Chemical Carcinogenesis in the Hamster Submaxillary Gland

Abstract

The submaxillary salivary glands of 34 male and female Syrian hamsters were implanted with 5 mg pellets of powdered 9,10-dimethyl-1, 2-benzanthracene. Groups of 4 animals were sacrificed at 4, 6, 8, 10,12, and 14 weeks. The 10 remaining animals were sacrificed at 8 months. Extremely large tumors were grossly visualized at the 8 month interval of sacrifice. A variety of microscopic alterations were noted including epithelial hyperplasia and metaplasia, connective tissue hyperplasia, and areas resembling a mixed tumor pattern; however, the only tumors produced were fibrosarcomas. It was suggested that in the salivary glands of experimental animals, although numerous tissue responses may occur, only one tissue usually undergoes neoplastic transformation. In the hamster, the connective tissue apparently plays this role.