Evaluation of RNA isolation procedures from human blood and its application for gene expression studies (Sod-1, Sod-2).
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Adult↗
Biomedical subjects
Jordi Ortuño
Publications and source records attributed to Jordi Ortuño.
MDMA (ecstasy) pharmacokinetics in a CYP2D6 poor metaboliser and in nine CYP2D6 extensive metabolisers.
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Area Under Curve↗
Contribution of cytochrome P450 2D6 to 3,4-methylenedioxymethamphetamine disposition in humans: use of paroxetine as a metabolic inhibitor probe.
BACKGROUND: 3,4-Methylenedioxymethamphetamine (MDMA) is a synthetic amphetamine derivative typically used for recreational purposes. The participation of cytochrome P450 (CYP) 2D6 in the oxidative metabolism of MDMA may suggest an increased risk of acute toxicity in CYP2D6 poor metabolisers. This study was aimed at assessing the contribution of CYP2D6 to MDMA disposition in vivo using paroxetine as a metabolic probe inhibitor. Paroxetine, a CYP2D6 inhibitor, was repeatedly administered before MDMA administration. STUDY DESIGN: This was a randomised, double-blind, crossover, placebo-controlled trial conducted in seven healthy male volunteers who were CYP2D6 extensive metabolisers. Treatment conditions (paroxetine/MDMA and placebo/MDMA) were randomly assigned. Each volunteer participated in two 3-day sessions. On days 1, 2 and 3 subjects received a single oral dose of paroxetine or placebo 20 mg. On the third day, a single oral dose of MDMA 100 mg was administered in both paroxetine and placebo conditions. METHODS: Plasma concentration-time profiles and urinary recoveries of MDMA and its metabolites were measured, as well as plasma concentrations of paroxetine, (3S,4R)-4-(4-fluorophenyl)-3-(3,4-methylenedioxyphenoxymethyl)-piperidine, and (3S,4R)-4-(4-fluorophenyl)-3-(3-methoxy-4-hydroxyphenoxymethyl)-piperidine (HM-paroxetine). RESULTS: Paroxetine given before MDMA resulted in significant increases of MDMA area under the plasma concentration-time curve from 0 to 27 hours (AUC(27)) [23%], AUC from zero to infinity (AUC(infinity)) [27%] and maximum plasma concentration (C(max)) [17%], without significant differences in MDMA time to reach C(max) (t(max)). MDMA elimination-related pharmacokinetic parameters showed a significant reduction of MDMA elimination rate constant (K(e)) [-14%] and plasmatic clearance (CL(P)) [-29%]. In the case of 3,4-dihydroxymethamphetamine (HHMA), a 21% decrease in C(max) with no significant differences in AUC(27), AUC(infinity), K(e) and elimination half-life) were found. 4-Hydroxy-3-methoxymethamphetamine (HMMA) showed a decrease in plasma concentrations with a reduction in AUC(27) (-28%), AUC(infinity) (-20%) and C(max) (-46%). In the case of 3,4-methylenedioxyamphetamine (MDA) an increase in C(max) (17%) and AUC(27) (16%) was found. Following paroxetine pretreatment, the urinary recovery (0-45 hours) of MDMA increased by 11%; HHMA and HMMA urinary recoveries were 27% and 16% lower, respectively compared with placebo. The ratio of C(max) values of paroxetine and its metabolite on days 1 and 3 showed a 3-fold reduction, with no differences in t(max). DISCUSSION AND CONCLUSION: The contribution of CYP2D6 to MDMA metabolism in humans is not >30%, therefore other CYP isoenzymes may contribute to O-demethylenation of MDMA. Accordingly, the relevance of genetic polymorphism in CYP2D6 activity on MDMA effects and MDMA-induced acute toxicity should be examined as well as the interactions of other CYP2D6 substrates with MDMA, once the enzyme is inhibited. The pharmacokinetics of HM-paroxetine in humans after the administration of repeated doses is reported for the first time in this study.
Adult↗
Paroxetine inhibits acute effects of 3,4-methylenedioxymethamphetamine on the immune system in humans.
