Insulin's actions?

[Kumar]

Hello,
Diabetic type2 people with insulin resistance or insulin in-sentiveness usually experience persisting hyperglycemia. It may result into persisting and more insulin secretion in view of that, higher glucose levels stimulate
insulin's secretion. Added insulin due to medication programmed to
diabetics may also expose added and persisting insulin to their tissues. Apart from hypoglycemic effect, insulin also has many other actions as indicated on following link;-

"Actions on cellular and metabolic level
http://en.wikipedia.org/wiki/Insulin "

Primarily, insulin may be considered as an anabolic hormone so its
excess exposure can also enhance glucose uptake by target cells many
times and also energy stores i.e. glycogen, fats and proteins. On the other
side, insulin's more exposure may cause decreased catabolism of these
energy stores.

As such, I want to understand;-

1. Whether diabetic type2 with insulin resistance and persisting
hyperglycemia have persisting insulin (natural or injected) in blood
and exposed to tissues?

2.Whether such more and persisting insulin will cause increased glucose
uptake, energy stores (glycogen, fats and proteins)?

3.Whether such more and persisting insulin will cause decreased
catabolism of energy stores? If yes, how body will compensate to such
condition on its excess energy need?

4.What can be the benefits and complications from such increased energy
stores and decreased catabolism of these energy stores as a result of
more and persisting insulin's exposure?

Insulin is also linked to Potassium & Phosphate transport into cells.


Best wishes.

 

[Kumar]

from "TextBOOK of Medical Physiology" by Guyton & Hall Ch.78.:-

"Effect of Insulin on Carbohydrate Metabolism
Immediately after a high-carbohydrate meal, the glucose that is absorbed into the blood causes rapid secretion of insulin, which is discussed in detail later in the chapter. The insulin in turn causes rapid uptake, storage, and use of glucose by almost all tissues of the body, but especially by the muscles, adipose tissue, and liver.
Insulin Promotes Muscle Glucose Uptake and Metabolism
During much of the day, muscle tissue depends not on glucose for its energy but on fatty acids. The principal reason for this is that the normal resting muscle membrane is only slightly permeable to glucose.. except when the muscle fiber is stimulated by insulin; between meals, the amount of insulin that is secreted is too small to promote significant amounts of glucose entry into the muscle cells.
However, under two conditions the muscles do use large amounts of glucose. One of these is during moderate or heavy exercise. This usage of glucose does not require large amounts of insulin, because exercising muscle fibers, for reasons not understood, become permeable to glucose even in the absence of insulin because of the contraction process itself.
The second condition for muscle usage of large amounts of glucose is during the few hours after a meal. At this time the blood glucose concentration is high and the pancreas is secreting large quantities of insulin. The extra insulin causes rapid transport of glucose into the muscle cells. This causes the muscle cell during this period to use glucose preferentially over fatty acids, as we discuss later.
Storage of Glycogen in Muscle. If the muscles are not exercising after a meal and yet glucose is transported into the muscle cells in abundance, then most of the glucose is stored in the form of muscle glycogen instead of being used for energy, up to a limit of 2 to 3 per cent concentration. The glycogen can later be used for energy by the muscle. It is especially useful for short periods of extreme energy use by the muscles and even to provide spurts of anaerobic energy for a few minutes at a time by glycolytic breakdown of the glycogen to lactic acid, which can occur even in the absence of oxygen.

Insulin independant uptake of glucose is indicated by excercising muscles. How?