Glycogen autophagy in newborn rat hepatocytes.
Glycogen autophagy in newborn rat hepatocytes was studied by using enzyme determinations and electron microscopy. Cyclic AMP induced glycogen autophagy in these cells. Glycogen-hydrolyzing acid glucosidase activity increased whereas acid mannose 6-phosphatase activity decreased in the liver of these animals. Parenteral glucose, which prevents postnatal glucagon secretion and tissue cyclic AMP elevation, and propranolol which antagonizes cyclic AMP, inhibited glycogen autophagy. Glucosidase activity decreased and phosphatase activity increased. These findings raise the possibility that cyclic AMP-induced autophagic mechanisms in newborn rat hepatocytes are associated with changes in the activity of acid mannose 6-phosphatase.
Kalamidas
S A
SA
Department of Anatomy, Histology and Embryology, Medical School, University of Ioannina, Greece.
Kotoulas
O B
OB
D000818:Animals; D000831:Animals, Newborn; D000242:Cyclic AMP / Q000378:metabolism; D005959:Glucosidases / Q000378:metabolism; D022781:Hepatocytes / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D008112:Liver Glycogen / Q000378:metabolism*; D008854:Microscopy, Electron; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D016707:Tissue Fixation
D008112:Liver Glycogen; D000242:Cyclic AMP; C023553:mannose-6-phosphatase; D010744:Phosphoric Monoester Hydrolases; D005959:Glucosidases