地塞米松对补体介导的PMN功能损害的保护实验研究

Protective effects of dexamethosone on complementinduced damage of polymorphonuclear neutrophils

目的：研究地塞米松对活化补体介导的ＰＭＮ功能损害的保护作用。方法：用酵母多糖活化人血清（ＺＡＨＳ）作用于人体外ＰＭＮ及小鼠体内ＰＭＮ，选择地塞米松（Ｄｅｘ）起显著保护作用的浓度和时间；进行体内、外保护效能试验。结果：①低剂量Ｄｅｘ（０．０８μｇ／ｍｌ）预处理，对极效量ＺＡＨＳ导致正常人、鼠ＰＭＮ功能损害无明显保护作用；大剂量Ｄｅｘ（１．２～１．６μｇ／ｍｌ）在ＰＭＮ应激后的第５小时前表现出明显保护作用（Ｐ＜０．０５），但此后却使ＰＭＮ细胞死亡、脱落；中等剂量Ｄｅｘ（０．４～０．８μｇ／ｍｌ）能使ＰＭＮ的ＩＣＢＡ、Ｏ－２和ＳＧ三项指标水平均显著高于实验组（Ｐ＜０．０５）；②Ｄｅｘ在小鼠体内保护效能同体外实验基本一致；③Ｄｅｘ的临界保护剂量：０．４μｇ／ｍｌ（体外）或２．５μｇ／２０ｇ鼠（体内），它对ＰＭＮ杀菌力的保护效能分别为２５．０３％（体外）和１９．０５％（体内）。结论：中等量Ｄｅｘ（０．４～０．８μｇ／ｍｌ）对体外ＰＭＮ的预处理，能显著而安全地保护ＺＡＨＳ所激化的ＰＭＮ的胞内杀菌功能。鼠体内的情况基本同体外一致（体内Ｄｅｘ剂量为２．５μｇ／２０ｇ小鼠，ＺＡＭＳ为０．５ｍｌ／２０ｇ小鼠）。

Objective: To investigate the protective effects of dexamethosone on damage of polymorphonuclear neutrophils (PMNs) induced by the activated complement. Methods: The zymosanactivated human serum (ZAHS) was added to monolayer culture of human PMNs and injected into the murine body to determine the optimal protective dose and time of dexamethasone and test its protective efficiency in vivo and in vitro. Results: 1) Pretreatment of low dose of dexamethasone (0.08 μg/ml) could not exert significant protective effects on ZAHSdisturbed PMNS while that of high dose of dexamethasone (1.2～1.6 μg/ml) could within 5 hours after treatment (P<0.05). However, the latter soon caused the death and falling off of PMNs. Pretreatment of middle dose of dexamethasone (0.4～0.8 μg/ml) could preserve ICBA, O-2 and SG to levels significantly higher than those in the experimental group (P<0.05). 2) The protective effects exerted in the murine body were consistent with those in vitro. 3) The critical protective dose of dexamethasone was 0.4 (g/ml in vitro or 2.5 μg/20g in vivo and its protective efficiency to ICBA was 25.03% in vitro or 19.05% in vivo. Conclusion: Pretreatment of PMNs with middle dose of dexamethasone can significantly and safely protect ICBA of PMNs from the disturbance of ZAHS.