Anti-inflammatory Agents Inhibit Leukocyte Accumulation and Vascular Leakage Induced by Trypsin and Trypsin-Digested Serum in Hamster Cheek Pouch

In the present study we investigated the effect of nordihydroguaiaretic acid (NDGA), indomethacin, and cortisone on trypsin-induced acute inflammation in the hamster cheek pouch. Permeability changes, evaluated by fluorescence microscopy after injection of FITC-dextran (MW 150,000), induced by trypsin (2.5 μM) and trypsinated serum (2.5 μM) were significantly suppressed by pretreatment with NDGA (20 mg/kg) and indomethacin (20 mg/kg). Pretreatment with cortisone (40 mg/kg) reduced the permeability changes induced by trypsinated serum but had no significant effect on trypsin-induced leakages. Accumulation of polymorphonuclear leukocytes, as calculated by a whole tissue histological technique, induced by trypsin or trypsinated serum, was significantly reduced by pretreatment with certisone, NDGA, or indomethacin. These results indicate a role of both cyclooxygenase and lipoxygenase products in trypsin-induced acute inflammation in the hamster cheek pouch.