In vitro alterations of tracheal epithelium of hamsters by carcinogens in organ culture.

In vitro organ culture of the hamster's trachea was improved and applied to a carcinogenesis research. The rotary culture enabled explants of tracheal epithelium to survive more than 8 weeks. The study was composed of 2 kinds of culture; untreated and treated with carcinogens. In the untreated culture, Eagle MEM medium had the same culture effect as RPMI 1640 medium. With prolongation of culture time (particularly longer than 5 weeks), irreversible degenerative changes appeared in epithelial cells. Culture for 4 weeks was usually thought to be appropriate for experimental research. In the treated culture, the effect of benzo-(a) pyrene (B(a)P) and B(a)P + cigarette smoking condensate-neutral fraction (CSC-NF) on tracheal epithelium was investigated with light and electron microscopies (TEM and SEM) and autoradiography. Atypical hyperplasia with or without lesions suggesting carcinoma in situ was induced by B(a)P + CSC-NF more evidently and frequently than by B(a)P alone. The present findings corroborated the cocarcinogenetic effect of CSC-NF.