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Characterization of system L and system y + amino acid transport activity in cultured vascular smooth muscle cells
Author(s) -
Low Boon Chuan,
Ross Ian K.,
Grigor Murray R.
Publication year - 1993
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041560323
Subject(s) - leucine , amino acid , lysine , biochemistry , amino acid transporter , chemistry , aminoisobutyric acid , biology , transporter , gene
The uptake of L‐leucine and L‐lysine into vascular smooth muscle cells cultured from the aortas of rats has been investigated. Both amino acids are taken up by saturable systems that are independent of the presence of a · Na + gradient and can be stimulated in trans by neutral bulky amino acids for leucine and cationic amino acids for lysine. Leucine uptake is inhibited competitively in cis by several neutral amino acids, whereas lysine uptake is inhibited strongly by other cationic amino acids but also significantly by neutral amino acids such as leucine. The leucine inhibition is noncompetitive. Cells preloaded with leucine and lysine could also export these amino acids and the rate of efflux was stimulated by the presence of appropriate amino acids in trans . These data are all consistent with leucine being transported largely if not entirely by System L and lysine by the System y + transporter. © 1993 Wiley‐Liss, Inc.