Effects of the anti-inflammatory serine esterase inhibitor, FOY, on phospholipase A2 (EC 3.1.1.4) activity in rabbit polymorphonuclear leukocytes.

Phospholipase A2 activity of polymorphonuclear leukocytes (PMNLs) towards radioactively labelled phosphatidylethanolamine is inhibited by FOY (ethyl 4-(6-guanidinohexanoyloxy)-benzoate methanesulfonate) in concentrations above 10(-4)M. The inhibition is noncompetitive with respect to the substrate employed and depends on the pH. Impairment of PMNL phospholipase A2 activity could play a role in the anti-inflammatory effect of FOY: the release of fatty acids from membrane phospholipids is reduced and consequently also the biosynthesis of bioactive oxygenated arachidonate metabolites, among them inflammatory mediators.