Goud P T, Goud A P, Laverge H, De Sutter P, Dhont M
Infertility Centre, Department of Obstetrics and Gynaecology, University Hospital, Ghent, Belgium.
Mol Hum Reprod. 1999 Mar;5(3):227-33. doi: 10.1093/molehr/5.3.227.
The occurrence of parthenogenetic activation is a major hurdle in obtaining sperm chromosome metaphases after heterospecific intracytoplasmic sperm injection (ICSI) of golden hamster oocytes with human spermatozoa. We addressed two potential contributors to parthenogenetic activation namely, post-ovulatory age of the oocyte and Ca2+ content of the injection medium. In serial experiments, hamster oocytes were retrieved at 11.5, 13, 16 and 21 h after the ovulatory dose of human chorionic gonadotrophin (HCG) and microinjected with human spermatozoa suspended alternately in a regular (1.9 mM Ca2+) or a Ca2+-free medium. A progressive decrease in the rates of male pronucleus (MPN) formation and metaphase entry and increase in the rates of parthenogenetic activation without male pronucleus occurred with increasing post-ovulatory age. The favourable influence of Ca2+-free injection medium on the mean rates of MPN and metaphase entry was restricted to the relatively older oocytes (MPN 16 h: 49.5 versus 32.3%, P< 0.008; 21 h: 22.2 versus 11.1%, P< 0.001; metaphase entry 16 h: 36.8 versus 25.1%, P< 0.02; 21 h: 13.3 versus 5.2%, P< 0.01 in the Ca2+-free and regular groups respectively). Our data confirm the increased activation sensitivity with post-ovulatory ageing and its adverse influence on the MPN formation and metaphase entry after heterospecific ICSI of hamster oocytes.
孤雌激活的发生是在用人类精子对金黄地鼠卵母细胞进行异种胞浆内单精子注射（ICSI）后获取精子染色体中期相的一个主要障碍。我们探讨了孤雌激活的两个潜在因素，即卵母细胞的排卵后年龄和注射介质中的钙离子含量。在系列实验中，在注射人绒毛膜促性腺激素（HCG）排卵剂量后的11.5、13、16和21小时采集金黄地鼠卵母细胞，并用分别悬浮于常规（1.9 mM钙离子）或无钙介质中的人类精子进行显微注射。随着排卵后年龄的增加，雄原核（MPN）形成率和进入中期的比率逐渐下降，而无雄原核的孤雌激活率增加。无钙注射介质对MPN平均率和进入中期的有利影响仅限于相对较老的卵母细胞（MPN 16小时：分别为49.5%对32.3%，P<0.008；21小时：22.2%对11.1%，P<0.001；进入中期16小时：36.8%对25.1%，P<0.02；21小时：13.3%对5.2%，P<0.01，分别为无钙组和常规组）。我们的数据证实了随着排卵后老化激活敏感性增加及其对金黄地鼠卵母细胞异种ICSI后MPN形成和进入中期的不利影响。
