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George A. Ricaurte

41 papers in the library · 4,115 citations · publishing 1985-2013

Papers

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Acquisition of MDMA self‐administration: pharmacokinetic factors and MDMA‐induced serotonin release

Addiction Biology June 14, 2013 Sarah Bradbury, Judith Bird, Joyce Colussi‐mas et al. 59 citations

Abstract The current study aimed to elucidate the role of pharmacokinetic ( PK ) parameters and neurotransmitter efflux in explaining variability in (±) 3, 4‐methylenedioxymethamphetamine ( MDMA ) self‐administration in rats. PK profiles of MDMA and its major metabolites were determined after the administration of 1.0 mg/kg MDMA (iv) prior to, and following, the acquisition of MDMA...

Discriminative‐stimulus effects of 3,4‐methylenedioxy‐N‐methylamphetamine (MDMA) and a novel MDMA quatenary analog

The FASEB Journal April 1, 2013 Jonathan M. Slezak, Melanie Mueller, George A. Ricaurte et al.

MDMA (ecstasy), popularized as a “club drug,” is a psychoactive and abused substance. It is often assumed that the behavioral effects of MDMA are due to central actions, though this has not been tested. Using a quaternary analog of MDMA (qMDMA) we tested that assumption by training male Sprague‐Dawley rats (n = 6) to discriminate intraperitoneal (i.p.) injections of 1.7 mg/kg of MDMA HCl from...

Inhibition of 3,4-methylenedioxymethamphetamine metabolism leads to marked decrease in 3,4-dihydroxymethamphetamine formation but no change in serotonin neurotoxicity: implications for mechanisms of neurotoxicity.

Synapse (New York, N.Y.) October 2011 Melanie Mueller, Jie Yuan, Concepcion Maldonado Adrian et al.

3,4-Methylenedioxymethamphetamine (MDMA)'s O-demethylenated metabolite, 3,4-dihydroxymethamphetamine (HHMA), has been hypothesized to serve as a precursor for the formation of toxic catechol-thioether metabolites (e.g., 5-N-acetylcystein-S-yl-HHMA) that mediate MDMA neurotoxicity. To further test this hypothesis, HHMA formation was blocked with dextromethorphan (DXM), which competitively...

Altered pain responses in abstinent (±)3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") users.

Psychopharmacology October 2011 Una D McCann, Robert R Edwards, Michael T Smith et al.

(±)3,4-Methylenedioxymethamphetamine (MDMA) is a popular recreational drug that has potential to damage brain serotonin (5-HT) neurons in humans. Brain 5-HT neurons play a role in pain modulation, yet little is known about long-term effects of MDMA on pain function. Notably, MDMA users have been shown to have altered sleep, a phenomenon that can lead to altered pain modulation. This study...

Sleep apnea in young abstinent recreational MDMA (“ecstasy”) consumers

Neurology July 4, 2011 Una D. Mccann, Francis P. Sgambati, Alan R. Schwartz et al. 1 citation

Background: Methylenedioxymethamphetamine (MDMA, "ecstasy") is a popular recreational drug of abuse and a selective brain serotonin neurotoxin.Functional consequences of MDMA neurotoxicity have defied ready characterization.Obstructive sleep apnea (OSA) is a common form of sleep-disordered breathing in which brain serotonin dysfunction may play a role.The present study sought to determine...

Metabolism and disposition of 3,4-methylenedioxymethamphetamine ("ecstasy") in baboons after oral administration: comparison with humans reveals marked differences.

The Journal of pharmacology and experimental therapeutics July 2011 Melanie Mueller, Amy K Goodwin, Nancy A Ator et al.

The baboon is potentially an attractive animal for modeling 3,4-methylenedioxymethamphetamine (MDMA) effects in humans. Baboons self-administer MDMA, are susceptible to MDMA neurotoxicity, and are suitable for positron emission tomography, the method most often used to probe for MDMA neurotoxicity in humans. Because pharmacokinetic equivalence is a key feature of a good predictive animal model,...

Identifying the serotonin transporter signal in Western blot studies of the neurotoxic potential of MDMA and related drugs

Synapse June 3, 2011 Michael W. McLane, Una D. Mccann, George A. Ricaurte 11 citations

A number of published studies have questioned the serotonin neurotoxic potential of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") and related drugs (fenfluramine, p-chloroamphetamine) based upon results from Western blot studies using a custom synthesized serotonin transporter (SERT) antibody that found no reduction in the abundance of a 50kDa protein after substituted amphetamine...

