What are the activators of phosphorylase kinase in a muscle cell?

well there are several phosphorylase kinases . Adenaline activates the cascade by turning on adenylyl kinase which produces cAMP The cAMP activates cAMP dependent protein kinase which then begins the cascade by phosphorylating and activating inhibitor I which blocks protein phosphatase. cAMPDPK can also phosphorylate some of the kinases and they in turn will activate the next kinase. Muscle alos contains a special phosphorylase b that is activated by AMP ( not cAMP). Phosphorylase a is the final active enzyme that cleaves glycogen to glucose -1phosphate