INFLUENCE OF N-PHENYLLINOLEAMIDE FROM TOXIC OIL SAMPLES ON THE LIPOXYGENASE METABOLISM OF EXOGENOUS ARACHIDONIC-ACID IN MOUSE PERITONEAL-MACROPHAGES

N-phenyliinoleamide (NPLA) is a useful marker for adulterated oil samples associated with cases of toxic oil syndrome (TOS). To date, NPLA has not reproduced the human poisoning episode in experimental animal models and, thus, its pathological role in the syndrome remains controversial. The present report describes the effect of NPLA on the lipoxygenase metabolism of exogenous arachidonic acid (AA) in mouse peritoneal macrophages (MPM). Results show that MPM cells exposed to 1 mM NPLA for 2 h, when subsequently incubated with exogenous H-3-AA, undergo a significant increase in the biosynthesis of H-3-12-hydroxyeicosatetraenoic acid (H-3-12-HETE) whereas levels of H-3-15-HETE are relatively stable. These data indicate that NPLA selectively potentiates the lipoxygenase metabolism of exogenous AA, supporting the possible implication of lipid peroxidative processes in the ethiopathology of TOS, although the relatively high NPLA concentration required 'in vitro' makes it unlikely that this xenobiotic could be directly related to human toxicity.