Researchers at the University of North Carolina have found a way to deliver long-lasting pain relief through a new therapeutic approach to acupuncture. The promising treatment, which they call PAPupuncture, gave several days of pain relief in animal studies.
Several years ago UNC scientists documented how injecting prostatic acid phosphatase (PAP) into the spine eased chronic pain in rodents. The only problem was PAP’s delivery.
“Spinal injections are invasive and must be performed in a clinical setting, and hence are typically reserved for patients with excruciating pain,” said principal investigator Mark J. Zylka, PhD, associate professor at the UNC Neuroscience Center. Zylka began looking at acupuncture as another delivery method for PAP.
“When an acupuncture needle is inserted into an acupuncture point and stimulated, nucleotides are released. These nucleotides are then converted into adenosine,” explained Zylka, who says adenosine gives pain relief, but for most acupuncture patients that relief only lasts for a few hours.
“We knew that PAP makes adenosine and lasts for days following spinal injection, so we wondered what would happen if we injected PAP into an acupuncture point,” Zylka said. “Can we mimic the pain relief that occurs with acupuncture, but have it last longer?”
To find out, Zylka and his colleagues injected PAP into the soft tissue area behind the knee. They discovered that pain relief from PAPupuncture lasted 100 times longer than a traditional acupuncture treatment, and was effective at reducing inflammatory pain and neuropathic pain. By avoiding the spine, researchers could also increase the dose of PAP.
“Pinning down the mechanisms behind acupuncture, at least in animal models, was critical,” said Zylka. “Once you know what chemicals are involved, you can exploit the mechanism, as we did in our study.”
The next step in PAP studies will be refining the protein for use in human trials. UNC has licensed the use of PAP for pain treatment to Aerial BioPharma, a biopharmaceutical company based in North Carolina.
Zylka says PAP could be used in any area where local anesthetics are used to treat pain. And it has the potential to last longer than a single injection.
“When it comes to pain management, there is a clear need for new approaches that last for longer periods of time,” said Julie Hurt, PhD, a postdoctoral fellow in Zylka’s lab.
The UNC study was published in the journal Molecular Pain. The research was funded by the National Institutes of Health.