Effects of nitrogen dioxide and 3-methylcholanthrene on pulmonary enzymes

Guinea pig lung phenol-O-methyltransferase, catechol-O-methyltransferase, and benzpyrene hydroxylase activities were examined after nitrogen dioxide and 3-methylcholanthrene treatment. While benzypyrene hydroxylase activity was enhanced by 3-methylcholanthrene, none of the pulmonary enzyme activities was altered after exposure to either 40 or 70 ppm of nitrogen dioxide for 2 hr.