METABOLISM OF 3, 4-DIHYDROXYPHENYLALANINE, ITS METABOLITES AND ANALOGS INVIVO IN RAT - URINARY-EXCRETION PATTERN
METABOLISM OF 3, 4-DIHYDROXYPHENYLALANINE, ITS METABOLITES AND ANALOGS INVIVO IN RAT - URINARY-EXCRETION PATTERN
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DOI：
10.3109/00498257809069575
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发表时间：
1978-01-01
期刊：
影响因子：
1.8
通讯作者：
LEASK, BGS
中科院分区：
文献类型：
--
作者：
GOODWIN, BL;RUTHVEN, CRJ;LEASK, BGS
The metabolism and interrelationships of orally and i.p. administered L-dopa, related amino acids and their metabolites were studied. Amino acids were decarboxylated. N-Methyldopa formed dopamine but not epinine. D-Dopa was absorbed from the intestine and metabolized by a series of reactions which resulted in greater decarboxylation than was observed after L-dopa. Transmination was a minor pathway. m-Hydroxylated phenylpyruvic acids were poorly reduced, but vanilpyruvic acid was reduced fairly readily. Lactic acids were largely unchanged. Lactic and pyruvic acids formed phenylethylamines and their metabolites. Small amounts of phenylpyruvic acids might be decarboxylated to phenylacetic acids. Glycine conjugates were formed from phenylacetic acids, a partially reversible change. 3,4-Dihydroxyphenylacetic acid was metabolized to homovanillic and m-hydroxyphenylacetic acids, especially when given orally. Little 3-hydroxy-4-methoxyphenylacetic acid was oxidized to 3,4-dihydroxyphenylacetic acid but some increase in m-hydroxyphenylacetic acid excretion was observed. 2-Phenylethanol analogs were largely converted to the corresponding acids. 3,4-Dihydroxyphenylethanol was partially m-O-methylated before oxidation. .beta.-Phenylethylamine analogs were oxidized mainly to phenylacetic acids, but a variable amount of analogous phenylethanol was also formed, especially from m-tyramine. Dopamine was O-methylated, a process not readily reversible. It was also p-dehydroxylated following oral and i.p. administration but not after oral neomycin; biliary excretion of amines might be involved in this sequence of events. N-Methylated amines were oxidized less readily than the parent amine. Differences in route of administration resulted in quantitative changes in degradation pathways, an effect deriving, to some extent, from p-dehydroxylation and O-methylation in the gut.
