Wolfe R R, Peters E J, Klein S, Holland O B, Rosenblatt J, Gary H
Am J Physiol. 1987 Feb;252(2 Pt 1):E189-96. doi: 10.1152/ajpendo.1987.252.2.E189.
In this study the rate of lipolysis (fatty acid and glycerol release into blood) has been quantified in both normal weight and obese volunteers after both 15 and 87 h of fasting. In each study, the basal rate and subsequent response to epinephrine infusion (0.015 microgram X kg-1 X min-1) were determined. The rate of appearance (Ra) of free fatty acids (FFA) and glycerol were quantified by infusion of [1-13C]palmitate and D-5-glycerol, respectively. Substrate flux rates per unit of body fat mass and lean body mass were calculated from total body water measurements using H2(18)O dilution. In normal volunteers, the basal Ra FFA and Ra glycerol rose markedly with 87 h of fasting, whereas the increases were more modest in the obese subjects. However, the rate of mobilization of fat, in relation to the lean body mass, was higher in the obese subjects than in the normal subjects after 15 h of fasting, and the values were similar in both groups after 87 h of fasting. There was an increased lipolytic response to epinephrine after fasting in both groups. This increased sensitivity may have resulted from the enhancement of fatty acid-triglyceride substrate cycling that occurred after fasting.
在本研究中，对正常体重和肥胖志愿者在禁食15小时和87小时后的脂肪分解速率（脂肪酸和甘油释放到血液中的速率）进行了量化。在每项研究中，测定了基础速率以及随后对肾上腺素输注（0.015微克×千克⁻¹×分钟⁻¹）的反应。游离脂肪酸（FFA）和甘油的出现率（Ra）分别通过输注[1-¹³C]棕榈酸酯和D-5-甘油进行量化。单位体脂质量和去脂体重的底物通量率根据使用H₂¹⁸O稀释法测得的总体水含量进行计算。在正常志愿者中，禁食87小时后基础FFA的Ra和甘油的Ra显著升高，而肥胖受试者的升高幅度较小。然而，在禁食15小时后，相对于去脂体重，肥胖受试者的脂肪动员速率高于正常受试者，禁食87小时后两组的值相似。两组在禁食后对肾上腺素的脂肪分解反应均增强。这种敏感性增加可能是由于禁食后脂肪酸 - 甘油三酯底物循环增强所致。
