Leone R M, Silman R E
J Pineal Res. 1985;2(1):87-94. doi: 10.1111/j.1600-079x.1985.tb00630.x.
Though melatonin is primarily metabolised to 6-hydroxy-melatonin, we have recently shown that it can also be demethylated to form N-acetyl-serotonin. The question therefore arises as to whether demethylation is a general metabolic pathway that can apply to other pineal methoxyindoles. To investigate this possibility we administered deuterated methoxy-tryptophol (dML) and deuterated methoxy-tryptamine (dMT) to rats and analysed the urine for the presence of deuterated methoxyindole acetic acid (dMIAA) and deuterated hydroxyindole acetic acid (dHIAA). The method of analysis was gas chromatography mass spectrometry (GCMS), where the relevant molecular ion and fragment ions were monitored. The results showed that the major metabolite in all cases was dMIAA. There was no evidence to suggest that the compounds had been demethylated to form dHIAA. The study therefore indicates that the demethylation of melatonin is a specific metabolic pathway that does not apply to other methoxyindoles.
尽管褪黑素主要代谢为6-羟基褪黑素，但我们最近发现它也可以去甲基化形成N-乙酰血清素。因此，问题就出现了，去甲基化是否是一种可以应用于其他松果体甲氧基吲哚的一般代谢途径。为了研究这种可能性，我们给大鼠施用了氘代甲氧基色醇（dML）和氘代甲氧基色胺（dMT），并分析尿液中是否存在氘代甲氧基吲哚乙酸（dMIAA）和氘代羟基吲哚乙酸（dHIAA）。分析方法是气相色谱质谱联用（GCMS），监测相关的分子离子和碎片离子。结果表明，所有情况下的主要代谢产物都是dMIAA。没有证据表明这些化合物已去甲基化形成dHIAA。因此，该研究表明褪黑素的去甲基化是一种特定的代谢途径，不适用于其他甲氧基吲哚。
