Effect of Methylcholanthrene on Tooth Germ Transplants: Additional Studies

Abstract

Guinea pigs received transplants treated with 20-methylcholanthrene to the eyes and brains, and mice ( dba Bar Harbor ) received them to the axillae. Untreated transfers served as controls. Transplants were allowed to remain in place for at least 100 days and upwards to more than a year. The hosts were sacrificed at regular intervals and explants recovered. Treated explants to the brains and axillae frequently attained a large size. In the axillae, recovered treated transfers were generally much larger in males than in females having several litters during the course of the experiment. Besides the regular H. and E. stain, Masson''s trichrome connective tissue stain and the Barnett-Seligman stain for protein bound sulfhydryl groups were em-ployed. The Masson staining reaction showed that most of the tissues surviving over these longer periods were of epithelial origin. The Barnett-Seligman stain showed the presence of sulfhydryl groups of protein in material designated as keratin confirming previous observations on the presence of keratin in methylcholanthrene treated explants. Persistance of epithelial remnants or the original explant was more evident in the pre-sence of methylcholanthrene than in its absence. Persisting cells, presumably from the outer enamel epithelium, seemed to attain some of the criteria for malignancy but did not actually become malignant within the periods of this experiment.