Experimental Carcinogenesis in Submandibular Glands of Hamsters

¹ School of Dentistry, University of Minnesota, Minneapolis

When 0.05 cc. of 0.5 per cent (250 mg.) 1:12 dimethylbenz() anthracene dissolved in liquid petrolatum was injected into the submandibular glands of 3-month-old hamsters, fibrosarcomas were induced between 10 and 14 weeks. The sequence of microscopic changes were, in order, degeneration of the parenchymatous and stromal tissue of the gland in the immediate environs of the injection site, fibrosis, and its subsequent transformation into fibrosarcomas of varying gradations. No changes of any significance were, however, noticed in the control glands. The tumor yield at the end of 18 weeks increased from 7.7 to 55.4 per cent with the change in concentration from 0.1 (50 mg.) to 1.0 per cent (500 mg.). All other factors being constant, the age of the animals up to 9 months did not change the number of tumors induced.