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Squires LN, Jakubowski JA, Stuart JN, Rubakhin SS, Hatcher NG, Kim WS, Chen K, Shih JC, Seif I, Sweedler JV. Serotonin Catabolism and the Formation and Fate of 5-Hydroxyindole Thiazolidine Carboxylic Acid. J Biol Chem 2006; 281:13463-13470. [PMID: 16537538 DOI: 10.1074/jbc.m602210200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Serotonin (5-HT) functions as a neurotransmitter and neuromodulator in both the central and enteric nervous systems of mammals. The dynamic degradation of 5-HT metabolites in 5-HT-containing nervous system tissues is monitored by capillary electrophoresis with wavelength-resolved laser-induced native fluorescence detection in an effort to investigate known and novel 5-HT catabolic pathways. Tissue samples from wild type mice, genetically altered mice, Long Evans rats, and cultured differentiated rat pheochromocytoma PC-12 cells, are analyzed before and after incubation with excess 5-HT. From these experiments, several new compounds are detected. One metabolite, identified as 5-hydroxyindole thiazoladine carboxylic acid (5-HITCA), has been selected for further study. In 5-HT-incubated central and enteric nervous system tissue samples and differentiated PC-12 cells, 5-HITCA forms at levels equivalent to 5-hydroxyindole acetic acid, via a condensation reaction between L-cysteine and 5-hydroxyindole acetaldehyde. In the enteric nervous system, 5-HITCA is detected without the addition of 5-HT. The levels of L-cysteine and homocysteine in rat brain mitochondria are measured between 80 and 140 microm and 1.9 and 3.4 microm, respectively, demonstrating that 5-HITCA can be formed using available, free L-cysteine in these tissues. The lack of significant accumulation of 5-HITCA in the central and enteric nervous systems, along with data showing the degradation of 5-HITCA into 5-hydroxyindole acetaldehyde, suggests that an equilibrium coupled to the enzyme, aldehyde dehydrogenase type 2, prevents the accumulation of 5-HITCA. Even so, the formation of 5-HITCA represents a catabolic pathway of 5-HT that can affect the levels of 5-HT-derived compounds in the body.
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Affiliation(s)
- Leah N Squires
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Jennifer A Jakubowski
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Jeffrey N Stuart
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Stanislav S Rubakhin
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Nathan G Hatcher
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Won-Suk Kim
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Kevin Chen
- Department of Molecular Pharmacology and Toxicology, Pharmaceutical Sciences Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Jean C Shih
- Department of Molecular Pharmacology and Toxicology, Pharmaceutical Sciences Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Isabelle Seif
- CNRS, Unité Mixte de Recherche 146, Institut Curie, 91405 Orsay, France
| | - Jonathan V Sweedler
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.
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Jin C, Burgess JP, Gopinathan MB, Brine GA. Chemical synthesis and structural elucidation of a new serotonin metabolite: (4R)-2-[(5′-hydroxy-1′H-indol-3′-yl)methyl]thiazolidine-4-carboxylic acid. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2005.11.153] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Medvedev AE, Halket J, Goodwin BL, Sandler M, Glover V. Monoamine oxidase A-inhibiting components of urinary tribulin: purification and identification. JOURNAL OF NEURAL TRANSMISSION. PARKINSON'S DISEASE AND DEMENTIA SECTION 1995; 9:225-37. [PMID: 8527006 DOI: 10.1007/bf02259663] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The endogenous monoamine oxidase (MAO) inhibitory activity, termed tribulin, contains several components. We have previously identified one of them, isatin, which is a selective inhibitor of MAO B. In the present study we have purified several further components of human urinary tribulin which act as selective inhibitors of MAO A. They have been identified by gas chromatography-mass spectrometry (GC-MS) as ethyl indole-3-acetate (and/or methyl indole-3-propionate), methyl indole-3-acetate and ethyl 4-hydroxyphenylacetate. IC50 values for MAO A were found to be 44 microM (105 microM for methyl indole-3-propionate), 88 microM and 120 microM, respectively, whilst those for MAO B were each greater than 1 mM. The artificial formation of these esters was excluded by carrying the parent acids, from which they are presumably synthesized, through the purification procedure. As tribulin output is increased during stress or anxiety, these results point to a possible role for tryptamine and tyramine pathways in such disorders.
