The aim of this study was to examine whether the isolated perfused bovine udder could be used as a suitable in vitro inflammation model. A common in vivo inflammation model is arachidonic acid-induced inflammation in mouse ears. As an in vitro substitute for this model, arachidonic acid was administered topically to the skin of an isolated perfused bovine udder and the subsequent changes in eicosanoid synthesis were examined. As with the mouse-ear model, there was a significant increase in eicosanoid synthesis (prostaglandins E(2) and F(2 alpha) and leukotrienes B(4) and C(4)/D(4)/E(4)) following topical irritation. This effect lasted for 3 hours. In addition, the changes in prostaglandin E(2) synthesis in the skin following irritation with arachidonic acid were measured by the microdialysis technique. In conclusion, the in vitro model described seems suitable for studies of pharmacological effects on eicosanoid synthesis.