The Experts below are selected from a list of 6213 Experts worldwide ranked by ideXlab platform
Santy Daya - One of the best experts on this subject based on the ideXlab platform.
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Acyclovir inhibits rat liver tryptophan-2,3-dioxygenase and induces a concomitant rise in brain serotonin and 5-Hydroxyindole acetic acid levels
Metabolic brain disease, 2008Co-Authors: Adrienne C. Müller, Santy DayaAbstract:Viral diseases of the brain may induce changes in neurotransmitter synthesis and metabolism. In experimental herpes simplex encephalitis, brain serotonin is reduced, whilst it’s major metabolite, 5-Hydroxyindole acetic acid and turnover is increased. It is well established that reduced levels of brain monoamines, serotonin and norepinephrine may contribute to the symptoms of clinical depression, which raises the possibility that this condition is prevalent in herpes simplex encephalitis. An inverse relationship exists between liver tryptophan-2,3-dioxygenase activity and brain serotonin levels and there is an interdependency between serotonin and norepinephrine levels. The aim of this study is to determine the effect of acyclovir, an antiviral used in the treatment of herpes simplex encephalitis, on rat liver tryptophan-2,3-dioxygenase activity in vitro and in vivo as well as on rat forebrain serotonin, 5-Hydroxyindole acetic acid and norepinephrine levels. The results show that acyclovir inhibits tryptophan-2,3-dioxygenase activity in vitro and in vivo, with a concomitant rise in serotonin and 5-Hydroxyindole acetic acid levels. However, acyclovir reduces the turnover of serotonin to 5-Hydroxyindole acetic acid, without any effect on norepinephrine levels. It appears that acyclovir may have the potential to reduce the clinical symptoms of depression in herpes simplex encephalitis. However, a greater turnover of serotonin to 5-Hydroxyindole acetic acid could possibly be masked by conversion of serotonin to 5-hydroxytryptophol, which needs to be investigated further.
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acetaminophen inhibits liver tryptophan 2 3 dioxygenase activity with a concomitant rise in brain serotonin levels and a reduction in urinary 5 Hydroxyindole acetic acid
Life Sciences, 2000Co-Authors: Santy Daya, Shailendra AnoopkumardukieAbstract:The effect of the analgesic agent, acetaminophen was determined on rat forebrain serotonin levels as well as hepatic tryptophan-2,3-dioxygenase (TDO) activity and urinary 5-Hydroxyindole acetic acid (5-HIAA). The results show that acetaminophen administration (100mg/kg) over three hours does not affect the holoenzyme of tryptophan-2,3-dioxygenase but significantly inhibits the apoenzyme. This inhibition is accompanied by a concomitant rise in forebrain serotonin levels. This phenomenon is also accompanied by a reduction in urinary 5-HIAA levels. These results suggest that acetaminophen use is accompanied by changes in brain serotonin levels due to inhibition of hepatic tryptophan-2,3-dioxygenase activity. This in turn could explain the possible abuse potential of acetaminophen and its effects on mood at high doses.
Shailendra Anoopkumardukie - One of the best experts on this subject based on the ideXlab platform.
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acetaminophen inhibits liver tryptophan 2 3 dioxygenase activity with a concomitant rise in brain serotonin levels and a reduction in urinary 5 Hydroxyindole acetic acid
Life Sciences, 2000Co-Authors: Santy Daya, Shailendra AnoopkumardukieAbstract:The effect of the analgesic agent, acetaminophen was determined on rat forebrain serotonin levels as well as hepatic tryptophan-2,3-dioxygenase (TDO) activity and urinary 5-Hydroxyindole acetic acid (5-HIAA). The results show that acetaminophen administration (100mg/kg) over three hours does not affect the holoenzyme of tryptophan-2,3-dioxygenase but significantly inhibits the apoenzyme. This inhibition is accompanied by a concomitant rise in forebrain serotonin levels. This phenomenon is also accompanied by a reduction in urinary 5-HIAA levels. These results suggest that acetaminophen use is accompanied by changes in brain serotonin levels due to inhibition of hepatic tryptophan-2,3-dioxygenase activity. This in turn could explain the possible abuse potential of acetaminophen and its effects on mood at high doses.
Olof Beck - One of the best experts on this subject based on the ideXlab platform.
