L-glutamate transport in renal plasma membrane vesicles

This review describes the uptake of L-glutamate by well-characterized preparations of renal brush border (liminal) and baso-lateral membrane vesicles derived from the plasma membrane of the polar proximal tubular cell. L-glutamate is taken up against its concentration gradient, from both sides, by co-transport systems in which the movement of the amino acid into the cell is coupled to the influx of Na+ and efflux of K+ down their respective electrochemical gradients. The presence of these ion gradient-energized systems, specific for L-glutamate, may account for the exceedingly high intracellular concentration of their metabolically important amino acid in the renal tubule.