CHRONIC EXPOSURE TO OZONE AND NITRIC-ACID VAPOR RESULTS IN INCREASED LEVELS OF RAT PULMONARY PUTRESCINE

In the past decade, there has been growing public concern for the huma n health effects of exposure to environmental pollutants. Ozone (O-3) is one of the most reactive components of photochemical air pollution. Despite extensive investigations by many laboratories on the function al, biochemical, and cellular effects of O-3 exposure in humans, anima ls, and in vitro systems, questions remain concerning the potential ad verse effects to human health represented by chronic near-ambient expo sure to this environmental pollutant. In the present investigation, th e influence of inhalation of O-3 and nitric acid (HNO3) vapor on polya mine levels was examined in rat lungs. Male F344/N rats were exposed n ose-only to 0.15 ppm O-3 and 50 mu g/m(3) HNO3 vapor alone and in comb ination for 4 hours/day, 3 days/week for a total of 40 weeks. At this time the animals were sacrificed and their lungs were examined for pol yamine contents. Exposure to O-3 and O-3 plus HNO3 vapor caused a sign ificant increase in the putrescine content of the lung compared to the air-exposed controls (P < 0.05). The concentrations of pulmonary sper midine and spermine were not significantly increased by exposure to ei ther O-3 or HNO3 vapor alone or in combination compared to the air-exp osed controls. The role of polyamines in repair and anti-inflammatory processes has been discussed.