Correlation between urinary melanin-related metabolites and tumour weight in melanoma-bearing mice.
Melanoma tissues produce not only 5-S-cysteinyldopa (5-S-CD), a pheomelanin precursor, but also 5,6-dihydroxyindoles, eumelanin precursors. We compared 5-S-CD and eumelanin-related metabolites regarding the correlation of their production in melanoma and excretion in urine, versus the weight of B16 mouse melanoma. It was found that B16 melanoma tissues produce 5,6-dihydroxyindole-2-carboxylic acid and its two O-methyl derivatives, the latter of which are partly conjugated with sulphuric acid and then excreted. These indolic metabolites are referred to as total indoles. Both total indoles and 5-S-CD in melanoma and in urine correlated well with each other and reflected the tumour weight. Total indoles had a four-fold greater level of excretion than 5-S-CD, suggesting that the urinary excretion of total indoles is a quantitatively more significant marker of melanoma progression in this melanoma.
Ito
S
S
School of Hygiene, Fujita-Gakuen Health University, Aichi, Japan.
Wakamatsu
K
K
Inoue
S
S
Fujita
K
K
D000818:Animals; D003548:Cysteinyldopa / Q000378:metabolism*; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives*; D007211:Indoles / Q000378:metabolism / Q000652:urine*; D008543:Melanins / Q000378:metabolism*; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology / Q000652:urine; D051379:Mice; D008810:Mice, Inbred C57BL; D009929:Organ Size
D007211:Indoles; D008543:Melanins; D003548:Cysteinyldopa; D004295:Dihydroxyphenylalanine; C033871:5,6-dihydroxyindole