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Occurrence and Distribution of 5‐Hydroxytryptophol in the Rat
Author(s) -
Cheifetz Sela,
Warsh Jerry J.
Publication year - 1980
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1980.tb09945.x
Subject(s) - urine , chemistry , lung , medicine , distribution (mathematics) , endocrinology , chromatography , biochemistry , biology , mathematical analysis , mathematics
The distribution of the serotonin metabolites 5‐hydroxytryptophol (5‐HTOL) and 5‐hydroxyindoleacetic acid (5‐HIAA) was determined in the rat by a sensitive and specific gas chromatography‐mass spectrometric assay. 5‐HTOL occurred in all tissues assayed, with highest concentrations in small intestine (mean ± S.E.M. = 193 ± 13 mg/g), lung (78.8 ± 13.2 mg/g), and liver (64.1 ± 4.9 mg/g). Brain 5‐HTOL concentrations (9.80 ± 0.36 mg/g) were only 1% of brain 5‐HIAA levels. Conjugated 5‐HTOL accounted for a significant fraction of the total 5‐HTOL concentrations in all tissues and varied from 20% in heart to 70% in kidney. In plasma and urine, 5‐HTOL occurred almost completely in conjugated form. Except for liver, 5‐HIAA concentrations were substantially greater than 5‐HTOL in all tissues, plasma, and urine. Highest 5‐HIAA concentrations occurred in brain (787 ± 28 mg/g), lung (744 ± 52 mg/g), and small intestine (424 ± 35 mg/g). 5‐HTOL concentrations in plasma and urine were about 25% of the respective 5‐HIAA levels. It is concluded that significant biotransformation of serotonin to 5‐HTOL in the rat occurs in the intestine, liver, and lung while in brain formation of 5‐HTOL represents a minor pathway of serotonin metabolism.