FSH诱导卵丘细胞分泌一种促减数分裂物质(英文)

本实验利用卵母细胞的体外培养模型，将小鼠卵丘－卵母细胞复合体（ＣＥＯ）和去卵丘卵母细胞（ＤＯ）在体外培养，系统研究了促性腺激素（ＦＳＨ、ｈＣＧ）诱导小鼠卵母细胞减数分裂的机制。结果显示，ＦＳＨ能剂量依赖性地诱导ＣＥＯ恢复减数分裂（Ｆｉｇ．１），但对ＤＯ无影响；ｈＣＧ对 ＣＥＯ、 ＤＯ皆无效果（Ｆｉｇ．２）；用 ＦＳＨ预处理ＣＥＯ时间达到１小时后，就能显著诱导卵母细胞成熟，２小时后作用达到最大；不再增强（Ｆｉｇ．３）；用 ＦＳＨ处理ＣＥＯ ２小时及２４小时的培养液，能诱导ＤＯ恢复减数分裂，但预处理卵丘细胞２４小时的培养液，并不能诱导ＤＯ恢复减数分裂（Ｆｉｇ．４Ａ）；这种培养液在７０℃下３０分钟后，仍能刺激ＤＯ成熟（Ｆｉｇ．４Ｂ）；甾醇类物质合成抑制剂酮康唑，可剂量依赖性地抑制ＦＳＨ的促减数分裂恢复作用（Ｆｉｇ．５）。这些结果说明， ＦＳＨ可能诱导卵丘－卵母细胞复合体中的卵丘细胞分泌一种促减数分裂恢复物质；该物质作用于卵母细胞，诱导其恢复减数分裂而成熟；这种物质可能是一种甾醇类物质。

FSH can Induce Mouse Cumulus Oocyte to Secrete a Meiosis-activating Substance in vitro

The present experiment used cultured mouse cumulus enclosed oocyte (CEO) and denuded oocyte (DO) to study the mechanism of the regulation of gonadotrophin in mouse oocyte meiotic resumption. The results showed: (1) FSH (10-200IU/L) induced dosedependent oocyte meiotic resumption in CEO but has no effect on DO. A maximum increase in GVBD was observed with 25-50 IU/L FSH. hCG (10-400IU/L) can not stimulate the oocytes to resume meiosis in CEO; (2) The presence of FSH (50 IU/L) for 1 h was sufficient to induce meiotic resumption, which after 2 h reached a plateau similar to that of continuous presence of FSH; (3) Spent-media of FSH priming CEO for 2h or 24h induced the resumption of meiosis, but spent-media of FSH primed cumulus cells alone for 24h showed no effect on oocyte meiotic resumption. Furthermore, heating the spent media from 24h culture of CEO with FSH did not alter the stimulating effect; (4) Ketoconazole (10~7-10~-3mM) inhibited the dose-dependent effect of FSH in stimulating the resumption of meiosis. These results suggest that FSH induces cumulus cells in CEO to secrete a meiotic activating substance, possible a sterol, which overcomes the arrest effect of HX on the resumption of meiosis and induces oocyte meiotic resumption.