Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ghrelin: A player in diabetes but not obesity?

10.05.2006


Ghrelin, a hormone long considered a key player in obesity, may instead take a major role in maintaining the balance between insulin and glucose and the development of diabetes, said Baylor College of Medicine researchers in a report in the current issue of the journal Cell Metabolism.



"Everybody has been pushing the connection between obesity and ghrelin," said Dr. Roy G. Smith, director of the BCM Huffington Center on Aging, "Companies have been developing ghrelin antagonists as anti-obesity drugs. Now these drugs may have a value in treating diabetes."

The downside is that the drugs may not forestall obesity.


In studies in his laboratory, mice bred to be deficient in both ghrelin (which stimulates appetite) and leptin (associated with controlling obesity) could be expected to be thin or of normal body weight, said Smith, also a professor of Molecular and Cellular Biology at BCM. That was a surprise, said the paper’s first author, Dr. Yuxiang Sun, a BCM instructor in the center.

"They were just as fat as the mice bred to lack only leptin," said Smith.

However, their glucose levels were lower than in leptin-deficient mice. When Sun did a glucose tolerance test on the mice, she found much lower levels in the animals that did not produce either ghrelin or leptin.

"They were more resistant to glucose because they secreted more insulin in response to the glucose challenge," said Smith.

When Sun and Smith investigated further, they found lower levels of uncoupling protein-2 (Ucp2) in cells called pancreatic islets (where insulin is made). Reducing Ucp2 improves the cell’s ability to make ATP, the cell’s energy molecule, thereby increasing the sensitivity of the pancreatic beta cell (the cell in the pancreas which produces insulin) to glucose-induced insulin release. Further tests in animals lacking ghrelin, showed that besides increased insulin secretion, their sensitivity to insulin was increased, said Sun. "That means glucose was cleared more efficiently."

While Smith sees a role for drugs that block ghrelin in treatment of type 2 diabetes (which usually occurs in adulthood and is often associated with obesity), he sounds a cautionary note.

"If through this process, you increase ATP production by the beta cell, you may in the long-term get oxidative stress which could eventually destroy the beta cell," he said. He said he does not yet have data to determine whether that is true or not.

In an accompanying analysis, Dr. Rexford S. Ahima of the University of Pennsylvania School of Medicine, wrote, "Overall, the studies provide compelling evidence that ghrelin has unique dual effects on glucose homeostasis (the balance between glucose and insulin), at least in a genetic model. Ghrelin antagonism (or blocking) may be a new approach for treating type 2 diabetes by improving insulin secretion in response to glucose and enhancing peripheral insulin action. The challenge is to ascertain if these results in rodents can be translated to patients."

Others who participated in the research include Drs. Mark Asnicar, Pradip K. Saha and Lawrence Chan, all of BCM.

April Sutton | EurekAlert!
Further information:
http://www.bcm.edu

More articles from Health and Medicine:

nachricht Using fragment-based approaches to discover new antibiotics
21.06.2018 | SLAS (Society for Laboratory Automation and Screening)

nachricht Scientists learn more about how gene linked to autism affects brain
19.06.2018 | Cincinnati Children's Hospital Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>