Regulation of gonadotropin receptors by luteinizing hormone in granulosa cells.
Regulation of gonadotropin receptors by luteinizing hormone in granulosa cells.
复制标题
颗粒细胞中黄体生成素对促性腺激素受体的调节。
作者：
M. Rao;J. Richards;A. Midgley;L. Reichert
与黄体化相关，LH 导致 FSH 和 LH 受体含量减少，而 PRL 受体含量增加。为了阐明 LH 调节其自身受体的机制是否涉及受体的占据和/或损失，在用雌二醇和 FSH 引发的未成熟垂体切除大鼠的排卵前卵泡中检查了黄体化剂量的 LH 的影响。 LH 给药 24 小时后，可测量的 LH 受体含量下降了 82%。激素血清浓度下降 24 小时，降至 LH 给药 2 小时后测量浓度的 1.4%。施用碘化 LH 来证明体内位点的占据，导致体内结合的激素量在一段时间内下降。占用率的下降与体外测量的可用站点数量的减少是平行的。此外，用大剂量的高度纯化的 hFSH 代替 LH 会诱导黄体化和相关的促性腺激素受体丧失。这些结果表明黄体生成剂量的 LH 和 FSH 通过占据以外的机制诱导促性腺激素受体的损失。
In association with luteinization, LH induces a decrease in the content of receptors for FSH and LH and an increase in that for PRL. To elucidate if the mechanism by which LH regulates its own receptors involved occupancy of sites and/or loss of receptors the effects of a luteinizing dose of LH were examined in the preovulatory follicles of immature hypophysectomized rats primed with estradiol and FSH. The measurable LH receptor content declined by 82% 24 h after LH administration. Serum concentration of the hormone declined by 24 h to 1.4% of the concentration measured 2 h after LH administration. Administration of iodinated LH to demonstrate occupancy of sites in vivo, resulted in a decline in the amount of hormone bound in vivo, over a period of time. This decline in occupancy paralleled the decrease in the number of available sites as measured in vitro. Furthermore, a large dose of highly purified hFSH administered in lieu of LH induced luteinization and an associated loss of gonadotropin receptors. These results indicate that luteinizing doses of LH and FSH induce a loss in gonadotropin receptors by mechanisms other than occupancy.