ALTERATION OF OZONE-INDUCED AIRWAY PERMEABILITY BY OXYGEN METABOLITESAND ANTIOXIDANTS

This study determined the interactive effects of O-3 and enzymatically -generated oxidants and antioxidants in the lung. Rats treated with di methylthiourea (DMTU) or H2O2, generated by glucose/glucose oxidase, w ere exposed for 2 h to 0.6 or 0.8 ppm O-3. A significant increase in t he flux of total albumin in the bronchoalveolar lavage (BAL) and a con comitant elevation in the transport of 99(m)Tc-diethylenetriaminepenta acetate (99(m)Tc-DTPA) from trachea to blood occurred after O-3 exposu re. Pretreatment of rats with DMTU prevented the albumin flux in the B AL. Intratracheal instillation of glucose/glucose oxidase produced a l ocalized response in trachea, but it did not affect the broncho-alveol ar 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 sugges tion that a balance of oxidant-antioxidant system may be critical in m aintaining respiratory integrity following O-3 exposure.