Gone are the days when expectant
mothers didn't understand that drinking could harm their
baby. Those who continue to drink through their pregnancies
are typically neither unaware of the risk, nor do they
drink in order to deliberately harm their baby. They
drink simply because they are addicted to alcohol.
But what if there were a way to
insulate the brain tissue of the fetus from damage,
even if we can't stop the alcoholic mother from drinking?
Preliminary research, based on our knowledge of how
alcohol injures the brain and causes fetal alcohol syndrome
(FAS), offers some hope that it may one day be possible.
"I'm an obstetrician first," says
Dr Cathy Spong of the US National Institutes of Health,
who's produced some of the most promising research,
most recently in the September issue of the American
Journal of Obstetrics and Gynecology. "I always
tell women that they shouldn't drink at all. But we
know that if women always followed that advice, there
wouldn't be any FAS. And yet there clearly is."
MEET
THE PEPTIDES
Dr Spong's work focuses on two peptides with known neuroprotective
qualities: SALLRSIPA (ADF-9) and NAPVSIPQ (NAP). The
first has been shown to improve glutamate neurotransmission
in vitro in hippocampal cultures. The second
is sometimes used after head injury to prevent toxicity
from overproduction of the cytokine tumour necrosis
factor-alpha. Both of these qualities are highly relevant
to FAS, since alcohol is thought to kill neurons in
the fetus partly by interfering with glutamate neurotransmission,
and partly by producing cytokines. Moreover, both peptides
have been shown in numerous studies to protect brain
cells from oxidative stress.
Armed with this knowledge, Dr Spong
and four colleagues at the NIH's National Institute
of Child Health and Human Development in Bethesda, MD,
designed two studies using a mouse model of FAS. First,
they succeeded in proving that the peptides, administered
one to three hours after alcohol, could greatly reduce
fetal growth restriction, microcephaly (a congenital
condition associated with incomplete brain development)
and oxidative damage in mice.
They then went on to repeat the
experiment using the Morris water maze, which tests
a mouse's ability to learn and remember. This time around
they administered peptides 30 minutes before giving
alcohol. As expected, the FAS-model mice were no quicker
at finding the water in the maze on the seventh day
than they had been on the first; they seemed to have
lost the ability to learn a new skill. But the mice
that had been treated with peptides before receiving
alcohol cut their average times nearly in half over
the course of the week. Their performance was not only
much better than that of the untreated FAS mice; it
was also quite close to that of mice that had never
been exposed to alcohol at all. (Intriguingly, the fastest
learning curve of all was found in mice that never received
alcohol, but did receive peptides.)
"What we want to do next is take
these same peptides and see what effect they might have
on children who've already been born with brain damage
from alcohol."
CANADIAN
ANTIOXIDANT HOPE
Dr Gideon Koren, together with three colleagues from
Toronto's Hospital for Sick Children, is also preparing
to study new ways to protect the fetus from the mother's
drinking. Dr Koren directs Sick Kids' Motherisk Program,
and is also editor of The Journal of Fetal Alcohol
Syndrome and Related Conditions. He's currently
recruiting high-risk pregnant women for a trial of antioxidants.
The hope is that high-dose vitamin E and C in combination
might scavenge some of the free radicals produced by
drinking, and reduce brain injury in the fetus.
Dr Koren says all attempts to mitigate
the harm of drinking face the same practical problem
when applied to mothers who are addicted to alcohol:
that women who need little temptation at the best of
times will treat any medication as a "license to drink."
"That thought came up right away
and we really agonized over it," says Dr Koren. "We
recognize that there is going to be a risk. But we also
see that we have a chance to protect the fetus, and
as long as there's a chance of doing that, we can't
deny treatment."
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