Induction of melanogenesis in vitro in the epidermal melanoblasts of newborn mouse skin by MSH.

The number of epidermal melanocytes positive to the dopa reaction increased when skin explants from newborn mice were cultured with MSH or dbc-AMP. These agents seem to induce melanogenesis in the pre-existing melanoblasts. This hormone-induced melanogenesis is suppressed by actinomycin D or cycloheximide, suggesting that the initiation of melanogenesis in the epidermal melanoblasts requires de novo transcription and translation.