Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High-strain tendons repair less frequently

26.05.2010
Appearing in the May 21 issue of JBC

In a discovery that seems counterintuitive, a study appearing in the May 21st Journal of Biological Chemistry has found that tendons in high-stress and strain areas, like the Achilles tendon, actually repair themselves less frequently than low-stress tendons. This study sheds some light on the increased susceptibility of certain tendons to injury during aging.

Tendons, composed of collagen and other proteins, serve to connect muscle to bone and thus are vital for movement. Considering their strenuous activity, tendons need to be continually repairing collagen damage to avoid buildup of degraded proteins that could cause serious complications. Not all tendons are equal though; some tendons, like those in the hand, are primarily used to maintain proper limb placement while others, like the Achilles tendon in humans and the superficial digital flexor tendon (SDFT) in horses, have to bear a lot of weight and strain.

It would be expected that high-strain tendons would repair more frequently, yet Dr Helen Birch at University College London and colleagues examined protein turnover in the tendons of horses of various ages and found that the high-strain SDFT (located at the rear of the limb) repairs much less frequently than the low-strain common digital extensor tendon (CDET, located at the front of the limb). Birch and colleagues used an approach called amino acid racemization to measure protein age in the horse tendons. Amino acids are always incorporated into proteins in a specific orientation called the L-form, but afterwards can spontaneously convert into a mirror image called the D-form. Therefore, by measuring the ratio of L and D amino acids over time, one can estimate the half-life of a protein.

Through this method, the researchers found that non-collagen proteins in tendon have an average half life of 2.2 years in SDFT and 3.5 years in CDET, which would be expected. However, SDFT collagen had a half-life of 198 years, compared to 34 years for CDET collagen. That means that every year, only 0.25% of the injury-prone collagen gets replaced in SDFT tissue. Over time, degraded protein and other mechanically-induced micro-damage could reduce the overall integrity of the tendon, which could lead to large-scale injuries. As to why the body would seemingly put its more important tendons at greater risk, the researchers suggest that it may be a trade off; too much repair may compromise the strength and stiffness of these tendons which are used heavily, so the body tries to preserve their structural integrity at the expense of increased injury risk later in life.

From the article: "Aspartic Acid racemization and collagen degradation markers reveal an accumulation of damage in tendon collagen which is enhanced with aging" by Chavaunne T. Thorpe, Ian Streeter, Gina L. Pinchbeck, Allen E. Goodship, Peter D. Clegg and Helen L. Birch

Corresponding Author: Helen Birch, Institute of Orthopaedics and Musculoskeletal Science, University College London, UK; e-mail: h.birch@ucl.ac.uk

Nick Zagorski | EurekAlert!
Further information:
http://www.asbmb.org

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>