ORIGIN OF PULMONARY TUMORS IN RATS INDUCED BY 4-NITROQUINOLINE 1-OXIDE

Abstract

Origin of pulmonary tumors in Buffalo rats induced by the subcutaneous injection of 4-nitroquinoline 1-oxide was investigated. Pulmonary tumors induced in 15 out of 70 rats were examined through serial sections to determine their relation to alveolar ducts, bronchus, and bronchiolus. For example, 19.3% of the tumors showed no relation to the bronchus, while 80.7% indicated direct relation to the bronchial epithelium. Several cases of focal metaplasia originating either from the alveolar area or from the bronchial epithelia were found.