Effect of Ultraviolet Light on RNA and Protein Synthesis in Differentiated Epidermal Cells

STUDIES of the effects of microbeam ultraviolet light on growing tissue culture cells have shown that nucleolar RNA synthesis decreases rapidly but protein synthesis is either not affected 1 or is decreased as a result of inhibition of nuclear RNA synthesis 2 . The influence of ultraviolet light energy on formation of macromolecules in more differentiated cells, however, has not been adequately studied. In the present study we examined the effects of heterochromatic ultraviolet light on RNA and protein synthesis in granular cells of human epidermis in vivo . These cells are differentiated epidermal cells which do not replicate, but do actively synthesize RNA and protein.