Substrate Identity in Mammalian Melanogenesis

A total of 45 chemical substances have been tested as substrates for melanogenesis identified by pigment formation in melanocytes of freshly plucked hair roots incubated in 1 mM solutions of the compounds. Melanocytes of human red and blond hair and of guinea-pig red-blond hair can utilize eatechol, tyrosine, dopa, and 14 of their derivatives as substrates for pigment formation. Melanocytes of human red and blond hair, but not guinea-pig red-blond hairs form pigment from dopamine and methyl dopa. Human and guinea-pig hair melanocytes form dark brown pigments from dopa, dopa methyl ester, and dopamine; lighter brown pigments from tyrosine, eatechol, dopa ethyl ester, dopa n-propyl ester, and dopa n-butyl ester; and golden yellow pigments from dopa isopropyl and isoamyl esters. Identification of the substrates utilized for melanogenesis may provide new clues to possible means of specifically affecting melanocyte function