was measured by ELISA and the expression of TNF-α,IL-6 mRNA was analyzed by RT-PCR. Results The contents of TNF-α and IL-6 in brain tissue in hypoxic-ischemic group were significantly higher than those in normal group and shamoperated group at 6h,24h,48h,72h after hypoxia respectively（ P 〈 0.05 ）, and riseds to the highest point at 24h, then gradually reduced ,dropped to normal level at 7d. The contents of TNF-α and IL-6 were significantly lower in pretreatment group than that in the hypoxic-ischemic group. And the expression of TNF-α,IL-6 in hypoxic-ischemic group were significantly higher than that in the normal and sham-operated groups at 24h after hypoxia. In pretreatment groups, The expression of TNF-α,IL-6 were significantly lower than that in hypoxic-ischemic group （P 〈 0.05 ）. Conclusion Progesterone exerts neuroprotective effect on hypoxic-ischemic encephalopathy-induced brain damage, the action mechanism was related with down-regulate the expression of TNF-α,IL-6, caused lessitter production of TNF-α and,IL-6 produced.