CAJ | 학술논문

目的：观察咖啡对胰岛素抵抗大鼠脂肪组织胰岛素受体底物（ IRS）-1、IRS-2及其酪氨酸、丝氨酸磷酸化的影响，评估咖啡对脂肪组织胰岛素受体后信号转导途径影响。方法 Wistar大鼠40只随机分为正常NC、CC、DC、IR组，每组10只。 NC组予正常饮食，CC组、DC组及IR组给予高脂饮食，CC组及DC组每日分别以含咖啡因咖啡和去咖啡因咖啡灌胃。12周后行口服葡萄糖耐量试验（ OGTT）；根据空腹血清胰岛素和空腹血糖水平及HO-MA-胰岛素抵抗指数（ HOMA-IR）反映外周组织胰岛素敏感性；RT-PCR检测大鼠脂肪组织IRS-1、IRS-2 mRNA及蛋白表达；Western blot测定脂肪组织IRS-1酪氨酸磷酸化和丝氨酸磷酸化程度。结果 OGTT显示IR组60和120 min血糖高于NC组（ P分别＜0．05、0．01）。 IR组、CC 组及DC组空腹血清胰岛素水平均高于NC 组（ P均＜0．05）。 IR组HOMA-IR高于NC组、CC组和DC组（P均＜0．05）。 NC组、CC组脂肪组织IRS-1 mRNA相对表达量均高于IR组（P均＜0．01），IRS-2 mRNA表达各组无显著差异（P均＞0．05）。各组大鼠脂肪组织IRS-1、IRS-2蛋白含量无明显差异（ P均＞0．05）。 NC组、CC 组、DC组脂肪组织IRS-1酪氨酸磷酸化水平高于IR组（ P均＜0．05），丝氨酸磷酸化水平低于IR组（P均＜0．05）。结论咖啡灌胃可改善高脂饮食大鼠胰岛素抵抗，其机制可能通过改变脂肪组织IRS-1转录及其酪氨酸/丝氨酸磷酸化水平，影响胰岛素抵抗大鼠胰岛素受体后信号转导。
목적：관찰가배대이도소저항대서지방조직이도소수체저물（ IRS）-1、IRS-2급기락안산、사안산린산화적영향，평고가배대지방조직이도소수체후신호전도도경영향。방법 Wistar대서40지수궤분위정상NC、CC、DC、IR조，매조10지。 NC조여정상음식，CC조、DC조급IR조급여고지음식，CC조급DC조매일분별이함가배인가배화거가배인가배관위。12주후행구복포도당내량시험（ OGTT）；근거공복혈청이도소화공복혈당수평급HO-MA-이도소저항지수（ HOMA-IR）반영외주조직이도소민감성；RT-PCR검측대서지방조직IRS-1、IRS-2 mRNA급단백표체；Western blot측정지방조직IRS-1락안산린산화화사안산린산화정도。결과 OGTT현시IR조60화120 min혈당고우NC조（ P분별＜0．05、0．01）。 IR조、CC 조급DC조공복혈청이도소수평균고우NC 조（ P균＜0．05）。 IR조HOMA-IR고우NC조、CC조화DC조（P균＜0．05）。 NC조、CC조지방조직IRS-1 mRNA상대표체량균고우IR조（P균＜0．01），IRS-2 mRNA표체각조무현저차이（P균＞0．05）。각조대서지방조직IRS-1、IRS-2단백함량무명현차이（ P균＞0．05）。 NC조、CC 조、DC조지방조직IRS-1락안산린산화수평고우IR조（ P균＜0．05），사안산린산화수평저우IR조（P균＜0．05）。결론가배관위가개선고지음식대서이도소저항，기궤제가능통과개변지방조직IRS-1전록급기락안산/사안산린산화수평，영향이도소저항대서이도소수체후신호전도。
Objective To observe the effect of coffee on the expression of insulin receptor substance ( IRS)-1 and IRS-2 and their tyrosine/serine phosphorylation in rats with insulin resistance ( IR) and to evaluate its effect on the post-re-ceptor signal transduction in adipose tissues .Methods Totally 40 Wistar rats were randomly divided into the normal con-trol ( NC) group, caffeinated coffee lavage ( CC) group, decaffeinated coffee lavage ( DC) group, and IR ( IR) group, with 10 rats in each group .Except for NC group , the other three groups were given high fat diet .Meanwhile , CC and DC groups, respectively, were treated with caffeinated coffee and decaffeinated coffee daily lavage for 12 weeks.Then the oral glucose tolerance test (OGTT) was given and homeostasis model assessment of insulin resistance (HOMA-IR) was em-ployed to assess the degree of insulin resistance .The levels of IRS-1 and IRS-2 and their mRNA in adipose tissues were de-tected by RT-PCR.And the tyrosine/serine phosphorylation was measured by Western blotting .Results IR group had higher blood glucose levels at the time of 60 and 120 min as compared with NC group (P<0.05, P<0.01, respectively). CC, DC, and IR groups displayed higher fasting insulin levels than NC group (all P<0.05).However, HOMA-IRs of CC, DC, and NC groups were all significantly lower than that of IR group (all P<0.05).Although no significant differ-ences were found in the levels of IRS-1 and IRS-2 as well as IRS-2 mRNA among the four groups (P>0.05), IRS-1 mR-NA of the NC and CC groups was higher than that of the IR group (all P<0.01).Higher tyrosine phosphorylation and low-er serine phosphorylation were exhibited in NC , CC, and DC groups as compared with the IR group (all P<0.05).Con-clusions Insulin resistance induced by high fat diet could be alleviated by coffee , whose mechanism may be explained by its effect on post-receptor signal transduction in adipose tissues by the alteration of IRS-1 mRNA as well as its tyrosine/ser-ine phosphorylation .