游泳训练对胰岛素抵抗大鼠白细胞介素6和过氧化物酶体增殖物激活受体γ表达的影响

Effects of swimming training on expressions of interleukin-6 and peroxisome proliferator-activated receptor-γ in rats with insulin resistance

目的观察游泳训练对胰岛素抵抗大鼠白细胞介素6(IL-6)和过氧化物酶体增殖物激活受体γ(PPAR-γ)表达的影响,初步探讨游泳训练改善胰岛素抵抗的作用机制。方法 8周龄正常雄性大鼠30只随机分为:正常饮食对照组(n=9),高脂高糖喂养造模组(n=21)。喂养6周后,将造模成功的18只胰岛素抵抗大鼠再随机分为2组:①模型组(n=9):继续予高脂高糖饮食;②运动组(n=9):高脂高糖喂养加游泳训练。造模6周和干预6周后采血,全自动生化分析仪测空腹血糖,放射免疫法测各组小鼠空腹胰岛素,计算胰岛素敏感指数(ISI)。干预6周后留取肝脏和大网膜脂肪组织,逆转录聚合酶链反应(RT-PCR)法检测IL-6、PPAR-γmRNA表达。免疫组化法测肝脏组织PPAR-γ蛋白表达。HE染色观察肝脏组织病理学变化。结果高脂高糖饲养6周后,造模组的空腹血糖、空腹胰岛素均高于对照组,其ISI低于对照组(ISI:-5.24±0.34比-4.11±0.33,P<0.01)。6周干预后,与模型组比较,运动组脂肪和肝脏组织IL-6mRNA表达降低(均P<0.05),ISI升高(lnISI:-5.10±0.31比-5.51±0.16,P<0.05),PPAR-γmRNA表达增加(P<0.05);免疫组化法中模型组肝脏组织PPAR-γ蛋白表达高于对照组,低于运动组(均P<0.05)。结论游泳训练可以明显改善胰岛素抵抗。可能与上调PPAR-γ、下调IL-6的表达有关。

Objective To investigate the effects and the mechanisms of swimming training on the expressions of interleukin-6 （IL-6） and peroxisome proliferator-activated receptor-γ（PPAR-γ） in rats with insulin resistance （IR）.Methods Thirty male Sprague-Dawley rats were randomly divided into normal diet group （control group, n= 9） and high-fat/high sucrose diet group （n= 21）. After six weeks of feeding, eighteen insulin resistance rat models induced by diet were randomly subdivided into the model group （feeding with high-fat/high-sucrose diet, n= 9） and the exercise group （feeding with high-fat/high-sucrose diet combined with swimming training, n= 9）. After six weeks of high fat diet and swimming interventions, the fasting plasma glucose （FPG） and the fasting insulin （FINS} of these rats were measured by automatic biochemical analysis instrument and radioimmunoassay, respectively. Insulin sensitive index （ISI） was calculated to ascertain the establishment of insulin resistance. The PPAR-γ and IL-6 mRNA expressions in liver and omental adipose tissues were estimated by reverse transcription polymerase chain reaction （RT-PCR） after six weeks of intervention. The protein expression of PPAR-γ was measured by immunohis- tochemistry. Liver histopathological changes were observed by HE staining method. Results After six week feeding with the high fat/high-sucrose diet, compared with the control group, the serum levels of FPG and FINS in high-fat/high-sucrose diet group were significantly hiher, but the LnISI level was significantly lower （ISI： -5.24±0.34 vs --4. 11±0.33, P〈0.01）. After six week intervention, compared with the model group, the expressions of IL-6 mRNA in adipose and liver tissues of the exercise group were significantly decreased （all P〈0.05）, while the ISI value （-5.10±0. 31 vs -5.51 ± 0.16, P〈0. 05） and the PPAR-γ mRNA expression were significantly increased. Immunohistochemistry method showed that the protein expression of PPAR-γ in the model group was higher than that in the control group, but was lower than that in the exercise group （all P〈0.05）. Conclusion Swim ming training can evidently improve insulin resistance, which may be related to the increase of PPAR 7 expression and the decrease of IL-6 level.