On June 17th scientists revealed that lack of a specific enzyme in the brain may be linked to addiction to opiates. A study funded by the National Institute on Drug Abuse (part of the National Institutes of Health) focused on how the absence of prohormone convertase 2, known as PC2, affects the concentration of mu opioid receptor (MOR).
As opiate addition is skyrocketing in the US, it is vital that scientists gain a better understanding of how addiction affects works in the human body, and if there are certain factors in brain chemistry that makes a person more susceptible to becoming addicted to various substances. Of the most commonly prescribed drugs in America, opiates follow only antibiotics and antidepressants, making it vital that doctors understand if a patient has a predisposition to addiction before prescribing the medication.
Opiates are sythentic opioids that are derived from opium. They are meant to mimic the effects of natural opioids, which are produced by the body, such as endorphins, which create good feelings. Prescription opioids, such as codeine and morphine, are designed to block pain signals in the body during and after injuries or extreme illness. These substances are highly addictive, whether someone is taking the prescribed versions or illegal ones, such as heroin. Medically speaking, addiciton occurs when the use of these opioids changes the biochemical balance in the brain.
An earlier study found that PC2 levels increase after a patient undergoes long-term morphine treatment. This new study looked at how lack of the enzyme in mice might impact opioid receptors, especially in sections of the brain that are tied to addiction, such as the reward and pain relief systems.
PC2 is responsible for converting pre-hormal substances in certain parts of the brain into active hormones. MOR is the receptor within the brain that binds opioids. Higher levels of MOR are believed to be linked to addiction. The new study removed PC2 from mice and then compared MOR levels to those in mice with normal amounts of PC2. Without PC2, the concentration of MOR levels was signicantly higher in areas of the brain linked to addiction to opiates.
While further study is needed, it is possible that these findings may help scientists develop a system to detect enzyme levels in patients before a doctor prescribes an opioid regimen. It may also fuel the development of medications that counteract drug cravings and, ultimately, help decrease addiction rates.
The full results of the study were presented at the 95th Annual Meeting of the Endocrine Society.