Loss of hypothalamic nuclear-bound progestin receptors: factors involved and the relationship to heat termination in female guinea pigs.
Loss of hypothalamic nuclear-bound progestin receptors: factors involved and the relationship to heat termination in female guinea pigs.
复制标题
下丘脑核结合孕激素受体的丧失：相关因素及其与雌性豚鼠绝热的关系。
DOI：
10.1016/0006-8993(85)90962-x
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发表时间：
1985
期刊：
影响因子：
2.9
通讯作者：
Blaustein,JD
中科院分区：
文献类型：
--
作者：
Brown,TJ;Blaustein,JD
对雌性豚鼠性感受性（热）终止是由于下丘脑细胞核中孕酮受体丢失的假设进行了检验。首先，我们试图找到一个最佳剂量的孕酮，这将导致一个延长的性接受期。卵巢切除豚鼠植入10%雌二醇胶囊。40小时后，每个人在每小时进行脊柱前凸测试之前接受了几种大小的黄体酮胶囊之一。令人惊讶的是，所有黄体酮剂量都没有导致热终止延迟。为了确定升高水平的雌二醇和孕酮是否维持升高水平的核孕酮受体，尽管对热持续时间没有影响，如上所述处理动物，除了仅植入一个尺寸的孕酮胶囊（3.0cm）或空胶囊。尽管血清孕酮浓度升高，核孕酮受体水平逐渐下降，并在大约相同的时间接近控制水平的热终止发生在类似的治疗动物。孕酮治疗后，胞浆中的孕酮受体水平下降，并在所有测量时间保持降低。为了进一步研究血孕酮浓度和保留核孕酮受体之间的关系，我们降低了血孕酮浓度，删除孕酮胶囊2小时后插入。在暴露于孕酮胶囊仅2小时的动物中，核孕酮受体水平逐渐下降，同时血清孕酮水平下降。在连续暴露于胶囊的动物中，核受体蛋白受体水平再次下降，但速度略慢。为了测试孕酮胶囊去除对雌性性行为的影响，如所述处理卵巢切除的豚鼠，并每小时测试脊柱前凸。与连续暴露于孕酮胶囊的动物相比，暴露于孕酮胶囊2小时的组中的动物较少变得具有性接受性。在那些确实有反应的动物中，热终止发生在接受类似治疗的动物的核孕激素受体水平恢复到对照水平的同时。这些实验支持了热终止是由于下丘脑细胞核中resistin受体丢失的假设。此外，他们证明，循环孕酮水平在调节核孕酮受体保留中起作用。
The hypothesis that the termination of sexual receptivity (heat) in female guinea pigs results from loss of progestin receptors from hypothalamic cell nuclei was tested. First, we attempted to find an optimal dose of progesterone that would result in a prolonged period of sexual receptivity. Ovariectomized guinea pigs were implanted with 10% estradiol capsules. Forty hours later, each received one of several sized progesterone capsules before being tested hourly for lordosis. Surprisingly, none of the progesterone doses resulted in delayed heat termination. In order to determine whether elevated levels of estradiol and progesterone maintain elevated levels of nuclear progestin receptors despite the lack of effect on heat duration, animals were treated as described above except that only one size progesterone capsule (3.0 cm) or an empty capsule was implanted. Despite elevated serum progesterone concentrations, nuclear progestin receptor levels decreased gradually and approached control levels at about the same time as heat termination had occured in similarly-treated animals. Cytosol progestin receptor levels decreased following progesterone treatment and remained lowered at all times measured. In order to further investigate the relationship between blood progesterone concentrations and retention of nuclear progestin receptors we decreased blood progesterone concentrations by removing progesterone capsules 2 h following insertion. Nuclear progestin receptor levels declined gradually concurrent with a decline in serum progesterone levels in animals exposed to progesterone capsules for only 2 h. In animals exposed to capsules continuously, nuclearprogestin receptor levels again decreased but at a slightly slower rate. In order to test the effect of progesterone capsule removal on female sexual behavior, ovariectomized guinea pigs were treated as described and tested hourly for lordosis. Fewer animals in the group exposed to progesterone capsules for 2 h became sexually receptive as compared to animals continuously-exposed to progesterone capsules. Of those animals that did respond, heat termination had occured by the same time that nuclear progestin receptor levels had returned to control levels in similarly-treated animals. These experiments support the hypothesis that heat termination results from the loss of progestin receptors from hypothalamic cell nuclei. In addition, they demonstrate that circulating progesterone levels play a role in regulating nuclear progestin receptor retention.