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Studies on the energy metabolism of opossum ( Didelphis Virginiana ) erythrocytes. I. Utilization of carbohydrates and purine nucleosides
Author(s) -
Bethlenfalvay N. C.,
Lima J. E.,
Waldrup T.
Publication year - 1984
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041200110
Subject(s) - inosine , biochemistry , dihydroxyacetone phosphate , fructose , chemistry , dihydroxyacetone , pentose phosphate pathway , metabolism , energy charge , chromatography , glycolysis , phosphate , glycerol , adenosine , adenylate kinase , enzyme
Opossum erythrocytes filtered through cellulose columns were used to estimate their permeability to D‐glucose and optimum inorganic phosphate requirement for D‐glucose utilization at pH 7.4 and 8.1. D‐Glucose readily penetrated opossum red cells; there was no measurable difference whether plasma or electrolyte solution served as the suspending medium. Optimum extracellular inorganic phosphate concentration for glucose utilization as indicated by red cell lactate production was pH‐dependent, with a sharp optimum of 30 mmol/liter at pH 8.1. Whereas glucose, fructose, mannose, dihydroxyacetone, adenosine, and inosine were readily utilized at pH 7.4 and Pi 30 mmol/liter as shown by net lactate and ATP production by the red cells, galactose and ribose as substrates were not metabolized. In electrolyte, Pi 30 mmol/liter, and pH 7.4 glucose utilization by opossum red cells averaged 3.5 μmol, at pH 8.1, 9.5 μmol/ml cells/hr were utilized. Red cells suspended in leukocyte‐free plasma utilized D‐glucose at a rate of 3.0 μmol/ml/hr at pH 7.5. Seven percent of D‐glucose flowed through the pentose phosphate pathway; this rate increased 11‐fold by methylene blue stimulation. The amount of D‐glucose recycled through the pentose phosphate pathway increased 300‐fold in the presence of the redox dye.