Non-selective cation channels in basolateral-membrane vesicles from pars recta of rabbit kidney proximal tubule. |
| |
| Authors: | J Blokkebak-Poulsen M I Sheikh and C Jacobsen |
| |
| Institution: | Institute of Medical Biochemistry, University of Aarhus, Denmark. |
| |
| Abstract: | The characteristics of 86Rb+ fluxes through conductive channels in basolateral-membrane vesicles isolated from pars recta of rabbit kidney proximal tubule were investigated. In RbCl-, KCl- and NaCl-loaded vesicles a transient and almost equal accumulation of 86Rb+ was observed. The uptakes of 86Rb+ were inhibited to the same extent by 10 mM-BaCl2 in all loadings. The accumulation was driven by an electrical diffusion potential. The 86Rb+ flux was dependent on intravesicular Ca2+. Increasing concentrations of Ca2+ gradually decreased the 86Rb+ uptake. At 10 microM-Ca2+ the radioisotope flux was below 20% of control. The vesicles containing the channel showed very low selectivity among the univalent cations K+, Rb+, Li+, Na+ and choline+. |
| |
| Keywords: | |
|
|
