Control of cell pH in immature primitive red cells from chick embryo.
1. The intracellular pH in primitive red cells from 4 day chick embryos was measured with the digitonin null-point method and the fluorescent indicator SNARF-1. At physiological pHe of 8.0 red cell pH is 7.39 at day 4. 2. The calculated proton equilibrium potential of -38 mV is in good agreement with previous measurements of Em (Engelke et al., 1988) and supports the conclusion that the Em is dominated by a proton conductance. 3. The sodium-proton exchanger is present in primitive red cells but quiescent under physiological conditions. 4. The results indicate that the bicarbonate-chloride exchange via Band 3 protein is impaired.
Sieger
U
U
Physiologisches Institut, Universität Regensburg, Germany.
Reinhardt
C
C
Baumann
R
R
D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism; D001639:Bicarbonates / Q000097:blood; D002245:Carbon Dioxide / Q000097:blood; D002352:Carrier Proteins / Q000097:blood; D002642:Chick Embryo; D002712:Chlorides / Q000097:blood; D004072:Digitonin; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism* / Q000502:physiology; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D017923:Sodium-Hydrogen Exchangers
D001457:Anion Exchange Protein 1, Erythrocyte; D001639:Bicarbonates; D002352:Carrier Proteins; D002712:Chlorides; D005456:Fluorescent Dyes; D017923:Sodium-Hydrogen Exchangers; D002245:Carbon Dioxide; D004072:Digitonin