title: Aminoacids--precursors of melanin synthesis in hamster melanoma.
abstract: The role of L-tyrosine, L-phenylalanine, L-dihydroxyphenylalanine (dopa) and L-tryptophan in melanin biosynthesis in melanotic hamster melanoma IC-Sofia was investigated with the aid of 14C-aminoacids. Tyrosine and phenylalanine were found to be the main melanin precursors: about 64.5% of total melanin labeling was due to tyrosine incorporation and 27.4% to phenylalanine incorporation. Negligible proportions of melanin radioactivity (5.7% and 2.4%, respectively) resulted from dopa and tryptophan utilization in melanin synthesis. The involvement of each of the aminoacids under investigation in melanin synthesis in vivo is discussed.
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D006224:Cricetinae; D005296:Ferrous Compounds / Q000494:pharmacology*; D007501:Iron / Q000494:pharmacology*; D007980:Levodopa / Q000378:metabolism; D008297:Male; D008543:Melanins / Q000096:biosynthesis*; D008545:Melanoma / Q000378:metabolism*; D008647:Mesocricetus; D009368:Neoplasm Transplantation; D010649:Phenylalanine / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000596:Amino Acids; D005296:Ferrous Compounds; D008543:Melanins; D014443:Tyrosine; D007980:Levodopa; D010649:Phenylalanine; D014364:Tryptophan; D007501:Iron