Identification of a specific transport system for L-arginine in human platelets.
The present study demonstrates that human platelets possess a specific L-arginine transport system able to provide adequate amounts of L-arginine for endogenous nitric oxide production. L-arginine uptake takes place through a saturable high affinity carrier-mediated Na(+)-independent process which is significantly inhibited by L-ornithine, L-lysine and N omega-methyl-L-arginine. The high affinity of the transport process and the pattern of inhibition are consistent with mediation of L-arginine transport via the Na(+)-independent y+ system. The data on the kinetic parameters of the transporter suggest a possible role for arginine plasma levels in the regulation of platelet nitric oxide production.
Department of Biochemical Sciences, University of Firenze, Italy.
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Vasta
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Meacci
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Farnararo
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Bruni
D001120:Arginine / Q000031:analogs & derivatives / Q000097:blood* / Q000494:pharmacology; D001692:Biological Transport; D001792:Blood Platelets / Q000378:metabolism*; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008239:Lysine / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis; D009952:Ornithine / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D019323:omega-N-Methylarginine
D002352:Carrier Proteins; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D012964:Sodium; D009952:Ornithine; D008239:Lysine