Modified activity-stress paradigm in an animal model of the female athlete triad
Modified activity-stress paradigm in an animal model of the female athlete triad
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DOI：
10.1152/japplphysiol.01137.2005
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发表时间：
2007-11-01
影响因子：
3.3
通讯作者：
Sanborn, Charlotte Barney
中科院分区：
文献类型：
--
作者：
DiMarco, Nancy M.;Dart, Lyn;Sanborn, Charlotte Barney
营养缺乏和相关月经不规律的运动女性有损害长期骨骼健康的风险，即女运动员三位一体。没有女性运动员三位一体的动物模型。本研究的目的是研究长期能量限制对自愿跑轮的雌性大鼠的动情周期、骨矿物质含量和瘦素水平的影响。12只雌性Sprague-Dawley大鼠（34日龄）在最初的14周内自由喂养，并给予跑步轮，提供基线和年龄相关数据。每日收集包括饮食摄入量、体重、发情周期和自愿跑步距离。在4月龄时，将大鼠随机分为两组，6只限制喂养大鼠（自由摄取量的70%）和6只继续自由喂养的大鼠作为对照组。计算每只动物的能量摄入量、能量消耗和能量利用率（能量摄入-能量消耗）。用RIA法测定血清雌二醇和瘦素浓度。采用双能x线骨密度仪测定股骨、胫骨骨密度和骨矿物质含量（BMC）。限饲大鼠在减重期和不发情期能量利用率下降（P = 0.002）。12周后，与对照组相比，限饲大鼠血清雌二醇（P = 0.002）和瘦素（P = 0.002）浓度降低，卵巢重量降低（P = 0.002），股骨（P = 0.041）和胫骨（P = 0.05） BMC降低。能量利用率降低导致早泄，BMC、雌激素和瘦素水平以及体重显著下降。最后，有一个关键水平的能量可用性来维持发情周期。
The exercising woman with nutritional deficits and related menstrual irregularities is at risk of compromising long-term bone health, i. e., the female athlete triad. There is no animal model of the female athlete triad. The purpose of this study was to examine long-term energy restriction in voluntary wheel-running female rats on estrous cycling, bone mineral content, and leptin levels. Twelve female Sprague-Dawley rats (age 34 days) were fed ad libitum and given access to running wheels during an initial 14-wk period, providing baseline and age-related data. Daily collection included dietary intake, body weight, estrous cycling, and voluntary running distance. At 4 mo, rats were randomized into two groups, six restrict-fed rats (70% of ad libitum intake) and six rats continuing as ad libitum-fed controls. Energy intake, energy expenditure, and energy availability (energy intake -energy expenditure) were calculated for each animal. Serum estradiol and leptin concentrations were measured by RIA. Femoral and tibial bone mineral density and bone mineral content (BMC) were determined by dual-energy X-ray absorptiometry. Restrict-fed rats exhibited a decrease in energy availability during Weight Loss and Anestrous phases (P = 0.002). Compared with controls after 12 wk, restrict-fed rats showed reduced concentrations of serum estradiol (P = 0.002) and leptin (P = 0.002), lower ovarian weight (P = 0.002), and decreased femoral (P = 0.041) and tibial (P = 0.05) BMC. Decreased energy availability resulted in anestrus and significant decreases in BMC, estrogen and leptin levels, and body weight. Finally, there is a critical level of energy availability to maintain estrous cycling.