Effects of ropivacaine on eicosanoid release from human granulocytes and endothelial cells in vitro

Objective: To examine the effects of ropivacaine, currently being investigated for treatment of ulcerative colitis, on the release of arachidonic acid metabolites. Material: Human granulocytes and endothelial cells. Treatment: Ropivacaine, lidocaine, hydrocortisone, 5-amino-salicylic acid or acetylsalicylic acid (10-1000 mu M). Methods: Leukotriene B-4, 5-hydroxyeicosatetraenoic acid, 6-keto PGF(1 alpha) and 15-hydroxyeicosatetraenoic acid were measured using immuno assays. Wilcoxon signed rank test was used for statistical calculations. Results: Ropivacaine dose-dependently inhibited zymosan-induced release of leukotriene B-4 and 5-hydroxyeicosatetraenoic acid whereas the release after ionophore stimulation was not affected. Ropivacaine was more potent than 5-aminosalicylic acid but less potent compared to hydrocortisone. Ropivacaine had only a weak inhibitory effect on the release of 15-hydroxyeicosatetraenoic acid from zymosan- or ionophore-stimulated cells. In contrast to hydrocortisone and 5-aminosalicylic acid, ropivacaine only weakly affected the release of 6-keto PGF(1 alpha) after stimulation with thrombin. Conclusions: The inhibited release of 5-lipoxygenase products may account for some of the anti-inflammatory effects of ropivacaine seen in the treatment of ulcerative colitis.