Glucagon is a hormone secreted by the pancreas in response to hypoglycemia.The main effect of glucagon is to raise blood glucose , an action completely opposite to that of insulin.
Normal levels of blood glucose
The normal levels of blood glucose (blood glucose concentration) are fasting are 70-100 mg/dl , and rarely pass 120 mg/dl measure 1h after a meal.
immediately after eating, the beta cells of the pancreas increase insulin secretion to prevent blood glucose from rising too much.
By effect of insulin, the excess glucose that is observed after a meal is converted to glycogen and stored in the liver and muscles .Insulin favors, on the other hand, the use of glucose as a source of energy by the body's cells.
Effects of glucagon on carbohydrate metabolism
Glucagon secretion
About 3 hours after a meal, glycemia begins to descend.This constitutes the main stimulus for glucagon secretion by the alpha cells of the pancreas.
This is the main difference between glucagon and insulin.While the main stimulus for insulin secretion is hyperglycemia, glucagon is hypoglycemia.
The main effect of glucagon is to increase blood glucose , while insulin is to reduce it.
As you can see, these two hormones have completely opposite stimuli and effects.But they really work harmoniously to maintain blood glucose within normal limits.
GLUCOGENOOLYSIS
Glucogenolysis is the chemical reaction by which glycogen is converted to glucose .
Glycogen is a molecule composed of thousands of glucose units.It is mainly stored in the liver and muscles.
An effect of glucagon is to degrade liver glycogen, and convert it again to glucose, which goes to blood with the aim of normalizing blood glucose.
Effects of glucagon on the metabolism of fats
In this way, the use of glucose is saved, which is needed to be used by the brain in circumstances in which this fuel is scarce.
Effects of glucagon on protein metabolism
Gluconeogenesis
etymologically, this word means new glucose formation .It consists of glucose formation from substances that are not carbohydrates.
Another effect of glucagon is to increase the absorption of amino acids by the liver.Some of these amino acids are converted into glucose, which passes into the blood, helping to normalize blood glucose levels.
Glucagon Medical Applications
glucagon is used to treat hypoglycemia .A Glucagon Subcutaneous Injection quickly elevates blood glucose.