Stallone D D, Levitsky D A
Cornell University, Division of Nutritional Sciences, Ithaca, New York 14850.
Int J Obes Relat Metab Disord. 1994 Oct;18(10):679-85.
Fenfluramine suppressess the body weight of experimental animals during chronic treatment by a mechanism that is not yet clear. The present research investigated the contributions of fenfluramine-induced alterations in food intake and two components of energy expenditure, resting energy expenditure (REE) and the thermic effect of food (TEF), to maintenance of a lowered body weight in male Long Evans rats. DI-Fenfluramine (20 mg/kg) produced an initial severe anorexia and weight loss. Food intake then increased steadily, reaching control levels by the fourth day of treatment. Tolerance to the anorectic effects of fenfluramine was not complete however -- food intake of fenfluramine-treated rats fell below control levels on 7 of the remaining 20 days of treatment. The body weight of fenfluramine treated rats remained significantly below control levels throughout the entire treatment period, but rose rapidly to control levels following fenfluramine withdrawal. REE was unaffected by fenfluramine treatment. By contrast, fenfluramine treatment significantly altered the TEF. Twenty-four hours after initiation of treatment the TEF of fenfluramine treated animals was higher than that of controls. On the 15th day of drug administration and the first day of fenfluramine withdrawal, however, the TEF of control and treated animals no longer differed. By contrast, on the second day of fenfluramine withdrawal the TEF of fenfluramine treated rats was suppressed to 17% of control levels. These findings suggest that the effect of fenfluramine on body weight involves modulation of both food intake and energy expenditure.
氟苯丙胺在长期治疗过程中会降低实验动物的体重，但其机制尚不清楚。本研究调查了氟苯丙胺引起的食物摄入量变化以及能量消耗的两个组成部分，即静息能量消耗（REE）和食物热效应（TEF），对雄性长 Evans 大鼠维持低体重的作用。二氟苯丙胺（20 毫克/千克）最初会导致严重的厌食和体重减轻。然后食物摄入量稳步增加，在治疗的第四天达到对照水平。然而，对氟苯丙胺厌食作用的耐受性并不完全——在剩余 20 天的治疗中，有 7 天氟苯丙胺处理组大鼠的食物摄入量低于对照水平。在整个治疗期间，氟苯丙胺处理组大鼠的体重显著低于对照水平，但在停用氟苯丙胺后迅速上升至对照水平。氟苯丙胺治疗对 REE 没有影响。相比之下，氟苯丙胺治疗显著改变了 TEF。治疗开始 24 小时后，氟苯丙胺处理组动物的 TEF 高于对照组。然而，在给药第 15 天和停用氟苯丙胺的第一天，对照组和处理组动物的 TEF 不再有差异。相比之下，在停用氟苯丙胺的第二天，氟苯丙胺处理组大鼠的 TEF 被抑制至对照水平的 17%。这些发现表明，氟苯丙胺对体重的影响涉及对食物摄入量和能量消耗的调节。
