MANCHESTER, England, Oct. 23 (UPI) -- Researchers at the University of Manchester found the number of opiate receptors in the brain increases to help the body combat chronic pain, which may lead to more effective methods of pain management.
Chronic pain, such as what arthritis patients live with, is pain that persists continuously for six months or more. Opioid-based medications are often prescribed for chronic pain, however their efficacy decreases over time as patients build up a tolerance to them.
The ability to alter brain chemistry and potentially manage pain using fewer drugs would be good for patients, researchers said.
"As far as we are aware, this is the first time that these changes have been associated with increased resilience to pain and shown to be adaptive," said Dr. Christopher Brown, a researcher at the University of Manchester, in a press release. "Although the mechanisms of these adaptive changes are unknown, if we can understand how we can enhance them, we may find ways of naturally increasing resilience to pain without the side effects associated with many pain killing drugs."
The researchers applied heat to the skin of 17 arthritis patients and 9 healthy people using a laser stimulator, measuring the levels of pain they each tolerated. During the experiment, the participants brains were mapped using positron emission tomography scans.
The scans showed that people who withstood more pain had more opioid receptors in their brains. The receptors respond to the body's natural painkilling opiates, endorphins, as well as pharmaceutical drugs.
"Although the mechanisms of these adaptive changes are unknown, if we can understand how we can enhance them, we may find ways of naturally increasing resilience to pain without the side effects associated with many painkilling drugs," Brown said.
The study is published in the journal Pain.