title: Hormonal control of glycogenolysis in isolated chick embryo hepatocytes.
abstract: Hepatocytes were isolated from 15-, 16-, 17-, and 18-day-old chick embryos. Glucagon, adrenaline, and dibutyryl cAMP (Bt2cAMP), individually or in combination, activated glycogenolysis in the isolated hepatocytes. The alpha-adrenergic agonist phenylephrine did not increase glycogen breakdown. The action of adrenaline was abolished upon treatment of hepatocytes with a combination of the hormone and propranolol, a beta-adrenergic blocker. The effects of glucagon, adrenaline, and dibutyryl cAMP on glycogenolysis were not additive. Either hormone induced an increase in the concentration of cAMP. The activities of dephosphophosphorylase kinase and phosphorylase a were stimulated by each hormone or Bt2cAMP. It appears likely that glucagon and adrenaline serve as physiological regulators of hepatic glycogen breakdown during embryogenesis in chickens.
authors.affiliation: Department of Biochemistry, University of Maiduguri, Nigeria.
authors.forename: I O
authors.initials: IO
authors.lastname: Onoagbe
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D002470:Cell Survival; D002642:Chick Embryo; D004837:Epinephrine / Q000494:pharmacology*; D005934:Glucagon / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000196:embryology* / Q000378:metabolism; D008112:Liver Glycogen / Q000378:metabolism*; D010656:Phenylephrine / Q000494:pharmacology; D010762:Phosphorylase a / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology
chemical_list: D008112:Liver Glycogen; D010656:Phenylephrine; D003994:Bucladesine; D000255:Adenosine Triphosphate; D005934:Glucagon; D011433:Propranolol; D007770:L-Lactate Dehydrogenase; D010762:Phosphorylase a; D005947:Glucose; D004837:Epinephrine