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Affiliation(s)
- A E Medvedev
- Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, Moscow, Russia
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Susilo R. [Metabolites of indoleamine neurotransmitters: key substances in alcoholism?]. PHARMAZIE IN UNSERER ZEIT 1994; 23:303-311. [PMID: 7972276 DOI: 10.1002/pauz.19940230509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Wlodek L, Rommelspacher H, Susilo R, Radomski J, Höfle G. Thiazolidine derivatives as source of free L-cysteine in rat tissue. Biochem Pharmacol 1993; 46:1917-28. [PMID: 8267641 DOI: 10.1016/0006-2952(93)90632-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The present study demonstrates that a variety of thiazolidine-4-(R)-carboxylic acids (TDs) which are the products of reactions of L-cysteine (cys) with carbonyl compounds could serve as a "delivery" system for cys to the cell. Liberation of the amino acid can occur enzymatically as well as non-enzymatically. The two possibilities have been proven by identification of representative compounds. The most specific substrate for mitochondrial enzymatic oxidation was thiazolidine-4-carboxylic acid (CF), the product of the reaction of cys with formaldehyde, and the least metabolized TD was 2-methyl-thiazolidine-4-carboxylic acid (CA), the product of the reaction of cys with acetaldehyde. TDs formed from cys and different sugars were not metabolized at all in mitochondria. N-Formyl-L-cysteine (NFC) the intermediate product of mitochondrial metabolism of CF was ascertained by 1H-NMR spectroscopy whereas N-acetyl-L-cysteine (NAC), the predicted metabolite of CA, was not detected, possibly due to a fast turnover. The further enzymatic hydrolysis of NFC as well as NAC to free cys was demonstrated to take place in the cytoplasm. Non-enzymatic hydrolysis of TDs depended on the chemical nature of the substituents in the thiazolidine (Th) ring. The most stable compound was unsubstituted Th and the least stable were CGlu(D) and CA. Following non-enzymatic ring opening and hydrolysis, CA was converted to methyl-djenkolic acid, which equilibrates with CA. We have identified this new compound by 1H-NMR spectroscopy. TDs may cause both a decrease and an increase in the levels of SH-groups in mitochondria. In the case of the stable CF, which is metabolized only enzymatically, an increase in the levels of SH-groups in mitochondria was observed. This suggests that enzymatic control of the breakdown of TDs prevents overflowing of the cell with thiol groups. The latter seems to be induced by high concentrations of those TDs which are hydrolysed non-enzymatically. This process leads finally to a decrease in free SH-groups by different mechanisms. The findings demonstrate two different mechanisms by which TDs can provide cys to the cells. The biological and pharmacological consequences are discussed.
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Affiliation(s)
- L Wlodek
- Institute of Medical Biochemistry, Medical Academy, Krakow, Poland
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Abstract
Although early interest in the biomedical relevance of tryptamine has waned in recent years, it is clear from the above discussion that the study of tryptamine is worthy of serious consideration as a factor in neuropsychiatric disorders. The study of [3H]-tryptamine binding sites indicates an adaptive responsiveness characteristic of functional receptors. The question raised by Jones (1982d) on whether tryptamine is acting centrally as a neurotransmitter or a neuromodulator still remains mostly unanswered, although the evidence cited within this review strongly suggests a modulatory role for this neuroactive amine (see also Juorio and Paterson, 1990). The synthesis and degradative pathways of tryptamine, as well as the intricate neurochemical and behavioral consequences of altering these pathways, are now more fully understood. It is not yet clear what the role of tryptamine is under normal physiological [homeostatic] conditions, however, its role during pathological conditions such as mental and physical stress, hepatic dysfunction and other disorders of metabolism (i.e. electrolyte imbalance, increased precursor availability, enzyme induction or alterations in enzyme co-factor availability) may be quite subtle, perhaps accounting for various sequelae hitherto considered idiopathic. The evidence for a primary role for tryptamine in the etiology of mental or neurological diseases is still relatively poor, although the observations that endogenous concentrations of tryptamine are particularly susceptible to pharmacological as well as physiological manipulations serve to reinforce the proposition that this indoleamine is not simply a metabolic accident but rather a neuroactive compound in its own right. Finally, one might wonder what proportion of the data attributed to modifications of 5-HT metabolism might, in fact, involve unrecognized changes in the concentrations of other neuroactive metabolites of tryptophan such as tryptamine.