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The Urinary Ratio of 5-Hydroxytryptophol to 5-Hydroxyindole-3-Acetic Acid in Surgical Patients with Chronic Alcohol Misuse
Alcohol (Fayetteville N.Y.), 1999Co-Authors: Claudia Spies, Olof Beck, Jörg Herpell, Christian Müller, Fritz Pragst, Stefan Borg, Anders HelanderAbstract:Abstract The urinary ratio of 5-hydroxytryptophol to 5-Hydroxyindole-3-acetic acid was reported to be elevated for a period of up to 22 h following acute alcohol ingestion. Therefore, the ratio could detect continuous alcohol consumption, in what was considered to be a high-risk surgical group, on the evening prior to surgery. The aim of this study was to determine the preoperative ratio of 5-hydroxytryptophol to 5-Hydroxyindole-3-acetic acid in patients with continuous preoperative alcohol misuse. Forty-two patients participated in this institutionally approved study, once their written informed consent had been obtained. Chronic alcoholics were defined by meeting the criteria of the Diagnostic and Statistical Manual of Mental Disorders criteria and an ethanol consumption ⩾60 g/day. The urine samples were taken preoperatively and determined by means of gas chromatography-mass spectrometry and high performance liquid chromatography. The urinary ratio of 5-hydroxytryptophol to 5-Hydroxyindole-3-acetic acid was significantly increased in chronic alcoholics. The ICU stay of these patients was significantly prolonged due to an increased incidence of pneumonia and sepsis. Five chronic alcoholics died, whereas no deaths occurred in the nonalcoholic group ( p = 0.05). As the measurement of the urinary ratio of 5-hydroxytryptophol to 5-Hydroxyindole-3-acetic acid could detect alcohol consumption immediately prior to operation, this marker could assist the carbohydrate-deficient transferrin in screening for patients with high-level dependency; these patients were considered to be at a high risk of developing intercurrent complications.
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urinary excretion of 5 Hydroxyindole 3 acetic acid and 5 hydroxytryptophol after oral loading with serotonin
Life Sciences, 1992Co-Authors: Anders Helander, Tina Wikstrom, Gun Jacobsson, Catharina Lowenmo, Olof BeckAbstract:Abstract The urinary excretion patterns of the serotonin (5-hydroxytryptamine; 5-HT) metabolites 5-Hydroxyindole-3-acetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTOL) were examined after ingestion of bananas, a food rich in 5-HT. The bananas contained on an average 25 μg 5-HT/g pulp. Both urinary 5-HIAA and 5-HTOL increased markedly (15- to 30-fold) shortly after eating 3–4 bananas, with the highest concentrations found in urine specimens collected after 2–4 h, and did not return to normal until after 8–10 h. The excretion of 5-HIAA increased from a control mean value of 3.9 mg/24 h to 12.7 mg/24 h, when conventional diets were supplemented with 3–4 bananas. The corresponding results for 5-HTOL were 16.8 μg/24 h and 60.7 μg/24 h, respectively. Of the banana-derived 5-HT ingested, 60–80% was recovered in the urine as 5-HIAA and only 0.3–0.5% as 5-HTOL. However, since both the time-course and relative increase in 5-HTOL was similar to that of 5-HIAA, there was no effect on the urinary 5-HTOL to 5-HIAA ratio. By contrast, acute alcohol consumption produced a considerable elevation of this ratio.
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determination of urinary 5 Hydroxyindole 3 acetic acid by high performance liquid chromatography with electrochemical detection and direct sample injection
Analytical Biochemistry, 1991Co-Authors: Anders Helander, Olof Beck, Mona Wennberg, Tina Wikstrom, Gun JacobssonAbstract:A method for the routine quantitative determination of the major serotonin metabolite 5-Hydroxyindole-3-acetic acid (5-HIAA) in urine is described. 5-HIAA was analyzed without prior sample cleanup, using an automated high-performance liquid chromatography system with isocratic elution and electrochemical detection (+0.60 V versus a Ag/AgCl reference electrode). The urine samples were mixed with a solution of the internal standard (5-Hydroxyindole-3-propionic acid) and centrifuged. The supernatant was transferred to sealed glass vials, and a 2-μl aliquot was injected directly onto a C18 reversed-phase analytical column, using an automatic sample injector. Samples of urine could be stored for several months at −80 or at +7°C for 2 days without loss of 5-HIAA. However, a gradual decline with time occurred in crude samples stored at room temperature or above, as well as in urine samples diluted with the mobile phase. The detector response was linear in the range of 0–65 μmol/l 5-HIAA, and the intra- and interassay coefficients of variation were about 5 and 7%, respectively (n = 10).
Mitsuhiko Miyazaki - One of the best experts on this subject based on the ideXlab platform.
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real time observation of the photoionization induced water rearrangement dynamics in the 5 Hydroxyindole water cluster by time resolved ir spectroscopy
Physical Chemistry Chemical Physics, 2018Co-Authors: Johanna Klyne, Otto Dopfer, Takamasa Ikeda, Kenji Sakota, Hiroshi Sekiya, Mitsuhiko Miyazaki, Ayumi Naito, Masaaki FujiiAbstract:Solvation plays an essential role in controlling the mechanism and dynamics of chemical reactions in solution. The present study reveals that changes in the local solute–solvent interaction have a great impact on the timescale of solvent rearrangement dynamics. Time-resolved IR spectroscopy has been applied to a hydration rearrangement reaction in the monohydrated 5-Hydroxyindole–water cluster induced by photoionization of the solute molecule. The water molecule changes the stable hydration site from the indolic NH site to the substituent OH site, both of which provide a strongly attractive potential for hydration. The rearrangement time constant amounts to 8 ± 2 ns, and is further slowed down by a factor of more than five at lower excess energy. These rearrangement times are slower by about three orders of magnitude than those reported for related systems where the water molecule is repelled from a repulsive part of the interaction potential toward an attractive well. The excess energy dependence of the time constant is well reproduced by RRKM theory. Differences in the reaction mechanism are discussed on the basis of energy relaxation dynamics.
