New research has uncovered a cascade of reactions within nerve cells that relay sensations of pain associated with inflammation. These findings, recently published in the British Journal of Pharmacology, indicate that medicines designed to curb this pathway may help relieve inflammatory pain in sufferers. Previous studies indentified a molecule called rac1, which maintains chronic neuropathic pain resulting from injury to the nervosu system. Jun Chen, MD, PhD, of the Fourth Military Medical University in China, and his colleagues wondered if Rac1 might also be involved with chronic inflammatory pain, which is caused by tissue injury, trauma, and diseases such as arthritis. It is estimated 20 percent of people worldwide suffer with chronic pain, with many cases being inflammatory pain.

"We found that Rac1 can be activated in chronic inflammatory pain and medication that curb this reaction can relieve pain, offering the promise of new medicines for pain treatment in the clinic," said Dr. Chen.

These findings were based on experiments involving lab anaimals: when investigators injected the paws of the lab animals with bee venom to cause inflammation, Rac1 was activated and set off a cascade of reactions involved in painperception. In contrast, giving the animanls a molecule that inhibits Rac1 (called NSC23766) before of after the bee venom injection reduced their paw flinches and their pain hypersensitivity.

The British Journal of Pharmacology