Kinetic aspects of rabbit blastocoele fluid accumulation: An application of electron probe microanalysis☆

[摘要] X-rayspectrometrybyelectronprobeexcitationwasusedtoanalyzethecontentofNa,Cl,K,Ca,Mg,S,andPinpicolitersamplesofblastocoelefluidobtainedfromsinglerabbitblastocysts.Therearesignificantchangesintheconcentrationsoftheseelementsbetweenstagesofdevelopmentofblastocystsinvivo.TheconcentrationofKincreasesapprox40%between110–135hrpostcoitum(p.c.)anddoesnotincreasefurtherby159hr.TheconcentrationsofClat110and135hrp.c.aresignificantlylowerthantheCllevelat159hrp.c.Theconcentrationsofmagnesiumareverylow(lessthan0.4mM)ateachstageofdevelopment.CaandSconcentrationsdonotchangeduringdevelopment,whereasPdecreasesfrom110–135hrp.c.Theratesofaccumulationofthesolutesintherabbitblastocoeleinvivohavebeenestimatedfromthemeasuredconcentrationsandfrompreviouslypublishedratesoffluidaccumulation.Theseanalysesindicatethateachtrophoblastcelltransportsaneverincreasingquantityofcertainsoluteswhichiscloselycorrelatedwiththeinwardmovementofwater.Rabbitblastocystsraisedinvitrofrom128–140hrp.c.canaccumulatefluidinthepresenceofincreasingconcentrationsofsucrose(40,80,120mM).ElectronprobemicroanalysisoftheblastocoelefluidundertheseconditionsshowsthattheblastocoeleconcentrationsofbothNaandCl(butnotK,Ca,Mg,S,andP)increase1mMinresponsetoevery2mMofsucrosegradientacrossthetrophectoderm.TheseresultsdirectlyindicatethattheaccumulationoffluidintheblastocoeleissecondarytotheactivetransportofNaCl.

[学科分类] 生物科学（综合）