Pubdate: 26 Nov 1998
Source: San Jose Mercury News (CA)
Contact:  http://www.sjmercury.com/
Copyright: 1998 Mercury Center
Author: Usha Lee McFarling, Mercury News Washington Bureau

STUDY TIES BRAIN CHEMICAL, ALCOHOLISM

WASHINGTON -- An intriguing brain chemical linked to obesity, anxiety and
depression may also play a key role in alcoholism, according to new
research published today.

The substance, called neuropeptide Y, is a wisp of a chemical that
powerfully shapes behavior because it alters the activity of brain cells.

The new findings show that ``knockout'' mice genetically engineered to lack
the gene responsible for neuropeptide Y production drink more alcohol than
normal mice. And like their human alcoholic counterparts, the mice have a
higher tolerance for alcohol.

Mice engineered to overproduce neuropeptide Y, meanwhile, drank less
alcohol and were more sensitive to its sleep-inducing effects.

``This strongly suggests that neuropeptide Y is an important player,'' said
Todd Thiele, a research psychologist at the University of Washington and
lead author of the study published in today's issue of the scientific
journal Nature.

Neuropeptide Y was identified just 16 years ago but is already a darling of
drug development efforts, because it is intimately linked to two
devastating medical problems: obesity and depression. Repeated injections
of the substance cause animals to gorge themselves and grow fat. Higher
levels of neuropeptide Y also relieve anxiety in rats.

The newest research has electrified the alcohol-research community because
it is the first direct evidence that neuropeptide Y also influences the use
of alcohol.

Because neuropeptide Y calms anxiety, the new findings suggest that some
alcoholics may be using alcohol to relieve stress. This may help explain
the persistent mystery of high alcoholism rates among people with anxiety
disorders, said George Koob, a professor of neuropharmacology at the
Scripps Research Institute in La Jolla, who researches the brain chemicals
and pathways that underlie addiction.

``This is an area no one's really talked about before,'' he said.

Researchers are reluctant to draw conclusions about the complex story of
human alcoholism from the simpler biology of animals. But they say
dissecting alcoholism into simpler components may eventually lead to drugs
to curb alcoholism.

Alcohol abuse affects 14 million Americans and is estimated to cost the
country nearly $250 billion in medical expenses, accidents and lost
workdays each year.

Animals lacking neuropeptide Y were more anxious than normal mice in the
study. But animals with extra neuropeptide Y weren't calmer, said Thiele.
In addition, all mice in the study ate the same amount and weighed the
same, suggesting that any links between stress, eating and drinking are
likely to be complex.

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Checked-by: Pat Dolan