The ionic basis of the membrane potential in the early Asterias embryo☆
[摘要] TheionicbasisoftherestingpotentialinthefertilizedAsteriasembryohasbeeninvestigated.Theresponseofthemembranepotential(asdeterminedbyintracellularmicroelectrodes)tochangesinexternalKconcentrationwasstableandreversibleupto200mMK.ThetimecourseandmagnitudeoftheresponseobserveduponchangesinexternalKisessentiallyindependentoftheconcentrationofexternalCl.ThereisasignificanteffectofNaiononthemembranepotential,especiallyatlowexternalK.TheresponseofthemembranepotentialtochangesinexternalKcouldbepredictedbyaformoftheconstantfieldequation.PlotsofeVFRTversusexternalK,inconjunctionwiththeconstantfieldequation,allowanestimateoftheinternalKconcentrationandtheratioofNatoKpermeability(PNaPK).TheseplotsindicateatthisstageofdevelopmentaninternalKconcentrationofapproximately200mMandaPNaPKof0.03.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
