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GB Segel, SA Feig, BE Glader, A Muller, P Dutcher and DG Nathan
Three models of disturbed erythrocyte metabolism, triose-depleted normal,
phosphoglycerate kinase (PGK)-deficient, and pyruvate kinase (PK)-deficient
cells, have been studied to examine further the role of PGK in erythrocyte
cation transport. Sodium (Na-+) and potassium (K-+) transport were reduced
only in cells fully depleted of triose. In such cells the PGK step
presumably was inoperative due to total lack of substrate;
2,3-diphosphoglycerate (2,3-DPG) then became the sole substrate source for
remaining steps in glycolysis. At increased intracellular Na-+
concentrations which normally stimulate transport and glycolysis,
triose-depleted cells had marked impairment of cation transport and
ouabain-inhibitable lactate and pyruvate production from 2,3-DPG.
PGK-deficient cells and normal cells with high intracellular Na-+
concentrations had similar increases in transport and ouabain- inhibitable
lactate production. PK-deficient cells with high intracellular Na-+
concentrations showed an appropriate increase in transport but less
stimulation of lactate production. Transport was not related to total
cellular adenosine triphosphate (ATP) concentration. These data suggested
that normal coupled cation transport occurred despite diminished metabolite
flow through PGK, as in PGK- or PK- deficient cells. Transport was
diminished only in triose-depleted cells where metabolite flow through PGK
was presumably absent. These data, therefore, support the concept that
transport and glycolysis interact at the PGK step, although impairment of
PGK must be profound before its effect on transport is evident.
This article has been cited by other articles:
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| Copyright © 1975 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
