Re: the blood brain barrier
Got the following from Eurekalert.
Contact: Tim Parsons
tparsons@umm.edu
410-328-9260
University of Maryland Medical Center
UM researchers discover 'key' to blood-brain barrier
Findings Could Lead to New Treatments for Brain Disorders
Researchers at the University of Maryland School of Medicine in
Baltimore have
identified a receptor in the human brain that regulates the interface
between the
bloodstream and the brain, which is known as the blood-brain barrier. This
breakthrough could lead to a better understanding of this nearly
impenetrable barrier
and to treatment of diseases that affect the brain, such as Multiple
Sclerosis, brain
tumors, meningitis, Alzheimer's disease, and HIV infection. The
findings are
published in the January issue of the Journal of Neurochemistry.
The blood-brain barrier is a collection of cells that press together to
block many
substances from entering the brain, while allowing others to pass. For
years, scientists
knew little about how this barrier was regulated or why certain
diseases are able to
manipulate the barrier and infect the brain. Earlier research conducted
at the
University of Maryland School of Medicine found that two proteins,
known as zonulin
and zot, unlock the cell barrier in the intestine. The proteins attach
themselves to
receptors in the intestine to open the junctions between the cells and
allow substances
to be absorbed. The new research indicates that zonulin and zot also
react with
similar receptors in the brain.
"The blood-brain barrier is like a gateway to the brain. It is almost
always locked,
keeping out many diseases. Unfortunately, it also keeps out medications
as well.
Almost nothing can pass," explains lead author Alessio Fasano, M.D.,
professor of
pediatrics and physiology at the University of Maryland School of
Medicine, and
director of Pediatric Gastroenterology at the University of Maryland
Hospital for
Children. "First we discovered the key, and now we've found the lock
that fits that key
to open the gateway into the brain. This discovery could help us open
that gateway,"
explains Dr. Fasano.
Dr. Fasano and his team studied brain tissue samples obtained from a
brain and tissue
bank at the University of Maryland. The brain tissue was treated with
purified zonulin
and zot proteins, then examined under a microscope. Researchers
observed the
zonulin and zot proteins binding with the brain tissue. Next, they
compared the results
to tests on tissue samples from the intestines.
"We've known about the blood-brain barrier for more than 100 years, but
we've never
been able to figure out how it worked. Now we have a new piece to the
puzzle," says
Dr. Fasano.
"The identification of these proteins in the human brain holds the
promise of allowing
us to deliver new types of medications across the blood-brain barrier.
It would be a
boon to humanity if the blood-brain barrier could be opened briefly,
and safely, to
allow passage of a new generation of drugs into the brain," says Ronald
Zielke, Ph.D.
co- author, professor of pediatrics and director of the brain and
tissue bank at the
University of Maryland School of Medicine.
Dr. Fasano adds that more research is needed to understand how zonulin
and zot work
during the formation and development of the brain. The current study
was funded by a
grant from the National Institutes of Health.
Best, Jeff Davis
"Everything's hard till you know how to do it."
Ray Charles
This archive was generated by hypermail 2b29 : Thu Jul 27 2000 - 14:02:11 MDT