不同运动对胰岛素抵抗大鼠肝脏脂肪酸代谢的影响及机制探讨

Effects of Different Exercises on the Metabolism of Free Fatty Acids in Liver of Insulin Resistance Rats and its Mechanisms

目的:探讨不同运动干预对胰岛素抵抗(IR)大鼠肝脏游离脂肪酸(FFA)及腺苷酸活化蛋白激酶(AMPK)、乙酰辅酶A羧化酶(ACC)、肉毒碱棕榈酰基转移酶(CPT1)含量的影响,探讨不同方式运动对IR大鼠肝脏FFA代谢的可能机制。方法:高糖高脂饲料喂养建立IR大鼠模型,并随机分为对照组(C组)、有氧运动组(E组)、抗阻运动组(R组)、有氧+抗阻联合运动组(RE组),随后运动组IR大鼠进行8周的不同运动干预,运动干预结束后36 h,检测肝脏FFA、AMPK、ACC、CPT1酶含量。结果:(1)8周不同运动干预后E组、R组、RE组肝脏FFA含量均显著低于C组(P<0.01),但各运动组间无显著差异(P>0.05);(2)8周不同运动干预后E组、R组、RE组AMPK、CPT1酶含量均显著高于C组(P<0.01),其中RE组显著高于E组、R组(P<0.01)。各运动组ACC酶含量均显著高于C组(P<0.01),但各运动组之间未见差异(P>0.05)。结论:(1)8周不同运动干预均能显著降低IR大鼠肝脏FFA含量,其机制可能与运动显著上调IR大鼠肝脏AMPK、CPT1酶含量,增强脂肪氧化利用有关;有氧与抗阻联合运动较单一运动对脂肪氧化效果更为显著;(2)8周不同运动干预未观察到IR大鼠ACC、CPT1的同步变化,AMPK通过ACC酶调节肝脏脂肪酸氧化可能存在其他机制,运动对于IR大鼠ACC酶含量的调节,尚需进一步研究。

Objective:To study the effects of aerobic exercise,resistance exercise and aerobic combined resistance exercise on liver free fatty acid(FFA),adenylate activated protein kinase(AMPK),acetyl coenzyme A carboxylase(ACC)and carnitine palmitoyltransferase(CPT1)in insulin resistance(IR)rats,to explore the possible mechanism of FFA metabolism in the liver of IR rats by different ways of exercise.Methods:IR rats were fed with high-sugar and high-fat diet and then fed with general diet.They were randomly divided into control group(group C),aerobic exercise group(group E),resistive exercise group(group R),aerobic+resistive combined exercise group(group RE).IR rats in exercise group were executed for 8 cycles(8 days as a cycle).36 hours after exercise intervention,the rat liver FFA,AMPK,ACC,CPT1 enzyme content were tested.Results:(1)The FFA content in liver of group E,group R and group RE was significantly lower than that of group C(P<0.01),but there was no significant difference among the exercise groups(P>0.05).(2)The AMPK and CPT1 enzymes in group E,R and RE were significantly higher than those in group C(P<0.01),and the ACC enzymes in group RE were significantly higher than those in group E and group R(P<0.01),while the ACC enzymes in each exercise group were significantly higher than those in group C(P<0.01),but there was no difference among the exercise groups(P>0.05).Conclusion:(1)Eight cycles of exercise can significantly reduce FFA content in the liver of IR rats,which may be related to the increase of AMPK and CPT1 enzymes in the liver of IR rats and the enhancement of lipid oxidation utilization by exercise;combined aerobic and resistance exercise has more significant effect on lipid oxidation than single exercise;(2)No synchronous changes of ACC and CPT1 were observed in the eight cycles of exercise intervention in different ways.There may be other mechanisms for AMPK to regulate fatty acid oxidation in the liver through ACC enzyme.The regulation of exercise on the content of ACC in IR rats needs further study.