Myophosphorylase is the muscle isoform of the enzyme glycogen phosphorylase. This enzyme helps break down glycogen (a form of stored carbohydrate) into glucose-1-phosphate, (not glucose) so that it can be utilized within the muscle cell. A deficiency is associated with Glycogen storage disease type V, also known as `McArdle`s Syndrome`. A case ...... Found on http://en.wikipedia.org/wiki/Myophosphorylase