The action of pancreatic hormones on the cyclic AMP content of isolated chicken hepatocytes

Abstract The hormonal control of cyclic AMP content was investigated in hepatocytes isolated by collagenase digestion from chicken liver. Glucagon (2.9 × 10 −7 M ) increased cyclic AMP content within 1 min, and the concentration continued to increase for at least 30 min. More than 90% of the total cyclic AMP measured remained within the cells during this time. Significant stimulation of glycogenolysis was obtained with a glucagon concentration (2.9 × 10 −11 M ) which had no detectable effect on cyclic AMP content. Half-maximal increases in cyclic AMP content and glucose production were produced by glucagon concentrations of approximately 10 −8 and 10 −10 M , respectively. Insulin (0.17–17 × 10 −9 M ) and avian pancreatic polypeptide (0.24–240 × 10 −9 M ) had no effect on cyclic AMP content either in the presence or absence of glucagon. Adrenaline increased cyclic AMP content, the minimum effective concentration being 5 × 10 −8 M . The cyclic AMP response to adrenaline reached a peak within 2.5 min, and the maximum increase was much less than that produced by glucagon.