Effect of the inhibitor of cdk and specific phosphodiesterase isoenzyme inhibitors on ovine oocytes meiotic maturation in vitro

The present works studied the effect of inhibitor of cdk and specific inhibitors of phosphodiesterase on ovine oocyte maturation. Milrinone and Rolipram are specific PDE inhibitors and Roscovitine(ROSC) is a selective inhibitors of the cyclin-dependent kinase. These chemicals are selected to evaluated the effect on meiotic resumption of ovine oocytes for 24 h in vitro. Oocytes that treated with ROSC for 24 h and subsequently allowed to undergo maturation for 24 h in the absence of the inhibitor media but have FSH(20 IU/L). Immature ovine cumulus oocyte complexes were recovered from ovaries collected at the abattoir. The doses of inhibitors was 50 #mu#mol/L in medium. At the end of the incubation, COC were denuded and oocytes werethen fixed and classified according to the status of nuclear maturation. The results revealed that both PDE3 inhibitor Milrinone and cdk inhibitor ROSC prevented oocyte spontaneous meiotic maturation. In contrast, the PDE4 inhibitor Rolipram had no effect. And ROSC have a high effect to maintain ovine oocytes in meiotic arrest than Milrinone. These results suggests that type 3 PDE and cyclin-dependent kinase have an important role in meiotic resumption of ovine oocytes, but the mechanisms underlying these effects are different and require further characterization.