Diabetes Over View

Significance Of Glucagon In Glucose Metabolism

It is quite a known fact that Glucagon plays an important role in controlling blood glucose concentrations. It has an opposing effect on the action of insulin. That is, glucagon has the effect of increasing blood glucose levels. Scientifically speaking, Glucagon is a linear peptide of 29 amino acids.

The Mode Of Action

Studies have clearly shown that the primary role of glucagon is to stimulate an increase in blood concentration of glucose. It has also been shown that, the brain has an absolute dependence on glucose as a fuel. This is primarily due to the reason that neurons cannot utilize other energy sources like fatty acids. The basic that any diabetic is told to remember is that when blood glucose levels fall below the normal range, additional glucose should be pumped into blood to avoid episodes of hypoglycemia. Glucagon induces the liver through a specific mechanism to dispense glucose to different parts of the body.

What happens at the liver level that Glucagon leads to breakdown of stored glycogen. As the blood glucose levels are higher than necessary, liver stores up the extra glucose as glycogen. The action of insulin helps in the process of converting glucose to glycogen. This stored up glycogen in the liver is utilized in such situations when the blood glucose levels fall below critical levels. Glucagon is secreted and acts on hepatocytes to activate the enzymes that convert glycogen stored in liver to glucose.

Glucagon activates hepatic gluconeogenesis, a pathway by which non-hexose substrates such as amino acids are converted to glucose. Thus glucagons provide an alternate choice of glucose to the body. This is important in the case of certain animals like cats and sheep, which can’t absorb much glucose from the intestine.

Through another mechanism called lipolysis of triglyceride glucagons promotes the conservation of glucose in the body. Glucagon manages this by providing fatty acid fuel instead of glucose to most cells.

Significance In Diabetes

Controlling the secretion and action of glucagons is of supreme importance in diabetes management as it can help in the control of insulin. In case of hypoglycemia, the secretion of glucagons can be increased to ward off the harmful effects of a dangerously low blood sugar.

Glucagon secretion is effective at a stage of increases blood levels of amino acids as it can convert excess amino acids to glucose by enhancing gluconeogenesis. Since high blood levels of amino acids also stimulate insulin release, this would be a situation in which both insulin and glucagon are active.

Exercise induces the secretion of glucagons, probably through an extremely low level of blood glucose. On the other hand high levels of blood glucose naturally inhibits the secretion of glucagon. It is not clear whether this reflects a direct effect of glucose on the alpha cell, or perhaps an effect of insulin, which is known to dampen glucagon release. The bottom line is that the control of the secretion of glucagons necessary for an effective control of blood glucose in diabetes. More studies are needed to perfect this mode of influencing blood sugar control.