Lindquist N G, Larsson B S, Lydén-Sokolowski A
Department of Toxicology, Uppsala University, Sweden.
Pigment Cell Res. 1987;1(3):133-6. doi: 10.1111/j.1600-0749.1987.tb00403.x.
The function of neuromelanin is not known, but some properties of the pigment suggest a protective action. Its unique ability to accumulate and retain several compounds, such as various amines and a number of metals, may protect the pigment-containing neurons from high exposure to harmful substances. This possible mechanism of protection may however in certain instances be of a double-edged nature, as accumulation of neurotoxic agents with a high melanin affinity may cause toxic concentrations in the neuro-melanin-containing cells. MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) seems to be such a compound, as it has been found to preferentially destroy neuromelanin-containing cells. The degree of MPTP neurotoxicity seems to be related to the amount of neuromelanin present in the particular species. It is possible that also manganese, which is known to cause an extrapyramidal disorder resembling Parkinson's disease, causes injury to neuromelanin-bearing neurons due to its melanin affinity. This mechanism may be involved in other forms of chemically induced Parkinsonism and possibly also in idiopathic Parkinson's disease, although the offending agent remains to be discovered.
神经黑素的功能尚不清楚，但该色素的一些特性表明其具有保护作用。它独特的积累和保留多种化合物的能力，如各种胺类和一些金属，可能保护含有该色素的神经元免受高剂量有害物质的侵害。然而，这种可能的保护机制在某些情况下可能具有双刃剑的性质，因为具有高黑色素亲和力的神经毒性剂的积累可能会在含有神经黑素的细胞中导致有毒浓度。MPTP（1-甲基-4-苯基-1,2,3,6-四氢吡啶）似乎就是这样一种化合物，因为已发现它会优先破坏含有神经黑素的细胞。MPTP神经毒性的程度似乎与特定物种中神经黑素的含量有关。已知会导致类似帕金森病的锥体外系疾病的锰，也可能因其对黑色素的亲和力而损伤含有神经黑素的神经元。这种机制可能与其他形式的化学诱导帕金森症有关，也可能与特发性帕金森病有关，尽管致病因素仍有待发现。
