Early A H, Wade G N, Lempicki R L
Center for Neuroendocrine Studies, Department of Psychology, University of Massachusetts, Amherst 01003-7720, USA.
Physiol Behav. 1999;65(4-5):763-8. doi: 10.1016/s0031-9384(98)00224-8.
Two experiments examined the effects of 72-h exposure to reduced environmental temperature (5 degrees C) on steroid-induced estrous behavior and neural estrogen-receptor immunoreactivity (ERIR) in ovariectomized Syrian hamsters. Cold exposure significantly inhibited sexual receptivity induced by sequential injections of estradiol benzoate (2.5 microg) and progesterone (500 microg), but only if the animals were not permitted to overeat (limited to 110% of ad lib intake at 22 degrees C). The suppression of sexual receptivity was accompanied by decreases in the number of detectable ERIR cells in the ventromedial hypothalamus (VMH) and by increases in the number of ERIR cells in the medial preoptic area (mPOA). The cold-induced decreases in estrous behavior and in VMH ERIR cells were prevented by lesions of the area postrema (AP), but AP lesions did not prevent the increases in mPOA ERIR cells. Thus, cold exposure mimics the effects of treatment with metabolic inhibitors, experimental diabetes, food deprivation, and insulin-induced fattening on these endpoints. These findings are consistent with the hypothesis that dwelling in the cold affects reproduction indirectly via its actions on metabolic fuel availability, rather than by acting directly on neuroendocrine processes.
两项实验研究了将去卵巢的叙利亚仓鼠暴露于低温环境（5摄氏度）72小时对类固醇诱导的发情行为和神经雌激素受体免疫反应性（ERIR）的影响。冷暴露显著抑制了连续注射苯甲酸雌二醇（2.5微克）和孕酮（500微克）所诱导的性接受能力，但前提是动物不被允许过度进食（限制在22摄氏度时自由进食量的110%）。性接受能力的抑制伴随着腹内侧下丘脑（VMH）中可检测到的ERIR细胞数量减少，以及内侧视前区（mPOA）中ERIR细胞数量增加。最后区（AP）损伤可防止冷诱导的发情行为和VMH中ERIR细胞数量减少，但AP损伤并不能阻止mPOA中ERIR细胞数量增加。因此，冷暴露模拟了用代谢抑制剂、实验性糖尿病、食物剥夺和胰岛素诱导肥胖治疗对这些终点的影响。这些发现与以下假设一致：处于寒冷环境通过影响代谢燃料的可用性间接影响繁殖，而不是直接作用于神经内分泌过程。
