THE OREXIN SYSTEM IN INSULIN RESISTANCE RAT MODEL INDUCED BY HIGH-FRUCTOSE DIET

摘要

Objective.To evaluate the effects of high-fructose diet on expression of orex in and its receptors,orexin1receptor and orexin2receptor in rat hypothalamus tissue,and to analysis the interaction of related fa ctors involved in regulating orexin and its receptors.Methods.Insulin resistan ce rat model induced by high fructose confirmed by the gold standard eug-lycaem ic clamping was employed and mRNA expression of orexin and its receptors OX 1 R and OX 2 R in hypothalamus,mRNA expression of leptin in adipose tissue were measured by reverse transcription poly-merase chain reaction.Serum insulin and triglyc eride levels were measured by chemiluminescence im-munoassay and biochemical en zyme techniques.Results.Expression of orexin mRNA decreased about 40%in hi gh fructose diet rats compared to control group,whereas expressi on of orexin1receptor and orexin2receptor mRNA increased up to4.4and5.1f old.Leptin mRNA expression in adipose tissue increased about 3 0%in comparison with control group.Blood glucose,serum insuli n and triglyceride have shown signi ?ficant higher levels than those in contro l group.Glucose infusion rate was much low-er in comparison with control group.Conclusi ons.High?fructose diet induces insulin resistance in rats with impact on orexi n and leptin regulations.Blood glucose,serum insulin,lipid metabolism and lep tin play an interactive role on orexin and its receptors regulation in rats.