Synthesis and Neurotoxicity Profile of 2,4,5-Trihydroxymethamphetamine and Its 6-(N-Acetylcystein-S-yl) Conjugate

Chemical Research in Toxicology May 10, 2011 Anne Neudörffer, Melanie Mueller, Claire-Marie Martinez et al. 5 citations

The purpose of the present study was to determine if trihydroxymethamphetamine (THMA), a metabolite of methylenedioxymethamphetamine (MDMA, "ecstasy"), or its thioether conjugate, 6-(N-acetylcystein-S-yl)-2,4,5-trihydroxymethamphetamine (6-NAC-THMA), play a role in the lasting effects of MDMA on brain serotonin (5-HT) neurons. To this end, novel high-yield syntheses of THMA and 6-NAC-THMA were...

Further studies on the role of metabolites in (+/-)-3,4-methylenedioxymethamphetamine-induced serotonergic neurotoxicity.

Drug metabolism and disposition: the biological fate of chemicals October 2009 Melanie Mueller, Jie Yuan, Anne Felim et al.

The mechanism by which the recreational drug (+/-)-3,4-methylenedioxymethamphetamine (MDMA) destroys brain serotonin (5-HT) axon terminals is not understood. Recent studies have implicated MDMA metabolites, but their precise role remains unclear. To further evaluate the relative importance of metabolites versus the parent compound in neurotoxicity, we explored the relationship between...

Direct Comparison of (±) 3,4-Methylenedioxymethamphetamine (“Ecstasy”) Disposition and Metabolism in Squirrel Monkeys and Humans

Therapeutic Drug Monitoring June 1, 2009 Melanie Mueller, Erin A Kolbrich, Frank T. Peters et al.

The present study compared the disposition and metabolism of the recreational drug (±) 3,4-methylenedioxymethamphetamine (MDMA, “ecstasy”) in squirrel monkeys and humans because the squirrel monkey has been extensively studied for MDMA neurotoxicity. A newly developed liquid chromatography-mass spectrometric procedure for simultaneous measurement of MDMA, 3,4-dihydroxymethamphetamine,...

Positron emission tomographic studies of brain dopamine and serotonin transporters in abstinent (+/-)3,4-methylenedioxymethamphetamine ("ecstasy") users: relationship to cognitive performance.

Psychopharmacology October 2008 Una D McCann, Zsolt Szabó, Melin Vranesic et al.

(+/-)3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") is a recreational drug and brain serotonin (5-HT) neurotoxin. Under certain conditions, MDMA can also damage brain dopamine (DA) neurons, at least in rodents. Human MDMA users have been found to have reduced brain 5-HT transporter (SERT) density and cognitive deficits, although it is not known whether these are related. This study sought...

Effects of (±) 3,4-Methylenedioxymethamphetamine (MDMA) on Sleep and Circadian Rhythms

The Scientific World Journal 2007 Una D. Mccann, George A. Ricaurte 52 citations

Abuse of stimulant drugs invariably leads to a disruption in sleep-wake patterns by virtue of the arousing and sleep-preventing effects of these drugs. Certain stimulants, such as 3,4-methylenedioxymethamphetamine (MDMA), may also have the potential to produce persistent alterations in circadian regulation and sleep because they can be neurotoxic toward brain monoaminergic neurons involved in...

Pharmacokinetic profile of single and repeated oral doses of MDMA in squirrel monkeys: relationship to lasting effects on brain serotonin neurons.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology February 2006 Annis Mechan, Jie Yuan, George Hatzidimitriou et al.

A large body of data indicates that (+/-)3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') can damage brain serotonin neurons in animals. However, the relevance of these preclinical data to humans is uncertain, because doses and routes of administration used in animals have generally differed from those used by humans. Here, we examined the pharmacokinetic profile of MDMA in squirrel monkeys...

Neuroimagen y neurotoxicidad inducida por MDMA (éxtasis)

Adicciones December 15, 2003 Una D. Mccann, George A. Ricaurte

El incremento del consumo de éxtasis (MDMA) por parte de los jóvenes ha obligado al estudio de efectos a corto y medio plazo sobre el SNC. En la última década, se demostró la existencia de neurotoxicidad serotoninérgica en el SNC. Recientemente aparecieron estudios tendentes a demostrar también daño dopaminérgico que se ha evidenciado en experimentación animal. Las diferentes técnicas de...

RETRACTED: Severe Dopaminergic Neurotoxicity in Primates After a Common Recreational Dose Regimen of MDMA ("Ecstasy")

Science September 27, 2002 George A. Ricaurte, Jie Yuan, George Hatzidimitriou et al. 179 citations Retracted

The prevailing view is that the popular recreational drug (±)3,4-methylenedioxymethamphetamine (MDMA, or “ecstasy”) is a selective serotonin neurotoxin in animals and possibly in humans. Nonhuman primates exposed to several sequential doses of MDMA, a regimen modeled after one used by humans, developed severe brain dopaminergic neurotoxicity, in addition to less pronounced serotonergic...

