Glutamate transport and renal function.

Brush border gamma-glutamyltransferase-glutaminase activity and the high-affinity glutamate transporter EAAC1 function as a unit in generating and transporting extracellular glutamate into proximal tubules as a signal that modulates intracellular glutamine/glutamate metabolism, paracellular permeability, and urinary acidification. The reported presence of a second glutamate transporter, GLT1, on the antiluminal tubule surface points to specific functional roles for each subtype in physiological and pathophysiological processes.