Studies in mice have revealed a novel mechanism for chronic pain relief (Zylka MJ et al. Neuron. 2008;60:111-122).
Researchers led by Mark J. Zylka of the University of North Carolina, in Chapel Hill, discovered that thiamine monophosphatase, the acid phosphatase expressed by the dorsal root ganglia in response to pain, is identical to a form of prostatic acid phosphatase (PAP) found in prostate tissue. This enzyme, which also is expressed in nociceptive neurons and many other tissues throughout the body, can dephosphorylate extracellular adenosine monophosphate to adenosine while activating A1-adenosine receptors in the dorsal spinal cord. In so doing, PAP functions as an ecto-5′-nucleotidase, which suppresses pain.
Hildreth CJ. Pain Relief. JAMA. 2008;300(21):2476. doi:10.1001/jama.2008.740