The effect of methotrexate on ex vivo lipoxygenase metabolism in neutrophils from patients with rheumatoid arthritis

J Rheumatol. 1994 Jan;21(1):55-8.


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.

Conclusion: Our results do not support the putative inhibitory effect of MTX on 5-LO metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arthritis, Rheumatoid / blood
  • Arthritis, Rheumatoid / drug therapy*
  • Arthritis, Rheumatoid / enzymology*
  • Humans
  • Lipoxygenase / metabolism*
  • Methotrexate / therapeutic use*
  • Neutrophils / enzymology*


  • Lipoxygenase
  • Methotrexate