# Non CNS Pain breakthrough



## trbell (Nov 1, 2000)

U.S. Department of Health and Human ServicesNATIONAL INSTITUTES OF HEALTHNIH NewsNational Institute on Drug Abuse http://www.nida.nih.gov/ EMBARGOED FOR RELEASEMonday, August 11, 20035:00 p.m. ETContact:Michelle Person(301) 443-6245NEW COMPOUND THAT ACTS ON PERIPHERAL RECEPTORS MAY BEPROMISING TREATMENT FOR SOME NERVE PAINResults of a new study in mice and rats show that acompound which acts on a specific type of cell receptorfound only outside the central nervous system decreases theanimals' pain responses. But the researchers caution thatstudies investigating the safety and efficacy of thiscompound in humans have yet to be done.The scientists hope this approach may lead to thedevelopment of pain-relief drugs that lack the debilitatingcentral nervous system side effects limiting theeffectiveness of currently available pharmaceuticals."Chronic pain is one of the most significant disease statesaffecting Americans, in terms of economic and socialimpacts," says Dr. Nora D. Volkow, Director of the NationalInstitute on Drug Abuse. "And, unfortunately, therapeuticoptions for the treatment of chronic pain are inadequate,partly because a number of drugs that can be used to treatpain have unpleasant side effects that limit theireffectiveness, and partly because some of them have thepotential for addiction and abuse."The study, funded by NIDA, part of the National Institutesof Health, will be published online the week of August 11in the "Proceedings of the National Academy of Sciences".Dr. T. Philip Malan, Jr., of the University of Arizona, Dr.Alexandros Makriyannis, of the University of Connecticut,and their colleagues, studied the activity of a newcompound called AM1241, which acts on CB2 cannabinoidreceptors. "This is one of the two types of receptors onwhich THC, the active ingredient in marijuana, acts," Dr.Malan says. "The CB2 receptors are in peripheral sites withimmune functions, while the CB1 receptors are in the centralnervous system -- the brain and spinal cord. The beauty ofhaving a compound that acts on the CB2 receptors is that youcan get pain relief without the central nervous system sideeffects of THC, such as sleepiness and anxiety."The scientists tested the chemical on mice and rats withneuropathic pain, a complex chronic pain state resultingfrom nerve injury or disease. They found that this compoundincreased the ability of the animals to withstand chronicpain that mirrored human models of neuropathic pain."Although this is far from being in clinical trials inhumans, any new avenue to treat pain is a very positivestep," Dr. Malan says. "Almost 6 million people in theUnited States may experience neuropathic pain. At almostany given time, about 1 person in 4 is experiencing sometype of pain and about 1 person in 8 has some type ofchronic pain. Pain costs the U.S. economy $120 billion to$180 billion per year. Even though we have therapies, manypeople continue to experience pain despite receivingtreatment. This may be partly because the side effects ofmany of the drugs we can use prevent patients from usingthe dose that provides the most intense relief."The next step, he says, is to test this compound in animalsto assess its potential toxicity. "We don't even know howit works. It may act on peripheral nerves, but CB2 receptorshave not yet been found there; it may act in some way toinhibit the release of chemicals like prostaglandins fromimmune cells that increase sensitivity to pain; or they maycause immune system cells to release substances that blockthe pain response."AM 1241 was developed by Dr. Makriyannis.The National Institute on Drug Abuse is a component of theNational Institutes of Health, U.S. Department of Healthand Human Services. NIDA supports more than 85 percent ofthe world's research on the health aspects of drug abuseand addiction. The Institute carries out a large variety ofprograms to ensure the rapid dissemination of researchinformation and its implementation in policy and practice.Fact sheets on the health effects of drugs of abuse andinformation on NIDA research and other activities can befound on the NIDA home page at <http://www.drugabuse.gov>.## --------------------------------------------- Co-Cure Web Site: http://www.co-cure.org/ Send posts to mailto:CO-CURE###listserv.nodak.edu Join or leave the list at http://www.co-cure.org/sub.htm Co-Cure is not a discussion list. Please do not reply to the list. ---------------------------------------------Bada


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