Eppig J J, Downs S M
Dev Biol. 1987 Feb;119(2):313-21. doi: 10.1016/0012-1606(87)90037-6.
The concentration of hypoxanthine in mouse follicular fluid has been estimated to be 2-4 mM, and although this concentration maintains meiotic arrest in fully grown mouse oocytes in vitro, oocyte maturation in vivo is not induced by a decrease in the concentration of this purine in follicular fluid (J. J. Eppig, P. F. Ward-Bailey, and D. L. Coleman, Biol. Reprod. 33, 1041-1049, 1985). In the present study, the effect of 2 mM hypoxanthine on oocyte growth and development in vitro was assessed and the ability of gonadotropins to stimulate oocyte maturation in the continued presence of hypoxanthine was determined. Oocyte-granulosa cell complexes were isolated from 10- to 11-day-old mice and cultured in the presence or absence of 2 mM hypoxanthine. Oocytes from 10- to 11-day-old mice are in mid-growth phase and, without further development, are incompetent of undergoing meiotic maturation. During a 12-day culture period the granulosa cell-enclosed oocytes approximately doubled in size and, regardless of the presence or absence of hypoxanthine, 50-70% developed competence to undergo germinal vesicle breakdown (GVBD). Hypoxanthine promoted the continued association of oocytes with their companion granulosa cells during the 12-day culture period, and therefore had a beneficial effect on oocyte development. Most of the oocytes that acquired GVBD competence in the absence of hypoxanthine underwent spontaneous GVBD. In contrast, 95% of the GVBD-competent oocytes were maintained in meiotic arrest by hypoxanthine. Following withdrawal of the hypoxanthine after the 12-day culture, 75% of the GVBD-competent oocytes underwent GVBD. These results show that hypoxanthine, and/or its metabolites, maintains meiotic arrest in oocytes that grow and acquire GVBD competence in vitro. Follicle-stimulating hormone (FSH), but not luteinizing hormone or human chorionic gonadotropin, induced oocyte GVBD in the continued presence of hypoxanthine. FSH stimulated oocyte maturation at a significantly (P less than 0.01) higher frequency than coculture of the granulosa cell-denuded oocytes with granulosa cells in the continued presence of hypoxanthine. FSH did not induce the maturation of denuded oocytes cocultured with granulosa cells.(ABSTRACT TRUNCATED AT 400 WORDS)
据估计，小鼠卵泡液中次黄嘌呤的浓度为2 - 4 mM，尽管该浓度能在体外维持完全成熟的小鼠卵母细胞减数分裂停滞，但卵泡液中这种嘌呤浓度的降低并不会诱导体内卵母细胞成熟（J. J. 埃皮格、P. F. 沃德 - 贝利和D. L. 科尔曼，《生物学繁殖》33卷，1041 - 1049页，1985年）。在本研究中，评估了2 mM次黄嘌呤对体外卵母细胞生长和发育的影响，并确定了促性腺激素在次黄嘌呤持续存在的情况下刺激卵母细胞成熟的能力。从10至11日龄小鼠中分离出卵母细胞 - 颗粒细胞复合体，在有或无2 mM次黄嘌呤的情况下进行培养。10至11日龄小鼠的卵母细胞处于生长中期，若不进一步发育，则无能力进行减数分裂成熟。在12天的培养期内，被颗粒细胞包裹的卵母细胞大小约增加一倍，无论有无次黄嘌呤，50 - 70%的卵母细胞发育出进行生发泡破裂（GVBD）的能力。次黄嘌呤在12天培养期内促进了卵母细胞与其相伴颗粒细胞的持续结合，因此对卵母细胞发育有有益作用。在无次黄嘌呤情况下获得GVBD能力的大多数卵母细胞会自发发生GVBD。相比之下，95%具有GVBD能力的卵母细胞被次黄嘌呤维持在减数分裂停滞状态。在12天培养后去除次黄嘌呤，75%具有GVBD能力的卵母细胞发生了GVBD。这些结果表明，次黄嘌呤和/或其代谢产物能维持在体外生长并获得GVBD能力的卵母细胞的减数分裂停滞。促卵泡激素（FSH），而非促黄体生成素或人绒毛膜促性腺激素，在次黄嘌呤持续存在的情况下诱导卵母细胞GVBD。FSH刺激卵母细胞成熟的频率显著（P小于0.01）高于在次黄嘌呤持续存在的情况下将去颗粒细胞的卵母细胞与颗粒细胞共培养。FSH不会诱导与颗粒细胞共培养的去颗粒细胞卵母细胞成熟。（摘要截取自400字）
