CONTROL OF CELL MULTIPLICATION IN EPIDERMIS.

Abstract

Summary Excision of a piece of skin, including epidermis and superficial dermis, from the dorsum of the ear of a hamster resulted in marked proliferation of cells in the ventral epidermis opposite the wound. Restoration of the excised tissue by grafting suppressed this hyperplastic response by 30 to 75% at various times, indicating that tissue-specific inhibition of mitotic activity occurs in epidermis. The suppression of host cell proliferation was correlated with the presence of tritium labelled thymidine within the graft cells. This suggests that metabolic activity within the graft, rather than the mere presence of a graft in the defect, is necessary for the inhibition of cell multiplication in the host epidermis.