Navigation Links
High-strain tendons repair less frequently
Date:5/25/2010

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.


'/>"/>

Contact: Nick Zagorski
nzagorski@asbmb.org
301-634-7366
American Society for Biochemistry and Molecular Biology
Source:Eurekalert

Related biology news :

1. Engineers create bone that blends into tendons
2. Human derived stem cells can repair rat hearts damaged by heart attack
3. Pittsburgh scientists identify human source of stem cells with potential to repair muscle
4. Enzyme alerts cells powerful army to repair DNA damage
5. Seattle Childrens Hospital leads $23.7 million NIH grant to study gene repair
6. Simulation reveals how body repairs balance after damage
7. Using nanotubes to detect and repair cracks in aircraft wings, other structures
8. Enhanced DNA-repair mechanism can cause breast cancer
9. Yale receives $8.4 million to study DNA repair in cancer cells
10. Building the future -- 21st century nano tools to repair the nervous system
11. Researchers probe a DNA repair enzyme
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/11/2016)... CHICAGO , Jan. 11, 2016  higi, ... via nearly 10,000 retail locations, web and mobile, ... than $40 million from existing investors. ... will be devoted to further innovate higi,s health ... app and web portal – including expanding services ...
(Date:1/7/2016)... -- This BCC Research report studies the global as ... identifying newer markets and exploring the expansion of the ... Includes forecast from 2015 to 2020. Use ... the expansion of the present application market for various ... technology, determine its current market size, and estimate the ...
(Date:1/6/2016)... 2016  Varam Capital, a provider of micro-finance inclusion ... deliver advanced authentication solutions to their clients. Varam supplies ... A loan of a few thousand rupees may make ... ability to purchase livestock or equipment for a small ... for a local store. ...
Breaking Biology News(10 mins):
(Date:2/3/2016)... 2016  Discovery Laboratories, Inc. (NASDAQ: DSCO ... KL4 surfactant therapies for respiratory diseases, today announced ... inducement award as a component of employment compensation ... President and Chief Executive Officer.  The award was ... 1, 2016 and granted as an inducement material ...
(Date:2/3/2016)... Ascendis Pharma A/S (Nasdaq: ASND ), ... TransCon technology to address significant unmet medical needs, today ... Leerink Partners Global Healthcare Conference Location: , Waldorf ... 2016 Time:  , 11:55am EST www.ascendispharma.com ... An audio webcast of this event will be posted ...
(Date:2/3/2016)... , Feb. 3, 2016 New ... more than $1 million for researchers in ... on health-related research that demonstrates exciting potential.   ... of funding for the New Jersey Health Foundation Research ... members at these educational institutions— Princeton University, Rutgers ...
(Date:2/3/2016)... ... 2016 , ... ProMIS Neurosciences is currently in the process ... propagating strains of Amyloid beta involved in Alzheimer’s disease. The Company plans to ... on from the first misfolded Amyloid beta target announced on Nov. 12, 2015, ...
Breaking Biology Technology: