FOR IMMEDIATE RELEASE
Contact: Christine Guilfoy
Office: (301) 634-7253
cguilfoy@the-aps.org
MSU Professor Earns Bowditch Award for Work on
Hypertension
BETHESDA, Md. (March 26, 2008) -- The American
Physiological Society has awarded Michigan State University Professor
Stephanie W. Watts the 2008 Henry Pickering Bowditch Memorial Award for
early-career achievement. The award goes to a scientist younger than 42
years whose accomplishments are both original and outstanding. It is the
Society’s second-highest award
Dr. Watts, a professor of pharmacology and toxicology,
has focused her research on whether serotonin (5-HT) plays a role in
hypertension. The story of her research is interesting not only because it
is important to find a treatment for this serious illness, but because her
research resembles a mystery novel, in which the detective has her eye set
on a likely suspect, only to find out that the bad guy may be the good guy.
Dr. Watts will present the Bowditch lecture “The love
of a lifetime: 5-HT in the cardiovascular system,” on Sunday, April 6, at
the APS session of Experimental Biology in San Diego. An audio of the
interview may be found at
www.lifelines.tv.
A silent killer
One-quarter of American adults suffer from
hypertension, also known as high blood pressure. In hypertension, the blood
vessels constrict, but because the body must transport the same amount of
blood, it causes the blood to flow under much greater pressure.
This places greater strain on the heart and the blood
vessels and can also damage the organs and tissues that receive the blood,
including the brain, heart and kidneys. The disease is known as the silent
killer because many people do not know they have the disease until it causes
serious health problems.
Most of the body’s serotonin, about 90%, is made in the
gastrointestinal tract, where it plays a role in digestion by helping the
smooth muscle of the intestines move. The remaining 10% of the body’s
serotonin is produced in the brain, where it plays a role in elevating mood,
signaling food satiety and regulating sleep cycles.
The body needs tryptophan, obtained through the diet,
to make serotonin. Tryptophan is found in a variety of foods, including
poultry.
Still a hypothesis
Years of research have yielded this about serotonin’s
effect on blood vessels:
Molecules, known as transporters, carry serotonin to
receptors in various parts of the body. Different receptors cause serotonin
to do different things. There are at least 17 such receptors in the human
body, making it difficult to unravel exactly how serotonin works.
Dr. Watts hypothesized that since it takes less
serotonin to make hypertensive blood vessels contract, that hypertensive
individuals may have a higher number of receptors. This could explain why
the blood vessels of hypertensive individuals react more strongly to
serotonin. She experimented with one receptor and found that blocking it
reduced blood pressure.
In 2006, Dr. Watts gave serotonin to both hypertensive
and normal rats, reasoning that serotonin would raise blood pressure in the
non-hypertensive rats and that the rats with hypertension would experience
an even greater rise in blood pressure. Instead, the serotonin reduced blood
pressure by 15-20% in the non-hypertensive rats and by 33% in the
hypertensive animals. Dr. Watts’ lab has repeated the experiment with the
same results.
The serotonin puzzle
So what to make of this latest clue, that serotonin
lowers blood pressure when it’s given to both hypertensive and
non-hypertensive rats? These results have Dr. Watts wondering if serotonin
levels rise because serotonin is trying to reduce blood pressure.
“I’m wondering if hypertensive people have higher level
of 5-HT because that’s a good thing,” Dr. Watts said. “Now we’re trying to
figure out the multiple ways 5-HT can play with the cardiovascular system to
cause these results.”
One possibility is that once an individual suffers
hypertension, it changes how the blood vessel works, toughening vessels to
handle the higher pressure and changing how it reacts in the presence of
serotonin. “It’s really hard to tell which is the cause and which is the
effect,” Dr. Watts said.
When Dr. Watts presents her lecture, she hopes to get
ideas from other physiologists who can help her resolve this puzzle. The
lecture will take place at 5:45 p.m., Sunday, April 6, at the APS session of
Experimental Biology 2008 in San Diego.
NOTE TO EDITORS:
The APS annual meeting is part of the Experimental Biology 2008 conference
that will be held April 5-9 at the San Diego Convention Center. The press is
invited to attend or to make an appointment to interview Dr. Watts. Please
contact Christine Guilfoy at (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 (www.The-APS.org/press)
has been an integral part of this discovery process since it was established
in 1887.
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