Effects of Actinomycin D and Cycloheximide on the Differentiation of Epidermal Melanocytes of Newborn Mice

Abstract

The increase in the number of epidermal melanocytes positive to the dopa reaction after birth was suppressed in C57BL/1OJ strain mice when injected with actinomycin D or Cycloheximide. On the other hand, no change was observed in the melanoblast-melanocyte population positive to the combined dopa-premelanin reaction. The initiation of melanogenesis in the skin of newborn mice, therefore, seems to require de novo transcription and translation. The increase in the number of melanocytes after treatment with α-MSH or DBc-AMP was also completely suppressed when mice were injected with actinomycin D or Cycloheximide. The results suggest that normal and hormone-induced differentiation of epidermal melanocytes requires de novo transcription and translation.