title: Cultured astrocytoma cells inhibit platelet aggregation by releasing a nitric oxide-like factor.
abstract: Cultured astrocytoma cells were tested for their ability to generate a nitric-oxide like factor using platelet aggregation as a bioassay. Incubation of astrocytoma cells with human washed platelets resulted in an inhibition of thrombin-induced platelet aggregation which was proportional to the number of astrocytoma cells added. The inhibition was potentiated by superoxide dismutase (SOD) and prevented by oxyhaemoglobin (oxyHb). The inhibitory activity of astrocytoma cells was also prevented by the NO biosynthesis inhibitor NG-monomethyl-L-arginine (MeArg), an effect reversed by co-incubation with L-arginine (L-Arg) but not D-arginine (D-Arg). These results demonstrate that astrocytoma cells release, independent of added agonist, a factor with the same pharmacological profile as NO, which is likely to be derived from L-arginine.
authors.affiliation: William Harvey Research Institute, St Bartholomew's Hospital Medical College, London, U.K.
authors.forename: V
authors.initials: V
authors.lastname: Mollace
authors.forename: D
authors.initials: D
authors.lastname: Salvemini
authors.forename: E
authors.initials: E
authors.lastname: Anggård
authors.forename: J
authors.initials: J
authors.lastname: Vane
mesh_terms: D001254:Astrocytoma / Q000503:physiopathology*; D002460:Cell Line; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D009569:Nitric Oxide / Q000378:metabolism*; D010108:Oxyhemoglobins / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors; D013482:Superoxide Dismutase / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000502:physiology
chemical_list: D010108:Oxyhemoglobins; D010975:Platelet Aggregation Inhibitors; D009569:Nitric Oxide; D013482:Superoxide Dismutase; D013917:Thrombin