黄芪改善高脂饲养大鼠胰岛素敏感性的机制研究

目的 :探讨黄芪改善高脂饲养大鼠胰岛素敏感性的机制。方法 :2 4只 SD大鼠随机分为正常对照组、高脂对照组、高脂黄芪干预组 ,每组各 8只 ,分别予以标准饲料和高脂饲料 ,干预组同时灌服黄芪。 7周后采用葡萄糖 -胰岛素耐量试验测量大鼠胰岛素敏感性值 (K) ,并观察不同部位脂肪组织质量的变化及其与 K值的关系。应用 TU NEL 法观察腹腔脂肪细胞凋亡的变化。结果 :7周后 ,高脂干预组大鼠经黄芪治疗后与正常对照组相比 K值减小 (P<0 .0 1 ) ,腹腔脂肪组织质量及脂肪细胞凋亡数未见明显差异 ,但与高脂对照组相比 K值明显增大 (P<0 .0 1 ) ,腹腔脂肪组织质量明显减少 (P<0 .0 1 ) ,脂肪细胞凋亡增加 (P<0 .0 1 )。 结论 :胰岛素抵抗与脂肪组织分布关系密切 ;黄芪改善高脂饲养大鼠胰岛素敏感性的机制可能是通过调控脂肪细胞凋亡 ,影响脂肪细胞的分布 ,从而改善胰岛素抵抗

Effect of Radix astragali on insulin sensitivity in high-fat-fed rats

Objective:To investigate effects of Radix astragali (RA) on relieving insulin resistance(IR) in adipose tissue of high fat fed(HF) rats. Methods: Twenty four SD rats were divided into 3 groups randomly( n =8):HF group, HF+RA group,and normal control group. Each group was fed equicalorically for 7 weeks, then insulin sensitivity was measured by glucose insulin tolerance test. The adipose tissues in subcutanea and retroperitoneal were weighted respectively. Sections of adipose tissue were fixed with 100% ethanol and stained by TUNEL technique with a kit to detect apoptotic nuclei. Results: (1)K values obtained from glucose insulin tolerance test were significantly increased in HF+RA group compared with that in HF group. (2) The fats in the retroperitoneal position were significantly increased in HF group compared with that in HF+RA group. (3) The number of TUNEL positive nuclei in retroperitoneal adipose tissue was much greater in HF+RA group than in HF group. Conclusion: RA can relieve insulin resistance of the high fat fed rat, which may be closely related to increment of adipocyte apoptosis and reduction of intro abdominal fat weight.