Neuromelanin synthesis in rat and human substantia nigra.

摘要: A relation between neuromelanin synthesis and vulnerability of dopaminergic neurons is suggested by the fact that heavily pigmented cells are preferentially lost in aging Parkinson's disease neurotoxin MPP+ (1-methyl-4-phenyl-pyridine) binds to neuromelanin. To elucidate mechanism synthesis, we studied formation melanin homogenates human rat substantia nigra tissue “in vitro”. It was found enzymatic processes accounted for 70% 90% tissue, respectively. The due activity monoamine oxidase (MAO), since it prevented selective inhibitors this enzyme. Both MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) inhibited formation, probably their ability inhibit MAO. No evidence involvement cytochrome P-450 monooxigenases, which have been postulated exist central catecholaminergic neurons. Proadifen reduced not necessarily because an inhibitor but rather as also a potent Some antioxidants like ascorbic acid, agents destroying hydrogen peroxide, formation. findings suggest involves MAO non-enzymatic oxidative processes.