Back to Search
Start Over
Mechanisms by Which Liver-Specific PEPCK Knockout Mice Preserve Euglycemia During Starvation
- Source :
- Diabetes. 52:1649-1654
- Publication Year :
- 2003
- Publisher :
- American Diabetes Association, 2003.
-
Abstract
- Liver-specific PEPCK knockout mice, which are viable despite markedly abnormal lipid metabolism, exhibit mild hyperglycemia in response to fasting. We used isotopic tracer methods, biochemical measurements, and nuclear magnetic resonance spectroscopy to show that in mice lacking hepatic PEPCK, 1) whole-body glucose turnover is only slightly decreased; 2) whole-body gluconeogenesis from phosphoenolpyruvate, but not from glycerol, is moderately decreased; 3) tricarboxylic acid cycle activity is globally increased, even though pyruvate cycling and anaplerosis are decreased; 4) the liver is unable to synthesize glucose from lactate/pyruvate and produces only a minimal amount of glucose; and 5) glycogen synthesis in both the liver and muscle is impaired. Thus, although mice without hepatic PEPCK have markedly impaired hepatic gluconeogenesis, they are able to maintain a near-normal blood glucose concentration while fasting by increasing extrahepatic gluconeogenesis coupled with diminishing whole-body glucose utilization.
- Subjects :
- Blood Glucose
Glycerol
medicine.medical_specialty
Endocrinology, Diabetes and Metabolism
Pyruvate cycling
Carbohydrate metabolism
Mice
Internal medicine
Glucokinase
Internal Medicine
medicine
Animals
Homeostasis
Muscle, Skeletal
Glycogen synthase
Mice, Knockout
biology
Lipid metabolism
Liver Glycogen
Citric acid cycle
Glucose
Glycogen Synthase
Endocrinology
Liver
Gluconeogenesis
Starvation
biology.protein
Phosphoenolpyruvate Carboxykinase (GTP)
Phosphoenolpyruvate carboxykinase
Subjects
Details
- ISSN :
- 1939327X and 00121797
- Volume :
- 52
- Database :
- OpenAIRE
- Journal :
- Diabetes
- Accession number :
- edsair.doi.dedup.....580d62b75a58a7702ea128b3aa36a45a
- Full Text :
- https://doi.org/10.2337/diabetes.52.7.1649