Kiens B, Lithell H, Mikines K J, Richter E A
August Krogh Institute, University of Copenhagen, Denmark.
J Clin Invest. 1989 Oct;84(4):1124-9. doi: 10.1172/JCI114275.
The effects of exercise and a physiological increase in plasma insulin concentration on muscle lipoprotein lipase activity (mLPLA), leg exchange of glucose, and serum lipoprotein levels were investigated in healthy young men. During euglycemic hyperinsulinemia (n = 7) at 44 mU.liter-1, m-LPLA in non-exercised muscle decreased from 30 +/- 7.4 mU.g-1 wet weight (w.w.) (mean +/- SE) to 19 +/- 3.3 (P less than 0.05). Furthermore, the decrease in m-LPLA correlated closely (r = 0.97, P less than 0.05) with the increase in leg glucose uptake. Moreover, basal m-LPLA correlated with the insulin-induced increase in leg glucose uptake (r = 0.93, P less than 0.05). In the control group (n = 6) in which saline was infused in place of insulin and glucose, m-LPLA in nonexercised muscle did not change with time. No change in m-LPLA was observed immediately after one-legged knee extension exercise, but 4 h after exercise m-LPLA was higher (P less than 0.05) in the exercised thigh (47 +/- 17.8 mU.g-1 w.w.) compared with the contralateral nonexercised thigh (29 +/- 6.3 mU.g-1 w.w.). This difference was not found 8 h after exercise. The triacylglycerol content of serum lipoproteins decreased during insulin infusion. It is concluded that in contrast to the effect on adipose tissue, physiological concentrations of insulin decrease m-LPLA in proportion to the effect of insulin on muscle glucose uptake, while muscle contractions cause a local, delayed, and transient increase in m-LPLA. Further-more, basal m-LPLA is an indicator of muscle insulin sensitivity.
研究了运动以及血浆胰岛素浓度生理性升高对健康年轻男性肌肉脂蛋白脂肪酶活性（mLPLA）、腿部葡萄糖交换和血清脂蛋白水平的影响。在血糖正常的高胰岛素血症期间（n = 7），胰岛素浓度为44 mU·升⁻¹时，未运动肌肉中的m-LPLA从30±7.4 mU·克⁻¹湿重（w.w.）（平均值±标准误）降至19±3.3（P<0.05）。此外，m-LPLA的降低与腿部葡萄糖摄取的增加密切相关（r = 0.97，P<0.05）。而且，基础m-LPLA与胰岛素诱导的腿部葡萄糖摄取增加相关（r = 0.93，P<0.05）。在对照组（n = 6）中，输注生理盐水代替胰岛素和葡萄糖，未运动肌肉中的m-LPLA随时间未发生变化。单腿膝关节伸展运动后即刻未观察到m-LPLA的变化，但运动后4小时，运动侧大腿的m-LPLA（47±17.8 mU·克⁻¹ w.w.）高于对侧未运动大腿（29±6.3 mU·克⁻¹ w.w.）（P<0.05）。运动后8小时未发现这种差异。胰岛素输注期间血清脂蛋白的三酰甘油含量降低。得出结论：与对脂肪组织的作用相反，生理浓度的胰岛素会使m-LPLA降低，其降低程度与胰岛素对肌肉葡萄糖摄取的作用成比例，而肌肉收缩会导致m-LPLA局部、延迟且短暂升高。此外，基础m-LPLA是肌肉胰岛素敏感性的指标。
