In vitro use of arresters of meiosis could improve cytoplasmic maturation of immature oocytes by controlling the period of prophase I. Phosphodiesterases (PDE) are responsible for the breakdown and concomitant inactivation of the cyclic nucleotides @entity268 and @entity6708 and are implicated in the regulation of oocyte meiotic maturation. Selective inhibitors of phosphodiesterase type 3 (PDE3) prevent meiotic resumption of @entity1 oocytes. This study evaluated the impact of @entity1167 by PDE3 inhibitor, @entity56228 , on developmental competence of geminal vesicle (GV)-stage oocytes from small antral follicles. Cumulus-oocyte complexes (COC), retrieved from antral follicles 24 h after eCG exposure and cultured in the presence of PDE3 inhibitor (10 microM) for an additional 24 h, remained arrested in the meiotic prophase. The GV configuration of oocytes before and after the arrest by PDE3 inhibitor was examined. After the period of @entity1167 , a significantly increased proportion of oocytes had acquired a nucleolus surrounded by a condensed chromatin rim at the GV, which is a morphological correlate of transcriptional repression. Removal of inhibitor resulted in 90.6% +/- 8.3% of oocytes with the first polar body extruded. Fertilization was significantly improved in oocytes that had been arrested compared with oocytes collected 24 h after eCG and undergoing in vitro maturation immediately. Embryonic preimplantation and live offspring rates of arrested oocytes were higher, although not significantly, than those of nonarrested oocytes. These results suggest that a temporal block of meiosis by PDE3 inhibitor promotes developmental competence of @entity19 oocytes retrieved from small antral follicles.

Effect of phosphodiesterase type 3 inhibitor on developmental competence of immature XXXX oocytes in vitro.

@entity268 :: ('CHEBI:17489', 'Chemical') :: ['cAMP'] @entity6708 :: ('CHEBI:16356', 'Chemical') :: ['cGMP'] @entity1 :: ('9606', 'Species') :: ['mammalian'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity56228 :: ('MESH:C097915', 'Chemical') :: ['Org 9935'] @entity1167 :: ('MESH:D006323', 'Disease') :: ['meiosis arrest']
@entity19 :: (10090,Species) :: ['mouse']
