title: Comparative measurements of potassium and chloride with ion-sensitive microelectrodes and x-ray microanalysis in cultured skeletal muscle fibers.
abstract: Data of the intracellular electrolyte concentration of potassium and chloride in cultured muscle cells measured by x-ray analysis were compared by using the different activity coefficients with intracellular potassium and chloride activities measured with double-barrelled microelectrodes. By using an activity coefficient of 0.6, 95% of the potassium microelectrode measurements are in accordance with the x-ray analysis values, in spite of a scattering of the values. Membrane potential and intracellular potassium values are linearly related. x-ray analysis and ion-sensitive microelectrodes measured the cytoplasmic chloride in the same range. Taking into account known activity coefficients, an error of 25% must be assumed with the intracellular chloride measurements. However, x-ray analysis and ion-sensitive microelectrode investigations are reliable tools to study intracellular potassium and chloride changes, which play an important role in membrane characteristics.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002712:Chlorides / Q000032:analysis*; D004577:Electron Probe Microanalysis; D004622:Embryo, Mammalian; D008564:Membrane Potentials; D008839:Microelectrodes; D009132:Muscles / Q000032:analysis* / Q000648:ultrastructure; D011188:Potassium / Q000032:analysis*; D051381:Rats
chemical_list: D002712:Chlorides; D011188:Potassium