Pleasure-blocking peptide points to addiction treatment
Although years of testing lie ahead, the discovery of a peptide that blocks a signaling pathway in the brain could see researchers taking a giant step to a treatment for drug addition.
A team led by Xia Zhang, associate professor in the Dept. of Psychiatry at the University of Saskatchewan, found that a naturally occurring enzyme known as PTEN acts on the brain cells sensitive to serotonin, a hormone associated with learning, sleep and mood, including the pleasurable ‘reward’ associated with addictive drugs.
The researchers, including scientists from the University of Toronto and Vanderbilt University in Tennessee, then designed a molecule called a peptide that was tailored to block PTEN. When drug-addicted and behaviourally conditioned rats were given this PTEN-blocking peptide, the drug reward process was shut down, as were cravings and the process of withdrawal.
The results of Zhang’s work will appear in the March issue of Nature Medicine, but in news reports, he warned that the researchers do not yet know if the synthetic peptide is either safe or effective in humans. That determination will only come after years of further testing.
“We have our peptide, but there’s a long way to go before a clinical application.”
Although only tested with nicotine and THC, the active ingredient in marijuana, Zhang believes the peptide could work for a wide range of addictive drugs including cocaine, heroin and even methamphetamine.
Zhang and his research associates at the U of S are part of the Neuropsychiatry Research Unit and the Neural Systems and Plasticity Research Group.