Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

OHSU scientists locate, characterize key hormone involved in appetite control

21.02.2003


Increasing hormone causes increase of appetite, eating



Researchers at Oregon Health & Science University (OHSU) have identified a key hormone involved in appetite control and demonstrated its effect on the brain. Scientists have shown that the hormone, called ghrelin, activates specialized neurons in the hypothalamus involved in weight regulation. The research involved scientists at several collaborating institutions, including: Yale Medical School, Baylor College of Medicine, the University of Alberta and Lilly Research Laboratories. The results are printed in the Feb. 20 edition of the journal Neuron.

Researchers believe this information could be used to develop drugs aimed at stimulating appetite in patients who have undergone extreme weight loss due to illness, a condition known as cachexia. These pharmaceuticals could also assist children who are developing at a slower than normal rate. Conversely, drugs aimed at limiting production of the hormone might be developed to reduce appetite for those battling severe obesity.


"Ghrelin is a hormone produced in the stomach with the ability to stimulate feeding when introduced to specialized weight regulation brain cells called neuropeptide Y neurons. In fact, past research has shown that when ghrelin levels are increased in mice for an extended period, the mice gain weight," said Michael Cowley, Ph.D., an assistant scientist in the Division of Neuroscience at the OHSU Oregon National Primate Research Center and lead author of the study. "In both mice and humans, ghrelin levels increase naturally in response to weight loss or reduced caloric intake. As expected, the hormone diminishes in response to food intake. In other words, it’s believed to be part of the body’s natural signaling system which informs the brain when it’s time to eat."

To pinpoint and witness the effects of ghrelin in the brain, the scientists used a method pioneered by OHSU researchers Cowley, Roger Cone, Ph.D., and Malcolm Low, M.D., Ph.D. The researchers used a fluorescent protein to highlight certain neurons, making the brain cells distinguishable from other surrounding neurons. They then used tiny electrodes to record cell activity in response to ghrelin.

"It is remarkable how such a relatively small group of interconnected neurons deep in the brain coordinate the daily signals of hunger and satiety with the body’s long-term energy stores to normally maintain a constant body weight," said Low, a scientist in the Vollum Institute at OHSU.

The research team also located a new source for ghrelin production in the body. The site is located in a section of the hypothalamus that had no previously known function and that is near the brain region affected by the hormone.

"This research shows that there are two sites where increased appetite may be generated, the stomach and the brain," explained Cone, a senior scientist at the OHSU Vollum Institute. "We hope future research will hopefully distinguish between the roles of these two production sites so that we may better understand weight regulation and energy homeostasis in the body."

These latest findings follow a study published in August 2002 that identified and characterized peripheral hormone peptide YY (PYY). PYY appears to have the opposite effect as ghrelin – reducing appetite instead of increasing it. OHSU researchers and their collaborators found that by introducing PYY into the bloodstreams of both humans and mice, a temporary, but measurable drop in appetite and food ingestion occurred.


###
This research was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases and the National Center for Research Resources, both components of the National Institutes of Health.


Jim Newman | EurekAlert!
Further information:
http://www.ohsu.edu/

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Tune your radio: galaxies sing while forming stars

21.02.2017 | Physics and Astronomy

Improved Speech Intelligibility and Automatic Speech-to-Text Conversion for Call Centers

21.02.2017 | Trade Fair News

36 big data research projects

21.02.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>