Pain. It's the most common complaint triggering patients to seek health care. Thankfully, researchers at The University of Texas Health Science Center at San Antonio (UTHSC) have discovered a new way to treat persistent pain.
"Pain serves an important protective function," said Kenneth Hargreaves, D.D.S., Ph.D., professor and chairman of UTHSC's department of endodontics. "If we injure our hand by touching a hot fire, then the perception of pain initiates reflexes to withdraw the hand while sending signals to the brain letting us know injury has occurred." Over time, the body should recover from injuries like this.
However, persistent pain lasting well beyond the time of actual injury involves suffering and requires treatment. Fortunately, Dr. Hargreaves and his team are on the verge of developing a new class of pain-relieving analgesics using a substance already in our bodies.
Dr. Hargreaves is investigating Neuropeptide Y (NPY) and its role in the human body to relieve persistent inflammatory pain. "NPY is of interest because it is one of the body's natural substances," Dr. Hargreaves said.
In January, Jennifer Gibbs, a joint D.D.S./Ph.D. student in her third year at the Health Science Center, proved through animal models that NPY truly is an analgesic compound. Her research showed NPY works to inhibit pain fibers in our nerves from activating.
"Jennifer's work is important because it recognizes the NPY system's involvement in regulating pain, and that suggests drugs that alter the NPY system could represent a whole new class of pain-relieving drugs," Dr. Hargreaves said. "We wanted to see whether NPY was good for relieving inflammatory pain. The answer is yes."
Theoretically, a synthetic form of NPY could be administered to patients with persistent pain. Clinical studies are under way to test NPY's effects on patients with severe toothache, a common type of inflammatory pain.
But this is just the beginning. Exciting news could be on the horizon for people at higher risk for pain, including the elderly and diabetics. In fact, neuropathic pain (pain often described as a burning numbness from nerve damage) is the next frontier in the pain management research. Dr. Hargreaves believes he and his team are starting to understand how NPY also works to relieve neuropathic pain.
"We know the NPY system is dramatically altered when nerves are injured. It's one of the most profound changes in the body. We think NPY also could be mediating neuropathic pain," Dr. Hargreaves said. "If so, this one natural peptide our body makes could be equally important for both kinds of pain."
Dr. Hargreaves and his team continue their pain research at the Health Science Center thanks to the National Institutes of Health. Their work has received a MERIT award, and Gibbs is working under an NIH training grant to continue her studies as a clinician scientist.
"Pain crosses all areas of health care. It's important in dentistry, medicine, nursing and allied health. As a dentist, I want to help people be more at ease at their appointments. People think of dental visits and pain as synonymous. Our goal is to make dentistry much more comfortable for patients," Dr. Hargreaves said. "The knowledge we find, fortunately, will be helpful for all health care professions."