2.3.1 Carbohydrates and the liver

After a carbohydrate-containing meal, the liver maintains plasma glucose concentration within a narrow range by taking up onequarter to one-third of the absorbed glucose, oxidizing some of it and storing the rest as glycogen or converting it into fat. In the postabsorptive state, the liver provides much needed glucose to the central nervous system and other glucose-utilizing tissues by breaking down glycogen (a process called glycogenolysis, GL) and/or by new formation of glucose from non-glucose precursors (a process called gluconeogenesis, GNG). Disturbances of any one of these processes can result in either hyperglycaemia or hypoglycaemia. This chapter focuses on glucose, the physiologically most important carbohydrate, and gives a brief overview of the pivotal role of the liver in glucose metabolism under normal and abnormal conditions.