Abstract
In order to clarify the relationship between nutrient status of ascorbic acid and the effect of ozone, rats unable to synthesize ascorbic acid, ODS-rats, were supplemented with ascorbic acid in drinking water at concentrations 0 to 10 g/L for 3 weeks, followed by exposure to 1 ppm ozone for 4 hours and their effects were studied.
1. The protective effect of ascorbic acid against ozone toxicity was demonstrated by the observation that an increase of protein concentration in bronchoalveolar lavage fluids (BALF) by ozone exposure was inversely proportional to the dose of ascorbic acid supplementation. On the othter hand, the decreased number of macrophages in BALF by ozone exposure was unaffected by the supplementation of ascorbic acid. These differences were assumed to be related to the protective action of ascorbic acid in the alveolar lining layer.
2. By ozone exposure, the ascorbic acid level in the lungs was decreased in proportion to the supplementation of ascorbic acid. It was more decreased in BALF than in tissue, and the oxidized form of ascorbic acid was increased in BALF. It is suggested that the reduction of ozone by ascorbic acid might occur in the alveolar lining layer.
3. The ascorbic acid level was increased in liver and was decreased in adrenal by ozone exposure. These observations show that the effect of ozone on ascorbic acid is not restricted to the lungs.
