抄録
To determine the intracellular ion activities of potassium and chloride, the present study was aimed to make single-barreled potassium sensitive and chloride sensitive liquid ion exchanger microelectrodes (K+-microelectrode and Cl--microelectrode, respectively), and to measure the intracellular K+ and Cl- activities in the toad urinary bladder epithelial cells.
The single-barreled K+- and Cl--microelectrodes were made by the modification of Walker's technique. A Pyrex capillary tube was pulled with a pipette puller so that the outer diameter of the tip was less than 1μm. The tip of the inner surface which was siliconized, was filled with a K+-sensitive or Cl--sensitive liquid ion exchanger and the stem was filled with 0.5 M KCl.
The characteristics of K+- and Cl--microelectrodes were examined. The sensitivity slope (sRT/zF 1n 10) and the standard potential of the K+-microelectrode was 59.04±0.03mV/10 fold of ionic activity and 22.20±0.69mV, respectively. The slope and the standard potential of the Cl--microelectrode was -54.38±0.19 and -42.23±0.90, respectively. The selectivity constant of K+-microelectrode was 53.96±4.00 for K+/Na+ and 3.48±0.15 for K+/NH4+. In addition, that of Cl--mlcroelectrode was 8.00±0.15 for Cl-/HCO3- and 63.59 ±1.20 for Cl-/H2PO4-.
The present authors attempted to determine the intracellular K+ and Cl- activities in the toad urinary bladder epithelial cells.
Under basal conditions, the intracellular K+ and Cl- activity was 41.2±0.5 and 49.9± 1.2mM, respectively.
It was suggested that K+ and Cl--microelectrodes could be available for determination of the intracellular K+ and Cl- activities in a clinical field.
