Another thing that I have repeatedly read here is about "liver panic" and how when the BG goes to low, the liver will dump "glucagon" into the blood to raise the BG. Well,the liver does dump stuff, but not Glucagon. It turns out that glucagon is actually produced naturally by a part of the pancreas called " the islets of Langerhans" (which to me sounds like a wonderful destination for a cruise or vacation, doesn't it?).
Here's a good explanation of what takes place in the blood, pancreas, and afterwards the liver when BG rises or falls:
http://bloodsugardiabetic.com/diabetestreatment/insulin/how-the-body-regulates-blood-sugar/
Blood Sugar Levels Rise
If blood sugar levels increase (e.g. after a meal), the beta cells of the islets of Langerhans in the pancreas produce insulin. The insulin has an effect on various organs of the body, increasing cell permeability to glucose and increasing enzyme activity in the cells allowing the glucose to be taken up and stored.
The liver and muscle tissue converts glucose to glycogen and stores it. This helps reduce the levels of sugar in the blood. In addition, the breakdown of fats in fat cells is inhibited, so that glucose will be used preferentially for energy.
Blood Sugar Levels Fall
The alpha cells in the islets of Langerhans of the pancreas product glucagon. Glucagon is “antagonistic” to insulin, basically having the opposite effect on the organs of the body. Glucagon increases the conversion of stored glycogen into glucose in the liver and muscles thereby increasing blood sugar levels.
Glucagon also increases the uptake of amino acids and glycerol into the liver so that more glucose can be synthesized.
The importance of glycogen as stored energy
Since all of the cells in your body require a continuous supply of energy, it is important that your body stores excess “energy” eaten during meals so that it can be used when food is less plentiful. Excess glucose is converted to glycogen by the mechanisms we saw above.
Glycogen is stored in the liver and the muscles. When your body is active, energy requirements increase and stored glycogen can be converted to glucose to be used as energy. If stored glycogen levels get too low however, cortisol is secreted from the adrenal cortex, and this stimulates the conversion of proteins and fats into glucose so energy levels can be maintained.
So what does the glucagon do?
Glucagon and Insulin
Glucagon increases the amount of glucose in the blood by accelerating the rate at which the liver converts stored glycogen into glucose and releases it into the blood. Insulin decreases the amount of glucose in the blood by transporting glucose from the blood and into the muscle cells. It also stimulates the conversion of glucose back into glycogen so that it can be stored.
It makes the liver dump glycogen, coverted into glucose, into the blood so that it can show up in your next PS reading!
And what happens when there is too much insulin? It does exactly what we don't want it to do:
Other Effects
Insulin also has a few other important roles in the body. Insulin facilitates the storing of excess glucose in the form of glycogen in the liver. Elevated levels of insulin also cause the liver to make more fatty acids. Insulin inhibits the breakdown of fat in adipose tissue for energy. Insulin also allows cells in the body to take up more amino acids, so that they can make more proteins
.
In balance, that's a good thing, and in a non-diabetic, it would do so in amounts that made sense in the body. But if insulin is excessive, and it cause the liver to store more glycogen, then when the BG goes too low, and the pancreas puts out glucagon, and it makes the liver dump the glucose from the glycogen, then the pancreas (and the insulin) is sort of working against itself, isn't it?
