INFLUENCE OF THE ANTI-INFLAMMATORY SERINE ESTERASE INHIBITOR GABEXATE MESILATE (FOY) ON AGGREGATION, LOCOMOTION AND ADHESION OF POLYMORPHONUCLEAR LEUKOCYTES

The effects of the anti-inflammatory serine esterase inhibitor, gabexate mesilate (Foy) were studied, on locomotion, autoaggregation and adhesion of polymorphonuclear leukocytes stimulated with the complement peptide C5a-desArg [anaphylatoxin]. The drug inhibited aggregation as well as spontaneous and directed migration of human leukocytes at concentrations of about 10-3 M. Adhesion of peritoneal guinea pig leukocytes to autologous aortic strips was reduced at about 20 times lower drug concentrations. The inhibitory drug effects were highly time- and temperature-dependent. Experiments with the 2 major drug metabolites, pHB [p-hydroxybenzoic acid ethyl ester] and .epsilon.GC [.epsilon.-guanidinocaproic acid], indicate that gabexate mesilate is not active by itself but rather by its hydrolytic aromatic metabolite pHB. The inhibitory effects on leukocyte activities observed apparently are not related to the anti-inflammatory effects of gabexate mesilate.