One of insulin's major functions is to prevent the use of fat as an energy source in the body. In doing so, it also pushes the body to take glucose out of the blood and store it as glycogen where it can be used as an energy source. By this process, insulin serves to actually reduce the glucose concentration in the blood.
By reducing this concentration, insulin production and function serves to prevent the complications brought on by the over-concentration of glucose, one of the major parts of diabetes. This over-concentration leads to an innumerable amount of problems.
Insulin is a hormone produced in the body by pancreas. This hormone regulates the body's use of sugar and other foods. Insulin speeds up the movement of nutrients from the blood stream into cells located mainly in lever, muscles and fat tissues.
When food is absorbed into the bloodstream, the pancreas increases the secretion of insulin into the blood. Insulin speeds the movement of nutrients from the bloodstream into target cells located mainly in liver, muscle, and fat tissues. Specialized protein molecules called insulin receptors lie on the surface of the target cells. Glucose and other simple sugars, produced by the digestion of more complex carbohydrates, are used by these cells for immediate energy or converted to glycogen for storage. Amino acids, produced by the digestion of proteins, move into cells and there form the building blocks for proteins. Fatty acids, produced by the digestion of fats, are converted to tryglycerides for storage and later used for energy.
Insufficient production of insulin in the body causes a form of diabetes called Type I diabetes in which levels of glucose increases in the blood. In a milder form of diabetes known as Type II diabetes, normal amounts of insulin is produced, but the body is unable to utilize the insulin properly.
Insulin is a hormone, secreted by the islets of Langerhans, which participate in carbohydrates' metabolism. Insulin is the most important hormone in carbohydrates' metabolism. Insulin contributes primarily in decreasing of blood glucose concentrations. Insulin increases membrane permeability to glucose. Insulin has a glucagon antagonistic action.
Blood glucose is the main regulating factor of insulin secretion. Fasting plasma glucose (80-100 mg / dL) is sufficient to trigger insulin secretion. Insulin release is increasing with glucose, yielding the maximum response to the 300-500 mg / dL.
Besides glucose, many other factors are influencing insulin secretion:
- Other monosaccharides like fructose, mannose, which have stimulating effect;
- Amino acids, especially arginine, lysine and leucine, that strongly stimulate insulin secretion.