Activity of rat liver enzymes responsible for glycogen metabolism after whole-body irradiation

• Published in: Biochimica et biophysica acta Vol. 252; no. 2; pp. 285 - 295
• Main Authors: Catravas, G.N., McHale, C.G.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 12.11.1971
• Subjects: Amylases - radiation effects; Animals; Enzyme Activation; Fasting; Female; Glucosidases - radiation effects; Glucosyltransferases - radiation effects; Glycoside Hydrolases - radiation effects; Liver - cytology; Liver - enzymology; Liver - radiation effects; Liver Glycogen - metabolism; Liver Glycogen - radiation effects; Nucleoside Diphosphate Sugars; Phosphorylases - radiation effects; Polysaccharides; Radiation Effects; Rats; Uracil Nucleotides
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(71)90009-2

1. 1. The activities of liver enzymes involved in the breakdown and synthesis of glycogen have been investigated in this study after whole-body exposure of rats to 1200 rads of X-ray of mixed gamma-neutron radiation. 2. 2. It was found that glycogen phosphorylase and amylo-1,6-glucosidase (debranching enzyme), both of which are involved in the breakdown of glycogen to “glucose” units, are inhibited by both qualities of radiation. A considerable inhibition in the activity of amylo-1,4→1,6 transglucosidase (branching enzyme) was also observed. In contrast, it was found that the activity of UDPglucose-glycogen transglucosylase which is responsible for the in vivo synthesis of 1,4-polysaccharides is enhanced whether the animal received X-rays or mixed gamma-neutron radiation. 3. 3. Electron micrographs verifeid the presence of large deposits of glycogen in liver of irradiated rats 48 h after their removal from the exposure room, although no food was given to these animals following irradiation.