SUBSTANCE USED TO FIGHT ALZHEIMERS FOUND IN NICOTINE

LOS ANGELES -- Nicotine-like compounds can improve memory and might one day
be used in pills to treat disorders like Alzheimer's disease, according to
research on laboratory animals.

But while the finding supports smokers' contention that cigarettes improve
their mental alertness, scientists warned that no one should ever reach for
a smoke.

``The relationship between lung cancer and smoking is clear and it's not
the way you want to prevent the onset of Alzheimer's disease,'' said Esther
Sabban, a biochemistry and molecular biology professor at New York Medical
College in Valhalla, N.Y.

Nor do scientists advocate turning to other sources of nicotine before
further studies substantiate early research on rats.

``Certainly, nicotine itself may have a useful place,'' said Edward Levin,
a neuroscientist at Duke University in Durham, N.C. But, he added: ``I
wouldn't want people to buy a pack of cigarettes or a patch or (nicotine)
chewing gum.''

Nevertheless, the scientists told reporters Sunday at the Society for
Neuroscience annual meeting that they're encouraged they can design
medications to capitalize on the benefits of nicotine without
cardiovascular and other side effects.

``These are exciting avenues for drug development, but we're not there
yet,'' Levin said.

Researchers are looking at nicotine because it's known to stimulate
receptors for acetylcholine, a nerve cell-signaling chemical important in
learning and memory. Alzheimer's patients have a shortage of receptors for
acetylcholine, Levin said.

But when they're given a nicotine patch, their attention improves. That
ability of nicotine to emulate acetylcholine and in essence ``trick the
brain'' has led scientists to target nicotine-like drugs that stimulate the
same receptors, said Darwin Berg, a researcher with the University of
California, San Diego.

Patrick Lippiello, a neuroscientist with R.J. Reynolds Tobacco Co. in
Winston-Salem, N.C., reported that the company has developed two compounds
that stimulate the brain receptors nicotine works on.

In rats, the substances increased both short- and long-term memory and
showed persistent benefits without toxic side effects, he said. They also
kept brain cells from dying when exposed to chemicals that normally kill them.

His research suggests the compounds might be taken as once-daily pills to
fend off the brain cell ravages of Alzheimer's disease.

R.J. Reynolds is seeking pharmaceutical industry partners to develop the
compounds for human use, he said.

Levin and his colleagues found another compound that stimulates nicotine
receptors and can improve learning and memory in brain-damaged rats.
Astra-Arcus Pharmaceuticals, which funded his research, has applied for a
patent on the compound.

In research into nicotine's other much-touted benefit -- its ability to
calm nerves -- Ms. Sabban said she is beginning to understand how
cigarettes can increase levels of stress hormones and at the same time
relax smokers.

When she gave rats injections of nicotine equivalent to smoking a single
cigarette, they produced more stress hormones.

But when she infused them with a steady dose of nicotine, she inhibited the
response of the adrenal gland, which is responsible for the fight-or-flight
outpouring of stress hormones.

The findings may explain why the nicotine patch can reduce the body's
response to stress and could guide development of ``new drugs that one day
can alleviate the harmful effects of stress,'' she said.

Checked-by: Pat Dolan