Jacobs Kevin A, Casazza Gretchen A, Suh Sang-Hoon, Horning Michael A, Brooks George A
Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
J Appl Physiol (1985). 2005 May;98(5):1720-31. doi: 10.1152/japplphysiol.00685.2004. Epub 2004 Dec 23.
We evaluated the hypothesis that fatty acid reesterification would be increased during rest and exercise in the midluteal menstrual cycle phase and during oral contraceptive use, when ovarian hormone concentrations are high, compared with the early follicular phase. Subjects were eight moderately active, weight-stable, eumenorrheic women (24.8 +/- 1.2 yr, peak oxygen consumption = 42.0 +/- 2.3 ml.kg(-1).min(-1)) who had not taken oral contraceptives for at least 6 mo. Plasma free fatty acid (FFA) kinetics were assessed in the 3-h postprandial state by continuous infusion of [1-(13)C]palmitate and [1,1,2,3,3-(2)H]glycerol during 90 min of rest and 60 min of exercise at 45% and 65% peak oxygen consumption in the early follicular and midluteal menstrual cycle phases and during the inactive- and high-dose phases following 4 mo of oral contraceptive use. Plasma FFA rates of appearance, disappearance, and oxidation increased significantly from rest to exercise with no differences noted between menstrual cycle or oral contraceptive phases or exercise intensities. Compared with either menstrual cycle phase, oral contraceptive use resulted in an increase in plasma-derived fatty acid reesterification and a decrease in the proportion of plasma FFA rate of disappearance that was oxidized at rest and during exercise. Endogenous and exogenous synthetic ovarian hormones do not exert a measurable influence on plasma FFA turnover or oxidation at rest or during moderate-intensity exercise in the 3-h postprandial state when carbohydrate use predominates. The increase in whole body lipolytic rate during exercise noted previously with oral contraceptive use is not matched by an increase in fatty acid oxidation and results in an increase in reesterification. Synthetic ovarian hormones contained in oral contraceptives increase lipolytic rate, but fatty acid oxidation during exercise is determined by exercise intensity and its metabolic and endocrine consequences.
与卵泡期早期相比，在月经周期黄体中期以及使用口服避孕药期间，当卵巢激素浓度较高时，脂肪酸再酯化在休息和运动期间会增加。研究对象为8名中度活跃、体重稳定、月经周期正常的女性（24.8±1.2岁，峰值耗氧量=42.0±2.3 ml·kg⁻¹·min⁻¹），她们至少6个月未服用口服避孕药。在卵泡期早期和黄体中期月经周期阶段以及使用口服避孕药4个月后的非活跃期和高剂量期，通过在90分钟休息和60分钟运动期间持续输注[1-(¹³)C]棕榈酸酯和[1,1,2,3,3-(²)H]甘油，在餐后3小时状态下评估血浆游离脂肪酸（FFA）动力学，运动强度分别为峰值耗氧量的45%和65%。从休息到运动，血浆FFA的出现率、消失率和氧化率显著增加，月经周期阶段或口服避孕药阶段以及运动强度之间未发现差异。与任何一个月经周期阶段相比，使用口服避孕药会导致血浆源性脂肪酸再酯化增加，以及休息和运动期间被氧化的血浆FFA消失率比例降低。在内源性和外源性合成卵巢激素在餐后3小时状态下，当碳水化合物利用占主导时，对休息或中等强度运动时的血浆FFA周转或氧化没有可测量的影响。先前观察到的使用口服避孕药时运动期间全身脂肪分解率的增加与脂肪酸氧化的增加不匹配，导致再酯化增加。口服避孕药中含有的合成卵巢激素会增加脂肪分解率，但运动期间的脂肪酸氧化取决于运动强度及其代谢和内分泌后果。
