15-HETE inhibits leukotriene B4 formation and synovial cell proliferation in experimental arthritis

Abstract

Leukotriene B 4 (LTB4) is formed by the 5-1ipoxygenase (5-LO) pathway of arachidonic acid (AA) metabolism. LTB4 is a potent stimulator of neutrophil function and in carragheenan induced arthritis we have previously demonstrated an accumulation of LTB4 in the synovial fluid [1]. 15-hydroxy-eicosatetraenoic acid (15-HETE), being a product of AA generated via the 15-LO enzyme, is not proinflammatory but inhibits 5-LO and 12-LO activity [2] and LTB4-induced chemotaxis [3]. In the present study we have shown that carragheenan induced arthritis was inhibited by intraarticular injections with the endogenous 5-LO inhibitor, 15-HETE.