Instituto Universitario IVI Valencia, Valencia, Spain.
Fertil Steril. 2012 Nov;98(5):1147-51. doi: 10.1016/j.fertnstert.2012.07.1116. Epub 2012 Aug 14.
To evaluate the dynamics of the nuclear maturation (NM) of in vitro-matured (IVM) oocytes and to determine the most favorable duration of meiosis II (MII) arrest in relation to the normal activation response.
Experimental.
University-affiliated infertility clinic.
PATIENT(S): Donated immature germinal vesicle oocytes (GV).
INTERVENTION(S): The GV underwent spontaneous IVM and the dynamics of NM studied by real-time monitoring. The IVM oocytes were parthenogenetically activated at different MII arrest points and their response assessed.
MAIN OUTCOME MEASURE(S): Moment of GV breakdown; extrusion of the first polar body; duration of MI and MII arrest; activation rate (AR) and type.
RESULT(S): Two GV populations-early (E-IVM, 18.4 ± 2.7 hours) and late (L-IVM, 26.3 ± 3.8 hours) maturing-were defined according to the time required for extrusion of the first polar body. Significantly more E-IVM than L-IVM exhibited a normal activation response (61.3% vs. 34.6%), but AR were similar (average, 88.6%) in both groups. Duration of the GV stage differed between the two groups, but MI arrest (14.0 ± 0.3 hours) was constant. The E-IVM arrested at MII for at least 4.3 hours displayed significantly lower AR and similar normal activation rates (61.3%) to E-IVM arrested for a shorter time (83.9% vs. 100%). The L-IVM displayed a similar AR (80.8%), but lower normal activation rates than E-IVM (34.6%), regardless of when activation took place.
CONCLUSION(S): The success of IVM depends on the NM timing rather than on the length of MII arrest.
评估体外成熟（IVM）卵母细胞的核成熟（NM）动力学，并确定与正常激活反应相关的最有利的 MII 期阻滞持续时间。
实验。
大学附属不孕诊所。
捐赠的不成熟生发泡卵母细胞（GV）。
GV 经历自发的 IVM，并通过实时监测研究 NM 的动力学。IVM 卵母细胞在不同的 MII 阻滞点进行孤雌激活，并评估其反应。
GV 破裂的时刻；第一极体的挤出；MI 和 MII 阻滞的持续时间；激活率（AR）和类型。
根据挤出第一极体所需的时间，定义了两个 GV 群体-早期（E-IVM，18.4±2.7 小时）和晚期（L-IVM，26.3±3.8 小时）成熟。与 L-IVM 相比，显著更多的 E-IVM 表现出正常的激活反应（61.3%对 34.6%），但两组的 AR 相似（平均，88.6%）。两组之间的 GV 阶段持续时间不同，但 MI 阻滞（14.0±0.3 小时）是恒定的。E-IVM 在 MII 期至少阻滞 4.3 小时，显示出明显较低的 AR 和与阻滞时间较短的 E-IVM 相似的正常激活率（61.3%对 83.9%）（83.9%对 100%）。L-IVM 显示出相似的 AR（80.8%），但与 E-IVM 相比，正常激活率较低（34.6%），无论何时发生激活。
IVM 的成功取决于 NM 的时间，而不是 MII 期阻滞的长度。