The effect of pretreatment with paroxetine on cell-mediated immune response and release of cytokines after the administration of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") was investigated in a double-blind, randomized, crossover, controlled clinical trial in which 12 healthy male recreational users of MDMA participated. Subjects received 20 mg/day paroxetine (or placebo) for the 3 days before MDMA challenge (100 mg). Acute MDMA administration produced a time-dependent decrease in CD4 T-helper cells, a decrease in the functional responsiveness of lymphocytes to mitogenic stimulation, a simultaneous increase in natural killer (NK) cells as well as cortisol and prolactin stimulation kinetics. A high increase in the release of anti-inflammatory cytokines (transforming growth factor-beta and interleukin-10) with a simultaneous decrease of anti-inflammatory response (interleukin-2) was also observed. Pretreatment with paroxetine partially reduced MDMA effects on CD4 T and NK cells, whereas totally inhibiting the suppression of the immune response to mitogens and alterations in cytokines release. MDMA-induced alterations in the immune system as well as antagonistic effects mediated by paroxetine show a trend toward baseline levels at 24 h. These findings suggest that acute effects of MDMA on immune system are mainly mediated by its interaction with the serotonin transporter and subsequent serotonin release with a possible participation of other neuroendocrine regulatory systems.
Adult↗
The rewarding properties of MDMA are preserved in mice lacking mu-opioid receptors.
The involvement of mu-opioid receptors in the rewarding properties of MDMA was explored in mu-opioid receptor knockout mice using the conditioning place preference paradigm. The associated release of dopamine in the nucleus accumbens was investigated by in vivo microdialysis. A significant rewarding effect of MDMA (10 mg/kg, i.p.) was observed in both wild-type and mu-opioid receptor knockout mice. MDMA (10 mg/kg, i.p.) also induced similar increases in dopamine and decreases in 3,4-dihydroxyphenylacetic acid and homovanillic acid in the nucleus accumbens dialysates of both wild-type and mu-opioid receptor knockout mice. No significant differences in basal levels of dopamine, 3,4-dihydroxyphenylacetic or homovanillic acids between wild-type and mu-opioid receptor knockout mice were observed. In summary, the present results suggest that, in contrast to what has been reported for other drugs of abuse such as opioids, ethanol, nicotine and Delta(9)-tetrahydrocannabinol, mu-opioid receptors do not play a major role in the rewarding properties of MDMA. These differences could be due to distinct mechanisms controlling dopamine release in the nucleus accumbens and suggest that the effects of MDMA on dopaminergic neurons are independent of micro -opioid receptors.
Adrenergic Uptake Inhibitors↗
Quantitative determination of paroxetine and its 4-hydroxy-3-methoxy metabolite in plasma by high-performance liquid chromatography/electrospray ion trap mass spectrometry: application to pharmacokinetic studies.
A high-performance liquid chromatography (HPLC) method with tandem mass spectrometric detection is described for the determination of paroxetine, an antidepressant drug, and its metabolite (3S,4R)-4-(4-fluorophenyl)-3-(4-hydroxy-3-methoxyphenoxymethyl)piperidine (HM paroxetine) in human plasma. Plasma samples were hydrolysed with hydrochloric acid and then analytes were extracted with ethyl acetate at alkaline pH. Extracts were analysed by HPLC coupled to an atmospheric pressure ionisation-electrospray (ESI) interface and an ion trap mass spectrometer. Chromatography was performed on a reversed-phase column using acetonitrile/0.02% formic acid (66:34, v/v) as a mobile phase. The mass spectrometer was operated in the multiple reaction monitoring mode. The method was validated over concentration ranges of 0.75-100 microg/L and 5-100 microg/L for paroxetine and HM paroxetine, respectively. Mean recoveries of 77% for paroxetine and 76% for HM paroxetine were found, with precision always better than 15%. The limits of detection and quantification were 0.20 and 0.70 microg/L for paroxetine, and 0.70 and 2.20 microg/L for its metabolite. The method was applied to the analysis of plasma samples obtained from nine healthy male volunteers administered with a single oral dose of 20 mg paroxetine. After the 20-mg dose, the mean peak plasma concentration was 8.60 microg/L for paroxetine and 92.40 microg/L for HM paroxetine showing a tenfold ratio between the metabolite and the parent drug along the entire time-concentration curve.
