Induction of melanogenesis in Schwann cell and perineural epithelium by 9,10-dimethyl-1,2-benzanthracene (DMBA) and 12-o-tetradecanoylphorbol-13-acetate (TPA) in BDF1 mice.

Six-week-old female BDF1 mice were treated with a single topical application of DMBA followed by repeated application of TPA on the clipped dorsal skin. Several weeks after DMBA application, the intradermal melanocytes of perifollicular melanocytic network began to proliferate to form melanocytic tumors in all treated mice skin. Besides these changes, single membrane-bound melanosomes and premelanosomes were found in the cytoplasm of perineural epithelia and Schwann cells with mesaxons of the nerve bundles involved, and the melanogenic activity of the Schwann cell and the perineural epithelium of the dermal peripheral nerve bundle was discussed in terms of a common feature of neuro-ectodermal cells.