title: Heparin inhibits FMLP and Con-A dependent activation of human polymorphonuclear leucocytes in vitro.
abstract: The effects in vitro of heparin on different functions of human neutrophilic leucocytes were assessed. Granulocyte aggregation, enzyme release and superoxide anion generation induced by FMLP (10(-6) M), ConA (30 micrograms/ml), and A 23187 (5 microM) were evaluated. Heparin was able to inhibit, in a dose-dependent way, FMLP-mediated and ConA-mediated granulocyte activation. Heparin inhibited cellular aggregation at the final concentration of 100-500 micrograms/ml, while the inhibiting effect on enzyme release and superoxide anion production was present at lower concentrations (10-100 micrograms/ml). No activity was observed on A 23187-induced granulocyte stimulation. The inhibiting effect of heparin on FMLP-induced granulocyte activation proved to be time-dependent. The hypothesis that an interaction of heparin with cells may possibly initiate the inhibitory effect is proposed.
mesh_terms: D000001:Calcimycin / Q000494:pharmacology; D003208:Concanavalin A / Q000037:antagonists & inhibitors*; D005966:Glucuronidase / Q000097:blood; D006098:Granulocytes / Q000187:drug effects; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects*; D009113:Muramidase / Q000097:blood; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000037:antagonists & inhibitors*; D009504:Neutrophils / Q000187:drug effects*; D013481:Superoxides / Q000097:blood
chemical_list: D003208:Concanavalin A; D013481:Superoxides; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D006493:Heparin; D009113:Muramidase; D005966:Glucuronidase