Nutritional regulation of hepatic glucose metabolism in fish |
| |
| Authors: | Enes P Panserat S Kaushik S Oliva-Teles A |
| |
| Institution: | Departamento de Zoologia e Antropologia, Faculdade de Ciências, Universidade do Porto, 4169-007, Porto, Portugal. enes@portugalmail.com |
| |
| Abstract: | Glucose plays a key role as energy source in the majority of mammals, but its importance in fish appears limited. Until now,
the physiological basis for such apparent glucose intolerance in fish has not been fully understood. A distinct regulation
of hepatic glucose utilization (glycolysis) and production (gluconeogenesis) may be advanced to explain the relative inability
of fish to efficiently utilize dietary glucose. We summarize here information regarding the nutritional regulation of key
enzymes involved in glycolysis (hexokinases, 6-phosphofructo-1-kinase and pyruvate kinase) and gluconeogenesis (phosphoenolpyruvate
carboxykinase, fructose-1,6-bisphosphatase and glucose-6-phosphatase) pathways as well as that of the bifunctional enzyme
6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase. The effect of dietary carbohydrate level and source on the activities
and gene expression of the mentioned key enzymes is also discussed. Overall, data strongly suggest that the liver of most
fish species is apparently capable of regulating glucose storage. The persistent high level of endogenous glucose production
independent of carbohydrate intake level may lead to a putative competition between exogenous (dietary) glucose and endogenous
glucose as the source of energy, which may explain the poor dietary carbohydrate utilization in fish. |
| |
| Keywords: | Carbohydrate Fish Gluconeogenesis Glycogen Glycolysis Nutrition |
| 本文献已被 PubMed SpringerLink 等数据库收录！ |
|
