Cyclic estradiol treatment normalizes body weight and restores physiological patterns of spontaneous feeding and sexual receptivity in ovariectomized rats
Cyclic estradiol treatment normalizes body weight and restores physiological patterns of spontaneous feeding and sexual receptivity in ovariectomized rats
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DOI：
10.1006/hbeh.2002.1835
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发表时间：
2002-12-01
影响因子：
3.5
通讯作者：
Geary, N
中科院分区：
文献类型：
--
作者：
Asarian, L;Geary, N
下丘脑-垂体-性腺轴的功能强烈影响许多物种的雌性自行车的进食和体重。为了检测血浆雌二醇的周期性变化是否足以重现自发进食、食物摄入和体重的正常模式，每四天给切除卵巢的Long-Evans大鼠皮下注射2 μ g苯甲酸雌二醇或单独注射油载体。通过7个治疗周期，周期性雌二醇治疗使体重增加和总食物摄入量的轨迹完全正常化。卵巢切除大鼠的摄食过多表现为自发进食量的增加。进餐频率降低，但不足以补偿进餐量的增加。雌二醇治疗使两个参数正常化。此外，在注射后第二天晚上，周期性雌二醇治疗导致膳食量进一步阶段性减少（和膳食频率增加）和食物摄入量减少。这一阶段性变化类似于完整大鼠发情期间发生的喂养变化。在第八个雌二醇治疗周期，注射0.5毫克孕酮后4小时，测量性感受性。与未接受雌二醇的大鼠相比，在处理周期模拟发情时的脊柱前凸评分最大，在模拟间情时的评分略有增加。最后，在第九个治疗周期测量的血浆雌二醇水平显示了血浆雌二醇水平的接近正常的周期模式。这些结果提供了第一个证明，诱导一个周期性的，接近生理模式的血浆雌二醇是足以维持正常水平的体重，自发喂养模式，总的食物摄入量，和（连同孕酮）性接受卵巢切除大鼠。(C)2002 Elsevier Science（美国）。
Hypothalamic-pituitary-gonadal axis function strongly influences feeding and body weight in cycling females in many species. To test the sufficiency of cyclic variations in plasma estradiol to reproduce normal patterns of spontaneous feeding, food intake, and body weight, ovariectomized Long-Evans rats were subcutaneously injected every fourth day with 2 mug estradiol benzoate or with the oil vehicle alone. Cyclic estradiol treatment completely normalized the trajectory of body weight gain and total food intake through seven treatment cycles. The hyperphagia of ovariectomized rats was expressed as an increase in spontaneous meal size. Meal frequency decreased, but not enough to compensate for the increase in meal size. Estradiol treatment normalized both parameters. In addition, cyclic estradiol treatment produced a further phasic decrease in meal size (and increase in meal frequency) and a decrease in food intake during the second night after injection. This phasic change is similar to the feeding changes occurring during estrus in intact rats. Sexual receptivity was measured during the eighth estradiol treatment cycle, 4 h after injection of 0.5 mg progesterone. Lordosis scores at the time of the treatment cycle modeling estrus were maximal, and scores at the time modeling diestrus were slightly increased over those of rats that did not receive estradiol. Finally, plasma estradiol levels, measured during the ninth treatment cycle, revealed a near-normal cyclic pattern of plasma estradiol levels. These results provide the first demonstration that the induction of a cyclic, near-physiological pattern of plasma estradiol is sufficient to maintain normal levels of body weight, spontaneous feeding patterns, total food intake, and (together with progesterone) sexual receptivity in ovariectomized rats. (C) 2002 Elsevier Science (USA).