Journal article
The influences of glucagon, epinephrine and adrenergic agents on glycogen phosphorylase a and pyruvate kinase activities in hepatocytes from juvenile and adult rabbits
Biochimica et biophysica acta. General subjects, Vol.717(1), pp.143-148
1982
DOI: 10.1016/0304-4165(82)90391-9
PMID: 7104386
Abstract
1. Glucagon, epinephrine, norepinephrine, isoproterenol and phenylephrine each increases significantly glucose appearance and glycogen disappearance from hepatocytes of both juvenile and adult fed rabbits. Such increases caused by catecholamines and adrenergic agonists are suppressed significantly by the β-adrenergic antagonist propranolol but are unchanged by the α-antagonist phentolamine. 2. Glucagon, epinephrine, norepinephrine, isoproterenol and phenylephrine each increases significantly glycogen phosphorylase
a activity and decreases significantly the pyruvate kinase activity ratio (assayed with 0.8 mM phospho
enolpyruvate ± 200
μM fructose 1,6-bisphosphate) in hepatocytes from both juvenile and adult rabbits. Changes induced by catecholamines and adrenergic agonists in the activities of both enzymes are significantly diminished by propanolol but unaltered by phentolamine. 3. These observations suggest that regulation of glycogenolysis and gluconeogenesis in rabbits by glucagon and catecholamines is at least partially due to activation of glycogen phosphorylase and inhibition of pyruvate kinase. Contrary to the age-related changes observed in the adrenergic nature of catecholamines' regulation of these two processes in rats, such regulation of both processes by catecholamines is β-adrenergic in rabbits regardless of age.
Details
- Title: Subtitle
- The influences of glucagon, epinephrine and adrenergic agents on glycogen phosphorylase a and pyruvate kinase activities in hepatocytes from juvenile and adult rabbits
- Creators
- Mark A Yorek - Guy and Bertha Ireland Research Laboratory, Department of Biochemistry, University of North Dakota School of Medicine, Grand Forks, ND 58202, USAJames B Blair - Department of Biochemistry, West Virginia University Medical Center, Morgantown, WV 26506, U.S.APaul D Ray - Guy and Bertha Ireland Research Laboratory, Department of Biochemistry, University of North Dakota School of Medicine, Grand Forks, ND 58202, USA
- Resource Type
- Journal article
- Publication Details
- Biochimica et biophysica acta. General subjects, Vol.717(1), pp.143-148
- Publisher
- Elsevier B.V
- DOI
- 10.1016/0304-4165(82)90391-9
- PMID
- 7104386
- ISSN
- 0304-4165
- eISSN
- 1872-8006
- Language
- English
- Date published
- 1982
- Academic Unit
- Fraternal Order of Eagles Diabetes Research Center; Endocrinology and Metabolism; Internal Medicine
- Record Identifier
- 9984094624302771
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