We have examined the possible influence of bovine pancreatic polypeptide (bPP) on glycogenolysis and gluconeogenesis in hepatocytes isolated from fed rats. The activity of glycogen phosphorylase a and pyruvate kinase, enzymes implicated in the hormonal regulation of these pathways, was also measured. Glycogenolysis was estimated by glucose release into the medium and gluconeogenesis by (U-14C) pyruvate incorporation into glucose. Addition of bPP to the incubation medium did not modify endogenous glucose production or glycogen phosphorylase a activity, either under basal conditions or on stimulation by glucagon (3 x 10(-10) M) or phenylephrine (10(-5) M). bPP also failed to alter both the incorporation rate of (U-14 C) pyruvate into glucose and pyruvate kinase activity, under basal conditions as well as in the presence of glucagon. Furthermore, time-course experiments revealed no effect of bPP on glycogen phosphorylase a or pyruvate kinase activities. These data indicate that pancreatic polypeptide is not implicated in the control of glucose production by isolated liver cells from fed rats.