ADHESIVE INTERACTIONS OF NEUTROPHILS AND LEUKOTRIENE SYNTHESIS

Cell-substrate and cell-cell adhesion of neutrophils has been found to slow down the calcium ionophore A23187-induced synthesis of 5-lipoxyg enase (5-LO) metabolites of arachidonic acid. Addition of the exogenou s substrate, arachidonic acid (AA), together with A23187, resulted in the enhanced production of leukotriene B4 (LTB4) and 5-hydroxyeicosate traenoic acid (5-HETE) by adherent neutrophils in comparison with thos e by the cells in suspension. We observed also the enhanced production of 5-LO metabolites in attached cells when we stimulated the cells by the combined action of phorbol 12-myristate 13-acetate (PMA) and A231 87. Thus, the adhesion to solid substrate and to other cells, an impor tant regulatory factor for the activity of many cells, is a powerful r egulator of leukotriene production by neutrophils.