Effects of forskolin-pulsing on oocyte meiotic resumption. (A) Forskolin dose response. Denuded oocytes (DO), maintained in meiotic arrest with 1mM mbcAMP, were pulsed with increasing concentrations of forskolin for 3 h, washed free of forskolin, and cultures were continued in mbcAMP alone for 17-18 h before assessment of GVB. Other oocytes were continuously cultured with or without 100 μM forskolin in the meiotic-arresting medium for 20-21 h. Groups with no common letter are significantly different. (B) Maturation kinetics. Oocytes were treated as in (A) for 3 h; then, post-pulse cultures were carried out in medium drops under oil, with meiotic maturation assessed after the designated time periods.