ABSTRACT
The liver plays an important role as a site for storage of glucose as glycogen, synthesis of triglyceride from fatty acids and glucose, and conversion of nutrients released from extrahepatic storage sites into forms more easily utilized by cells. Glucose can be oxidized by virtually all living cells, and is the primary source of energy for those lacking mitochondria (hence the inability of these cells to oxidize lipid). Although free fatty acids and ketone bodies may be oxidized by tissues containing mitochondria, the brain retains a strong requirement for glucose and fails to function properly when glucose supplies fall below 1 mg/kg/min. The brain’s dependency on glucose is protected by the counter-regulatory hormone system, which generally prevents glucose concentrations from falling below a critical limit, which would lead to serious brain dysfunction.
