Arner P, Engfeldt P, Nowak J
J Clin Endocrinol Metab. 1981 Dec;53(6):1207-12. doi: 10.1210/jcem-53-6-1207.
To assess the influence of fasting on the lipolytic effect of catecholamines in vivo noradrenaline (NA) was infused to 15 obese subjects before and after 7 days of fasting. The infusion of 7.5 microgram/min NA for 10 min was associated with a greater lipolytic response during than before fasting, as judged from changes in the plasma FFA and glycerol levels. The hemodynamic effects of NA were similar in both conditions. NA sensitivity was tested by infusing the hormone at an increasing rate from 0.05-2 microgram/min. During fasting, there was a 10-fold increase in the sensitivity to the lipolytic effect of NA, and the NA infusion significantly reduced the mean serum insulin level. Before fasting, the insulin level was constant during NA infusion. The increments in the plasma NA concentration were similar in both conditions. When insulin was infused at a constant rate, and graded NA doses were infused simultaneously, no lipolytic effect of NA at rates of 1 and 2 microgram/min significantly increased the plasma glycerol level. Thus, fasting enhances the lipolytic effect of NA in vivo, and this effect is due to increased sensitivity to NA and also to NA-induced depression of the circulating insulin level.
为评估禁食对儿茶酚胺在体内脂解作用的影响，对15名肥胖受试者在禁食7天前后输注去甲肾上腺素（NA）。从血浆游离脂肪酸（FFA）和甘油水平的变化判断，以7.5微克/分钟的速率输注NA 10分钟，在禁食期间比禁食前产生更大的脂解反应。在两种情况下，NA的血流动力学效应相似。通过以0.05 - 2微克/分钟的递增速率输注该激素来测试NA敏感性。在禁食期间，对NA脂解作用的敏感性增加了10倍，并且NA输注显著降低了平均血清胰岛素水平。在禁食前，输注NA期间胰岛素水平保持恒定。在两种情况下，血浆NA浓度的增加相似。当以恒定速率输注胰岛素并同时输注分级的NA剂量时，1和2微克/分钟速率的NA的脂解作用均未显著增加血浆甘油水平。因此，禁食增强了NA在体内的脂解作用，这种作用归因于对NA敏感性的增加以及NA诱导的循环胰岛素水平降低。
