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Paper on Toxic Party Drug Is Pulled Over Vial Mix-Up Constance Holden Science September 12, 2003 PDF version Last year scientists at Johns Hopkins University School of Medicine created a stir with a report in Science suggesting that people who use the party drug ecstasy may damage their dopamine neurons, raising their risk of Parkinson's disease. This week on page 1479 they publish a retraction: Owing to a misla-beled bottle, they say, they were using the wrong drug in their experiments. The toxic effects they ascribed to ecstasy (methylenedioxymethamphetamine, or MDMA) were caused by a sister drug, methamphetamine, which is known to be toxic to dopamine neurons. Both drugs were delivered to the lab on the same day and in identical bottles, but the labels were switched. A spokesperson for the drug supplier, Research Triangle Institute (RTI) in Re-search Triangle Park, North Carolina, says, "We are conducting a thorough review of our procedures, even though we do not have any evidence that an error occurred at RTI." Cognitive neuroscientist Jon Cole of the University of Liverpool, U.K., expressed doubts from the beginning about the study's implications for disease risk (Science, 27 September 2002, p. 2185). "If MDMA and [Parkinson's] were linked, we would be seeing hundreds, if not thousands, more young-onset Parkinson's disease cases," he says. Now, he says, "I think they should...abandon" the quest to link the two. Study author George Ricaurte insists, however, that the retraction is by no means the last word on the issue of MDMA-induced dopamine neurotoxici-ty in primates, which he says "is [still] an open question." He also notes that the retraction doesn't affect the well-established find that MDMA is toxic to neurons that communicate by means of the messenger serotonin. The study in question found surprisingly strong reactions — including two deaths — and "profound dopamine toxicity" in primates given injections of what the researchers thought was MDMA (Science, 27 September 2002, p. 2260). The doses were no higher than the equivalent of what a human would get in one all-night "rave." They concluded that even brief exposure to MDMA may cause brain damage and raise a person's risk of developing Parkinson's disease, which is the result of dead dopamine neurons. But the team's subsequent attempts to replicate the results with oral doses, from a different batch of MDMA, failed. So did a repeat of the injection approach. The researchers then became suspicious of their original drug supply. Although the bottle labeled MDMA had been discarded, they discovered that their bottle of "methamphetamine" actually contained MDMA. A check of preserved animal brains from the experiment revealed methamphetamine and not a trace of MDMA. Ricaurte says he's not planning to abandon this line of inquiry. MDMA is toxic to dopamine neurons in mice, he says. "In what we've done so far, we do not see an effect in monkeys," but various regimens remain to be tested. From now on, he says, lab members will test selected chemicals to be sure they are what they say they are.
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