Tumor promotion and the induction of epidermal ornithine decarboxylase activity in mechanically stimulated mouse skin.

Wounding by incision was a promoting stimulus in mouse skin previously initiated with 7,12-dimethylbenz-(a)anthracene. Skin massage elicited a marked proliferative response in skin but was not a promoting stimulus. Wounding mouse skin, either by multiple scalpel incisions or by stripping with silicon carbide paper, led to a marked induction of ornithine decarboxylase activity. In both instances activity was maximal between 20 and 26 hr after wounding, with a secondary rise at 72 hr. Skin massage did not lead to a detectable increase in ornithine decarboxylase activity over the same time period.