肥胖对非致死性肺炎小鼠血液生理指标、4种细胞因子和免疫器官指数的影响

Effects of obesity on blood physiological parameters,four cytokines and immune organs index in response to nonfatal pneumonia in mice

为探讨肥胖对非致死性肺炎全身性免疫反应的影响,将高脂诱导的肥胖小鼠分为Ⅰ、Ⅱ组,非肥胖小鼠分为Ⅲ、Ⅳ组,Ⅰ、Ⅲ组滴鼻40μL含4×10^9cfu大肠埃希菌菌液,Ⅱ、Ⅳ组滴鼻40μL生理盐水,于感染后2、6、12、24、48、72、96 h检测各组小鼠免疫器官指数、血液生理指标、血清细胞因子。结果显示,高脂饲喂8周,Ⅱ组体质量,血液WBC、GRA、MID数量,血清TNF-α、IL-6、IL-10、抵抗素浓度均显著高于Ⅳ组,脾质量及指数、胸腺质量及指数显著低于Ⅳ组（P〈0.05）。感染后,Ⅰ组脾指数2-72 h显著高于Ⅱ组,2、6、48、72、96 h显著高于Ⅲ组（P〈0.05）,胸腺指数6、12 h显著低于Ⅱ组,72、96 h显著低于Ⅲ组（P〈0.05）。Ⅰ、Ⅲ组血液WBC、GRA、MID在感染后先升高后降低最后恢复至对照组水平,24 h时显著低于对照组（P〈0.05）。试验期间Ⅰ组WBC、GRA、MID均显著高于Ⅲ组（P〈0.05）。感染后,Ⅰ、Ⅲ组血清TNF-α、IL-6、IL-10和抵抗素浓度于2 h显著升高（P〈0.05）,除Ⅲ组抵抗素外,均维持高浓度至48 h,Ⅰ组4种细胞因子2 h和6 h显著高于Ⅲ组,96 h显著低于Ⅲ组（P〈0.05）。表明高脂饮食诱导的肥胖对全身性炎症反应的敏感性提高,增强了免疫反应。

To investigate the impact of obesity on systemic immune responses of nonfatal pneumonia,high-fat induced obese mice were divided into group Ⅰ,Ⅱ,and the mice fed with standard diet were divided into group Ⅲ,Ⅳ. Group Ⅰ,Ⅲ were infused intranasally by 40 μL bacteria solution containing 4 × 109 cfu Escherichia coli（ E. coli）,and group Ⅱ,Ⅳ were given the same dose of saline. The blood physiological parameters,cytokines in serum and indexes of immune organs of all groups were detected at 2,6,12,24,48,72 and 96 h post-infection. As a result,fed with high-fat diet for 8 weeks,the mice had greater WBC,GRA,MID counts,higher concentrations of TNF-α,IL-6,IL-10 and resistin,and lower indexes of spleen and thymus. After infection,indexes of spleen ingroup Ⅰ were higher than those in group Ⅱ during 2 to 72 h,and in group Ⅲ at 2,6,48,72 and 96. Indexes of thymus in groups Ⅰ were lower than those in group Ⅱ at 6,12 h and in group Ⅲ at 72,96 h post-infection. During infection,WBC,GRA,MID counts increased firstly,then decreased,finally decreased to the controls in group Ⅰ,Ⅲ,and were both lower than those in control groups at 24 h post-infection. In the experimental period,WBC,GRA,MID counts in group Ⅰ were higher than those in group Ⅲ. The concentrations of TNF-α,IL-6,IL-10 and resistin elevated at 2 h post-infection,and maintained high concentrations to 48 h post-infection except resistin in group Ⅲ. The four cytokines in group Ⅰ were higher than those in group Ⅲ at 2,6 h,and lower at 96 h post-infection. The results revealed that experimental mice presented systemic inflammatory responses during nonfatal pneumonia,and obesity enhanced the immune responses to inflammation to promote the abreaction of inflammation.