The material covered in this set of articles was originally presented at Experimental Biology '98, in San Francisco, CA, on April 20, 1998. Here, the participants recount important elements of current research on the role of glutamate transporter activity in cellular signaling, metabolism, and organ function. W. A. Fairman and S. G. Amara discuss the five subtypes of human excitatory amino acid transporters, with emphasis on the EAAT4 subtype. M. A. Hediger discusses the expression and action of EAAC1 subtype of the human excitatory amino acid transporter. I. Nissim provides an overview of the significant role of pH in regulating Gln/Glu metabolism in the kidney, liver, and brain. J. D. McGivan and B. Nicholson describe some characteristics of glutamate transport regulation with regard to a specific experimental model of the bovine renal epithelial cell line NBL-1. Finally, T. C. Welbourne and J. C. Matthews introduce the "functional unit" concept of glutamate transport and how this relates to both glutamine metabolism and paracellular permeability.