FOR IMMEDIATE RELEASE
April 21, 2009
Contact:
Christine Guilfoy
Office: (301) 634-7253
cguilfoy@the-aps.org
Translating the Conversation Between the
Brain and Blood Vessels
Two researchers on neural control of the cardiovascular system
receive APS awards
 BETHESDA, Md. (April 21, 2009) — When Francois
Abboud began his work at the University of Iowa in 1960, little was known
about the constant physiological chatter between the brain and the blood
vessels. His research since has helped unravel how this chatter adjusts
blood pressure and blood flow to meet the body’s constantly changing
demands.
The work has already led to clinical advances, and more
may be on the way: Dr. Abboud defined the identity of a sensor in the nerve
endings in the carotid artery in the neck that rapidly lowers blood pressure
when stimulated. A clinical trial is now underway to see if people who are
hypertensive can lower their blood pressure by using a pacemaker-like device
that stimulates the nerve endings in the blood vessels.
Ann M. Schreihofer focuses on the role the brain plays
in increasing sympathetic nervous activity, which contributes to many forms
of hypertension (high blood pressure). Her Medical College of Georgia
laboratory studies the links between conditions such as obesity and the
chronic intermittent hypoxia that happens in sleep apnea and chronic
activation of the sympathetic nervous system.
“We’re studying why people who are obese become
hypertensive,” Dr. Schreihofer said of one aspect of her work. “We believe
this is due to something about the obese state: We don’t know what that is,
but we’re starting to rule things out.” Indeed, the Schreihofer laboratory
has already answered one question: Does hypertension occur because the brain
loses its ability to sense that the blood vessels are stretching under high
pressure? In a study with obese rats, they found the rats’ brains could
sense the stretch but still became hypertensive, eliminating that mechanism
as a possibility.
APS recognizes important
research
The American Physiological Society (APS)
presented its highest award, the Walter B. Cannon Award, to Dr. Abboud. He
is the 27th recipient of the Cannon Award, which goes to an
outstanding scientist, and delivered the Walter B. Cannon Physiology in
Perspective lecture on April 18. The lecture is part of the 122nd
annual meeting of the APS, which is part of Experimental Biology 2009.
The Society has awarded Dr. Schreihofer
the Henry Pickering Bowditch Memorial Award for early-career achievement.
She is the 53rd recipient of the award, which goes to a scientist
younger than 42 years whose accomplishments are both original and
outstanding. It is the Society’s second-highest award. Dr. Schreihofer
presented the Bowditch lecture on April 19, at the APS
session of Experimental Biology 2009.
Distinguished careers
Dr. Abboud is the Edith King Pearson Chair in
Cardiovascular Research and director of the Cardiovascular Research Center
at the Carver College of Medicine at the University of Iowa. He is a
past-president of the American Heart Association, a former editor of
Physiology in Medicine (Annals of Internal Medicine) and past president of
the Association of American Physicians. He is a member of the
National Academies of Science and the American Academy of
Arts and Sciences.
Dr. Schreihofer has won three previous awards from The
American Physiological Society. She established her own laboratory at the
Medical College of Georgia in 2001. Still at the beginning of her career,
she has already co-authored more than 35 studies in peer-reviewed journals,
including the Journal of Physiology, Journal of Neuroscience
and the American Journal of Physiology.
Dr. Abboud has helped discover how the brain uses
hormones to orchestrate blood flow to different parts of the body. This
helped explain how the brain sends blood to the gastrointestinal tract after
eating, but redirects it to the heart and muscles if we start running, for
example.
Recently, his team has been looking at which genes
regulate ion channels, microscopic gates that move chemicals in and out of
cells, and that play a role in the signaling between the brain and the blood
vessels. In experiments with animals, Dr. Abboud and his colleagues deleted
one specific ion channel and found that the animals developed high blood
pressure. Work is now planned to develop a blood test to identify patients
who suffer high blood pressure or heart failure because of a problem with
the gene that regulates the channel, Dr. Abboud said.
New work underway
Dr. Schreihofer’s laboratory has identified
neurotransmitters that are at work in the brain stem that regulate
sympathetic nervous activity. Neurotransmitters relay signals from one nerve
cell to another, allowing nerve cells to ‘talk’ to each other. The
Schreihofer laboratory will:
-
Test the hypothesis that neurons that inhibit sympathetic
activity lose their ability to do so. This may allow the neurons that
stimulate sympathetic activity to get the upper hand, which leads to
hypertension.
-
Study how the brain stem neurons that regulate breathing
impact neurons that control blood pressure. The neurons that integrate
these systems are in very close proximity in the ventral lateral medulla
and play a role in affecting both breathing and blood pressure. This
connection is intriguing because it raises the possibility that
improving respiratory function could be a way to reduce the sympathetic
activity that leads to obesity and hypertension.
************
Editor’s Notes: To arrange an interview with Dr.
Abboud or Dr. Schreihofer, please contact Christine Guilfoy (301) 634-7253
or at
cguilfoy@the-aps.org.
Physiology
is the study of how molecules, cells, tissues and organs function to create
health or disease. The American Physiological Society (APS) has been an
integral part of this scientific discovery process since it was established
in 1887.
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