[Fluorimetric assay of 3-o-methyldopamine and 4-0-methyldopamine in rat urine and o-methylation of dopamine].
A new method for the isolation and determination of 3-O-methyldopamine (3 MD) and 4-O-methyldopamine (4 MD) in the urine of Rat has been described. The administration of L-dopa enabled us to detect 4 MD in the urine with a molar ratio 4 MD/3 MD = 0.07. This ratio decreased with the simultaneous treatment of S-adenosylmethionine (SAM). This result might explain the therapeutic L-dopa+SAM in the treatment of parkinsonism, 4 MD being neurotoxic. The low level of 4 MD compared with the level of isovanillic acid, found by other authors, seems to indicate that the 4-O-methylation pathway takes place via dihydroxyphenylacetic acid.
D000818:Animals; D003846:Deoxyepinephrine / Q000302:isolation & purification / Q000652:urine*; D004298:Dopamine / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000652:urine; D007980:Levodopa / Q000378:metabolism; D008297:Male; D008745:Methylation; D051381:Rats; D012436:S-Adenosylmethionine / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods
D007980:Levodopa; D012436:S-Adenosylmethionine; D003846:Deoxyepinephrine; D004298:Dopamine
Dosage fluorimétrique de la 3-O-méthyldopamine et de la 4-O-méthyldopamine dans l'urine de rat et O-méthylation de la dopamine