It is one of the vital hormones, whose overproduction as well as its deficiency can have serious consequences. We are talking about insulin.
What is insulin?
Insulin is a hormone, also called a messenger substance, of particular importance. Not least because no other hormone can replace it, it is essential for human survival. However, insulin is not only found in humans, but also in all other vertebrates, which with their 58,000 known species represent the majority of all animals living on earth. Insulin is a protein, or albumin. Like all other proteins, insulin consists of a chain of different amino acids. Namely, there are two chains of amino acids; one chain consists of 21, the other of 31 amino acids strung together. At the beginning of its synthesis, insulin consists of a total of three chains. Insulin loses its last chain by the time it is finally produced. Insulin is produced by the pancreas. More precisely, it is the so-called beta cells of a certain section of the pancreas, also called islets of Langerhans.
Examine and measure insulin levels
When examining a person’s insulin balance, doctors take a reverse approach. Instead of examining insulin levels themselves, they examine blood glucose levels. If these are higher than the tolerance range for normal values allows, doctors assume that insulin levels are too low. Conversely, too low blood glucose levels are evidence that insulin is being produced in excessively high quantities and is consequently present in excessively high concentrations in the blood plasma. This conclusion is based on the fact that only insulin is capable of influencing blood glucose levels to any appreciable extent, which allows blood glucose levels to be directly inferred from insulin levels. In order to rule out possible falsifications, the patient must appear for the blood sample on an empty stomach. If he were to take carbohydrates such as sugar before the blood test, his (healthy) body would produce more insulin, which would falsify the comparison of his blood glucose values with the standard values. The standard values of blood sugar in fasting patients are 70-99 mg/dl. Shortly before a meal, i.e. when a person is hungry, blood glucose is in the low range, which is why the body does not produce any additional insulin. Only after a meal does the body secrete insulin in order to be able to utilize the carbohydrates ingested. The amount of insulin secreted depends on the proportion of carbohydrates or sugar in the meal eaten. Over the course of the day, the body of a healthy adult produces about two grams of insulin.
Function, effect, and tasks
The main task of the messenger insulin is to regulate the amount of sugar in the blood. Through food, humans absorb carbohydrates, which include all types of sugar. In the intestine, the various types of sugar are broken down into simple sugars called glucose. As a source of energy, it enters the blood plasma. Insulin is needed to enable it to reach the tissues, namely the muscles and the liver, for utilization and storage. In its function as a key factor, it “opens” the cells so that the sugar can enter the cell interior. While muscles utilize them for combustion, i.e. energy production, they are stored as a reserve in the liver, which absorbs around half of all blood sugar. Insulin’s counterpart is the hormone glucagon. Its task is to transport stored sugar, which has been fed into the liver, for example, back into the blood plasma. It is supposed to reach muscles via the bloodstream, where it can be utilized as an energy supplier. Like insulin, it is produced by the islets of Langerhans in the pancreas, although not by beta cells but by alpha cells found there.
Diseases
Various diseases can occur in connection with insulin. The most relevant are diabetes and hypoglycemia (low blood sugar). In diabetes mellitus, where type 1 and 2 are distinguished, it is roughly outlined a deficiency or utilization problem with insulin. Either the body does not produce the messenger substance in the necessary quantity or the cells have lost their sensitivity to insulin, i.e. they do not react to the messenger substance even if it were available in sufficient quantity.The consequence of the deficiency or resistance to insulin is that blood glucose levels would rise uncontrollably. There is no cure, however, the lack of insulin can be compensated by external injections of insulin preparations. The counterpart of insulin deficiency is hypoglycemia. Here, the body either produces too much of the hormone or the body is too sensitive to insulin. The result is the same: blood glucose levels drop to life-threatening levels (hypoglycemia).
