Tryptophane transport in cultures of human fibroblasts.

Abstract

SummaryA method is described which permits kinetic studies of amino acid transport in cultures of human fibroblasts. Approximately linear kinetics of uptake were found to obtain during the first 8 minutes of incubation in medium containing puromycin and L-tryptophane H3, in the absence of other amino acids (“non-competitive medium”). Specific activities of monolayers pulsed in such media were more than 10 times those which were obtained in the presence of competing amino acids. The rate of uptake (in non-competitive medium) for one strain was almost double the mean rate obtained for 4 other presumably normal diploid strains, suggesting that the method might be useful as a marker for in vitro somatic cell genetic studies. The potential usefulness of the method for investigations of cystinuria and Hartnup Disease are discussed.