The development of an active transport system for potassium in the embryonic avian erythrocyte☆

[摘要] Measurementsweremadeofwater,Na,andKcontentofthealbumin,yolk,subembryonicliquid,andwholeblastulaofthechick24hrafterfertilization.TheclosesimilarityofcellNaandKconcentrationstothoseofthesubembryonicliquid(Na,22:27;K,24:31)andtheabsenceofouabain-inhibitableuptakeof42Kbytheblastulasuggestedthatcellsandsubembryonicliquidwereindiffusionequilibrium.ThelossofvirtuallyallnonerythrocytecellsuponthetransferofthedeembryonatedblastulatoaculturemediumallowsinvestigationforevidenceofdevelopmentofanNa:Kpumpintheerythrocyte.At24hrtheculturedcellsmaintainedcationgradientsof40:140mequiv/literforNaand49:5mequiv/literforK.At48hrthefigureswere33:140mequiv/literforNaand58:5mequiv/literforK.Thecellsculturedfor24hrtookup13.4%ofavailable42Kwithoutouabainand2.8%with10−5Mouabain,(P<0.001).At48hrthecellstookup14.2%of42Kwithoutouabainand4.9%withouabain(P<0.001).ItappearsthatnocellinthechickblastulacantransportKactivelyat24hr,but48hrafterfertilizationanactivetransportmechanismcanbeidentifiedwhichcancreateandmaintaintransmembraneKgradients.

[学科分类] 生物科学（综合）