Sensitivity of chicken and rat adipocytes and hepatocytes to isologous and heterologous pancreatic hormones

Abstract

Isolated chicken and rat adipocytes and hepatocytes were used to compare chicken vs mammalian pancreatic hormones in regulating glucose and lipid metabolism. Porcine glucagon is twice as potent as chicken glucagon in eliciting lipolysis in both rat and chicken adipocytes. A less but marked bignificant difference exists between the two glucagon hormologs when glucose release by isolated hepatocytes is measured. Chicken adipocytes respond to lower concentrations (1 ng/ml) of glucagon than rat adipocytes (5 ng/ml). Hepatocytes from both animal species responded to glucagon at concentrations of 1 ng/ml. Chicken insulin is slightly more potent than porcine insulin both in inducing glucose utilization and in inhibiting glucagon-stimulated lipolysis in rat adipocytes. Glucose utilization, basal lipolysis, and the rate of glucagon-stimulated lipolysis of the chicken adipocyte are unaltered by insulin concentrations which are 1000 times greater than those required to affect rat adipocytes. The antilipolytic action of avian pancreatic polypeptide (APP) was compared with the bovine homolog of APP, namely bovine pancreatic polypeptide (BPP). BPP is not was effective as APP in inhibiting glucagon-stimulated lipolysis in the chicken adipocyte, and neither APP nor BPP inhibit glucagon-stimulated lipolysis in the rat adipocyte.