Relevance of free tryptophan in serum to tissue tryptophan concentrations

Madras, Bertha K.; Cohen, Edith L.; Messing, Rita B.; Munro, Hamish N.; Wurtman, Richard J.

doi:10.1016/0026-0495(74)90027-4

Cited by 151 publications

(48 citation statements)

References 19 publications

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“…European investigators suggest that brain tryptophan concentration is a function of free tryptophan levels in the plasma (34)(35)(36). In contrast, American workers indicate that brain tryptophan concentrations correlate with total (free plus bound) plasma tryptophan levels (37,38). This study demonstrates that in the case ofthis indole alcohol (which does not gain access to brain via a carrier mediated transport system), brain uptake is minimally affected by serum binding phenomena and thus is a function of total plasma tryptophol levels.…”

Section: Methodsmentioning

confidence: 99%

Rapid distribution of tryptophol (3-indole ethanol) to the brain and other tissues.

Cornford¹,

Bocash²,

Braun³

et al. 1979

J. Clin. Invest.

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A B S T R A C T Tryptophol (3-indole ethanol) is a compound which induces sleep, and is formed: (a) in the liver after disulfiram treatment, and (b) by the parasite in trypanosomal sleeping sickness. We prepared, purified, and characterized radiolabeled tryptophol for the purpose of defining its tissue distribution in animals. Tryptophol was found to be highly lipophilic, with an octanol: water partition coefficient of 29.8. Brain extraction, determined after intracarotid injection, was high (brain uptake index = 117+3.5%), and nonsaturable, suggesting the absence of a carrier system. After intravenous administration, tryptophol distribution to tissues correlated with relative blood flow. More than 85% of the radioactivity remaining in brain 2-5 min after intravenous injection co-migrated with tryptophol standards when analyzed by thin-layer chromatography. Other evidence suggested that tryptophol binds to serum and in vivo may be stripped from serum albumin and taken up by brain in a single capillary transit. Our study suggests that in states such as trypanosomal sleeping sickness or disulfiram treatment, remotely formed tryptophol gains ready access to brain (it is 100% cleared in a single capillary passage), and could thus cause somnolence.

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Section: Methodsmentioning

confidence: 99%

Rapid distribution of tryptophol (3-indole ethanol) to the brain and other tissues.

Cornford¹,

Bocash²,

Braun³

et al. 1979

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…A similar trend was also observed for methionine and serotonin although differences were not statistically significant, however no difference was observed for kynurenine between case and control. Tryptophan circulates in blood in a free and albumin bound form (32). Noteworthy in our study, we only measured total tryptophan and not free tryptophan.…”

Section: Amino Acids and Biogenic Aminesmentioning

confidence: 98%

Plasma Biomarkers of Poor Muscle Quality in Older Men and Women from the Baltimore Longitudinal Study of Aging

Moaddel

Fabbri

Khadeer

et al. 2016

GERONA

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Aging is characterized by progressive decline in muscle mass, strength, and quality all of which contribute to functional impairment, falls, mobility disability, and frailty. Circulating factors may provide clues on the mechanisms for decline in muscle quality with aging. Characterizing the metabolic profile associated with reduced muscle quality in older persons could have important translational implications for the early identification of subjects at high risk of developing sarcopenia and the identification of targets for new preventive strategies and treatments. In a pilot cross-sectional, case-control study nested in the Baltimore Longitudinal Study on Aging, we compared circulating metabolites between 79 participants with low muscle quality ratio and 79 controls with high muscle quality, matched by age, sex, and height. The concentrations of 180 metabolites were determined by LC MS/MS, using the Biocrates p180 system, a targeted metabolomics approach. Participants with low muscle quality had significantly higher levels of leucine, isoleucine, tryptophan, serotonin, and methionine, while those with high muscle quality had significantly lower levels of putrescine and the selected phophatidylcholine (PCs) and lysoPCs. The results of this study open a new road for future investigations aimed at identifying new metabolic pathways involved in the decline of muscle quality with aging.

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“…Brain tryptophan was determined as described by Madras, Cohen, Messing, Munro & Wurtman (1974) and NA and dopamine by the method of Shellenberger & Gordon (1971). Brain 5-HT, 5-HIAA and melatonin were determined fluorometrically after reaction with O-pthaldialdehyde (OPT).…”

Section: Neurochemical Studiesmentioning

confidence: 99%

Effects of Melatonin on Sleep and Neurochemistry in the Rat

Holmes

Sugden

1982

British J Pharmacology

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The effects of intraperitoneally administered melatonin on sleep and brain neurochemistry in the rat were studied by use of EEG recording and standard fluorescence techniques. Melatonin, 10 mg/kg, reduced time to sleep onset and time spent awake but increased both slow wave and paradoxical sleep. Qualitatively similar but smaller effects were produced by a dose of 2.5 mg/kg. Neither dose of melatonin altered normal EEG patterns or disrupted normal sleep behaviour. Melatonin, 20 mg/kg, did not significantly alter concentrations of tryptophan, 5‐hydroxytryptamine, 5‐hydroxyindoleacetic acid, noradrenaline or dopamine in any part of the brain. It is concluded that the sleep promoting activity of melatonin cannot be related to gross changes in brain indoleamine and catecholamine levels.

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Relevance of free tryptophan in serum to tissue tryptophan concentrations

Cited by 151 publications

References 19 publications

Rapid distribution of tryptophol (3-indole ethanol) to the brain and other tissues.

Rapid distribution of tryptophol (3-indole ethanol) to the brain and other tissues.

Plasma Biomarkers of Poor Muscle Quality in Older Men and Women from the Baltimore Longitudinal Study of Aging

Effects of Melatonin on Sleep and Neurochemistry in the Rat

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