N-乙酰半胱氨酸对胰岛素抵抗大鼠肺损伤的作用

EFFECT OF N-ACETYLCYSTEINE ON RATS WITH LUNG INJURY INDUCED BY INSULIN RESISTANCE

目的观察N-乙酰半胱氨酸(NAC)对高脂饮食诱导胰岛素抵抗大鼠肺损伤的作用。方法选取40只健康雄性SD大鼠,随机分为对照组(NC组,n=10,普通饲料喂养)和高脂组(HF组,n=30,高脂饲料喂养),HF组喂养12周确定建模成功后再随机分为高脂对照组(HFN组,n=15)和高脂+NAC组(HF+NAC组,n=15),其中HF+NAC组在喂饲高脂饲料同时予以NAC 300mg/(kg·d)灌胃处理,NC组和HFN组给予相同体积的生理盐水灌胃。灌胃4周后,采集大鼠静脉血测定空腹血糖、胰岛素、血脂水平,并检测肺组织中丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性,采用免疫组化技术检测肺组织中白细胞介素6(IL-6)的表达。结果与NC组相比,HFN组大鼠胰岛素敏感性下降,糖耐量减低;HF+NAC组和NC组与HFN组相比,肺组织中MDA含量减低,但差异无统计学意义(P>0.05)。HF+NAC组肺组织中SOD活性较HFN组升高(F=3.491,P<0.05),IL-6的表达较HFN组明显降低(F=5.924,P<0.05)。结论 NAC对减轻高脂饮食诱导的胰岛素抵抗大鼠肺损伤有明显作用,其机制可能与减轻氧化应激及炎症反应有关。

Objective To investigate the protective effect of N-acetylcysteine（NAC）on lung injury in rats with high-fatdiet-induced insulin resistance. Methods Forty healthy male rats were selected and randomized to control group（NC group,n=10）and high-fat-fed group（HF group,n=30）.The rats in the control group were fed with normal diet,and those in the high-fat diet group were fed with high-fat diet.When the models were successfully created,they were then divided into high fat control group（HFN group,n=15）,and high fat＋NAC group（HF＋NAC group,n=15）.Of which,the rats in HF＋NAC group were given NAC 300mg/（kg·d）by lavage with high-fat diet simultaneously.The rats in NC group and HFN group were given normal saline of the same volume with the same method.Four weeks after lavage,blood samples were extracted from angula vein to detect fasting blood glucose（FBG）,insulin and blood lipid levels,and the concentration of MDA and activity of SOD in the lung were measured as well.The expression of IL-6in lung was detected using immunohistochemistry. Results Compare with NC,insulin sensitivity and glucose tolerance of rats in HFN decreased.Compared with HFN group,the concentration of MDA in HF＋NAC group and NC group decreased,but the difference was not significant（P〉0.05）.The activity of SOD in HF＋NAC group was higher versus HFN group（F=3.491,P〈0.05）,and the expression of IL-6in lung tissue was much lower（F=5.924,P〈0.05）.Conclusion N-acetylcysteine plays a notable protection on lung injury in high-fat-diet rats due to insulin resistance,the mechanism is probably related to reducing oxidative stress and inflammatory response.