Differential Effects of Specific Phosphodiesterase Isoenzyme Inhibitors on Bovine Oocyte Meiotic Maturation

[摘要] ThedifferentialregulationofcAMPlevelswithintheoocyteandsomatic(cumulus)cellcompartmentsofthebovinefollicle,andthesubsequentregulationofoocytemeioticmaturationwasexaminedthroughspecificcell-typelocalisationofphosphodiesterases(PDEs).SelectivePDEinhibitorswereusedtomodulatecAMPlevelsineachofthetwofollicularcompartmentsandtoexaminetheireffectsonoocytemeioticmaturation.Ovarieswereobtainedfromanabattoirandcumulus-oocytecomplexes(COC)wereaspiratedfromantralfolliclesintoculturemediumsupplementedwith4mg/mlBSAand2mM3-isobutyl-1-methylxanthine(IBMX).COC,denudedoocytes(DO),ormuralgranulosacells(MGC)wereculturedeitherwithorwithoutforskolinorFSH,inthepresenceofspecificPDEinhibitors;eithermilrinone(PDE3inhibitor),cilostamide(PDE3inhibitor),orrolipram(PDE4inhibitor).COC/DOcultureswereassessedformeioticprogressionandcAMPcontent,andMGCforcAMPproduction.Thetype3PDEinhibitor,butnotthetype4,preventedspontaneousmeioticmaturationandelevatedintraoocytecAMPincultureddenudedoocytes.Incontrast,thetype4PDEinhibitorhadnoeffectontheoocyte,butelevatedmuralgranulosaandcumuluscellcAMPproduction.TheresultsofthisstudyindicatethatspecificPDEsubtypesaredifferentiallylocalisedwithinthetwocompartmentsofthebovinefollicle—thetype3PDEintheoocyteandthetype4PDEinthegranulosacells.Inaddition,oocytecAMPlevelsareprimarilyregulatedinbovineoocytesbyitsdegradationbyPDE,whereasgranulosacellcAMPlevelsarecontrolledmainlybyactiveadenylatecyclase,withbothsourcesabletoparticipateinoocytemeioticregulation.

[学科分类] 生物科学（综合）

[关键词] oocyte;meiotic maturation;meiotic inhibition;cAMP;phosphodiesterase;granulosa cell