Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Muscle loss in elderly linked to blood vessels' failure to dilate

20.05.2010
Post-meal blood vessel expansion naturally occurs in young, not old, and restoration through drug therapy could dramatically improve strength and health of elders

Why do people become physically weaker as they age? And is there any way to slow, stop, or even reverse this process, breaking the link between increasing age and frailty?

In a paper published online this Wednesday in the Journal of Clinical Endocrinology & Metabolism, University of Texas Medical Branch at Galveston researchers present evidence that answers to both those questions can be found in the way the network of blood vessels that threads through muscles responds to the hormone insulin.

Normally, these tiny tubes are closed, but when a young person eats a meal and insulin is released into the bloodstream, they open wide to allow nutrients to reach muscle cells. In elderly people, however, insulin has no such "vasodilating" effect.

"We were unsure as to whether decreased vasodilation was just one of the side effects of aging or was one of the main causes of the reduction in muscle protein synthesis in elderly people, because when nutrients and insulin get into muscle fibers, they also turn on lots of intracellular signals linked to muscle growth," said UTMB's Dr. Elena Volpi, senior author of the paper. "This research really demonstrates that vasodilation is a necessary mechanism for insulin to stimulate muscle protein synthesis."

Volpi and her collaborators reached this conclusion after an experiment in which they infused an amount of insulin equivalent to that generated by the body in response to a single meal into the thigh muscles of two sets of young volunteers. One group had been given a drug that blocked vasodilation, while the other was allowed to respond normally. Measurements of muscle protein synthesis levels where made using chemical tracers, while biopsies yielded data on specific biochemical pathways linked to muscle growth.

"We found that by blocking vasodilation, we reproduced in young people the entire response that we see in older persons — a blunting of muscle protein response and a lack of net muscle growth. In other words, from a muscle standpoint, we made young people look 50 years older," Volpi said.

Such results point the way to what could be a powerful new therapy for age-related frailty and the health and quality-of-life problems that come with it.

"Eventually, if we can improve muscle growth in response to feeding in old people by improving blood flow, then we're going to have a major tool to reduce muscle loss with aging, which by itself is associated with reduction in physical functioning and increased risk of disability," Volpi said.

Other authors of the paper ("Insulin Stimulates Human Skeletal Muscle Protein Synthesis via an Indirect Mechanism Involving Endothelial-Dependent Vasodilation and Mammalian Target of Rapamycin Complex 1 Signaling") were lead author and postdoctoral fellow Kyle Timmerman, medical student Jessica Lee, assistant professor Hans Dreyer, research scientist Shaheen Dhanani, graduate students Erin Glynn and Christopher Fry, assistant professor Micah Drummond, associate professor Melinda Sheffield Moore, and professor Blake Rasmussen. Specialized metabolic studies were conducted by the staff of the UTMB Clinical Research Center, part of the university's Institute for Translational Sciences. The National Institute on Aging, the UTMB Claude D. Pepper Center Older Americans Independence Center, the National Institute of Child Health and Human Development and the UTMB Clinical Translational Sciences Award supported this study.

ABOUT UTMB: Established in 1891, Texas' first academic health center comprises four health sciences schools, three institutes for advanced study, a research enterprise that includes one of only two national laboratories dedicated to the safe study of infectious threats to human health, and a health system offering a full range of primary and specialized medical services throughout Galveston County and the Texas Gulf Coast region. UTMB is a component of the University of Texas System.

The University of Texas Medical Branch at Galveston
Public Affairs Office
301 University Boulevard, Suite 3.102
Galveston, Texas 77555-0144

Jim Kelly | EurekAlert!
Further information:
http://www.utmb.edu

More articles from Health and Medicine:

nachricht A whole-body approach to understanding chemosensory cells
13.12.2017 | Tokyo Institute of Technology

nachricht Research reveals how diabetes in pregnancy affects baby's heart
13.12.2017 | University of California - Los Angeles Health Sciences

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

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>