These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Fasting and diabetes alter adipose tissue glycogen synthase.
    Author: Kaslow HR, Eichner RD.
    Journal: Am J Physiol; 1984 Nov; 247(5 Pt 1):E581-4. PubMed ID: 6437248.
    Abstract:
    In a previous report (J. Biol. Chem. 254: 4678-4683, 1979), we showed that fasting blunted the ability of insulin to promote glucose incorporation into glycogen in vitro. In addition, we showed that glycogen synthase activity was altered in two ways: the concentration of glucose 6-P causing half-maximal activation increased, and positive cooperativity appeared in the glucose 6-P activation of the enzyme. We now show that streptozotocin-diabetes causes the same changes in glucose incorporation and glycogen synthase activity. We show that these changes in glycogen synthase activity persist during enzyme purification; thus it is likely the changes are a result of a structural alteration of the enzyme. Because glycogenolysis of a glycogen particle from rabbit skeletal muscle also caused the appearance of positive cooperativity, we propose that both phosphorylation and glycogenolysis are involved in the appearance of positive cooperativity.
    [Abstract] [Full Text] [Related] [New Search]