中文摘要：

目的：研究高脂肪膳食诱导的胰岛素抵抗（IR）大鼠胰腺组织中增食欲素（orexin）及其受体的变化规律。方法：IR大鼠模型采用高脂肪膳食诱导并经钳夹技术证实。采用微型血糖仪和化学发光免疫分析法测定全血葡萄糖和血清胰岛素的变化。应用实时定量PCR和Western印迹杂交分析检测胰腺组织中orexin及orexin受体（OXR）mRNA和蛋白质在IR状态下的表达改变。结果：高脂肪膳食喂养4周后，实验组大鼠葡萄糖输注率由对照组（12．5±0．6）mg·kg^-1·min^-1下降至（7．6±0．4）mg·kg^-1·min^-1。实验组大鼠的体重、全血葡萄糖、血清胰岛素水平高于对照组，分别为26％、25％和30％（P〈0．05）；高脂肪膳食诱导的IR大鼠胰腺组织中orexin mRNA和蛋白质的表达比对照组减少约71％和63％，而OX，RmRNA和蛋白质的表达比对照组降低约49％和67％（P〈0．05），OX2R mRNA和蛋白质的表达改变不明显。结论：高脂肪膳食可诱导大鼠体内产生IR，并抑制胰腺中orexin及其OX1R基因的转录和翻译。Orexin系统可能是参与调节脂肪一胰岛轴的主要因素。

英文摘要：

AIM： To evaluate the expression of orexin and its receptors in rat pancreatic tissue with insulin resistance. METHODS ： Rat model with insulin resistance induced by high - fat diet was confirmed by euglycemic clamp. Serum glucose and insulin were measured by chemiluminescent immunoassay. The expressions of orexin gene and its receptors （OX1 R and OX2R） in rat pancreatic tissue were identified by real -time PCR and Western blooding. RESULTS： After 4 weeks high - fat diet, the glucose infusion rate significantly decreased from （ 12. 5 ± 0. 6） mg· kg^-1·min^-1 to （7.6 ±0. 4） mg · kg^-1·min^-1 （P 〈0. 05 ）. Body weight, serum glucose and insulin increased 26%, 25% and 30%, respectively （P〈0.05）. Moreover, the expressions of orexin mRNA and protein decreased about 71% and 63%, and OXIR mRNA and protein reduced about 49% and 67% in rat pancreatic tissue with insulin resistance, respectively, compared to normal rat （P 〈0. 05）. However, the expression of OX2R mRNA and protein did not decreased obviously. CONCLUSION： High - fat diet induces insulin resistance in Wistar rat. The transcription and translation of orexin and OXI R genes in rat hypothalamus are down - regulated in insulin resistance. Orexin system may play a role in insulin resistance and lipid -pancreatic island metabolism.