Role of oxygen reactive species in Schistosoma mansoni egg-induced granulomatous inflammation.

The role of oxygen reactive species in granulomatous hypersensitivity was explored using a model of pulmonary granulomas induced by intravenous injection of eggs from the parasite Schistosoma mansoni. Macrophages from sychronously developing lesions spontaneously released significant quantities of superoxide anion (26 nmoles/10(6)/2h) by 8 days of development. In contrast, the non-T cell foreign body (Sephadex bead) granuloma macrophages produced only (2 nmoles/10(6)/2h) small quantities. Daily administration of the oxygen scavenger, alpha-tocopherol, by either oral or parenteral routes caused up to 60% suppression of granuloma size. Moreover, parenteral administration of specific inactivators of 0-2 and H2O2, superoxide dismutase and catalase respectively, resulted in a 30 to 40% reduction in granuloma size. These data suggest that oxygen reactive species take part in the generation of hypersensitivity granulomas.