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Affiliation(s)
- D D Mousseau
- Neuroscience Research Unit, André-Viallet Clinical Research Center, Hôpital St-Luc (University of Montréal), Québec, Canada
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Chapter 2 Mammalian Alkaloids II. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/s0099-9598(08)60135-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Helander A, Gogoll A. Mechanisms for plasma-mediated activation of human blood cell aldehyde dehydrogenase. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1136:259-64. [PMID: 1520702 DOI: 10.1016/0167-4889(92)90115-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Aldehyde dehydrogenase (ALDH; EC 1.2.1.3) activity assays were carried out on isolated human blood cells in phosphate-buffered saline (PBS) and in PBS mixed with human plasma. In assays with intact erythrocytes or sonicated leukocytes, the presence of 50% (v/v) or greater of plasma in the reaction mixtures produced a 2-fold increase in the rate of aldehyde oxidation. In corresponding assays with sonicated erythrocyte samples, the ALDH activity was enhanced on an average 1.5-fold, whereas a slight decrease was observed in assays with intact leukocytes. The ALDH inhibitor disulfiram almost completely abolished the enzyme activity both in the absence and presence of plasma. In assays with sonicated leukocytes, the activation effect could be antagonized by EDTA, indicating that it was caused largely by divalent cations. With sonicated erythrocytes, a significantly reduced ALDH activity was found only with the highest concentration of EDTA tested, and since a similar reduction was obtained also when plasma was omitted, the plasma-mediated activation of erythrocyte ALDH was suggested to be due to a different mechanism. After separation of plasma by gel filtration, an active fraction was identified by GC-MS and 1H-NMR to contain pyruvic acid, lactic acid and glucose. When tested at physiological plasma concentrations, pyruvic acid caused an increase in erythrocyte ALDH activity similar to that obtained with plasma, while lactic acid and glucose did not. Pyruvic acid did not activate the leukocyte ALDH. Based on these results, it is indicated that the plasma-mediated activation of erythrocyte ALDH is due to pyruvic acid, which reoxidizes NADH via lactate dehydrogenase (EC 1.1.1.27) and, thereby, increases the rate of dissociation of NADH from the terminal enzyme-NADH complex, the rate-limiting step in the ALDH pathway.
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Affiliation(s)
- A Helander
- Department of Zoophysiology, Uppsala University, Sweden
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Leinweber FJ. Drug disposition in the mammalian eye and brain: a comparison of mechanisms. Drug Metab Rev 1991; 23:133-246. [PMID: 1868775 DOI: 10.3109/03602539109029758] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- F J Leinweber
- Department of Drug Metabolism, Hoffmann-La Roche, Nutley, New Jersey 07110
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Markey SP, Boni RL, Yergey JA, Heyes MP. Mass spectrometric determinations of tryptophan and its metabolites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1991; 294:41-50. [PMID: 1837685 DOI: 10.1007/978-1-4684-5952-4_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- S P Markey
- Laboratory of Clinical Science, National Institute of Mental Health, NIAAA, Bethesda, Maryland 20892
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Susilo R, Rommelspacher H, Höfle G. Formation of thiazolidine-4-carboxylic acid represents a main metabolic pathway of 5-hydroxytryptamine in rat brain. J Neurochem 1989; 52:1793-800. [PMID: 2470854 DOI: 10.1111/j.1471-4159.1989.tb07259.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Incubation of 5-hydroxytryptamine (5-HT) with rat brain homogenate resulted in the formation of (4R)-2-[3'-(5'-hydroxyindolyl)-methyl]-1,3-thiazolidine-4-carboxyl ic acid (5'-HITCA) as the major metabolite. The substance represents the condensation product of 5-hydroxyindole-3-acetaldehyde with L-cysteine. The chemical structure was confirmed by chromatographic and chemical methods as well as by fast atom bombardment mass spectrometry. Incubation of 5-HT in the presence of L-cysteine yielded the thiazolidine as the main metabolite up to 4 h. Under these conditions, the concentration of 5-hydroxyindole-3-acetic acid (5-HIAA) amounted to about 20% and 57% of 5'-HITCA (0.5 h and 4 h, respectively). In contrast to these findings, indole-3-acetic acid (IAA) was identified as the major metabolite when tryptamine was incubated under similar conditions. (4R)-2-(3'-Indolylmethyl)-1,3-thiazolidine-4-carboxylic acid (ITCA) was found to be the main conversion product of tryptamine only during the first 30 min. To investigate the fate of the thiazolidines, radiolabelled and unlabelled ITCA was incubated with rat brain homogenate. The compound was degraded enzymatically and rapidly. Subcellular fractionation revealed that the enzyme activity was present mainly in the cytosolic fraction whereas the preparation of mitochondria showed less activity. The responsible enzyme is presumably a carbon-sulfur lyase (EC 4.4.1.-). The major metabolite was isolated by HPLC and identified by mass spectrometry as well as by comparison with reference compounds to be IAA.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R Susilo
- Institut für Neuropsychopharmakologie, Freie Universität Berlin, F.R.G
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