Rates of effux and intracellular concentrations of potassium, sodium and chloride ions in isolated fat-cells from the rat.
1. The metabolism of K(+), Na(+) and Cl(-) has been investigated in isolated fat-cells prepared from the epididymal adipose tissue of rats. 2. Methods are described for measuring the intracellular water space, the rates of loss of intracellular (42)K(+), (22)Na(+) and (36)Cl(-) and the intracellular concentrations of K(+), Na(+) and Cl(-) in isolated fat-cells. 3. The intracellular water space, measured as the [(3)H]water space minus the [carboxylic acid-(14)C]inulin space, was 3.93+/-0.38mul./100mg. cell dry wt. 4. The first-order rate constants for radioisotope effluxes from isolated fat-cells were 0.029min.(-1) for (42)K(+), 0.245min.(-1) for (22)Na(+) and 0.158min.(-1) for (36)Cl(-). 5. The intracellular concentrations of K(+), Na(+) and Cl(-) were 146m-equiv./l., 18.6+/-2.9m-equiv./l. and 43+/-2.4m-equiv./l. respectively. 6. The total intracellular K(+) content of isolated fat-cells was determined by atomic-absorption spectrophotometry to confirm the value obtained from the radioisotope-efflux data. 7. The ion effluxes from isolated fat-cells were: K(+), 1.5pmoles/cm.(2)/sec., Na(+), 1.6pmoles/cm.(2)/sec., and Cl(-), 2.4pmoles/cm.(2)/sec. 8. The membrane potential of isolated fat-cells calculated from the Cl(-) distribution ratio was -28.7mv.
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D002712:Chlorides / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008564:Membrane Potentials; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D011194:Potassium Isotopes; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D012975:Sodium Isotopes; D013053:Spectrophotometry; D014316:Tritium; D014867:Water / Q000032:analysis
D002712:Chlorides; D011194:Potassium Isotopes; D012975:Sodium Isotopes; D014867:Water; D014316:Tritium; D010042:Ouabain; D012964:Sodium; D011188:Potassium