Natural Molecule Offers Long-Lasting Pain Relief

Release Date:
Alison Davis, NIGMS

NIGMS grantee Dr. James Eisenach of Wake Forest University Medical Center has found that one of the simplest molecules in the body, a chemical messenger called adenosine, can provide long-lasting relief from chronic pain. When injected together with morphine into the spinal cords of rats, a compound that boosted levels of adenosine in the body had profound effects, completely eliminating a particular type of chronic pain that morphine alone could not control. Although such "neuropathic" pain is somewhat rare, it can be a debilitating feature of some cancer drug treatments, chronic nerve damage, and certain diseases like shingles.

Dr. Eisenach's research on adenosine--and his general approach that aims to improve existing clinical knowledge and treatments--is an example of the valuable contributions that basic studies on animals can continue to provide even after drugs are in wide use. In this sense, his work may influence the design and interpretation of clinical trials set to investigate spinally administered adenosine in people. Ultimately, it is hoped, doctors might be able to prescribe a "tonic" of several different pain drugs at once, which would minimize some of the inescapable dose-related side effects, such as sedation and constipation, of narcotics like morphine.

A less obvious but equally important anticipated payoff of Dr. Eisenach's research will be a clearer understanding of how nerve transmission gone awry can trigger pain. Teasing out the mechanisms of how morphine and adenosine cooperate at the molecular level could have broad implications for treating a variety of other types of pain provoked by both drugs and disease.


Lavand'homme PM, Eisenach JC. Exogenous and endogenous adenosine enhance the spinal antiallodynic effects of morphine in a rat model of neuropathic pain. Pain 1999;80:31-6.

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