TRANSCELLULAR BIOSYNTHESIS OF LEUCOTRIENE C4 DURING INTERACTIONS BETWEEN NEUTROPHILS AND PLATELETS OR ENDOTHELIAL-CELLS

The majority of cells possess the enzymes necessary for the biosynthesis of metabolites of arachidonic acid (eicosanoids). Vascular cells, platelets, neutrophils and eosinophils produce prostacycline, thromboxane A2, leucotriene (LT) B4 and LTC4 respectively, Recent studies have shown that cellular cooperation in vitro, in particular between platelets and neutrophils, could also produce LTC4. This type of reaction is called transcellular metabolism and is accompanied by a transfer of substrate (LTA4) from neutrophil to platelet to produce LTC4. Synthesis of LTC4 occurs in vitro via the same process when neutrophils and endothelial cells are brought into contact. The transcellular biosynthesis could therefore represent a considerable source of production in vivo of this mediator, as a complement to its direct formation by eosinophils and mast cells.