Administration, Oral↗
Hydroxytyrosol disposition in humans.
BACKGROUND: Animal and in vitro studies suggest that phenolic compounds in virgin olive oil are effective antioxidants. In animal and in vitro studies, hydroxytyrosol and its metabolites have been shown to be strong antioxidants. One of the prerequisites to assess their in vivo physiologic significance is to determine their presence in human plasma. METHODS: We developed an analytical method for both hydroxytyrosol and 3-O-methyl-hydroxytyrosol in plasma. The administered dose of phenolic compounds was estimated from methanolic extracts of virgin olive oil after subjecting them to different hydrolytic treatments. Plasma and urine samples were collected from 0 to 12 h before and after 25 mL of virgin olive oil intake, a dose close to that used as daily intake in Mediterranean countries. Samples were analyzed by capillary gas chromatography-mass spectrometry before and after being subjected to acidic and enzymatic hydrolytic treatments. RESULTS: Calibration curves were linear (r >0.99). Analytical recoveries were 42-60%. Limits of quantification were <1.5 mg/L. Plasma hydroxytyrosol and 3-O-methyl-hydroxytyrosol increased as a response to virgin olive oil administration, reaching maximum concentrations at 32 and 53 min, respectively (P <0.001 for quadratic trend). The estimated hydroxytyrosol elimination half-life was 2.43 h. Free forms of these phenolic compounds were not detected in plasma samples. CONCLUSIONS: The proposed analytical method permits quantification of hydroxytyrosol and 3-O-methyl-hydroxytyrosol in plasma after real-life doses of virgin olive oil. From our results, approximately 98% of hydroxytyrosol appears to be present in plasma and urine in conjugated forms, mainly glucuronoconjugates, suggesting extensive first-pass intestinal/hepatic metabolism of the ingested hydroxytyrosol.
Adult↗
Determination of N,N-dimethyltryptamine and beta-carboline alkaloids in human plasma following oral administration of Ayahuasca.
Ayahuasca is a South American psychotropic beverage prepared from plants native to the Amazon River Basin. It combines the hallucinogenic agent and 5-HT(2A/2C) agonist N,N-dimethyltryptamine (DMT) with beta-carboline alkaloids showing monoamine oxidase-inhibiting properties. In the present paper, an analytical methodology for the plasma quantification of the four main alkaloids present in ayahuasca plus two major metabolites is described. DMT was extracted by liquid-liquid extraction with n-pentane and quantified by gas chromatography with nitrogen-phosphorus detection. Recovery was 74%, and precision and accuracy were better than 9.9%. The limit of quantification (LOQ) was 1.6 ng/ml. Harmine, harmaline, and tetrahydroharmine (THH), the three main beta-carbolines present in ayahuasca, and harmol and harmalol (O-demethylation metabolites of harmine and harmaline, respectively) were measured in plasma by means of high-performance liquid chromatography (HPLC) with fluorescence detection. Sample preparation was accomplished by solid-phase extraction, which facilitated the automation of the process. All five beta-carbolines were measured using a single detector by switching wavelengths. Separation of harmol and harmalol required only slight changes in the chromatographic conditions. Method validation demonstrated good recoveries, above 87%, and accuracy and precision better than 13.4%. The LOQ was 0.5 ng/ml for harmine, 0.3 ng/ml for harmaline, 1.0 ng/ml for THH, and 0.3 ng/ml for harmol and harmalol. Good linearity was observed in the concentration ranges evaluated for DMT (2.5-50 ng/ml) and the beta-carbolines (0.3-100 ng/ml). The gas chromatography and HPLC methods described allowed adequate characterization of the pharmacokinetics of the four main alkaloids present in ayahuasca, and also of two major beta-carboline metabolites not previously described in the literature.
Administration, Oral↗
Determination of MDMA and its metabolites in blood and urine by gas chromatography-mass spectrometry and analysis of enantiomers by capillary electrophoresis.
