Fatehi A N, Zeinstra E C, Kooij R V, Colenbrander B, Bevers M M
Department of Farm Animal Health, Utrecht University, The Netherlands.
Theriogenology. 2002 Mar 1;57(4):1347-55. doi: 10.1016/s0093-691x(01)00717-8.
The aim of this study is to identify the effect of cumulus cells removal prior to the in vitro fertilization of matured bovine oocytes on cleavage rate. Denuded, matured oocytes were fertilized in presence or absence of loose cumulus cells, cumulus cell conditioned IVF medium (CCCM), charcoal-treated CCCM and charcoal-treated CCCM supplemented with progesterone at a final concentration of 150 ng/ml. After 18 h of incubation with sperm, the presumptive embryos were cultured on a BRL monolayer and the percentage of cleaved embryos was evaluated on Day 4. Removal of cumulus cells prior to IVF significantly reduced the cleavage rate (25% for denuded oocytes versus 56% for cumulus-oocyte complexes (COCs)). The addition of loose cumulus cells partially restored the effect of denudation (cleavage rate: 37% for denuded oocytes supplemented with loose cumulus cells versus 27% for denuded oocytes and 58% for COCs). CCCM also had a positive effect on the cleavage rate of oocytes denuded prior to IVF (36% for denuded oocytes fertilized in CCCM versus 14% for denuded oocytes). Treating the CCCM with charcoal resulted in complete loss of its effect on cleavage rate (18% for denuded oocytes fertilized in charcoal-treated CCCM versus 34% for denuded oocytes fertilized in CCCM). The addition of progesterone to charcoal-treated CCCM partially restored the reduction of the cleavage rate caused by charcoal treatment (27% for denuded oocytes fertilized in charcoal-treated CCCM supplemented with progesterone versus 14% for denuded oocytes fertilized in charcoal-treated CCCM and 36% for denuded oocytes fertilized in CCCM). In conclusion, removal of cumulus cells prior to IVF adversely affects the cleavage rate through loss of a factor secreted by these cells. This factor probably is progesterone.
本研究的目的是确定在成熟牛卵母细胞体外受精前去除卵丘细胞对卵裂率的影响。去除卵丘细胞的成熟卵母细胞在有或无松散卵丘细胞、卵丘细胞条件培养液（CCCM）、经活性炭处理的CCCM以及添加终浓度为150 ng/ml孕酮的经活性炭处理的CCCM存在的情况下进行受精。与精子孵育18小时后，将假定胚胎培养在牛胚肾（BRL）单层细胞上，并在第4天评估卵裂胚胎的百分比。体外受精前去除卵丘细胞显著降低了卵裂率（去除卵丘细胞的卵母细胞为25%，而卵丘 - 卵母细胞复合体（COCs）为56%）。添加松散卵丘细胞部分恢复了去卵丘处理的影响（卵裂率：添加松散卵丘细胞的去除卵丘细胞的卵母细胞为37%，去除卵丘细胞的卵母细胞为27%，COCs为58%）。CCCM对体外受精前去除卵丘细胞的卵母细胞的卵裂率也有积极影响（在CCCM中受精的去除卵丘细胞的卵母细胞为36%，去除卵丘细胞的卵母细胞为14%）。用活性炭处理CCCM导致其对卵裂率的影响完全丧失（在经活性炭处理的CCCM中受精的去除卵丘细胞的卵母细胞为18%，在CCCM中受精的去除卵丘细胞的卵母细胞为34%）。向经活性炭处理的CCCM中添加孕酮部分恢复了由活性炭处理导致的卵裂率降低（在添加孕酮的经活性炭处理的CCCM中受精的去除卵丘细胞的卵母细胞为27%，在经活性炭处理的CCCM中受精的去除卵丘细胞的卵母细胞为14%，在CCCM中受精的去除卵丘细胞的卵母细胞为36%）。总之，体外受精前去除卵丘细胞通过失去这些细胞分泌的一种因子而对卵裂率产生不利影响。这种因子可能是孕酮。
