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Query: UMLS:C0267964 (
PAA
)
2,561
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
3-(Phenylamino)alanine (
PAA
), a contaminant found in L-tryptophan tablets, has been discussed as a possible cause of eosinophilia-myalgia syndrome (EMS). We administered
PAA
(100 mg/kg) by gastric gavage to Wistar rats to determine its distribution and metabolism. We developed a purification procedure, using Bond Elut
SCX
cartridges followed by high performance liquid chromatography (HPLC) in order to determine levels of
PAA
. The level of
PAA
in blood was 4.22 micrograms/ml at 5 h and urinary excretion was 21.7 micrograms for 5 h and 84.6 micrograms between 5 and 24 h. The amount of
PAA
in the contents of the large intestine at 5 h was 0.76 microgram, indicating poor transfer of
PAA
to the large intestine. However, the highest concentration of
PAA
was 12.3 micrograms/g in the brain, indicating the passage of
PAA
through the blood-brain barrier. In addition to detecting
PAA
in the blood and organs, we also detected four metabolites of
PAA
in urine. We used gas chromatography mass spectrometry to identify
PAA
in rat liver, as well as N-(hydroxyphenyl)glycine, N-phenylglycine, 3-(pheylamino)lactic acid, and 3-(hydroxyphenylamino)-lactic acid in rat urine. These results suggest that the degradation pathway of
PAA
is similar to that of phenylalanine.
...
PMID:Identification of four metabolites of 3-(phenylamino)alanine, a constituent in L-tryptophan products implicated in eosinophilia-myalgia syndrome, in rats. 780 90
Methods for the separation, identification, and quantitative assay of contaminants of L-tryptophan implicated in eosinophilia-myalgia syndrome (EMS) are described. Propylsulfonic acid (PRS), benzenesulfonic acid (
SCX
), and octyl-derivatized silica (C8) bonded-phase cartridges were used for the separation; LC-MS and GC-MS for identification; and HPLC-UV-fluorescence detection for quantitative analyses of norharman, harman, tetrahydro-beta-carboline-3-carboxylic acid (TCCA), 1-methyltetrahydro-beta-carboline-3-carboxylic acid (MTCA), 1,1'-ethylidenbis(tryptophan) (EBT), and 3-(phenylamino)alanine (
PAA
). The tissue distribution, excretion, and metabolism of these contaminants of L-tryptophan associated with EMS after acute and chronic dosage regimens are described. Considerable amounts of EBT were observed in the large intestine of rats administered EBT, showing a transfer without decomposition in gastric fluid. In addition, MTCA was detected in the blood and urine as well as the organs of rats treated with EBT, suggesting MTCA as a major metabolite of EBT.
PAA
accumulated markedly in the brain, among the organs of rats, after both acute and chronic administration of
PAA
, while MTCA accumulated in the kidneys of rats after chronic dosage of MTCA. Ethanol and/or acetaldehyde-induced formation of MTCA, as well as tryptophan-induced formation of TCCA, occurred endogenously in man and animals.
...
PMID:Tetrahydro-beta-carboline-3-carboxylic acids and contaminants of L-tryptophan. 1090 31
