不同配比高n-3/n-6多不饱和脂肪酸对大鼠胰岛素抵抗的影响

目的探讨长期摄入高脂不同n-3/n-6多不饱和脂肪酸(PUFAs)构成比的饮食后,大鼠胰岛素敏感性及血清炎症因子表达水平的变化。方法 40只刚断乳雄性SD大鼠适应性喂养7天后,根据体重随机分为4组:空白对照组(基础饲料)、高脂组(猪油)、高脂1∶1组(n-3/n-6为1∶1)和高脂1∶4组(n-3/n-6为1∶4),每组10只。每周记录一次大鼠体重,喂养16周处死动物,检测大鼠血脂、血清胰岛素敏感性和血清炎症因子(IL-6、TNF-α和hs-CRP)表达水平。结果与空白对照组相比,其他3个组体重显著上升(P<0.05);高脂1∶1组胰岛素敏感性与空白对照组比较,差异无显著性,且显著高于高脂组和高脂1∶4组(P<0.05);与高脂组相比,高脂1∶1组血清TNF-α和hs-CRP表达水平显著下降(P<0.05)。结论长期摄取高多不饱和脂肪酸同样具有肥胖风险,提高n-3PUFAs在膳食构成中的比重可以有效抑制炎症因子表达,改善胰岛素敏感性,预防胰岛素抵抗的发生。

Effects of dietary different ratios of high n-3/n-6 polyunsaturated fatty acids on insulin resistance in rats

Objective To study the effects of dietary different ratios of high-fat n-3/n-6 polyunsaturated fatty acids(PUFAs) on insulin sensitivity and pro-inflammatory cytokines expression in serum of rats.Methods 40 young male SD rats(n=10) after adaptive feeding 7d were randomly divided into 4 groups,fed by common diet,high fat diet,high fat with n-3/n-6 1∶1 PUFAs diet,and high fat with n-3/n-6 1∶4 PUFAs diet.The animals were weighted weekly and sacrificed at 16 weeks,then blood lipids,serum insulin sensitivity and pro-inflammatory cytokines(IL-6,TNF-α and hs-CRP) were determined.Results Compared with normal control group,three high fat groups result in a significant increase of body weight gain.Insulin sensitivity of high fat 1∶1 group had no significant difference with normal control,but is significantly higher than high-fat and high-fat 1∶4 group(P<0.05).Compared with high fat group,pro-inflammatory cytokines expression of high fat 1∶1group decreased significantly(P<0.05).Conclusion High dietary polyunsaturated fatty acids appears associated with a trend towards obesity risk,however,increase of the proportion of n-3 PUFAs dietary composition effectively decreased the expression of pro-inflammatory cytokines,then,improved insulin sensitivity and prevented insulin resistance.