Date Published: 30 July 2005
Research at Liverpool University (UK) helps to explain the role of calcium in muscle contraction
New research into muscle contraction was announced by Liverpool University (www.liverpool.ac.uk) on 29th July 2005 and is published in this week’s issue of the journal Nature.
Muscles contract and relax to allow the body to perform crucial activity. Electrical signals tell the muscle when to contract, but when the muscle needs to relax, the signal is deliberately ignored. Until now scientists have been unable to understand how the body ignores this signal.
The team found that calcium, which allows muscle contraction to take place, enters the body’s cells in response to electrical signals.
The calcium fills up a small structure in the cell and when this is full and starts to empty, it forces the muscle to relax by preventing any more calcium entering the cell, even when it receives contraction signals.
Professor Susan Wray, who heads the Department of Physiology at the University of Liverpool explained:
“ Electrical signals in nerves and muscles are important for all activity, from thinking to drinking. It is important for the body to be active, but it is also important for it to relax, so that it doesn’t over work itself. For example, in childbirth the uterus contracts and relaxes at regular intervals to allow a baby to pass through the birth canal.
_ But when we get cramps for example, our muscle is contracting too hard or too often and in the case of the ureter it would cause kidney damage. It is therefore crucial that our muscles have periods of relaxation and we have now uncovered how this occurs. This understanding should allow doctors to work more accurately with the body’s natural mechanisms when treating patients.”
The research is supported by the Medical Research Council, MRC - a national organization funded by the UK tax-payer whose business is medical research to improving human health for everyone.
Source: Liverpool University