In Vivo Production of Leukotriene B-4 and Leukotriene C-4 in Rabbit Colitis Relationship to Inflammation

Leukotriene B-4, a proinflammatory compound, recently has been identified as the major metabolite of arachidonic acid in tissue incubations of human and animal colitis. To determine the relationship of inflammation to the in vivo production of leukotrienes, rabbit colitis was induced by formalin enema followed by intravenous infusion of immune complexes, and serial samples were collected by rectal dialysis. Leukotrienes B-4 and C-4 were measured by radioimmunoassay after high-pressure liquid chromatography. Prostaglandin E-2 was assayed after Sephadex chromatography. Leukotrienes were not detected in control animals. Eicosanoid production progressively increased during development of inflammation and correlated with severity of inflammatory cell infiltration [p < 0.01]. Methylprednisolone decreased prostaglandin E-2 but did not significantly reduce leukotrienes or inflammation. These data demonstrate that in vivo production of leukotrienes B-4 and C-4 correlates with indices of inflammation, consistent with the concept that these eicosanoids contribute to the inflammation of colitis.