Navigation Links
Study offers new insights into the mechanics of muscle fatigue
Date:1/17/2013

A study in The Journal of General Physiology examines the consequences of muscle activity with surprising results, indicating that the extracellular accumulation of potassium that occurs in working muscles is considerably higher than previously thought.

Muscle excitation involves the influx of sodium ions and efflux of potassium ions. Although the fraction of ions that cross the muscle membrane with each contraction is minute, repeated activity can lead to substantial changes in the intracellular and extracellular concentrations of sodium and potassium ions. The extent of these changes, however, has been unclear. Now, Torben Clausen from Aarhus University in Denmark provides quantitative analyses of the changes in intracellular and extracellular ion concentration resulting from stimulation of a leg muscle in rats, providing insight into how they vary with muscle activity.

Clausen measured the changes in concentration of sodium, potassium, and chloride ions in working rat extensor digitorum longus (ESL) muscles. Remarkably, when their muscles were stimulated to fire at a rate of 5 Hz (comparable to that in the legs of a person riding a bicycle) for five minutes, sufficient intracellular potassium was lost to lead to an extracellular concentration that would interfere with further excitation. These results suggest that accumulation of extracellular potassium is a much larger contributor to muscle fatigue than previously thought, which may be of particular importance in such conditions as hyperkalemic periodic paralysis and other channelopathies that affect skeletal muscle. These changes in ion distribution are opposed through the action of the "Na+/K+ pump"which expends energy to move sodium out of the cell and potassium into itand will therefore be even more pronounced under disease- and injury-related conditions associated with decreased pump activity.


'/>"/>

Contact: Rita Sullivan King
news@rupress.org
212-327-8603
Rockefeller University Press
Source:Eurekalert

Related biology news :

1. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
2. Law that regulates shark fishery is too liberal: UBC study
3. New study will help protect vulnerable birds from impacts of climate change
4. Study jointly led by UCSB researcher supports theory of extraterrestrial impact
5. BYU study: Using a gun in bear encounters doesnt make you safer
6. 15-year study: When it comes to creating wetlands, Mother Nature is in charge
7. Pycnogenol (French maritime pine bark extract) shown to improve menopause symptoms in new study
8. Crystal structure of archael chromatin clarified in new study
9. EU-funded study underlines importance of Congo Basin for global climate and biodiversity
10. University of Houston study shows BP oil spill hurt marshes, but recovery possible
11. Study demonstrates cells can acquire new functions through transcriptional regulatory network
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/1/2016)... -- Today, the first day of American Heart Month, the ... first of its kind workplace health solution that leverages ... first application of Watson to ... Welltok will create a new offering that combines AHA,s ... on Welltok,s health optimization platform. The effort is intended ...
(Date:1/25/2016)...  Glencoe Software, the world-leading supplier of image data ... provide the data management solution OMERO Plus for the ... Photo - http://photos.prnewswire.com/prnh/20160125/325328LOGO ... Phenotypic analysis measures the characteristics and behavior of ... states such as health and disease, the presence or ...
(Date:1/20/2016)... , Jan. 20, 2016   MedNet Solutions , ... entire spectrum of clinical research, is pleased to announce ... significant achievements are the result of the company,s laser ... iMedNet eClinical , it,s comprehensive, easy-to-use and highly ... --> Key MedNet growth achievements in 2015 ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... , February 10, 2016 Early-career researchers ... Peru , Uganda and ... work in health and nutrition   Indonesia , ... Uganda and Yemen are being honored ... epidemiology. They are also celebrated for mentoring young women scientists who are ...
(Date:2/10/2016)... NX Prenatal Inc., a US based ... for early warning of adverse pregnancy outcomes, announced ... by Dr. Thomas McElrath of Brigham ... Medicine,s (SMFM) annual meeting held in ... The presentation reported initial positive top-line results regarding ...
(Date:2/10/2016)... York (PRWEB) , ... February ... ... (NASDAQ: REGN) today announced that it has joined the Human Vaccines Project, ... for infectious diseases and cancer. , The Human Vaccines Project brings ...
(Date:2/10/2016)... DUBLIN , Feb. 10, 2016  Allergan plc ... today announced that Brent Saunders , Allergan,s CEO ... in a fireside chat session at the RBC Capital ... 12:30 p.m. ET at The New York Palace Hotel ... presentation will be webcast live and can be accessed ...
Breaking Biology Technology: