Researchers identify a new molecular player in chronic pain

Toronto, ON August 20, 2003 Researchers at the Hospital for Sick Children and the National Institute of Health Sciences in Japan have identified a molecule that causes neuropathic pain, a sharp and chronic pain associated with nerve injury and diseases affecting the nervous system. This finding may lead to a new and previously unknown way of treating chronic pain. This research was reported in the August 14 issue of the scientific journal Nature.

Neuropathic pain is a common and severely disabling state that affects millions of people worldwide. This type of pain may be experienced after nerve injury or from diseases that affect peripheral nerve function, such as diabetes, and can also be a component of pain in other conditions, such as cancer. Neuropathic pain can be so severe that even the light touch of clothing can be intensely painful and is often resistant to all treatments available.

“We have found that cells in the spinal cord use the P2X(4) receptor to induce neuropathic pain. This discovery suggests that an agent that could block the receptor could be an effective therapy for this debilitating pain,” says study co-author Dr Michael Salter, senior scientist at HSC and director of the University of Toronto Centre for the Study of Pain. “Our research is now focused on developing more specific and potent blockers that will be able to reach P2X(4) receptors in the spinal cord when given by mouth or systemic injection.”

The work was primarily done in the laboratory of principal investigator Dr Kazu Inoue at the National Institute of Health Science. Dr Makoto Tsuda, lead author of the study, is a research fellow supported by the HSC Research Training Centre in the laboratory of Dr Salter. This research was supported by grants from the Ministry of Education, Science, Sports, and Culture of Japan, and from the Japan Health Sciences Foundation. Dr Salter is an Investigator of the Canadian Institutes of Health Research.