McGinnis M Y, Lumia A R, McEwen B S
Brain Res. 1985 May 13;334(1):19-25. doi: 10.1016/0006-8993(85)90562-1.
In this experiment we tested the hypothesis that the potentiation of feminine sexual behavior following olfactory bulb removal in female rats would be associated with increased ovarian steroid receptor binding in brain. Ovariectomized adult female rats underwent either bilateral olfactory bulb removal (BOB) or a sham operation and were exposed to 100% estradiol (E2) in silastic capsules for 4 or 6 h. Following behavior testing, either cell nuclear estrogen receptor levels were measured in amygdala, hypothalamus, preoptic area and pituitary, or cytosol progestin receptors levels were determined in cortex, preoptic area and hypothalamus. After 6 h E2 exposure, BOB females showed increasing lordosis responding with increasing progesterone (P) doses, at levels significantly higher than those of sham-operated rats. After 4 h E2 exposure bulbectomized rats showed both a facilitation of lordosis and elevated estrogen receptor levels in amygdala. Sham-operates showed neither response to the 4 h E2 stimulus. For both BOB and sham groups, progestin receptors were induced after 6 h E2 exposure, but were uninduced after 4 h E2 exposure. Additional rats were exposed to 5% E2 for 24 or 48 h, followed by P. Lordosis was potentiated in BOB rats at 24 h; sham-operates showed high levels of lordosis only after 48 h of 5% E2 exposure. Proceptivity was enhanced in BOB rats after both 24 and 48 h of 5% E2 exposure. In contrast, proceptivity was rarely observed in sham-operates, or in either group after 4 or 6 h E2 exposure. We propose that increased estrogen receptor binding in the amygdala may provide a biochemical basis for the increased estrogen sensitivity found in olfactory bulbectomized female rats.
在本实验中，我们检验了这样一个假设：雌性大鼠摘除嗅球后雌性性行为的增强与大脑中卵巢甾体受体结合增加有关。成年去卵巢雌性大鼠接受双侧嗅球摘除术（BOB）或假手术，并在硅橡胶胶囊中暴露于100%雌二醇（E2）4或6小时。行为测试后，在杏仁核、下丘脑、视前区和垂体中测量细胞核雌激素受体水平，或在皮质、视前区和下丘脑中测定胞质孕酮受体水平。暴露于E2 6小时后，BOB组雌性大鼠随着孕酮（P）剂量增加，脊柱前凸反应增强，其水平显著高于假手术大鼠。暴露于E2 4小时后，摘除嗅球的大鼠不仅脊柱前凸得到促进，杏仁核中的雌激素受体水平也升高。假手术组对4小时E2刺激均无反应。对于BOB组和假手术组，暴露于E2 6小时后诱导产生孕酮受体，但暴露于E2 4小时后未诱导产生。另外的大鼠暴露于5% E2 24或48小时，随后给予P。BOB组大鼠在24小时时脊柱前凸增强；假手术组仅在暴露于5% E2 48小时后才表现出高水平的脊柱前凸。暴露于5% E2 24和48小时后，BOB组大鼠的接受性均增强。相比之下，假手术组很少观察到接受性，在暴露于E2 4或6小时后两组均未观察到接受性。我们认为，杏仁核中雌激素受体结合增加可能为摘除嗅球的雌性大鼠中发现的雌激素敏感性增加提供生化基础。