Validity of [123I]β‐CIT SPECT in detecting MDMA‐induced serotonergic neurotoxicity

Synapse September 5, 2002 Liesbeth Reneman, Jan Booij, Jan B. A. Habraken et al. 33 citations

Abstract Recent [ 123 I]β‐CIT single‐photon emission computed tomography (SPECT) studies revealed decreased serotonin transporters (SERT) density in the brain of humans with a history of MDMA (“Ecstasy”) use. However, [ 123 I]β‐CIT SPECT has until now not been validated as a method for detecting such serotonergic lesions. Therefore, the present study was undertaken. Following baseline [ 123...

Use of MDMA and Other Illicit Drugs by Young Adult Males in Northern Spain

European Addiction Research 2002 Julio Bobes, Pilar A. Sáiz, María Paz García‐portilla et al. 34 citations

<i>Aim: </i>To measure the prevalence of 3,4-methylenedioxymethamphetamine (MDMA) and other drug use in young males entering compulsory military service in Asturias (northern Spain) and to define trends in MDMA use in this group during the period from 1995 to 1999. We also sought to determine whether MDMA users have distinct personality features or higher levels of sensation seeking....

(±)3,4-Methylenedioxymethamphetamine (‘Ecstasy’)-Induced Serotonin Neurotoxicity: Studies in Animals

Neuropsychobiology 2000 George A. Ricaurte, Jie Yuan, Una D. Mccann 291 citations

The popular recreational drug, (±)3,4-methylenedioxymethamphetamine (MDMA; ‘Ecstasy’) is a potent and selective brain serotonin (5-HT) neurotoxin in animals. MDMA-induced 5-HT neurotoxicity can be demonstrated using a variety of neurochemical, neuroanatomical and, more recently, functional measures of 5-HT neurons. Although the neurotoxic effects of MDMA in animals are widely accepted, the...

(±)3,4-Methylenedioxymethamphetamine (‘Ecstasy’)-Induced Serotonin Neurotoxicity: Clinical Studies

Neuropsychobiology 2000 Una D. Mccann, Victoria Eligulashvili, George A. Ricaurte 192 citations

(±)3,4-Methylenedioxymethamphetamine (MDMA, ‘Ecstasy’) is a brain serotonergic neurotoxin in experimental animals, including nonhuman primates. It is also an increasingly popular recreational drug of abuse, and doses of MDMA that are used recreationally overlap with those that produce serotonin (5-HT) neurotoxicity in animals. Studies in human MDMA users probing for evidence of brain...

Altered Serotonin Innervation Patterns in the Forebrain of Monkeys Treated with (±)3,4-Methylenedioxymethamphetamine Seven Years Previously: Factors Influencing Abnormal Recovery

Journal of Neuroscience June 15, 1999 George Hatzidimitriou, Una D. Mccann, George A. Ricaurte 338 citations

The recreational drug (±)3,4-methylenedioxymethamphetamine (MDMA, “Ecstasy”) is a potent and selective brain serotonin (5-HT) neurotoxin in animals and, possibly, in humans. The purpose of the present study was to determine whether brain 5-HT deficits persist in squirrel monkeys beyond the 18-month period studied previously and to identify factors that influence recovery of injured 5-HT axons....

Positron emission tomographic evidence of toxic effect of MDMA (“Ecstasy”) on brain serotonin neurons in human beings

The Lancet October 1, 1998 Ud Mccann, Zsolt Szabó, Ursula Scheffel et al. 664 citations

Quantitative PET studies with a ligand selective for 5-HT transporters can be used to assess the status of 5-HT neurons in the living human brain. We show direct evidence of a decrease in a structural component of brain 5-HT neurons in human MDMA users.

In vivo detection of short- and long-term MDMA neurotoxicity?a positron emission tomography study in the living baboon brain

Synapse June 1, 1998 Ursula Scheffel, Zsolt Szabó, William B. Mathews et al. 146 citations

The present study evaluated short- and long-term effects of MDMA (3,4-methylenedioxymethamphetamine) in the baboon brain using PET and [11C](+)McN 5652, a potent 5-HT transporter ligand, as well as [11C]RTI-55, a cocaine derivative which labels both 5-HT and dopamine transporters. Following baseline PET scans with [11C](+)McN5652, [11C](-)McN5652 (the inactive enantiomer of the active...

Adverse reactions with 3,4-methylenedioxymethamphetamine (MDMA; 'ecstasy').

Drug safety August 1996 U D McCann, S O Slate, George A. Ricaurte

3,4-Methylenedioxymethamphetamine (MDMA; 'ecstasy') is an increasingly popular recreational drug in the US, Western Europe and Australia. In animals, including nonhuman primates, MDMA is known to damage brain serotonin (5-hydroxytryptamine; 5-HT) neurons. It is not known whether MDMA damages serotonin neurons in the human brain but there is some indication that it may. Although the large...