A gas chromatography-mass spectrometry (GC-MS) method was used for the simultaneous quantitation of 3,4-methylenedioxymethamphetamine (MDMA) and the 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), and 4-hydroxy-3-methoxyamphetamine (HMA) metabolites in plasma and urine samples after the administration of 100 mg MDMA to healthy volunteers. Samples were hydrolyzed prior to a solid-phase extraction with Bond Elut Certify columns. Analytes were eluted with ethyl acetate (2% ammonium hydroxide) and analyzed as their trifluoroacyl derivatives. Linear calibration curves were obtained at plasma and urine concentration ranges of 25-400 ng/mL and 250-2000 ng/mL for MDMA and HMMA, and of 2.5-40 ng/mL and 100-1000 ng/mL for MDA and HMA. Following the same urine preparation procedure but without the derivatization step, a capillary electrophoresis (CE) method for enantiomerical resolution of compounds was developed using (2-hydroxy)propyl-beta-cyclodextrin at two different concentrations (10 and 50mM in 50mM H3PO4, pH 2.5) as chiral selector. Calibration curves for the CE method were prepared with the corresponding racemic mixture and were linear between 125 and 2000 ng/mL, 50 and 1000 ng/mL, and 125 and 1500 ng/mL for each enantiomer of MDMA, MDA, and HMMA, respectively. Stereoselective disposition of MDMA and MDA was confirmed. HMMA disposition seems to be in apparent contradiction with MDMA findings as the enantiomer ratio is close to 1 and constant over the time.
3,4-Methylenedioxyamphetamine↗
3,4-Methylenedioxymethamphetamine (ecstasy) and alcohol interactions in humans: psychomotor performance, subjective effects, and pharmacokinetics.
3,4-Methylenedioxymethamphetamine (MDMA) is frequently consumed in association with alcohol. The effect of this combination in humans has not been previously investigated. Nine male healthy volunteers received single oral doses of 100 mg of MDMA plus 0.8 g/kg ethanol, 100 mg of MDMA, 0.8 g/kg of ethanol, and placebo in a double blind, double dummy, randomized crossover trial. Measurements included psychomotor performance, subjective effects, and pharmacokinetics. Plasma concentrations of MDMA showed a 13% increase after the use of alcohol, whereas plasma concentrations of alcohol showed a 9 to 15% decrease after MDMA administration. The MDMA-alcohol combination induced longer lasting euphoria and well being than MDMA or alcohol alone. MDMA reversed the subjective sedation induced by alcohol but did not reduce drunkenness feelings. MDMA did not reverse the actions of alcohol on psychomotor abilities. Combined use of MDMA and alcohol causes dissociation between subjective and objective sedation. Subjects may feel euphoric and less sedated and might have the feeling of doing better, but actual performance ability continues to be impaired by the effect of alcohol. Confirmation of these findings in further studies will be highly relevant in terms of road safety.
Adult↗
On-site testing of 3,4-methylenedioxymethamphetamine (ecstasy) in saliva with Drugwipe and Drugread: a controlled study in recreational users.
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Central Nervous System Stimulants↗
Usefulness of sweat testing for the detection of MDMA after a single-dose administration.
Nine healthy male subjects and recreational users of 3,4-methylenedioxymethamphetamine (MDMA) participated in a study aimed to assess the usefulness of sweat testing for the detection of MDMA after a single 100-mg dose. Sweat was collected for up to 24 h with the PharmChek sweat patches from which drugs were eluted and then analyzed by immunoassay and gas chromatography-mass spectrometry using deuterated internal standards. The usefulness of a rapid onsite test, the Drugwipe immunochemical strip test, was also assessed. In the sweat patches, MDMA was detected as early as 1.5 h after consumption and peaked at 24 h. Intersubject variability was large; peak MDMA concentrations for the same dose varied in magnitude 30-fold. MDMA concentrations ranged between 3.2 and 1326.1 ng/patch. Only traces of the minor metabolite 3,4-methylenedioxyamphetamine were detected. In all subjects, the onsite test with the Drugwipe was positive at 1.5 h (peak time of MDMA plasma concentration). However, few false-negative results (18%) appeared in the first 6 h after administration. Both sweat patch testing and the onsite sweat strip test may find useful application for noninvasive monitoring of MDMA abuse in sweat.
3,4-Methylenedioxyamphetamine↗