title: Dopa inhibits induced proliferative activity of murine and human lymphocytes.
abstract: L-DOPA, the product of enzymatic hydroxylation of L-tyrosine, is released by melanotic melanoma cells in vivo and in vitro. Here we report that DOPA at pharmacologically relevant micromolar doses dramatically inhibits the stimulation of DNA synthesis by lipopolysaccharide and concanavalin A in murine splenocytes and human lymphocytes, having little or no effect on unstimulated (control) lymphocytes or proliferating fibroblasts. Therefore we propose that melanogenically active melanoma cells can inhibit the host's immune response via the release of DOPA and/or its oxidation products.
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, Albany Medical College, NY 12208.
authors.forename: A
authors.initials: A
authors.lastname: Slominski
authors.forename: G G
authors.initials: GG
authors.lastname: Goodman-Snitkoff
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004261:DNA Replication / Q000187:drug effects; D004295:Dihydroxyphenylalanine / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007536:Isomerism; D007980:Levodopa / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008214:Lymphocytes / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000276:immunology
chemical_list: D008070:Lipopolysaccharides; D003208:Concanavalin A; D007980:Levodopa; D004295:Dihydroxyphenylalanine