我们应用20-甲基胆蒽作用于离体培养的大鼠气管组织,发现在作用后的第一、二周内,即可在气管粘膜上皮发生早期癌变。实验方法:培养液为自配199培养液加10％牛血清及Hanks平衡盐类溶液。为防止细菌污染,在培养液中适当加入卡那霉素、庆大霉素及二性霉素乙。致癌物质选用20-甲基胆蒽(简称20— We applied 20-methylcholanthrene to act on the tracheal tissues of rat in vitro. It was found that in the first and second weeks after infection, early canceration of the epithelium of the tracheal mucosa occurred. Experimental method: The culture fluid was self-assembled 199 culture fluid plus 10% bovine serum and Hanks balanced salt solution. In order to prevent bacterial contamination, kanamycin, gentamycin, and amphotericin B are appropriately added to the culture solution. Carcinogens use 20-methyl-cholesterol (20 for short)