Excess of glycogen in muscle reduces resistance in hard physical exercise in mice

Glycogen (black particles) accumulates in large amounts in the muscle due to the absence of the protein glycogenin. Image: Giorgia Testoni, IRB Barcelona
Glycogen (black particles) accumulates in large amounts in the muscle due to the absence of the protein glycogenin. Image: Giorgia Testoni, IRB Barcelona
Research
(07/07/2017)

In 2009, the Jamaican athlete Usain Bolt set a world record in 100-meter dash thanks mostly to a source of energy called glycogen. This molecule, a polysaccharide created by glucose chains, is stored in the muscle and is released during short and intense exercises.

Glycogen (black particles) accumulates in large amounts in the muscle due to the absence of the protein glycogenin. Image: Giorgia Testoni, IRB Barcelona
Glycogen (black particles) accumulates in large amounts in the muscle due to the absence of the protein glycogenin. Image: Giorgia Testoni, IRB Barcelona
Research
07/07/2017

In 2009, the Jamaican athlete Usain Bolt set a world record in 100-meter dash thanks mostly to a source of energy called glycogen. This molecule, a polysaccharide created by glucose chains, is stored in the muscle and is released during short and intense exercises.

 

Although the basics of glycogen biology were thought to be well established, a pre-clinical study conducted on mice and published in the journal Cell Metabolism, and led by the Institute of Biomedical Research (IRB Barcelona) is changing some previous assumptions completely. The research, which also has the participation of the University of Barcelona, states that glycogen synthesis does not need a protein called glycogenin and that high levels of glycogen affect the muscle activity in endurance exercises on mice.


“These results change our views on glycogen synthesis and the function of glycogenin in muscle physiology”, says Joan Guinovart, who led the study and is professor at the Department of Biochemistry and Molecular Biomedicine of the University of Barcelona, and director of the Institute of Biomedical Research (IRB Barcelona). “From a clinical perspective, our study reveals the underlying mechanisms in glycogen storage disease XV, a minority genetic disorder recently described in humans for the first time”.

More information