title: Effect of heavy metals and alkali metals on L-leucine uptake by human blood platelets.
abstract: The transport of L-leucine into human blood platelets was characterized as a function of time and amino acid concentration in the medium. Inhibition analyses showed that L-leucine uptake can be only partially inhibited by other amino acids including those which are believed to be transported by the same L system. When Cu2+, Zn2+, Mg2+, Co2+, Fe2+, Ba2+, or Cd2+ were introduced into the transport medium to the final concentrations of 2.5 and 5.0 mM, they inhibited significantly the L-leucine uptake into platelets. In contrast, the initial rate of L-leucine uptake was enhanced by Cu+ ions. Ceruloplasmin, a copper transporting protein, caused almost a complete inhibition of L-leucine uptake.
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000494:pharmacology; D001693:Biological Transport, Active / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D001798:Blood Proteins / Q000494:pharmacology; D002412:Cations / Q000494:pharmacology*; D002570:Ceruloplasmin / Q000494:pharmacology; D006801:Humans; D007930:Leucine / Q000378:metabolism*; D008673:Metals, Alkaline Earth / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D001798:Blood Proteins; D002412:Cations; D008673:Metals, Alkaline Earth; D002570:Ceruloplasmin; D007930:Leucine