Influence of sequence duration and number of electrical pulses upon rabbit oocyte activation and parthenogenetic in vitro development.

Electroactivation of in vivo mature young rabbit oocytes was investigated here. The effects of four or eight electrical pulse treatment over 90, 150 or 270 min upon oocyte activation frequency and type, and even upon their subsequent in vitro development, were studied. The lowest activation frequency was observed after applying four-pulses over 90 min (54%). However, extending four-pulse treatment duration over 150 or 270 min induced more oocytes to activate (from 84% to 100%), as did the eight pulsing treatments (from 91% to 97%). With eight pulses, extending treatment duration improved the normal activation rates (from 47% to 76%; P<0.05). Nevertheless, the haploid morulae and blastocyst rates decreased significantly with extended eight pulsing treatment duration (morulae: from 94% to 41% and blastocysts: from 31% to 0%).