Navigation Links
Fatty foods -- not empty stomach -- fire up hunger hormone
Date:6/5/2009

CINCINNATINew research led by the University of Cincinnati (UC) suggests that the hunger hormone ghrelin is activated by fats from the foods we eatnot those made in the bodyin order to optimize nutrient metabolism and promote the storage of body fat.

The findings, the study's author says, turn the current model about ghrelin on its head and point to a novel stomach enzyme (GOAT) responsible for the ghrelin activation process that could be targeted in future treatments for metabolic diseases.

The laboratory study, led by Matthias Tschp, MD, UC associate professor of psychiatry and internal medicine, is published online ahead of print Friday, June 5, 2009, in the journal Nature Medicine.

Ghrelin is a hormone that was believed to accumulate during periods of fasting and is found in the body in high concentrations just before meals. It is dubbed the "hunger hormone" because it has been shown that administration of pharmacological doses acts in the brain to stimulate hunger and increase food intake in animal models and humans.

The ghrelin hormone is unique in that it requires acylation (the addition of a fatty acid) by a specific enzyme (ghrelin O-acyl transferase, or GOAT) for activation. Originally it was assumed that the fatty acids attached to ghrelin by GOAT were produced by the body during fasting.

The new data by Tschp and his team suggests that the fatty acids needed for ghrelin activation actually come directly from ingested dietary fats. In a departure from an earlier model that was upheld for nearly a decade, Tschp says, it appears that the ghrelin system is a lipid sensor in the stomach that informs the brain when calories are availablegiving the green light to other calorie-consuming processes such as growing.

Tschp and his team used mouse models to test the effects of over expressing the GOAT enzyme, or "knocking it out." They found that, when exposed to a lipid-rich diet, mice without GOAT accumulated less fat than normal mice, while those with over-expressed GOAT accumulated more fat mass than normal mice.

"When exposed to certain fatty foods, mice with more GOAT gain more fat," says Tschp. "Mice without GOAT gain less fat since their brain does not receive the 'fats are here, store them' signal."

Tschp says that although his study can't be immediately extrapolated to humans, recent human studies at the University of Virginia measured (separately) active and inactive ghrelin concentrations. Those studies showed that during fasting, active ghrelin levels were flat, but during the presence of fat from foods, ghrelin levels peaked with meals as previously described. Tschp says these human studies support the new model for ghrelin.

"Our GOAT studies in mice offer an explanation of what could have been happening during the longer fasting periods in these human studies," Tschp adds. "Without dietary fats, ghrelin peaks remain inactive and don't affect storage of fat.

"We are particularly interested in how ghrelin may be involved in the rapid benefits of gastric bypass surgery," says Tschp. "This powerful obesity therapy frequently reduces appetite and improves metabolism before substantial weight loss occurs. Intriguingly, this procedure causes food to bypass the stomach and gut sections that contain GOAT/ghrelin cells, which, based on this newly described model, would prevent ghrelin activation."


'/>"/>

Contact: Dama Kimmon
dama.kimmon@uc.edu
513-558-4519
University of Cincinnati Academic Health Center
Source:Eurekalert

Related biology news :

1. Omega fatty acid balance can alter immunity and gene expression
2. Eating fatty fish once a week reduces mens risk of heart failure
3. Fattysaurus or thinnysaurus? How dinosaurs measure up with laser imaging
4. Cortisol and fatty liver: Researchers find cause of severe metabolic disorders
5. Atomic structure of the mammalian fatty acid factory determined
6. Scientists suspect omega-3 fatty acids could slow acute wound healing
7. Trans-fatty acids and insulin sensitivity
8. Typical North American diet is deficient in omega-3 fatty acids
9. University of Alberta researchers report breakthrough in lowering bad cholesterol, fatty acid levels
10. Omega-3 fatty acids protect against Parkinsons, study says
11. ADA releases updated position statement on functional foods
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/3/2017)... WASHINGTON , April 3, 2017 /PRNewswire-USNewswire/ ... single-cell precision engineering platform, detected a statistically ... cell product prior to treatment and objective ... highlight the potential to predict whether cancer ... prior to treatment, as well as to ...
(Date:3/29/2017)... the health IT company that operates the largest health ... today announced a Series B investment from BlueCross BlueShield ... investment and acquisition accelerates higi,s strategy to create the ... activities through the collection and workflow integration of ambient ... secures data today on behalf of over 36 million ...
(Date:3/24/2017)... DUBLIN , Mar 24, 2017 Research ... Vehicle Access System Market Analysis & Trends - Industry Forecast to ... ... poised to grow at a CAGR of around 15.1% over the ... This industry report analyzes the market estimates and forecasts for ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... (PRWEB) , ... October 11, 2017 , ... Personal eye wash is a basic first ... eye at a time. So which eye do you rinse first if a dangerous substance ... Plum Duo Eye Wash with its unique dual eye piece. , “Whether its ...
(Date:10/11/2017)... and LAGUNA HILLS, Calif. , Oct. ... Cancer Research, London (ICR) and University ... SKY92, SkylineDx,s prognostic tool to risk-stratify patients with multiple myeloma ... MUK nine . The University of Leeds ... partly funded by Myeloma UK, and ICR will perform the ...
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building and ... rebranding initiative announced today. The bold new look is part of a transformation ... moves into a significant growth period. , It will also expand its service offering ...
(Date:10/10/2017)... 10, 2017 International research firm Parks Associates announced ... at the TMA 2017 Annual Meeting , October 11 in ... residential home security market and how smart safety and security products impact ... Parks Associates: Smart Home ... "The residential security market has ...
Breaking Biology Technology: