ALTERATION OF OZONE-INDUCED AIRWAY PERMEABILITY BY OXYGEN METABOLITES AND ANTIOXIDANTS

This study determined the interactive effects of O-3 and enzymatically-generated oxidants and antioxidants in the lung. Rats treated with dimethylthiourea (DMTU) or H2O2, generated by glucose/glucose oxidase, were exposed for 2 h to 0.6 or 0.8 ppm O-3. A significant increase in the flux of total albumin in the bronchoalveolar lavage (BAL) and a concomitant elevation in the transport of 99(m)Tc-diethylenetriaminepentaacetate (99(m)Tc-DTPA) from trachea to blood occurred after O-3 exposure. Pretreatment of rats with DMTU prevented the albumin flux in the BAL. Intratracheal instillation of glucose/glucose oxidase produced a localized response in trachea, but it did not affect the broncho-alveolar permeability. The results demonstrate an additive effect of O-3 and an enzymatically-generated oxidant, and an antagonistic effect of an antioxidant in rats exposed to O-3 The observations support the suggestion that a balance of oxidant-antioxidant system may be critical in maintaining respiratory integrity following O-3 exposure.