Abstract
Using knockout and transgenic technology, genetically modified animal models allowed us to understand the role of glucagon signalling in metabolism. Mice with a global deletion of the glucagon receptor gene (Gcgr) were designed using gene targeting. The phenotype of Gcgr-/-mouse provided important clues about the role of Gcgr in foetal growth, pancreatic development and glucose and lipid homeostasis. The lack of Gcgr activation was associated with: (i) hypoglycaemic pregnancies, poor foetal growth and increased foetal-neonatal demise; (ii) altered cytoarchitecture of pancreatic islets; (iii) altered glucose, lipid and hormonal milieu; (iv) reduced gastric emptying; (v) altered body composition and protection from diet-induced obesity; (vi) altered energy state; (vii) impaired hepatocyte survival; (viii) altered metabolic response to prolonged fasting and exercise and (ix) prevented development of diabetes in insulin-deficient mice. In contrast, mice overexpressing the Gcgr on pancreatic β-cells displayed an increase insulin secretion, pancreatic insulin content and β-cell mass, and partially protected against hyperglycaemia and impaired glucose tolerance when fed a high-fat diet. These findings suggest that glucagon signalling plays a significant role in the regulation of glucose and lipid homeostasis. Treatment options designed to block Gcgr activation may have negative implications in the treatment of diabetes.
Original language | English (US) |
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Pages (from-to) | 144-150 |
Number of pages | 7 |
Journal | Diabetes, Obesity and Metabolism |
Volume | 13 |
Issue number | SUPPL. 1 |
DOIs | |
State | Published - Oct 2011 |
Keywords
- Diabetes
- Gcgr knockout mouse model
- Glucagon
- Glucagon signalling
- Hypoglycaemia
- Islets
- Pancreas
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism
- Endocrinology