The European Journal of Pharmacology has received an e-mail from George Ricaurte, principal author of the recently retracted Science paper on the effects of the recreational drug Ecstasy (methylenedioxymethamphetamine, or MDMA), which may indicate that another paper will have to be retracted. Editorial representatives of the journal would not describe the contents of the e-mail, but told The Scientist that a decision on the matters therein will be taken at tomorrow's (September 18) editorial board meeting.

The Baltimore Sun last week reported that according to a spokesperson for the Ricaurte group, Una McCann, "a letter of retraction had been sent to a medical journal, which she declined to identify until editors there decide how to handle the matter."

McCann's admission indicated that experiments other than the one reported in Science may also have used the wrong chemical. The letter of retraction to Science indicated that the suspect container for Ecstasy was now empty, suggesting much use must have been made of it. The controversial issue of whether MDMA is neurotoxic is one of the group's principal fields of work.

McCann told the Sun that the new study to be retracted involved rats and was not designed to look at toxicity to dopamine cells. The European Journal of Pharmacology paper involves rats and looks at the effect of MDMA on the density of serotonin transporter.

The group published several papers on related issues in several journals in 2002, the year of publication of the retracted Science study. In that study, mislabeled vials meant that experimental animals were being given not Ecstasy, but methamphetamine ("speed"), which is known to be toxic to the dopamine system. Ecstasy immediately affects the serotonin system, but its long-term effects are disputed.

Among the journals that published related work by the Ricaurte group, the Journal of Neurochemistry and the Journal of Pharmacology and Experimental Therapeutics told The Scientist that they have not received any letter. No other journals contacted have yet indicated that they have received a letter from the Ricaurte group, but not all editorial departments had responded by press time. Neither McCann nor Ricaurte was available for comment.