Byskov A G, Andersen C Y, Leonardsen L, Baltsen M
Laboratory of Reproductive Biology, Juliane Marie Center for Children, Women and Reproduction, University Hospital of Copenhagen, DK-2100 Copenhagen, Denmark.
J Exp Zool. 1999 Oct 15;285(3):237-42.
In mammals two meiosis activating sterols (MAS) have been found to activate meiotic resumption in mouse oocytes, in vitro. FF-MAS (4, 4-dimethyl-5alpha-cholesta-8,14,24-triene-3beta-ol) was extracted from human preovulatory follicular fluid and T-MAS (4, 4-dimethyl-5alpha-cholest-8,24-diene-3beta-ol) from bull testicular tissue. Quite unexpected, these two sterols, which introduce the cholesterol biosynthetic pathway from lanosterol, may be locally acting substances with important physiological function for reproduction. FF-MAS and T-MAS are present in the preovulatory follicular fluid of different mammalian species and have the capacity to initiate resumption of meiosis in mouse oocyte cultured in the presence of hypoxanthine, a natural meiosis maturation inhibitor. FF-MAS is produced by the cumulus cells of intact oocyte-cumulus complexes upon FSH-stimulation and provides the oocyte with a go-signal for the resumption of meiosis. T-MAS constitutes the vast majority of MAS found in the mammalian testis and in the human ejaculate; in particular a high concentration is found in the spermatozoa. T-MAS may be produced by the spermatids and the presence of T-MAS in spermatozoa may suggest that T-MAS plays a role in fertilization by affecting the second meiotic division.J. Exp. Zool. (Mol. Dev. Evol.) 285:237-242, 1999.
在哺乳动物中，已发现两种减数分裂激活甾醇（MAS）可在体外激活小鼠卵母细胞的减数分裂恢复。卵泡液源性减数分裂激活甾醇（FF-MAS，4,4-二甲基-5α-胆甾-8,14,24-三烯-3β-醇）是从人排卵前卵泡液中提取的，而睾丸源性减数分裂激活甾醇（T-MAS，4,4-二甲基-5α-胆甾-8,24-二烯-3β-醇）是从公牛睾丸组织中提取的。非常出乎意料的是，这两种从羊毛甾醇引入胆固醇生物合成途径的甾醇，可能是具有重要生殖生理功能的局部作用物质。FF-MAS和T-MAS存在于不同哺乳动物物种的排卵前卵泡液中，并且有能力在次黄嘌呤（一种天然的减数分裂成熟抑制剂）存在的情况下，启动培养的小鼠卵母细胞减数分裂的恢复。FF-MAS是由完整的卵母细胞-卵丘复合体的卵丘细胞在促卵泡激素刺激下产生的，并为卵母细胞提供减数分裂恢复的启动信号。T-MAS是在哺乳动物睾丸和人类精液中发现的MAS的绝大部分；特别是在精子中发现高浓度的T-MAS。T-MAS可能由精子细胞产生，并且精子中T-MAS的存在可能表明T-MAS通过影响第二次减数分裂在受精过程中发挥作用。《实验动物学杂志（分子发育与进化）》285:237 - 242，1999年。
