Glucose Homeostais

·        It is the maintenance of normal glucose pool in spite of its tendency to become abnormal following meal and during fasting/starvation.

·        Normally the rate of glucose entry into glucose pool is equal to that of glucose removal from the pool to maintain the normal glucose pool.

·        Liver plays central role in glucose homeostasis by its glucostatic function.

·        Glucostatic functions of liver is the intrinsic capacity of liver to maintain normal blood glucose concentration in spite of hyperglycemic and hypoglycemic tendency following meal and fasting or starvation respectively.

·        Mechanism of glucostatic functions of liver:

o   In hyperglycemia(following meal) liver reduces blood glucose concentration to normal by

§  Glycogenesis

§  Lipogenesis

o   In hypoglycemia(following fsting) liver raises blood glucose concentration to normal by

§  Glycogenolysis

§  Gluconeogenesis

·        Importance of normal glucose pool and glucostatic function of liver.

o   Normal glucose pool and normal blood glucose concentration is essential for optimum activity of neuron and brain.

o    In hyperglycemia, ECF osmotic pressure increases compared to that of ICF. This causes loss of water from neuron leading to cerebral dehydration and impaired neuron/brain activity.

o   In hypoglycemia neuron/ brain activity is grossly impaired due to the scarcity of its metabolic fuel.

·        Therefore both hyperglycemia and hypoglycemia causes cerebral impairment. That is why glucose pool and blood glucose concentration is to be maintained by the glucostatic function of liver for the interest of neuron/brain.