22Sodium and 45Calcium uptake during embryonic induction in Rana pipiens☆
[摘要] Theuptakesof22Naand45CabyearlyembryosofRanapipiensandbyhybridembryosofR.pipiensfemales×R.sylvaticamaleshavebeenmeasured.IntracellularNauptakeincreasessharplyatmidgastrula,whereasCauptakerisesabruptlyatneuralplatestage.Arrestedhybridgastrulaeshowloweruptakeof22Naand45Ca,indicatingthatnormalintracellularincreasesinuptakeofisotopesarecorrelatedwithdevelopment,notwithdurationofexposuretoisotopeorchangesinpermeabilitywithtime.Uptakeof22NabyhybridembryosisremarkablyincreasedbyprostaglandinE1(acompoundwhosephysiologicalroleinvolvesthetransportofNaacrosscellmembranesdependinguponCamobilizationandtransport).Curvesforuptakeof22Naand45Cabytheyolkregionoftheembryocloselyresemblethoseforwholeembryosatthesamestages.Atneuralplate,anteriorregionsofneuralplateplusarchenteronroofexhibithigherratesofuptakethanmoreposteriorexplants.Theexperimentsshowthat,astheembryodevelops,theuptakeof22Naand45Caincreases.WesuggestthatNaandCaarereleasedfrompreviouslyboundstate,possiblyfromyolkplatelets,andthuscanexchangewiththeisotopes.Ifso,theexperimentssupporttheviewthatnormalembryonicinductionisinitiatedbychangesinintracellularcations,assuggestedbyourearlierstudiesusingacellculturesystem.
[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]
