【摘要】 目的研究高脂饮食对大鼠胃促生长素(ghrelin)表达的影响。方法雄性SD大鼠9只喂以基础饲料作为对照组(CF),27只喂以高脂饲料15w产生饮食诱导肥胖大鼠(DIO)14只和饮食诱导肥胖抵抗大鼠(DIO–R)7只,再将DIO大鼠随机分为两组,一组改用基础饲料(DIO–HF/LF),另一组继续用高脂饲料(DIO–HF)喂养至23w,对照组和DIO-R组饲料不变。分别于15w和23w末过夜禁食后,次晨采尾血或断头取血,检测空腹血糖和胰岛素含量,取胃底部组织用RT-PCR、免疫印迹方法检测ghrelin表达水平。结果DIO–HF/LF组体重显著低于DIO–HF组而高于CF组(P<0.05);DIO–R组与CF组体重无显著性差异。DIO–HF组胃ghrelin的表达低于DIO–HF/LF及CF组,与DIO–R组无显著性差异,DIO–HF/LF和CF组间无显著性差异。结论高脂饮食诱导的肥胖大鼠可通过降低胰岛素敏感性来减少ghrelin的表达。肥胖大鼠经过低脂干预后,可改善胰岛素敏感性从而增加胃内ghrelin的表达。高脂饮食诱导的肥胖抵抗大鼠胃内ghrelin表达低于对照组,故认为肥胖抵抗产生的原因之一是ghrelin的低表达限制了能量摄入。更多还原

【Abstract】 Objective: To study the effect of high-fat diet on expression of orexigenic hormone (ghrelin) in stomach of rats. Method: Thirty-six male SD rats were randomly divided into two groups and fed with standard diet (normal control group, CF) and high-fat diet respectively. At the end of 15th week, the high-fat diet fed rats were designated as dietary induced obesity (DIO) and dietary induced obesity resistant (DIO–R) according to their final body weights. Blood samples were collected by caudal vein for measurement of fast blood glucose and blood insulin levels. Then half of the DIO rats were switched to standard diet (DIO– HF/LF), the other DIO rats (DIO–HF), CF and DIO-R rats continued their primary diet. At the end of the experiment by the 23rd week, all rats were killed by decapitation after 10 h fasting, plasma was collected for testing the concentrations of blood glucose and insulin. Stomachs were collected to measure the expression of ghrelin by reverse transcription polymerase chain reaction (RT–PCR) and Western blotting. Results: The final weights of DIO– HF/LF were lower than those of DIO–HF rats whereas higher than those of CF rats, and there were no significant differences between DIO–R and CF groups. The level of ghrelin expression in DIO-HF group was lower than DIO–HF/LF and CF group, and no significant difference was found among those in other two groups. Conclusion: The expression of ghrelin in stomachand the sensibility of insulin were degraded in DIO rats. When DIO rats switched to standard fat diet, the body weight gain could be reduced, and the insulin sensibility improved and the expression of ghrelin increased from low to normal level. DIO–R rats can remain lower expression of ghrelin than CF rats, which might be related to obesity resistance.更多还原