Activation and migration of leukocytes and vascular leakage induced by serum-opsonized zymosan particles in hamster cheek pouch.

The effect of topically applied serum-opsonized zymosan (SOZ) and zymosan-activated serum (ZAS) was studied in the hamster cheek pouch. Our data suggest that early vascular leakage, evaluated by intravital fluorescence microscopy after injection of FITC-dextran, and accumulation of polymorphonuclear granulocytes (PMNGs), quantitated in fixed whole tissue specimens, induced by ZAS and SOZ were caused by complement activation, whereas the late leakages (greater than 20 min after SOZ application) was PMNG-dependent. Inhibition of prostaglandin and leukotriene synthesis by indomethacin, nordihydroguaiaretic acid (NDGA), and BW755C influence early and late vascular leakage as well as accumulation of PMNGs. These drugs also inhibited the activation of hamster PMNGs in vitro, as evaluated by chemiluminescence, in a dose-dependent manner. (-)-Terbutaline, an adrenergic beta agonist, decreased vascular leakage but had no effect on PMNG activation and accumulation.