Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Estrogen’s Effects on Fat Depends on Where It’s Located

30.07.2013
Article published in the American Journal of Physiology: Endocrinology and Metabolism

Women have long bemoaned the fact that they tend to store more fat than men, particularly after menopause. Although it’s well established that estrogen, the primary sex hormone present during women’s childbearing years, is responsible for this effect, exactly how estrogen exerts this influence has been unknown.

Previous research has shown that body fat both absorbs estrogen and other sex hormones circulating in the blood as well as produces its own sex hormones, though researchers have been unsure what role that plays in fat accumulation. Also not completely understood is why women tend to accumulate fat in the stereotypical “pear” shape, with more fat in the buttocks and thighs—a shape that’s thought to be healthier than men’s stereotypical “apple” shape, with more fat around the belly.

Gathering clues to answer these questions, Kathleen M. Gavin and her colleagues at East Carolina University examined how estrogen locally affects fat accumulation in these key areas by slowly infusing the hormone into the buttocks and belly in overweight women while also giving them drugs or having them exercise to speed up fat breakdown. They found that estrogen’s effects on these fat deposits was highly dependent on the deposits’ specific location and the fat-burning interventions themselves.

The article is entitled “Estradiol Effects on Subcutaneous Adipose Tissue Lipolysis in Premenopausal Women are Adipose Tissue Depot Specific and Treatment Dependent” (http://bit.ly/1aKKegY). It appears in the June edition of the American Journal of Physiology: Endocrinology and Metabolism, published by the American Physiological Society.

Methodology

Gavin and her colleagues recruited 17 overweight-to-obese premenopausal women, all between the ages of 18 and 44 years old. After an initial visit to the lab to gather a variety of information on each study participant, including weight, height, percent fat and lean mass, and VO2 max (a measure of physical fitness), the researchers subjected each participant to a variety of interventions meant to speed up lipolysis, or fat breakdown/mobilization. Through probes inserted directly in the fat of the participants’ buttocks and abdomen, the researchers slowly infused two drugs, either individually or together, that encourage lipolysis. They also had participants perform a bout of exercise at an intensity similar to a standard exercise session. Such “submaximal” exercise is known to optimally break down fat.

Participants performed this exercise both by itself and while the drugs were being infused. To test the effects of estrogen, the researchers also performed each of these conditions while estrogen was also being slowly infused into participants’ fat deposits. To measure fat breakdown, the researchers used a technique called microdialysis to look for a marker (glycerol) left behind when stored fat is broken down for eventual production of energy.

Results

The researchers found that estrogen’s effects differed tremendously depending on the fat- mobilizing interventions themselves and where the fat deposit was located. For example, estrogen blunted fat breakdown in the abdomen if it was infused while a particular fat-mobilization drug called isoproterenol was also being infused, but it didn’t have this effect in the buttocks. When a second fat mobilizing drug was given along with the first while participants were at rest, fat breakdown didn’t change any further. However, when both drugs were injected together during exercise or when the volunteers exercised without the drugs, fat breakdown increased in the abdomen, but less so in the buttocks.

Importance of the Findings

These results suggest that estrogen has different effects within fat tissue depending on its location. Together, these effects could help maintain premenopausal women’s “pear” shape even in the face of exercise or other signals the body receives to break down fat. They could also help generate some new ideas on how estrogen in fat may influence why postmenopausal women tend to accumulate more fat in the abdomen.

The authors suggest that more research is necessary to better understand the mechanisms behind how and why estrogen acts in these differential ways.

Study Team

In addition to Kathleen M. Gavin, the study team also includes Elizabeth E. Cooper, Dustin K. Raymer, and Robert C. Hickner, all of East Carolina University.

NOTE TO EDITORS: To schedule an interview with a member of the research team, please contact Donna Krupa at dkrupa@the-aps.org, @Phyziochick, or 301.634.7209. The article is available online at http://bit.ly/1aKKegY.

Physiology is the study of how molecules, cells, tissues, and organs function in health and disease. Established in 1887, the American Physiological Society (APS) was the first US society in the biomedical sciences field. The Society represents more than 11,000 members and publishes 14 peer-reviewed journals with a worldwide readership.

Donna Krupa | Newswise
Further information:
http://www.the-aps.org

More articles from Health and Medicine:

nachricht Routing gene therapy directly into the brain
07.12.2017 | Boston Children's Hospital

nachricht New Hope for Cancer Therapies: Targeted Monitoring may help Improve Tumor Treatment
01.12.2017 | Berliner Institut für Gesundheitsforschung / Berlin Institute of Health (BIH)

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: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>