Stimulation of melanogenesis by cholecalciferol in cultured human melanocytes : A possible mechanism underlying pigmentation after ultraviolet irradiation.

Abstract

TOMITA, Y., FUKUSHIMA, M. and TAGAMI, H. Stimulation of Melanogenesis by Cholecalciferol in Cultured Human Melanocytes: A Possible Mechanism Underlying Pigmentation after Ultraviolet Irradiation. Tohoku J, exp. Med., 1986, 149(4), 451-452- An increase in the amount of tyrosinase was demonstrated in the cultured human melanocyte after 6-day culturing with cholecalciferol (vitamin D₃) by increased intensity of the immunofluorescent staining using monoclonal antibody against tyrosinase. Furthermore, the melanocytes became more dendritic as noted in those in the skin after the irradiation of ultraviolet. However, 7-dehydrocholesterol (pro-vitamin D₃) or 1α, 25-dihydroxy-vitamin D₃ (activated vitamin D₃) did not induce any such effect on the cultured human melanocytes. Since cholecalciferol is known to be photo-chemically converted by the ultraviolet irradiation from pro-vitamin D₃ produced in the skin, the so-far-unknown mechanism of human skin pigmentation after the ultraviolet irradiation may be partly explained by this stimulating effect of vitamin D₃ on the melanocytes.