title: The effect of methotrexate on ex vivo lipoxygenase metabolism in neutrophils from patients with rheumatoid arthritis.
abstract: OBJECTIVE
  To examine the effect of methotrexate (MTX) administered in vivo on the production of the 5-lipoxygenase (5-LO) metabolites of arachidonic acid by neutrophils from subjects with rheumatoid arthritis.
  
  
  METHODS
  Neutrophils were isolated from peripheral blood samples taken 12 h before and 12 h after the ingestion of an oral dose of MTX and stimulated in vitro by calcium ionophore A23187. Lipid extracts of cell suspensions were assayed for leukotriene B4 (LTB4), the all-trans isomers of LTB4, 20-hydroxy LTB4 and 5-hydroxyeicosatetraenoic acid by high pressure liquid chromatography.
  
  
  RESULTS
  An increase in the production of all measured 5-LO metabolites was seen between the pre and postdose assessments.
  
  
  CONCLUSIONS
  Our results do not support the putative inhibitory effect of MTX on 5-LO metabolism.
authors.affiliation: Rheumatology Unit, Royal Adelaide Hospital, Australia.
authors.forename: J S
authors.initials: JS
authors.lastname: Hawkes
authors.forename: L G
authors.initials: LG
authors.lastname: Cleland
authors.forename: S M
authors.initials: SM
authors.lastname: Proudman
authors.forename: M J
authors.initials: MJ
authors.lastname: James
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy* / Q000201:enzymology*; D006801:Humans; D008084:Lipoxygenase / Q000378:metabolism*; D008727:Methotrexate / Q000627:therapeutic use*; D009504:Neutrophils / Q000201:enzymology*
chemical_list: D008084:Lipoxygenase; D008727:Methotrexate