Cincinnati—The University of Cincinnati (UC) College of Medicine is
receiving up to $5 million for obesity research from the Procter &
Gamble Company (P & G). The collaborative project will be conducted
by scientists at P & G and the UC Obesity Research Center and
consists of several parts that will provide a better understanding of
how appetite-controlling neurotransmitters in the brain control food
intake and body weight. The three UC scientists who will be responsible
for the different aspects of this study are: Stephen Woods, PhD,
director of the Obesity Research Center and professor of psychiatry;
Randy Seeley, PhD, associate professor of psychiatry; and Patrick Tso,
PhD, professor of pathology and laboratory medicine.
the National Institutes of Health (NIH), obesity is considered second
only to cigarette smoking as a cause of preventable deaths in the
United States. Cancer, heart disease, and diabetes are all associated
with obesity. The latest NIH figures also show that 55 percent of
Americans should be considered overweight. This research strives to
determine why higher fat diets increase body weight and if the body
becomes more efficient in storing fat when given a steady diet of
higher fat foods. According to Woods, the researchers want to find out
why a high-fat diet causes one to eat more and become obese.
researchers in Woods' laboratory will conduct experiments to examine
the role of several hormones that control food intake and body weight
through their interaction with each other and their influence on the
brain. Leptin is a hormone released by fatty adipose tissue into the
bloodstream and is thought to carry biochemical messages to the brain
to curb appetite. Insulin is released by the pancreas to convert
carbohydrates into fat that is stored in the body as adipose tissue.
Woods says that they are striving to understand how body fat may alter
the secretion of hormones that affect hunger.
Tso's laboratory is
currently conducting experiments to study the signals produced by the
small intestine during the active absorption of a fatty meal. In
particular, investigators from his laboratory discovered that the small
intestine produces a satiety (feeling of fullness) factor which is very
potent in reducing food intake. This research was supported in part by
a University Exploratory Award from P & G, which is given each year
for innovative research to only three scientists in the country.
active research projects being conducted in his lab focus on how fat,
and especially cholesterol, is absorbed by the small intestine. Tso is
also investigating to see how the intestine is involved in the
development of obesity when the diet is high in fat.
Seeley will lead researchers in experiments to concentrate on specific
neural circuits in the brain that control appetite and obesity. One
example involves a melanocortin-4 receptor (MC-4 receptor) in the
brain. Results of research done by Seeley and Woods suggest that when
the MC-4 receptor is inhibited or blocked chemically, the brain cannot
receive the normal chemical signal to stop eating. Eating too much then
leads to a weight gain and eventually obesity. The MC-4 receptor is
best known for its ability to regulate skin and hair color, but it is a
vital link in the transmission of biochemical messages from leptin to
the brain, says Seeley and Woods.
"The MC-4 receptor is like a
doorway," says Seeley. "If the doorway or receptor is blocked, the
brain never receives the chemical message from leptin that tells the
body to stop eating. A better understanding of the MC-4 receptors may
help us develop new drugs or foods that will prevent or reverse obesity
by correcting the chemical pathways for appetite control," he adds.