Wednesday March 1 2:14 PM ET
By ALEX DOMINGUEZ Associated Press Writer
Marijuana-like compounds ease tremors in mice with a condition similar to multiple sclerosis, researchers say in a study that appears to corroborate patients who say pot helps them deal with the disease.
The relief apparently wasn't because the mice were stoned, but because the compounds hit the right buttons in the nervous system, the British researchers reported in Thursday's issue of the journal Nature.
The compounds tested were synthetic but included the chemical equivalent of THC, the main ingredient in marijuana. Five of the six compounds tested reduced tremors and spasticity.
"This lends credence to the anecdotal reports that some people with MS have said that cannabis can help control these distressing symptoms,'' said Lorna Layward, one of the study's authors. Layward heads the research arm of the Multiple Sclerosis Society of Great Britain and Northern Ireland.
Stephen Reingold, vice president of research at the National Multiple Sclerosis Society, said it would be wrong to assume the results would hold true for humans. He said further research should be conducted.
"What this doesn't tell us is that smoking marijuana is good for MS,'' Reingold said.
More than 300,000 Americans have MS, in which the body attacks myelin, the sheath that insulates nerve fibers. That can produce stiffness, tremors, paralysis, loss of vision, numbness and pain. The cause is unknown, and there is no cure.
In the new work, the compounds injected into the mice stimulated structures called cannabinoid receptors on the surface of nerve cells. The work indicates the receptors are involved in the regulation of muscle tone, said David Baker of University College in London, who led the study.
The symptoms were not eased merely by the sedative effect of cannabinoids, since some of the compounds don't bind with the receptor known to be responsible for marijuana's high. Other signs of sedation, such as a drop in body temperature, also were not found, Baker said.
Baker said the work could lead to compounds that can treat MS symptoms without the high of marijuana, which can affect memory.
"We've tapped into and exposed this natural system,'' he said. "And that's why this is important.''
The role of marijuana in treating illness has been the subject of debate, with some states passing laws allowing its use for medicinal purposes. Some patients with AIDS, glaucoma and cancer say marijuana can ease pain, nausea and other symptoms.
Layward said other researchers in Britain are planning to test marijuana derivatives on MS patients.
Dr. Robert Lisak, co-director of the Multiple Sclerosis Center at the
Detroit Medical Center, said the mouse disease is not exactly analogous
to multiple sclerosis in humans, but the work is encouraging.