Glucose metabolism and liver

Abstract

Liver is a main organ to regulate energy metabolism, nutrients production, storage and supply to the whole body. Glucose is the essential energy source for the whole body organs, especially for brain which has no ability to synthesize glucose and store glycogen or utilize non-glucose nutrients. Liver plays pivotal role to regulate glucose metabolism by precise regulation of glycogenolysis and gluconeogenesis, which are controlled not only by endocrine system, insulin and its counterregulatory hormones, but also by neuronal network, autonomic nervous system and brain. Recent development of molecular biology and gene analysis has revealed the precise molecular mechanism of hepatic carbohydrate metabolism and regulatory system by endocrine system, insulin or glucagon signaling pathway and those hormone-induced transcription of effector molecules, CREB, FoxO1, ChREBP, SREBPs, PGC1 or several kinds of enzymes. Recent studies also revealed that organ-to-organ network medicated autonomic neural system plays important roles in hepatic glucose metabolism. Energy controlling system of carbohydrate metabolism by the liver and organ-to-organ network is excellent to starvation, however dose not adapt to the persistent satiety. Excessive energy intake causes hepatic dysregulation of glucose and lipid metabolism which promote insulin resistance, diabetes mellitus or non-alcoholic fatty liver disease.