Amino Acid Transport: Evidence for Genetic Control of Two Types in Human Kidney

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Science  17 Mar 1967:
Vol. 155, Issue 3768, pp. 1428-1430
DOI: 10.1126/science.155.3768.1428


A mutation affecting renal transport of proline, hydroxyproline, and glycerine occurs in man. In the presumed homozygote there is still significant residual transport of these compounds; however, this remaining function is saturated at normal concentrations of substrate in the plasma and is not inhibited by L-proline in the expected way. The presumed heterozygote has partial loss of a transport system common to the three substrates, which becomes saturated at high concentrations of substrate and is inhibited by L-proline. Two different types of transport systems are proposed: a common system and systems with lower capacity and greater specificity. The two types of transport appear to be controlled by separate genes.