人类成熟卵母细胞经慢速冷冻保存后纺锤体形态变化的研究

Objective: Meiotic spindle destruction is one of the critical problems responsible for the low survival and vitality of the frozen-thawed metaphaseⅡ(MⅡ) human oocytes. This study is designed to discover how long the meiotic spindles need to reorganize well. Material and method: 89 MⅡoocytes of 14 consenting patients undergoing ovarian stimulated cycles were collected in the Reproductive Center of Shandong University and Shandong Provincial Hospital. 71 oocytes of 11 patients were cryopreserved with a 1.5mol/L 1,2-propanediol +0.3mol/L sucrose solution . After thawing, oocytes from the same patient were divided randomly into 3 groups and incubated at 37℃ for 1,3,5 hours respectively before immunostaining of tubulin and chromatin and at last visualizing by confocal microscopy.18 oocytes retrieved from 3 patients as control were immunostained without freezing. Result: Statistically significant increase was observed in spindle configurations of oocyte from 3 hours incubation compared to 1 hour incubation(P<0.05), while no differences were found in 3 hours, 5 hours and control groups. And we didn’t find statistical differences in the chromosomes configurations of the four groups(P<0.05). Conclusion: After 3 hours incubation the spindle is reorganized in most of the oocytes while 2 more hours incubation doesn’t give apparent rise to the percentage of the spindle configuration. It suggests that proper cryopreserved procedures could protect the meotic spindle well and oocytes should at least be cultured for 3 hours after thawing for spindle reasons before routine intracytoplasmic sperm injection(ICSI) was carried out.