Localization of polycyclic hydrocarbon carcinogens in the lung following intratracheal instillation in gelatin solution

The deposition and localization of benzo(a)pyrene (BP) suspended in a gelatin-0.9 percent NaCl solution was studied in hamster lungs by ultraviolet fluorescence microscopy. BP was deposited primarily in the alveolar region of the lung. Although large numbers of BP-filled macrophages were seen in the upper airways by 24 hr after an instillation, little BP appeared to penetrate into the bronchial epithelium. The intratracheal instillation of polycyclic hydrocarbons in a gelatin-0.9 percent NaCl solution appears to be a useful model when it is desired to deliver the carcinogen dose to the peripheral lung.