Where Does Glucagon Come From?
Glucagon released from three organs in the body, the hypothalamus (in the brain); small concentration from intestines; and mainly from alpha cells in the pancreas.
How Does Glucagon Work?
The main job of Glucagon is working to counterbalance the actions of insulin, as you may know, insulin works to lower the hyperglycemia (high sugar in the blood), therefore, Glucagon works to increase the blood glucose levels as needed by the body organs.
But, why Glucagon increases the blood glucose, isn’t unusual for the blood glucose level to be high?
Actually, Glucagon is a part of the balanced rhythm by the human body, in this process, some elements work to increase the vital levels until it becomes high normal, then other elements work to keep these normal levels inside the safe limits, the reality of these balance formulas isn’t dangerous to the body, but they made to keep the Normal body status.
Glucagon starts to compensate for low glucose 4 hours after you eat a meal, and can still be working for 4 days when starvation occurs, but no more than 8 days.
Glucagon works by turns on three biological processes:
- Stimulating the breakdown of stored glucose as glycogen inside the liver cells, the process is known as Glycogenolysis, it means breaking the glycogen bulk and converts it into usable glucose units for energy demand.
- Stimulating Adipose tissues to break down fats to produce ketones for energy demands, the process called (Lipolysis or ketogenesis), which means lipid metabolism into ketones. ketone levels must be maintained to the safe level or can be a signal of danger as well. see ketone levels chart
- Generation of new additional glucose units from “non-carbohydrate carbon substrates” such as lactate, glycerol, propionate and glucogenic amino acids, this process called “gluconeogenesis”, also when glycogen used up, the body starts to break down proteins of the muscles into amino acids and converts them to new glucose to compensate low energy. gluconeogenesis occurs in the liver and kidney and stimulated by the diabetogenic hormones (glucagon, growth hormone, epinephrine, and cortisol)
While Inhibits and stops these process:
- Before anything, Stops the glucose storing process through liver glycogen synthesis, thus keeping the glucose unstored to be used by the body.
- Inhibition of glycolysis, which means decreasing or stop the continuous breaking down of already made glucose
For these reasons the blood glucose must be maintained and need to be elevated to the Normal state by glucagon:
- Starvation; As glucose concentration be (50 mg %) as the insulin drops and glucagon increases too enhance the glucose levels in the blood. However, when glucose levels elevated up to (300 mg %), this will stimulate insulin to work while gradually stop glucagon secretions, which makes the blood glucose to back to normal levels (70 – 110 mg/dL)
- Fasting state; early after a meal the blood glucose become higher and insulin increases to make a use of that glucose, 2 hours after the meal glucose levels reaches the optimum level then consumed by the body organs for energy purposes, then glucose levels become lower with the time and insulin starts to decrease and glucagon stimulated again to compensate the demand of glucose in the blood. 4 days is the time of glucagon stimulation after fasting and starvation but shut down up to 8 days.
- Glucose lowering medicines; taking an overdose of insulin shots will accidentally decrease your blood glucose levels to unwanted low levels, then glucagon starts to compensate.
side effects as a medicine
Does glucagon affect muscle?
Scientifically, the epinephrine is mediated in the gluconeogenesis process which affects the cardiac and smooth muscle tissues through what’s medically known as “beta-adrenergic response”, but don’t affect directly the muscles as there are no glucagon receptors on muscles.
Normal Levels for Children, Newborn, and Adults
What should the normal glucagon level be?
|Age||Normal Range in pg/mL|
|<= 6 hours||100 – 650|
|1 – 2 days||70 – 450|
|2 – 4 days||100 – 650|
|4 – 14 days||Gradually goes down to adult levels|
|>14 days||< or = 80|
Any glucagon reading below normal ranges deserves the treatment with glucagon shots to keep the blood glucose and glucagon levels at its optimum.
Treatment with glucagon and side effects
Treatment by glucagon intramuscular takes 10 minutes to work to inhibits liver protein synthesis, but still, stands there for up to 6 hours to be stimulated by low blood glucose, once stimulated it stores the glucose pathophysiological range for diabetic patients.