Navigation Links
Growth hormone's link to starvation may be clue to increasing life span, researchers find

DALLAS June 27, 2008 Researchers at UT Southwestern Medical Center have determined that starvation blocks the effects of growth hormone via a mechanism that may have implications in treating diabetes and extending life span.

"It's been well-established that growth is blunted during starvation. But our work shows that this is not just from running out of energy. It's much more sophisticated than that," said Dr. Steven Kliewer, professor of molecular biology and senior author of a study available online and appearing in today's issue of the journal Cell Metabolism.

Using genetically altered mice, the researchers found that during fasting, the actions of growth hormone are blocked by a fat-burning hormone called FGF21.

"It's something that we hadn't anticipated," said Dr. Kliewer.

Growth hormone has many functions in the growth and reproduction of cells, such as controlling the length of developing arm and leg bones in children.

Growth hormone has several other functions, however, even in adults. It promotes the breakdown of fats, stimulates creation of protein and increases levels of IGF-1 (insulin-like growth factor-1), a hormone that promotes growth. Too much growth hormone can cause insulin resistance, resulting in diabetes, and lead to other disorders.

In the current study, mice that were genetically altered to produce excess FGF21 grew to be much smaller than ordinary mice, even though they ate more and had more fat in proportion to their size.

Paradoxically, and to the researchers' surprise, the altered, smaller mice produced much greater amounts of growth hormone than normal.

Why didn't the altered mice grow larger than normal in response? The researchers found that FGF21 does not block the production of growth hormone; rather, it works to prevent growth hormone from activating the genes it normally controls.

Interfering with the actions of growth hormone has been shown to increase life span in mice, Dr. Kliewer said.

"In addition, intermittent fasting which increases FGF21 concentrations also extends life span in mice. This raises the intriguing possibility that FGF21 might be a longevity factor," Dr. Kliewer said.

"This is something that we're beginning to test in the lab," he said. "But our genetically engineered mice have all the classic hallmarks of extended life span: growth hormone resistance, low concentrations of IGF-1, increased insulin sensitivity and small size."

FGF21 is already being tested in human clinical trials for treatment of obesity and diabetes in adults, but the new findings linking FGF21 to interference with growth hormone might indicate that caution is needed before using it in children or teens, Dr. Kliewer said.


Contact: Aline McKenzie
UT Southwestern Medical Center

Related biology news :

1. Blue light used to harden tooth fillings stunts tumor growth
2. Scientists find potential protein biomarkers for growth hormone
3. Synthetic cocoa chemical slows growth of tumors in human cell lines
4. NYU dental professor discovers biological clock linking tooth growth to other metabolic processes
5. T-cadherin affects blood vessel growth in breast cancer, hormone from fat cells may play a role
6. Faster koa tree growth without adverse ecosystem effects
7. Popular apple variety harbors unusual cell growth
8. Yale scientists show that a microRNA can reduce lung cancer growth
9. New UC analysis shows alarming increase in expected growth of Chinas carbon dioxide emissions
10. Alarming growth in expected CO2 emissions in China, finds UC analysis
11. A compound extracted from olives inhibits cancer cells growth and prevents their appearance
Post Your Comments:
Related Image:
Growth hormone's link to starvation may be clue to increasing life span, researchers find
(Date:11/12/2015)... 2015   Growing need for low-cost, easy ... been paving the way for use of biochemical ... analytes in clinical, agricultural, environmental, food and defense ... in medical applications, however, their adoption is increasing ... continuous emphasis on improving product quality and growing ...
(Date:11/10/2015)... NEW YORK , Nov. 10, 2015 /PRNewswire/ ... refers to behavioral biometrics that helps to identify ... prevent fraud. Signature is considered as the secure ... for the identification of a particular individual because ... offers more accurate results especially when dynamic signature ...
(Date:11/4/2015)... , November 4, 2015 ... new market report published by Transparency Market Research "Home Security ... Trends and Forecast 2015 - 2022", the global home security ... 30.3 bn by 2022. The market is estimated to ... period from 2015 to 2022. Rising security needs among ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... 2015 SHPG ) announced today that ... Jaffray 27 th Annual Healthcare Conference in New ... 8:30 a.m. EST (1:30 p.m. GMT). --> SHPG ) ... participate in the Piper Jaffray 27 th Annual Healthcare Conference ... December 1, 2015, at 8:30 a.m. EST (1:30 p.m. GMT). ...
(Date:11/24/2015)... QUEBEC CITY , Nov. 24, 2015 /PRNewswire/ ... (the "Company") announced today that the remaining 11,000 ... Common Share Purchase Warrants (the "Series B Warrants") ... agreement were exercised on November 23, 2015, which ... Common Shares.  After giving effect to the issuance ...
(Date:11/24/2015)... ... November 24, 2015 , ... InSphero AG, the leading ... culture models, has promoted Melanie Aregger to serve as Chief Operating Officer. ... on the management team and was promoted to Head of InSphero Diagnostics ...
(Date:11/24/2015)... Nov. 24, 2015 Capricor Therapeutics, Inc. ... on the discovery, development and commercialization of first-in-class therapeutics, ... Executive Officer, is scheduled to present at the 2015 ... 10:50 a.m. EST, at The Lotte New York Palace ... . --> ...
Breaking Biology Technology: