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Regulation of L ‐arginine uptake by Ca 2+ in human platelets
Author(s) -
Giovine Marco,
Signorello Maria Grazia,
Pozzolini Marina,
Leoncini Giuliana
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)01422-2
Subject(s) - platelet , chemistry , arginine , biochemistry , microbiology and biotechnology , biology , immunology , amino acid
L ‐Arginine uptake and Ca 2+ changes in unstirred platelets activated by thrombin, collagen and Ca 2+ ionophore A23187 were evaluated. Thrombin did not affect L ‐arginine uptake at short incubation times (2–15 min), but at prolonged times slowed down the amino acid transport. Collagen was ineffective. A23187 decreased the L ‐arginine uptake in a dose‐dependent manner, producing the maximal inhibition at 5 μM. In FURA 2‐loaded platelets collagen did not modify Ca 2+ basal level, thrombin induced a late Ca 2+ rise and A23187 dose‐dependently increased cytosolic Ca 2+ , eliciting the highest increase at 5 μM. It is likely that L ‐arginine uptake is inversely modulated by Ca 2+ concentrations and is inhibited during platelet stimulation with agonists which induce cytosolic Ca 2+ elevation.