胰岛素抵抗小鼠脂肪组织肿瘤坏死因子α和脂联素mRNA表达与有氧运动的影响

背景:有研究表明有氧运动可通过调节脂肪组织过氧化物酶体激活物增殖受体γ及其相关脂肪因子进而影响胰岛素敏感性,但其影响结果及作用机制至今少有报道。目的:观察有氧运动后,胰岛素抵抗C57BL/6小鼠脂肪组织过氧化物酶体激活物增殖受体γ、肿瘤坏死因子α和脂联素mRNA及蛋白表达水平的变化,分析有氧运动对胰岛素抵抗小鼠影响的作用机制。方法:C57BL/6小鼠经高脂饮食喂养10周后建立胰岛素抵抗动物模型,建模后将小鼠随机分为安静组与运动组。运动组进行为期6周,75%VO2max强度跑台运动;安静组同等条件下饲养不运动。使用RT-PCR和Western blot法检测两组脂肪组织过氧化物酶体激活物增殖受体γ,脂联素、肿瘤坏死因子αmRNA和蛋白表达。结果与结论:6周有氧跑台运动对小鼠脂肪组织过氧化物酶体激活物增殖受体γ表达差异无显著性意义(P>0.05),但可显著增加小鼠脂肪组织脂联素的表达(P<0.01),降低肿瘤坏死因子α的表达(P<0.05);并且可显著降低血液中三酰甘油、游离脂肪酸水平(P<0.05,P<0.01)。结果提示有氧运动可能通过调节过氧化物酶体激活物增殖受体γ相关脂肪因子-脂联素和肿瘤坏死因子α的表达来间接调节脂肪组织对胰岛素的敏感性。有氧运动可以显著增加机体组织对胰岛素的敏感性,从而改善C57BL/6小鼠胰岛素抵抗的症状。

Effects of aerobic exercise on expression of tumor necrosis factor alpha and adiponectin in adipose tissues of insulin resistant mice

BACKGROUND:Research has shown that aerobic exercise can affect insulin sensitivity through regulate the expression of peroxisome proliferators activated receptor γ (PPARγ) and related adipokines.But its mechanism has few reported.OBJECTIVE:To investigate the possible mechanisms of aerobic exercise improving insulin resistance,study the effect of aerobic exercise on insulin resistant mice by observing the changes of the mRNA and protein expression of PPARγ,tumor necrosis factor (TNF-α) and adiponectin in adipose tissue of insulin resistance C57BL/6 mice.METHODS:C57BL/6 mice were fed by high fat diet for 10 weeks to establish animal models of insulin resistance.Then the mice were randomly divided into quiet and exercise groups.The exercise group was acclimatized to the motorized treadmill by running 60min per day at the intensity of 75% VO2max,for 6 weeks.The expression of PPARγ,adiponectin,TNF-α mRNA and protein in mouse adipose tissues of two groups were detected by RT-PCR and Western blot.RESULTS AND CONCLUSION:There was no significantly change on the expression of PPARγ mRNA and protein between groups (P>0.05),but exercise could obviously increased adiponectin expression (P<0.01),decreased TNF-α expression (P<0.05),and dramatically decreased serum triacylglycerol and free fatty acid levels (P<0.05,P<0.01).The findings demonstrated that,aerobic exercise indirectly regulates adipose tissue insulin sensitivity by regulating PPAR-γ related adipokines expression.Aerobic exercise could significantly enhance insulin sensitivity and attenuates insulin resistance in C57BL/6 mice.