Inhibition of thymidine incorporation in primary rat hepatocytes by porcine pancreatic polypeptide.

The concentration of pancreatic polypeptide (PP), a peptide released by meal ingestion, was suppressed in obese mice and in humans, and earlier studies have suggested a metabolic function of PP in adipocytes and liver. These observations have prompted the examination of the metabolic role of PP in rat hepatocytes. These studies have examined the role of porcine PP in the control of [3H]-thymidine incorporation in adult rat hepatocytes maintained in the presence of insulin, glucagon and epidermal growth factor (EGF). Upon long-term exposure of cultured hepatocytes to porcine PP, basal (insulin and glucagon-maintained cells) and EGF-stimulated [3H]-thymidine incorporation were inhibited. Basal incorporation was inhibited with an ED50 of 23 pM. Thus, the long-term PP function may be suppression of stimulated thymidine incorporation and cellular replication.