New cannabis drug target found

CBC News

Scientists in Alberta have discovered a second receptor for cannabis, a finding that could one day help to harness the benefits of the drug without the side-effects.

Cannabinoids are chemicals that are responsible for the psychoactive properties of THC, the active ingredient in marijuana.

One cannabinoid receptor is found mainly in the brain. Drugs that target it reduce nausea and vomiting from treatments for cancer and AIDS, but are also mind altering.

Scientists have been looking for a new receptor in the brain for years, said Keith Sharkey, a professor of physiology and biophysics at the University of Calgary. Sharkey and his colleagues in the U.S. and Italy are the first to identify the second potential drug target in laboratory animals.

The early-stage research shows the second receptor is found throughout the body's central nervous system. The spleen, part of the immune system, contains high levels of the receptor.

Lab tests showed the second receptor works in the brains of rats and ferrets, and levels can be manipulated.

The results suggest that nausea could be treated by turning on both receptors in local regions of the brain, the team reports in Friday's issue of the journal Science.

"This discovery has changed the way we think about the flow of information within the brain, and how the brain communicates with other parts of the body," said Raphael Mechoulam, a cannabinoid scientist and professor of medicinal chemistry at Hebrew University of Jerusalem, in a release.

The research was sponsored by the Canadian Institutes of Health Research, National Institutes of Health, and the Alberta Heritage Foundation for Medical Research.