The effect of pyridoxal on potassium fluxes in the Ehrlich mouse ascites tumor cell

✍ Scribed by Hempling, H. G. ;Hare, Daphne

• Publisher: Wiley (John Wiley & Sons)
• Year: 1965
• Tongue: English
• Weight: 808 KB
• Volume: 65
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030650316

✦ Synopsis

To determine the extent of coupling between the transport of potassium and the transport of amino acids by the Ehrlich mouse ascites tumor cell, we have investigated the effect of pyridoxal on potassium fluxes. We have chosen a low Concentration of pyridoxal (1 mM) known to increase the cell to medium ratios for glycine. It was found that pyridoxal reduced potassium efflux and influx in the steadystate without significant change i n oxygen consumption. At normal levels of cell potassium and in the steady-state, glycine and pyridoxal together had no effect on potassium fluxes. However, when a net gain of potassium occurred as in a transfer of cells from low temperature to room temperature, glycine and pyridoxal together reduced influx, efflux, and net flux of the ion. In addition, glycine alone reduced potassium influx significantly in contrast to its stimulatory effect in the steady-state. It is suggested that the steady-state fluxes for potassium are a balance between a n active influx and a passive mediated efflux. The active influx may be reduced i n the presence of glycine while pyridoxal may exert its predominant effect on the passive efflux. To explain the stimulation of the influx and efflux of potassium by glycine in the steadystate, it is hypothesized that the ion makes use of a n exchange system for potassium under circumstances where glycine prevents the use of the pathway of active influx.