Oral N-acetylcysteine protects against perfluoroisobutene toxicity in rats.

1. Perfluoroisobutene, a pyrolysis product of polyetrafluoroethene may cause pulmonary oedema and death when inhaled. Oral N-acetylcysteine has shown protection against inhalation of perfluoroisobutene and in this study we have tried to elucidate the mechanism by which protection is mediated. 2. Protection against the lethal effects of inhaled perfluoroisobutene has been shown when N-acetylcysteine has been orally administered 4, 6 or 8 h before gas exposure. 3. Plasma levels of cysteine, glutathione and N-acetylcysteine were increased for up to 7 h following oral administration of Nac. 4. N-acetylcysteine was not detected in the bronchioalveolar lavage fluid following oral administration. 5. Duration of protection in vivo has been related to the duration of increased thiol levels in the plasma.