Dephosphophosphorylase kinase and

Epinephrine is a hormone that causes extremely rapid responses. One of the responses to this hormone is an increased liberation of liver glycogen as glucose. This reaction has been found to be limited by the enzyme phosphorylase. Liver phosphorylase exists as the active enzyme and as the inactive, dephosphophosphorylase. Epinephrine, and also the hyperglycemic factor, glucagon, have been found to stimulate the formation of active phosphorylase. This stimulation is mediated by an adenine nucleotide liberated from cell particles by an action of the hormones. The liberation of the nucleotide has been demonstrated in cell-free systems. The nucleotide in an unexplained manner, perhaps indirectly or after metabolic conversion to another form, alters the activity of either the kinase or the phosphatase so that the steady-state concentration of active phosphorylase is increased, i ... 

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