胃促生长素与高脂饮食诱导大鼠肥胖的关系

Relationship of ghrelin and obesity induced by high-fat diet in rats

目的探讨胃促生长素在高脂饮食诱导大鼠肥胖中的作用。方法采用40只健康雄性SD大鼠,按体重随机分为高脂实验组和基础对照组,分别给予高脂饲料(30只)和基础饲料(10只)喂养12周。实验结束时,将高脂组大鼠根据体重分为饮食诱导肥胖(DIO)和饮食诱导肥胖抵抗(DIR)大鼠,观察各组大鼠能量摄入、体重增长情况,比较血浆胃促生长素、血糖、胰岛素及血脂水平的差异;逆转录聚合酶链反应(RT-PCR)测定胃壁组织胃促生长素前体信使核糖核酸(mRNA)的表达水平。结果DIO大鼠能量摄入、体重增长显著高于DIR和对照组大鼠(P<0.05),而DIR大鼠与对照组相比差异无显著性(P>0.05);DIO大鼠血浆胃促生长素和胃壁胃促生长素前体mRNA的表达水平均低于DIR大鼠和基础对照组(P<0.01)。结论高脂饮食下胃促生长素表达和释放减少与能量摄入过多和肥胖的发生密切相关。

To explore the effects of expression and secretion of ghrelin on high-fat diet induced obesity in rats. Methods Forty male SD rats were randomly divided into high-fat diet group （ n = 30） and chow fed control group （n = 10）, and given either high-fat diet or chow for twelve weeks. Then the high-fat diet group was subdivided into dietary induced obesity （DIO） and dietary induced obesity resistant （DIR） group according to the final body weight. Fasting plasma ghrelin were determined by RIA. Reverse transcription-polymerase chain reaction （RT-PCR） was used to measure the expression of preproghrelin mRNA in gastric tissue. Results Cumulative caloric intake, body weight in DIO group were significantly higher than those in DIR and control group. Both fasting plasma ghrelin concentration and the preghrelin expression in gastric tissue were significantly lower in DIO group than in DIR and control group. Conclusion Lower expression and secretion of ghrelin were closely associated with high-fat diet induced obesity and their higher caloric intake.