The quick
take home here is that adiponectin is involved directly with the establishment
of the dangerous abdominal fat associated with Cardio issues.
The
interesting question to answer is why does the hormone level fail to increase
with increasing body fat? It is all a
good argument for using alternate day fasts (Google 'arclein diet') to bring one’s weight to its best
base level. At base level such a
hormonal system should be optimized in terms of their benefit which is
something that seems likely anyway.
This may lead
to a clear understanding of the pathways that support outright obesity.
Released: 12/23/2010
Source: UT Southwestern Medical Center
Newswise — New findings
by UT Southwestern
Medical Center
researchers may solve a 17-year-old mystery about how the so-called “starvation
hormone” affects multiple biological systems, including preventing insulin
sensitivity and promoting cell survival.
The results connect
multiple observations about how the hormone adiponectin functions and
eventually could lead to new treatments for conditions ranging from diabetes
and weight loss to heart disease and cancer.
“Until now, there
wasn’t really an obvious connection between all these different phenomena,”
said Dr. Philipp Scherer, professor of internal medicine and cell biology and
senior author of the study appearing online today and in a future edition of Nature Medicine.
In this study, the
researchers used models of inducible cell suicide in both pancreatic beta
cells, which produce insulin, and cardiomyocytes, which are specific muscle
cells located in a part of the heart known as the myocardium, to determine how
the single hormone could exert such different influences.
“This paper shows that
the common theme among all these different activities relies on adiponectin’s
interaction with a specific subset of lipids known as ceramides,” said Dr.
Scherer, who directs the Touchstone
Center for Diabetes Research.
Ceramides are a family
of lipid molecules known to promote cell suicide, or apoptosis. High levels of
ceramides have been shown to promote diabetes by sabotaging signaling pathways
induced by insulin and killing beta cells.
When the researchers introduced
adiponectin into cells, they found that the hormone triggers the conversion of
ceramides from a destructive force into one that helps cells survive and
inhibits cell death.
“Adiponectin
essentially provides a makeover of this ugly cousin,” Dr. Scherer said.
Dr. William Holland,
lead author and postdoctoral fellow in internal medicine, said the new findings
have implications for the treatment of numerous diseases including diabetes and
cancer.
“One beauty of this
study is that the findings are in both animal models and in vitro,” Dr. Holland
said. “We were able to show using these models of apoptosis in the beta cell
and the heart that we can protect those cells from cell death with
adiponectin.”
Adiponectin, which Dr.
Scherer discovered in 1994, not only controls sensitivity to insulin but also
is known to play an integral role in metabolism and obesity. Prior research has
shown that when adiponectin levels are high, the body stores excess fat in
adipocytes, or fat cells, to protect against possible starvation during lean
times. These fat deposits lie primarily in the subcutaneous tissue.
As a person accumulates
more fat, however, adiponectin levels decline. Once adiponectin levels start
dropping, the body begins storing fat in dangerous places such as the heart,
liver and muscle tissues – where it can cause inflammation and pave the way for
heart disease. That’s why researchers think that adiponectin levels could be a
good predictor of whether someone is at risk of developing diabetes, heart
disease or cancer.
Overall, the new
findings “endorse the idea that adiponectin is very important and is probably a
key manipulator of lipid levels,” Dr. Scherer said.
Other UT Southwestern
researchers involved in the study include Drs. Kai Sun, Joseph Rutkowski, Zhao
Wang and Kathryn Davis, postdoctoral research fellows in internal medicine;
Vincent Tenorio, summer student research fellow; and Dr. Nils Halberg, former
postdoctoral research fellow in internal medicine. Researchers from the University of Pennsylvania ,
Eli Lilly, Duke University
Medical Center ,
Duke-NUS Graduate Medical School Singapore , Colorado
State University ,
the University of
Copenhagen and Merck
Research Laboratories also contributed to the study.
The study was supported
by the National Institutes of Health.
This news release is
available on our World Wide Web home page at
http://www.utsouthwestern.edu/home/news/index.html
http://www.utsouthwestern.edu/home/news/index.html
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