激素对新生鼠高氧肺损伤及血清前列腺素E2、白三烯B4的影响

摘要

Objective To investigate the effect of antenatal and postnatal eorticosteroid therapy on hyperoxiainduced lung injury and the serum levels of prostaglandin E2 (PCE2) and leukotriene R4 (lLl?B4) in neonatal rats.Methods The Sprague-Dawley neonatal rats were exposed to high-eoneentration oxygen environment ( ≥ 90％) to induce byperoxic lung injury. Rats were divided into 4 groups consisting of the hyperoxia with antenatal corticosteroid therapy group, the hyperoxia with postnatal cortieosteroid therapy group, the hyperoxia control group and the air control group (n= 14 per group). Rats were sacrificed for the observation of the survival rate, weight, lung index,radical alveolar counts (RAC), pathological changes, apoptosis index (AI), and the serum levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) after a 14-day exposure to either byperoxia or air. Results Compared with the air control group, there were the lower survival rate and weight (P ＜ 0.05 or ＜ 0.01) , and higher lung index (P ＜0.05) in three byperoxia groups, but no statistical significance was found among three byperoxia groups. The pathological changes of lungs were obvious among byperoxia groups. The RAC in the air control group was higher than Ihose in three hyperoxia groups (P ＜ 0.05) , and in the hyperoxia with either prenatal or poslnatal corticosteroid therapy groups was higher than that in the hyperoxia control group (P ＜ 0.05) , but no statistical difference was observed between the antenatal and the postnatal eorticosteroid therapy groups. There were a few apoptotic cells in lungtissue in the air control group qith a lower AI compared with those in other three groups (P ＜ 0.05 for all). AI in the hyperoxia control group was higher than those in two hyperoxia with eortieosteroid therapy groups (P ＜ 0.05) , and no significant difference was shown between two groups with either antenatal or postnatal cortieosteroid therapy. The levels of PGE2 and LTB4 in the air control group were the lowest among all four groups (P ＜ 0.05 for all). There were not statistical difference in the level of PGE2 among three hyperoxia groups, and the levels of LTB4 in the hyperoxia with corticosteroid therapy groups were significantly lower than that in the hyperoxia control group (P ＜ 0.05), but the level of LTB4 was not shown significant difference between two groups with corticosteroid therapy. Conclusions Either antenatal or postnatal corticosteroid therapy can reduce lung injury, increase RAC, and decrease the apoptosis of lung cells in neonatal rals with hyperoxia-induced lung injury. This effect may probably relate to LTB4, PGE2 and other inflammatory factors.%目的 研究产前与产后激素应用对新生鼠高氧肺损伤及血清前列腺素E2、白三烯B4的影响.方法 将新生鼠分为产前激素 + 高氧组、生后激素 + 高氧组、高氧对照组与空气对照组,每组14只,分别置高氧或空气中14 d.观察指标包括新生鼠病死率、体质量、肺系数、辐射状肺泡计数(RAC)、组织病理变化.原位末端标记法(TUNEL)检测肺泡细胞凋亡指数(AI),酶联免疫吸附法(ELISA)测定血清中PGE2、LTB4值.结果 三组置高氧中新生鼠存活率与体质量均明显低于空气对照组(P均＜ 0.05),肺系数则明显高于空气对照组(P ＜ 0.05),但三组间比较差异无统计学意义(P ＞ 0.05).置高氧中三组新生鼠肺组织病理变化明显.空气对照组的RAC最高,两组激素组RAC高于高氧对照组(P ＜ 0.05),而使用激素的两组间差异无统计学意义(P ＞ 0.05).空气对照组肺组织中可见少数凋亡细胞,AI低于其余各组(P ＜ 0.05).高氧对照组AI高于激素组(P ＜ 0.05),激素组间两组比较差异无统计学意义(P ＞ 0.05).四组中空气对照组的PGE2最低(P ＜ 0.05),高氧三组间比较差异无统计学意义(P ＞ 0.05).空气对照组LTB4也最低(P ＜ 0.05),与高氧对照组相比,使用激素的两组LTB4明显降低(P ＜ 0.05),但此两组间比较差异无统计学意义(P ＞ 0.05).结论 产前与产后激素应用均可减轻新生鼠高氧肺损伤程度,增加辐射状肺泡计数,减少细胞凋亡,并可能与LTB4、PGE2等炎性因子有关.而产前与产后激素应用对比无差异.