Estacio M A, Yamada S, Tsukamura H, Hirunagi K, Maeda K
Laboratory of Animal Reproduction, School of Agricultural Sciences, Nagoya University, Japan.
Brain Res. 1996 Apr 22;717(1-2):55-61. doi: 10.1016/0006-8993(96)00022-4.
The present study examined the effect of 48-h fasting and 1-h immobilization on estrogen receptor immunoreactivity in selected hypothalamic areas and the nucleus of the solitary tract (NTS) in ovariectomized rats. Fasting induced an increase in ER-immunoreactive cells in the paraventricular nucleus (PVN), periventricular nucleus (PeVN) and NTS compared with the unfasted control group. Similarly, immobilization caused an increase in ER-positive cells in the same areas, PVN, PeVN and NTS, versus the non-immobilized group. There was no significant increase in the number of ER-immunoreactive cells in the preoptic area (POA), arcuate nucleus (ARC) or ventromedial hypothalamic nucleus (VMH) following fasting and immobilization. Our previous work in ovariectomized rats with estrogen microimplants in the brain revealed that the PVN and A2 region of the NTS are the feedback sites of estrogen in activating the neural pathway to suppress pulsatile LH secretion during 48-h fasting. The result in the food-deprived rats suggests that estrogen modulation of the suppression of LH secretion during fasting is partly due to the increase in estrogen receptors in the PVN and A2 region. The physiological significance of the increase in neural ER following immobilization remains to be elucidated.
本研究检测了48小时禁食和1小时固定对去卵巢大鼠特定下丘脑区域及孤束核（NTS）中雌激素受体免疫反应性的影响。与未禁食的对照组相比，禁食导致室旁核（PVN）、室周核（PeVN）和NTS中雌激素受体免疫反应性细胞增加。同样，与未固定组相比，固定导致相同区域（PVN、PeVN和NTS）中雌激素受体阳性细胞增加。禁食和固定后，视前区（POA）、弓状核（ARC）或下丘脑腹内侧核（VMH）中雌激素受体免疫反应性细胞数量没有显著增加。我们之前对脑内植入雌激素微丸的去卵巢大鼠的研究表明，PVN和NTS的A2区域是雌激素在48小时禁食期间激活神经通路以抑制促黄体生成素（LH）脉冲式分泌的反馈位点。食物剥夺大鼠的结果表明，禁食期间雌激素对LH分泌抑制的调节部分归因于PVN和A2区域雌激素受体的增加。固定后神经雌激素受体增加的生理意义仍有待阐明。
