It is indicated that pinealectomy causes a decrease in hepatic and muscular glucogenesis
which provides an increase in the blood levels of glucose and a decrease in insulin, while it may be responsible for glucose intolerance and impaired insulin secretion as well.
Insulin mediates peripheral glucose disposal and suppresses glucogenesis
in the liver.
In the absence of insulin, the body cannot use the glucose available, hormones are activated to increase glucose levels, and the liver activates glucogenesis
. These combined effects result in an increase in serum glucose, hyperglycemia (Craig, 1998).
These may involve a complex interplay of lipolysis, glucogenesis
, and ketogenesis and transport and utilization of glucose and ketones by the brain and peripheral tissues as discussed previously (5).
He even argues that the body needs no carbohydrates at all because it can produce the carbs it needs from its own body fat and the proteins we eat by a process called glucogenesis
When an individual encounters a stressor, the physiological response includes activation of the hypothalamicpituitary-adrenal system and production of stress hormones known as catecholimines (adrenaline and noradrenaline) and glucocorticoids. These hormones are secreted by the adrenal gland to promote lipolysis and glucogenesis
. Lipolysis and glucogenesis
create energy sources for cells such as free fatty acids, triglycerides, and glucose, enabling the body to respond appropriately to stressful situations.[1,3] Unfortunately, if the energy sources are not used, as with many psychological stressors, the risk for developing disease increases.
Gluconeogenesis from amino acids is one of the mechanisms of hepatic glucogenesis
. In the present study, threonine, serine, and glycine concentrations in the liver were significantly decreased after exercise.