Effects of PDE-resistant cAMP analog pulsing on oocyte maturation. mbcAMP-arrested DO were pretreated 3 h with increasing concentrations of Sp-cAMP-AM (A) or SP-5,6-DCI-cBIMPS (B) and then washed and cultured in mbcAMP alone for 17-18 h before assessment of GVB. Oocytes continuously cultured in mbcAMP or mbcAMP plus Sp-cAMP-AM (A) or SP-5,6-DCI-cBIMPS (B) for 20-21 h served as controls. Groups with no common letter are significantly different. (C) Western analysis of pPRKA and pACACA in SP-5,6-DCI-cBIMPS-pulsed GV-stage oocytes. After 3 h pretreatment in 1 mM mbcAMP plus 6 mM SP-5,6-DCI-cBIMPS, DO were washed and cultured 2 h in mbcAMP. DO cultured in mbcAMP or mbcAMP plus 200 μM SP-5,6-DCI-cBIMPS for 5 h served as controls. The mean pPRKA/ACACA and pACACA/ACACA ratios from 4 blots are shown, normalized to the mbcAMP alone group.