15-HETE is the main eicosanoid formed by human colonic mucosa

Eicosanoids were measured in colonic biopsies from eleven patients with active ulcerative colitis and from thirteen controls. Eicosanoid formation was measured after the addition of arachidonic acid and stimulation with calcium ionophore A23187. The 15-lipoxygenase derivative 15-hydroxy-eicosatetraenoic acid (15-HETE) was the predominant product formed in all biopsies. The amount of 15-HETE formed was dependent on the site of biopsy and decreased in the controls in biopsies taken in an aboral direction in the colon. The formation of 15-HETE and that of prostaglandin E2 (PGE2) and PGF2 alpha was proportional to the histologically obtained inflammation score. The role of 15-H(P)ETE as a mediator in ulcerative colitis should, therefore, be considered in addition to the effects of known modulators such as leukotriene B4 (LTB4) and PGE2.