Effect of activation with Ca ionophore A23187 and puromycin on the development of human oocytes that failed to fertilize after intracytoplasmic sperminjection

Objective: To determine the effect of sequential oocyte activation with cal cium ionophore A23 187 (A23187) and puromycin on oocytes that were unfertil ized after intracytoplasmic sperm injection (ICSI). Design: Laboratory examination. Setting: The in vitro fertilization(embryo transfer unit in Tokushima Unive rsity Hospital. Patient(s): Discarded unfertilized oocytes following ICSI. Intervention(s): All 172 oocytes that showed no evidence of normal fertiliz ation 18 hours after ICSI were exposed to A23187 (5 muM) for 5 minutes and consequently were treated with puromycin (10 mug/mL) for; 5 hours. Main Outcome Measure(s): The activation rate, proportion of oocytes that sh owed two pronuclei with the second polar body (2PN2PB), and cleavage rate w ere calculated. Chromosomal analysis of the oocytes with 2PN2PB was also pe rformed. Result(s): The treatment activated 146 out of 172 oocytes (84.9%) and 30.1% of the activated oocytes showed 2PN2PB. Sixteen of 25 oocytes with 2PN2PB (64.0%) cleaved. There was no difference in the activation rate, proportion of activated oocytes with 2PN2PB, or cleavage rate between oocytes that we re injected; with a motile spermatozoon and those injected with an immotile spermatozoon. Chromosomal analysis showed a normal diploid set of chromoso mes (n = 46) in four of five analyzable oocytes. Conclusion(s): The sequential treatment of calcium ionophore A23187 and pur omycin activates unfertilized oocytes after ICSI. The resultant oocytes wit h 2PN2PB can cleave. (C) 2001 by American Society for Reproductive Medicine .