<prompt> Cyclic AMP increase the rate of glycogenolysis byPromoting the formation of phosphorylaseActing as a cofactor for glycogen phosphorylaseFurnishing phosphate for the phosphorylysis of glycogenActing as a precursor of 5 AMP which is a cofactor for glycogen phosphorylase  <response>: The roles of cAMP and inorganic phosphate Pi in the regulation of muscle glycogenolysis during exercise have been investigated in humans using the needle biopsy technique. The fraction of phosphorylase a in resting muscle was as a mean 23, but the rate of glycogenolysis was extremely low. Epinephrine infusion increased cAMP in muscle by 3-fold and transformed 80 of phosphorylase to the form 