Glycogen phosphorylase longer cause the phosphorylation cascade that ends with formation of (active) glycogen phosphorylase a. These modifications initiated by insulin end glycogenolysis in order to preserve what glycogen stores are left in the cell and trigger glycogenesis (rebuilding of glycogen). Phosphorylase a and phosphorylase b each exist in two forms a T (tense) inactive state and R (relaxed) state. Phosphorylase b is normally in the T state, inactive due to the physiological presence of ATP and Glucose 6 phosphate, and Phosphorylase a is normally in the R state (active). An isoenzyme of glycogen phosphorylase exists in the liver sensitive to glucose
Equine exertional rhabdomyolysis cell membranes may then be damaged if the horse is forced to continue work, which allows muscle enzymes and myoglobin to leak into the bloodstream. The body builds up a store of glycogen from converted carbohydrates in muscle cells. Glycogen, a fuel used by muscles for energy, is depleted during work and restocked when a horse rests. Oxygen-carrying blood metabolizes glycogen, but the blood can not flow fast enough to metabolise the excess stored glycogen. The glycogen that is not metabolized aerobically (by the oxygenated blood) must then be metabolized anaerobically, which then creates the cell waste products and heat,