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sequential microhydration of cationic 5 Hydroxyindole 5hi infrared photodissociation spectra of 5hi wn clusters w h2o n 4
Physical Chemistry Chemical Physics, 2018Co-Authors: Johanna Klyne, Mitsuhiko Miyazaki, Masaaki Fujii, Otto DopferAbstract:Most biochemical processes occur in aqueous solution. Here, we characterize the initial microhydration steps of the 5-Hydroxyindole cation (5HI+) in its 2A′′ ground electronic state by infrared photodissociation (IRPD) spectroscopy of 5HI+–Wn–Lm clusters (W = H2O, L = Ar and N2, n ≤ 4, m ≤ 2) in a molecular beam and dispersion-corrected density functional theory calculations (B3LYP-D3/aug-cc-pVTZ). Characteristic size- and isomer-dependent XH stretch frequencies (X = O, N) of 5HI+–Wn reveal information about the preferred cluster growth and solvation energies. The IRPD spectrum of 5HI+–W is a superposition of the spectra of two isomers, in which W is H-bonded to the acidic NH or OH group, whereby OH⋯W hydrogen-bonds (H-bonds) are stronger than NH⋯W H-bonds. Spectra of larger 5HI+–Wn clusters (n ≥ 2) elucidate the competition between interior ion solvation and the formation of H-bonded water networks. The nature and strengths of the competing H-bonds are quantified by the noncovalent interaction approach. Comparison to results for neutral 5HI–W and 5HI+–Ln clusters with nonpolar ligands reveals the effects of ionization and ligand type on the intermolecular interaction potential and cluster growth. Comparison to corresponding microhydrated clusters of the phenol, indole, and pyrrole cations illustrates the effects of substitution of functional groups and addition of aromatic rings on the hydration process.
Gun Jacobsson - One of the best experts on this subject based on the ideXlab platform.
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urinary excretion of 5 Hydroxyindole 3 acetic acid and 5 hydroxytryptophol after oral loading with serotonin
Life Sciences, 1992Co-Authors: Anders Helander, Tina Wikstrom, Gun Jacobsson, Catharina Lowenmo, Olof BeckAbstract:Abstract The urinary excretion patterns of the serotonin (5-hydroxytryptamine; 5-HT) metabolites 5-Hydroxyindole-3-acetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTOL) were examined after ingestion of bananas, a food rich in 5-HT. The bananas contained on an average 25 μg 5-HT/g pulp. Both urinary 5-HIAA and 5-HTOL increased markedly (15- to 30-fold) shortly after eating 3–4 bananas, with the highest concentrations found in urine specimens collected after 2–4 h, and did not return to normal until after 8–10 h. The excretion of 5-HIAA increased from a control mean value of 3.9 mg/24 h to 12.7 mg/24 h, when conventional diets were supplemented with 3–4 bananas. The corresponding results for 5-HTOL were 16.8 μg/24 h and 60.7 μg/24 h, respectively. Of the banana-derived 5-HT ingested, 60–80% was recovered in the urine as 5-HIAA and only 0.3–0.5% as 5-HTOL. However, since both the time-course and relative increase in 5-HTOL was similar to that of 5-HIAA, there was no effect on the urinary 5-HTOL to 5-HIAA ratio. By contrast, acute alcohol consumption produced a considerable elevation of this ratio.
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determination of urinary 5 Hydroxyindole 3 acetic acid by high performance liquid chromatography with electrochemical detection and direct sample injection
Analytical Biochemistry, 1991Co-Authors: Anders Helander, Olof Beck, Mona Wennberg, Tina Wikstrom, Gun JacobssonAbstract:A method for the routine quantitative determination of the major serotonin metabolite 5-Hydroxyindole-3-acetic acid (5-HIAA) in urine is described. 5-HIAA was analyzed without prior sample cleanup, using an automated high-performance liquid chromatography system with isocratic elution and electrochemical detection (+0.60 V versus a Ag/AgCl reference electrode). The urine samples were mixed with a solution of the internal standard (5-Hydroxyindole-3-propionic acid) and centrifuged. The supernatant was transferred to sealed glass vials, and a 2-μl aliquot was injected directly onto a C18 reversed-phase analytical column, using an automatic sample injector. Samples of urine could be stored for several months at −80 or at +7°C for 2 days without loss of 5-HIAA. However, a gradual decline with time occurred in crude samples stored at room temperature or above, as well as in urine samples diluted with the mobile phase. The detector response was linear in the range of 0–65 μmol/l 5-HIAA, and the intra- and interassay coefficients of variation were about 5 and 7%, respectively (n = 10).
