wonder drug

["Devine, James" <jdevine@xxxxxxx>]

>From the munchies to a slimming drug
David Adam
Tuesday January 27, 2004
The Guardian [UK]

Sanofi's potential blockbuster obesity and anti-smoking drug Rimonabant
has its roots in efforts to understand why smoking cannabis tends to
make people feel insatiably hungry. Scientists reasoned that if taking
the drug gave people the so-called munchies, then identifying and
blocking the brain pathways responsible might stop others overeating.

It works by binding to and blocking a receptor protein found on the
surface of brain cells. These receptors are set up to receive chemical
molecules acting as messengers, and when they do, this triggers a
chemical reaction that sends an instruction to the brain. The scientists
found that chemicals called canna-binoids, which occur naturally in
cannabis, bound to these receptors and made the cells issue an
instruction to eat.

The body also produces several cannabinoids of its own, which bind to
the same receptor and issue the same instruction. Rimonabant's trick is
that it looks similar enough to these endogenous messenger molecules to
bind the receptor, but different enough not to cause the "eat" message
to be passed on. It then tends to hang around on the receptor protein,
effectively acting as a protective cap that stops the genuine
cannabinoid signal molecules from binding.

Results from trials have shown encouraging weight loss. Obese patients
given the highest doses of the drug lost an average of 4kg each in 16
weeks compared to a control group. Scientists have found that it also
seems to suppress a nicotine addict's urge to smoke and others are
investigating whether it could be used to combat alcoholism.

Steve Alexander, a neuroscientist who works on cannabinoid receptors at
Nottingham University says drugs like Rimonabant tap into pathways of
the brain associated with pleasure. "The brain processes you undergo as
you eat nice food are very similar to what you do when you smoke
cannabis or inject heroin."

------------------------
Jim Devine jdevine@xxxxxxx &  http://bellarmine.lmu.edu/~jdevine