As world statistics show, more than 20% of the population of our planet suffers from diabetes. Moreover, most of these people were diagnosed with insulin-dependent diabetes, which is not possible to cure. But this does not mean that the patient can not lead a normal life. All you need to do is provide your body with insulin. For this purpose, special injections are used, the formulation of which is carried out strictly according to the scheme prescribed by the doctor. But what is the mechanism of insulin action? And how does he help diabetics?
The role of insulin in the human body
Insulin is a special hormone that is involved in carbohydrate metabolism. It is he who is engaged in the splitting of glucose and ensures the saturation of the body's cells with the necessary energy. The pancreas is involved in the production of this hormone. When the integrity or functioning of the cells of this organ is disturbed, insulin is produced in small quantities, as a result of which the body begins to experience a deficiency in it, which is manifested by an increase in blood sugar levels.
At the same time, the work of the kidneys and liver is disrupted, toxic substances begin to accumulate in the body, which negatively affect all internal organs and systems. First and foremost, the vascular system suffers. Under the influence of sugar and toxic substances, the tone of the walls of blood vessels decreases, they become fragile and brittle, against the background of which the risks of stroke and myocardial infarction increase several times.
Increased sugar content in the blood affects the regenerative processes in the body. This is especially noticeable as the skin. Any cuts and wounds heal for a very long time, often being infected and develop into ulcers. And this is also dangerous, since with the suppuration of ulcers the likelihood of developing gangrene also increases.
Mechanism of action
Speaking about how insulin acts in the body, it should be noted that it works directly through the receptor protein. It is a complex integral protein of the cell membrane, which consists of 2 subunits. In medicine, they are marked as a and b. Each of these subunits has its own polypeptide chain.
Polypeptide chains of insulin subunits
The action of insulin is as follows: first, it enters into communication with the a-subunit, thus changing its conformation. After that, the b-subunit is involved in the process, which triggers a branched chain of reactions for the activation of enzymes necessary for the breakdown of glucose and its assimilation in cells.
It should be noted that despite the fact that the effect of insulin in the body has been studied by scientists for many centuries, its biochemical properties have not been fully studied. However, it has already become known that in the whole process secondary “intermediaries” take part, which are diacylglycerols and inositol triphosates. They provide the activation of protein kinase C with a phosphorylating effect and are associated with intracellular metabolism.
These mediators provide an enhanced supply of glucose into the cells of the body, thereby saturating them with energy. First, the insulin-receptor complex is immersed in the cytosol, and then destroyed in the lysosomes, after which degradation processes occur - part of the insulin is destroyed, and the other part of it is sent to the cell membranes and re-inserted into them.
Insulin is a hormone that has a direct effect on metabolic processes throughout the body. Many of its effects are observed due to its active action on a number of enzymes. He is the only one of its kind, which helps reduce blood sugar levels. This happens due to:
- increased absorption of glucose by cell membranes;
- activation of glycolysis enzymes;
- increased activity of glycogen production;
- reducing the synthesis of gluconeogenesis, which is responsible for the formation of glucose in the liver cells.
The main properties of insulin
Insulin is the only hormone that enhances the uptake by the cells of the amino acids necessary for their normal functioning, as well as the supply of potassium, magnesium and phosphate ions to them. In addition, insulin enhances the production of fatty acids by converting glucose to triglycerides. If the body is deficient in insulin, then this leads to the mobilization of fats and their deposition in the tissues of the internal organs.
The anti-catabolic effect of insulin on the body is caused by a decrease in the protein hydrolysis process, due to which their degradation is reduced (due to the fact that diabetes in patients has insulin deficiency, protein degradation increases, resulting in a decrease in muscle tone and weakness occurs).
In addition, insulin reduces lipolysis, thereby reducing the concentration of fatty acids in the blood and the risks of cholesterol disease, thrombophlebitis, etc. become much smaller.
Effect on carbohydrate metabolism
As it has already become clear, insulin is a hormone that is involved in almost all the processes occurring in the body. But since we are talking directly about diabetes, it is necessary to consider in more detail the effect of insulin on carbohydrate metabolism.
In the event that the body is deficient in this hormone, this entails a violation of the process of glucose penetration through muscle cells, resulting in a decrease in energy reserves. When the level of insulin rises to normal values, this process is restored, and naturally.
The body's need for insulin, depending on the degree of physical exertion
However, with increased physical activity, cell membranes increase their permeability and absorb much more glucose than usual. And this happens even if the blood sugar level is very low. But the risks of hypoglycemic coma in this case increase several times.
The insulin receptor plays an important role in the process of glucose homeostasis. If it is broken, it leads to degenerative changes in the cells, which provokes the development of many diseases, among which are not only diabetes, but also cancer.
Considering the action of insulin, it is impossible not to say about its effect on the liver. It is in this organ that the body puts off excess glucose like a prozapas, releasing it only when the blood sugar level drops to critical levels.
And another important point: insulin, as mentioned above, is involved in the process of glycolysis, activating the synthesis of certain enzymes, without which the splitting and uptake of glucose by cells is impossible.
Action on protein metabolism
Insulin plays an important role not only in carbohydrate metabolism, but also in protein. It is this one that ensures the breakdown of proteins that come with food into amino acids, which activate the synthesis of their own proteins in the body. With insulin deficiency, this process is disturbed, leading to various complications. In addition, insulin accelerates the transcription of DNA, stimulating the formation of RNA.
Action on fat metabolism
Insulin is also actively involved in lipogenesis - the synthesis of fatty acids. Their formation occurs in the process of decomposition of carbohydrates. And fatty acids are also very important for the body, because without them there is a violation of fat metabolism, which is accompanied by the development of obesity and the deposition of fat cells in the internal organs.
With the development of diabetes, you need to act immediately. As a rule, people first diagnosed with type 2 diabetes, and only if diets and medication rules are not followed, type 1 diabetes develops, in which it is simply impossible to do without insulin injections.
With the development of type 1 diabetes mellitus, only insulin injections can return to normal life.
To date, the following types of insulin preparations are distinguished:
- Quick action. The action begins already after 5 minutes after subcutaneous administration and reach its maximum peak after 1 hour. But, such drugs have one drawback - they act not for long, and their introduction must be carried out before each meal or at the onset of a hypoglycemic coma.
- Short acting. Efficacy is observed 30 minutes after administration. Such injections are also used before meals. However, its action lasts much longer than that of fast-acting insulin.
- Medium action. Such drugs are used in combination with fast or short-acting insulins. Efficiency after taking them is observed for several hours.
- Long acting. Hypoglycemic drugs, the effectiveness of which is observed throughout the day. However, it is also necessary to use such preparations with insulins of short and fast action. They are applied several times a day before eating at regular intervals.
Which drug will be prescribed to the patient depends on his individual characteristics and the severity of the course of the disease. In order to choose the right remedy, doctors need to study in more detail the molecular properties of blood. For this, biochemistry of venous blood and finger blood is done.
According to the results of the examination, the doctor will be able to choose not only the drug, but also its dosage, which will be the most effective and safe for the patient. Since the wrong dosage of insulin can lead to hypoglycemia and serious complications. Therefore, self-medication is by no means impossible. Insulin injections should be administered under the strict supervision of a physician.