Improvement of meiotic competence of follicular oocytes by artificial techniques

1.化学方法提高卵泡卵母细胞的减数分裂能力用针头和刀片机械分离卵巢中不同大小的卵母细胞。这种方法从一个卵巢中获得26.2，7.4个完全皱眉的卵母细胞。卵丘包被的卵母细胞在含10%胎牛血清的TCM199中进行体外培养，90m直径的卵母细胞均未恢复减数分裂。然而，在直径超过91m的卵母细胞中观察到生发泡破裂(GVDB)，在直径超过101m的卵母细胞中观察到极体的形成，在直径121m的卵母细胞中，约80%的卵母细胞能够挤出极体。在直径101~120m的卵母细胞中，在含有二丁酰环腺苷3‘，5’-单磷酸的培养液中，具有第一极体的卵母细胞比例增加。这些观察结果表明，二丁酰环腺苷3‘，5’-单磷酸可以提高牛…的减数分裂能力。结论：1.培养中含碱卵母细胞较多。体外培养的小鼠卵泡卵母细胞在改良的Krebs-Ringer溶液中培养72h以上后，可自发分割形成含有或不含不清楚片段或染色质的“卵裂球”。从牛卵泡液中分离出的糖胺多聚糖(GAG)，加入浓度为0.25 mg/ml或更高的悬浮培养液中，可剂量依赖性地抑制去卵丘小鼠卵母细胞的自发分裂。活性物质经Dowex1-x2柱层析分离得到。用0.5M氯化钠洗脱的部分生物活性最强。从商业饲料中提纯的BFF-GAG、透明质酸和硫酸软骨素的制备防止了分割的发生。透明质酸比硫酸软骨素更有效。结果表明，GAGS可防止卵母细胞体外退化。较少

1. Improvement of meiotic competence of follicular oocytes by chemicalsOocytes of various sizes were isolated from ovaries by mechanical dissection using the gauge-needle and razor blade. This method yielded 26.2 7.4 growing and fully frown oocytes from an ovary. Cumulus-enclosed oocytes dissociated from the ovaries were cultured in vitro in a TCM 199 containing 10% fetal calf serum, none of the 90 m-diameter oocytes resumed meiosis. However germinal vesicle breakdown (GVDB) was observed in oocytes of which diameter exceeded 91 m. Polar body formation was observed in oocytes which have the diameter exceeding 101 m. About 80% of the 121 m-diameter oocytes were able to extrude the polar body. The percentage of oocytes with first polar body increased when incubated in the medium containing dibutyryl cyclic adenosine 3',5'-monophosphate in 101-to 120 m-diameter oocytes. These observations indicate that dibutyryl cyclic adenosine 3',5'-monophosphate can improve the meiotic competence of bov … More ine oocytes in culture.2. Prevention of soontaneous degeneration of mouse oocytes in culture by ovarian glycosaminoglycansMouse follicular oocytes cultured for more than 72 h in modified Krebs-Ringer solution in vitro undergo spontaneous segmentation to form "blastomeres" with or without unclear fragments or chromatin. Glycosaminoglycans(GAGs) isolated from bovine follicular fluid(bFF) and added to the suspending medium at concentrations of 0.25mg/ml or greater prevented the occurence of spontaneous segmentation in isolated cumulus-free mouse oocytes in a dose-dependent manner. The active material was isolated from bFF by chromatography on dowex 1-x2. The fraction eluted with 0.5 M NaCl plssessed the greatest biological activity. Preparations of purified bFF-GAGs and hyaluronic acid and chondroitin sulfate from a commercial soutce prevented the occurence of segmentation. Hyaluronic acid was more potent than chondroitin sulfate. The results indicate that GAGs prevent degeneration of oocyte in vitro. Less