ANTINEUTROPHIL SERUM ATTENUATES DEXTRAN SULFATE SODIUM-INDUCED COLONIC DAMAGE IN THE RAT

Background: The role of neutrophils in experimental colonic damage ind uced by dextran sulfate sodium is uncertain. We test the hypothesis th at neutrophils are of pathogenic significance and anti-neutrophil seru m will attenuate the colonic damage induced by oral dextran sulfate so dium in rats. Methods: Rabbit anti-rat neutrophil serum (anti-neutroph il serum) or control rabbit serum was administered to, and circulating neutrophil count was monitored in, rats before and during feeding of dextran sulfate sodium or regular rat diet for 2 weeks. Histologic fea tures of mucosal damage were evaluated in hematoxylin and eosin-staine d proximal and distal colonic sections by a blinded observer. Results: Oral dextran sulfate sodium induces weight loss, diarrhea, peripheral neutrophilia, and colonic damage. Anti-neutrophil serum induced neutr openia and significantly attenuated the weight loss, the neutrophil in filtration in the colon, and the mucosal necrosis and pathologic index in the distal colon. Conclusion: The data showing that anti-neutrophi l serum attenuates distal colonic mucosal injury induced by dextran su lfate sodium support the hypothesis that neutrophils play a pathogenic role in this model of colonic mucosal damage.