Inhibitory effect of LY 255283 on the synthesis of leukotriene B4 and thromboxane A2 in human peripheral blood polymorphonuclear leukocytes and monocytes

Abstract

LY 255283 [(1-(5-ethyl-2-hydroxy-4-(6-methyl-6-)1H-tetrazol-5-yl)-heptyloxy) phenyl)ethanone], a specific leukotriene B4 (LTB4) receptor antagonist, inhibited the production of LTB4 in human peripheral blood polymorphonuclear leukocytes (PMNL) and in monocytes activated by calcium ionophore A23187. In human monocytes activated by ionophore it inhibited also the production of thromboxane B2 (TXB2). The effect of LY 255283 on 5-lipoxygenase (5-LO) and LTA4 hydrolase activities which catalyse the production of LTB4 and LTA4 has not been studied yet. It is thought that LY 255283 may inhibit the production of LTB4 and TXA2 by antagonising the effect of ionophore-induced LTB4 on 5-lipoxygenase and cyclooxygenase in human peripheral blood PMNL and monocytes.