Response of Transplanted Skin of Newborn and Suckling Mice to Application of 20-Methylcholanthrene^*

In subcutaneous syngenesiografts¹ of skin of newborn or suckling mice, epithelial growth and migration were intensified, and cyst formation was accelerated, as the age of the donor increased. Conversely, the ability of the outgrowing epithelium to form hair follicles and sebaceous glands decreased with advancing age of the skin at the time of grafting. The reaction of the recipient was more pronounced against transplants of older skin than against those of younger skin, but ultimately all grafts were destroyed.

A solution of 0.3 per cent of 20-methylcholanthrene applied to the skin of newborn mice previous to grafting stimulated epithelial proliferation and migration and the development of appendages. These effects decreased with the increasing age of the donor. In grafts of 7-day-old skin, pronounced keratinization interfered with the migration of the epithelium and the ensuing cyst formation. The reaction of the recipient was more vigorous against painted than against nonpainted tissue. No carcinomas developed in the painted transplants, and the grafts were finally destroyed.