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
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Emergence of beta adrenergic-responsive hepatic glycogenolysis in male rats during post-maturational aging. Author: Katz MS, McNair CL, Hymer TK, Boland SR. Journal: Biochem Biophys Res Commun; 1987 Sep 15; 147(2):724-30. PubMed ID: 2820413. Abstract: Adrenergic-stimulated glycogenolysis (estimated as glucose output) was determined in hepatocytes from 7, 14, 20, and 24 mo old male Fischer 344 rats. Glucose output in response to the beta adrenergic agonist isoproterenol was minimal at 7 mo but increased progressively with increasing age. At all ages the isoproterenol response was concentration dependent and was inhibited by the beta adrenergic antagonist propranolol. Stimulation of glucose output by the mixed alpha-beta agonist epinephrine also increased between 7 and 24 mo. Glycogenolytic responses to alpha agonist (assessed in the presence of epinephrine and excess beta antagonist), glucagon, and forskolin did not increase substantially with age and at 24 mo were less than the response to beta agonist. In hepatocyte homogenates adenylate cyclase activation by beta agonist but not glucagon and forskolin increased between 7 and 24 mo. These results suggest that adrenergic stimulation of glycogenolysis, which in young adult male rats is generally attributed to alpha adrenergic-mediated processes, becomes mediated predominantly by beta adrenergic-responsive adenylate cyclase during post-maturational aging.[Abstract] [Full Text] [Related] [New Search]