The influences of glucagon, epinephrine and alpha- and beta-adrenergic agents on glycogenolysis in isolated rabbit hepatocytes and perfused livers.

1. Glucagon, epinephrine, norepinephrine, dibutyryl cyclic AMP, isoproterenol and phenylephrine each enhance glycogenolysis in isolated perfused rabbit livers and/or hepatocytes. 2. Such enhancement by epinephrine, norepinephrine, isoproterenol and phenylephrine is eliminated by propranolol but unaltered by phentolamine, suggesting that stimulation of glycogenolysis by each of these agents involves beta-adrenergic-mediated mechanism(s). 3. Data obtained with hepatocytes from 16--20-week-old rabbits and from 7--8-week-old rabbits are identical as far as enhancement of glycogenolysis by beta-adrenergic stimulation is concerned, implying that the nature of functional adrenergic receptors in rabbit liver does not change during the process of maturation.