Suda K, Izawa T, Komabayashi T, Tsuboi M, Era S
Department of Physiology, University of Gifu School of Medicine, Japan.
J Appl Physiol (1985). 1993 Jun;74(6):2935-9. doi: 10.1152/jappl.1993.74.6.2935.
The effect of exercise training on the antilipolytic action of insulin was studied in rat adipocytes. Exercise training enhanced lipolysis induced by norepinephrine. Insulin dose dependently inhibited norepinephrine- (1 microM) stimulated lipolysis in both groups. Its inhibition rate was significantly greater in the trained than in the control group. Thus, exercise training enhanced the antilipolytic action of insulin. In the control group, insulin (1,000 microU/ml) reduced the displacement rate of [3H]CGP-12177 binding to adipocytes by low concentrations of (-)-norepinephrine. The slope factor without insulin was 0.76, whereas that with insulin was 0.95. In the trained group, insulin did not affect the competition binding of (-)-norepinephrine for [3H]CGP-12177. The displacement rate of [3H]CGP-12177 binding from adipocytes by low concentrations of (-)-norepinephrine was significantly greater in the trained than in the control group. The number of surface beta-adrenergic receptors per adipocyte was smaller in the trained than in the control group. Cilostamide, which blocks the antilipolytic action of insulin, restored lipolysis in both groups. The recovery rate was significantly greater in the trained than in the control group. These findings suggest that the enhanced antilipolytic action by insulin in the trained group occurs at a site distal to the binding of norepinephrine to beta-adrenergic receptors and that it is due to the increased activity of particulate low-Michaelis constant phosphodiesterase.
在大鼠脂肪细胞中研究了运动训练对胰岛素抗脂解作用的影响。运动训练增强了去甲肾上腺素诱导的脂解作用。两组中胰岛素均呈剂量依赖性抑制去甲肾上腺素（1微摩尔）刺激的脂解作用。训练组中其抑制率显著高于对照组。因此，运动训练增强了胰岛素的抗脂解作用。在对照组中，胰岛素（1000微单位/毫升）降低了低浓度（-）-去甲肾上腺素与脂肪细胞结合的[3H]CGP-12177的置换率。无胰岛素时的斜率因子为0.76，而有胰岛素时为0.95。在训练组中，胰岛素不影响（-）-去甲肾上腺素对[3H]CGP-12177的竞争结合。低浓度（-）-去甲肾上腺素从脂肪细胞中置换[3H]CGP-12177结合的速率在训练组中显著高于对照组。训练组中每个脂肪细胞表面β-肾上腺素能受体的数量比对照组少。西洛他唑可阻断胰岛素的抗脂解作用，使两组的脂解作用恢复。训练组的恢复率显著高于对照组。这些发现表明，训练组中胰岛素增强的抗脂解作用发生在去甲肾上腺素与β-肾上腺素能受体结合的远端位点，并且这是由于微粒型低米氏常数磷酸二酯酶活性增加所致。
