Role of ghrelin in ameliorating insulin resistance in fructose-fed rats and its mechanism / 中华内分泌代谢杂志

ABSTRACT

Thirty-two male Sprague-Dawley rats were divided into control group (n =16) and fructose group (n =16) fed with 10％ fructose solution.After 4 weeks,the rats of two groups were treated with saline and 50 nmol/kg ghrelin for 6 weeks,respectively (each group n =8).Fasting plasma glucose,insulin,and blood lipid profile were measured.Insulin receptor (Ins-R) mRNA expression in muscle was detected by RT-PCR.The phosphorylation of insulin receptor substrate-1 (IRS-1) was measured by Western blot.The results showed that insulin level and homeostasis model assessment for insulin resistance index (HOMA-IR) in fructose group were higher than those in control group [(13.1±3.6 vs 9.0 ± 1.5) μU/ml,P＜0.05 ;2.78 ± 0.14 vs 1.81± 0.13,P ＜0.01)].After ghrelin treatment,plasma insulin concentration [(9.6 ± 2.5) μU/mL,P＜0.05] and HOMA-IR (1.96 ± 0.12,P＜0.01)significantly decreased,along with increased Ins-R mRNA and IRS-1 phosphorylation in skeletal muscle (P ＜0.01).These results suggest that ghrelin can ameliorate insulin resistance in fructose-fed rats by restoring Ins-R function.