Grifolagargal投与量が高フルクトース食誘発インスリン抵抗性ラットに及ぼす影響

抄録

The purpose of the present study was to evaluate the effects of Grifolagargal (mushroom) extracts on insulin resistance induced by high-fructose diet. Male rats of Wistar strain aged 7 weeks were divided into 3 groups. Those are 1) high-fructose diet group (Fructose 60% content;Fru) (Experiment 1), 2) Fru + Grifolagargal group (Grifolagargal1.5% (Experiment 1 and 2) or 2.0% (Experiment 3);FG) and 3) normal diet group (Control). The rats in 3 groups were breeded for 3 (Experiment 1 and 2) or 4 weeks (Experiment 3). Then, after fasting for 16 hours, a sequential euglycemic clamp experiment with two different insulin infusion rates of 3.0 (Experiment 1 and 3)or 6.0(Experiment 2) (L-clamp) and 30.0 mU/kgBW/min (H-clamp) was performed. The glucose infusion rate (GIR) was assumed to be an index of the action of insulin for 60-90 and 150-180 minutes. As a result, in the all Experiment, the Fru group markedly reduced GIRs in L-clamp compared with Control group. And in the Experiment 2, a significant difference was not able to be confirmed between FG and Fru groups. However, in the Experiment 3, GIRs in FG group were higher than Fru. Consequently, the effects of Grifolagargalextractwith GIRs inL-clamp were shown in the case of dosage 2.0%. While, in H-clamp, GIR in FG group were increased by Grifolagargal extracts compared with Fru group, and reached the almost same levels as in Control group. And the effects with GIRs in H-clamp had no relation to dosage and insulin infusion rate. Therefore, it was suggested that the administration of Grifolagargal extracts affect insulin sensitivity, and insulin responsiveness. And dosage would influence the amelioration of insulin sensitivity.