Are L-tyrosine and L-dopa hormone-like bioregulators?
Some amino acids have bioregulatory functions, which far exceed those of precursors for proteins or of substrates for specific enzymes. Two of these amino acids, L-tyrosine and L-dopa, are precursors to melanin and catecholamines. In vertebrates, they can act as inducers and regulators of the melanogenic apparatus and of MSH receptors--two quite complex functions that could hardly be performed by mere substrates. Focussing on the pigmentary system as a study model, we therefore explore the hypothesis that L-tyrosine and L-dopa act as hormone-like bioregulators in mammals, with melanocytes regulating tyrosine and dopa activity via their metabolic consumption.
Slominski
A
A
Toolan Institute for Medical Research, Bennington, VT 05201.
Paus
R
R
D000818:Animals; D006728:Hormones / Q000502:physiology*; D007980:Levodopa / Q000494:pharmacology*; D008322:Mammals / Q000502:physiology*; D008544:Melanocytes / Q000502:physiology; D008954:Models, Biological; D010858:Pigmentation / Q000502:physiology; D014443:Tyrosine / Q000502:physiology*
D006728:Hormones; D014443:Tyrosine; D007980:Levodopa