高脂饮食诱导的胰岛素抵抗大鼠内脂素的表达水平

目的:研究高脂饮食诱导的胰岛素抵抗(IR)对大鼠脂肪内脏脂肪素(visfatin)表达水平的影响。方法:将24只雄性SD大鼠随机分为正常对照组和高脂饮食组。适应性饲养后,测定空腹血糖(FBG)和空腹血清胰岛素(FINS),分别喂以正常饲料和高脂饲料。12周后,检测两组大鼠体重、FBG和FINS,用HOMA模型评价胰岛素抵抗指数,处死,分离附睾、肠系膜、折返腹膜脂肪以及肾脏脂肪垫,称重,计为内脏脂肪重量。利用逆转录-多聚酶链反应(RT-PCR)分别检测两组大鼠内脏脂肪中visfatin表达的差异,并分析HOMA-IR值、内脏脂肪量分别与visfa-tin/β-actin光密度比值之间的相关关系。结果:高脂饮食成功诱导了胰岛素抵抗,高脂喂养组大鼠的内脏脂肪明显增多,其FBG轻度升高(P>0.05)、FINS明显升高、HOMA-IR明显升高(P<0.05)。高脂饮食组大鼠的内脏脂肪中visfatin表达显著高于对照组(P<0.05)。HOMA-IR值、内脏脂肪量分别与visfatin/β-actin光密度比值呈正相关(均为P<0.01)。结论:高脂饮食诱导的胰岛素抵抗大鼠内脏脂肪组织中visfatin mRNA表达明显增加,且其表达与HOMA-IR和内脏脂肪量之间呈正相关,提示visfatin在胰岛素抵抗的发生和发展过程中起有一定的作用。

Relationship Between the Expression of Visfatin in Visceral Fat Tissue and Insulin Resistance Induced by High Fat Diet in Rats

Objective: To explore the effect of the high fat diet(HFD) induced insulin resistance(IR) on the expression of visfatin in the visceral fat tissue of SD rats.Methods: Twenty-four SD rats were randomly divided into HFD and control group equally.After one week's adaptive feeding,fasting blood glucose(FBG) and plasma insulin(pINS) were measured,then rats in control group were fed with regular diet and rats in HFD group were fed with self-made HFD to induce IR models.Both groups were fed 12 weeks before the measurement of FBG and pINS,meanwhile the HOMA insulin resistance index(HOMA-IR) was also evaluated.Then all the rats were killed and fat of epididymis,mesentery,folded peritoneum and the fat pad of kidney were isolated as visceral fat,which would be weighed as visceral fat mass.Expression level of visfatin mRNA of visceral fat were measured by RT-PCR separately in each group.Results: IR was successfully induced by HFD;rats in high fat diet group had a great increase in visceral fat mass(P<0.01) and displayed obvious visceral obesity.Their FBG increased slightly(P>0.05),while pINS and HOMA-IR increased significantly(both P<0.01),which showed that the rats with HFD had developed obvious IR.Compared with control group,the visfatin expression of visceral fat tissue in HFD group were significantly higher(P<0.05).HOMA-IR and visceral fat mass had a positive correlation with visfatin/β-actin respectively.Conclusion: Rats with IR that induced by HFD have significantly higher levels of visfatin mRNA in the visceral fat tissues,and visfatin mRNA expression levels have a positive correlation with HOMA-IR and visceral fat mass,which suggests the possible role visfatin performed in the occurrence and development of IR.