甲烷饱和生理盐水对内毒素导致急性肺损伤模型大鼠的保护作用

Protective effects of methane saturated saline on endotoxin-induced acute lung injury in rats

背景:研究表明甲烷在肠道、肝脏、心肌等多种缺血再灌注损伤疾病中具有显著的抗氧化和抗凋亡作用。甲烷对急性肺损伤的保护作用未见相关研究。目的:分析甲烷饱和生理盐水对由于内毒素导致的大鼠急性肺损伤的保护作用及其可能的机制。方法:内毒素(20 mg/kg)诱导大鼠急性肺损伤。实验分为空白组,对照组(甲烷饱和生理盐水),急性肺损伤组,急性肺损伤组+甲烷组(急性肺损伤甲烷饱和生理盐水治疗)。24 h后取材测定肺组织湿干质量比,苏木精-伊红染色及电镜组织学检查,ELISA法检测肺泡灌洗液中肿瘤坏死因子α、白细胞介素6、白细胞介素1β炎症因子的质量浓度,并检测肺组织丙二醛和超氧化物歧化酶活性;TUNEL检测肺组织中细胞凋亡情况;Western blot法检测肺组织中caspase-3含量。结果与结论:①空白组和对照组在各项指标上均无显著差异;②与空白组相比,急性肺损伤和急性肺损伤+甲烷组肺组织湿干质量比显著增加(P <0.05),肺组织的炎症反应强度、氧化应激水平和凋亡率均显著增高(P<0.05);③与急性肺损伤组相比,急性肺损伤+甲烷组肺组织湿干质量比,炎症因子、细胞凋亡率、caspase-3表达及丙二醛含量均有显著降低(P <0.05),超氧化物歧化酶活性提高(P <0.05);④结果说明,甲烷饱和生理盐水可以通过降低肺组织氧化应激水平,抑制炎症因子表达,减少细胞凋亡等途径治疗由于内毒素导致的大鼠急性肺损伤。

BACKGROUND:Methane has been shown to have significant antioxidant and anti-apoptotic effects in many diseases,such as intestine,liver,myocardium and other ischemia/reperfusion injury.The protective effect of methane on acute lung injury(ALI)has not been studied.OBJECTIVE:To investigate the protective effect of methane saturated saline on ALI induced by endotoxin in rats and its possible mechanism.METHODS:ALI in rats was induced by endotoxin(20 mg/kg).The experiment was divided into blank,control(methane saturated saline),ALI,ALI and methane(ALI treated by methane saturated saline)groups.After 24 hours,the wet/dry weight ratio of lung tissue was detected.Hematoxylin-eosin staining and electron microscopy were conducted.The contents of tumor necrosis factorα,interleukin 6,and interleukin 1βin alveolar lavage,and activity of malondialdehyde and superoxide dismutase in lung tissue were determined by ELISA.Cell apoptosis was measured by TUNEL.The content of caspase-3 in lung tissue was detected by western blot assay.RESULTS AND CONCLUSION:There was no significant difference in each index between blank and control groups.Compared with the blank group,the wet/dry weight ratio,inflammatory reaction in lung tissue,oxidative stress and apoptotic rate were significantly increased in the ALI and ALI and methane groups(P<0.05).Compared with the ALI group,the wet/dry weight ratio,inflammatory cytokines,apoptotic rate,caspase-3 expression and malondialdehyde content were significantly decreased,and superoxide dismutase activity was significantly increased in the ALI and methane group(P<0.05).In summary,methane saturated saline can treat ACI caused by endotoxin by reducing the level of oxidative stress in lung tissue,inhibiting the expression of inflammatory factors and reducing apoptosis.