Growth hormone - is composed of approximately 190 amino acid hormone that is synthesized and secreted somatotrophic cells in the anterior pituitary. He is involved in the control of several complex physiologic processes, including growth and metabolism. Growth hormone is also used as a medicament in the treatment of both humans and animals.

Physiological effects of growth hormone

Direct effects are the result of growth hormone binding to its receptors in certain cells. In fat cells, for example, have growth hormone receptors, which stimulate the cleavage of triglycerides and inhibits the ability of the organism to accumulate circulating lipids.

Indirect effects are mediated primarily insulin-like growth factor I (IGF), a hormone that is produced by the liver and other tissues in response to growth hormone. The main part of effects that growth hormone has on the growth process is in fact the result of exposure of IGF to target cells.

Growth

Growth - a very complex process, requiring coordinated action of several hormones. The main function of growth hormone in the stimulation of growth is to stimulate the liver to develop IGF. In turn, IGF stimulates proliferation of chondrocytes (cartilage cells), which ensures the growth of bone tissue. Furthermore, growth hormone has a direct impact on the growth of bone stimulates the differentiation of chondrocytes.

IGF plays a key role in the formation of muscle tissue. It stimulates the proliferation and differentiation of myoblasts and capture of amino acids and protein synthesis in muscle and other tissues.

Metabolic Effects

The growth hormone has a significant effect on the metabolism of proteins, lipids and carbohydrates. In particular, it stimulates protein anabolism in many tissues. This increases the grip amino acid and protein synthesis and decreases protein oxidation. Participating in the metabolism of carbohydrates, growth hormone, helps to maintain normal blood glucose levels. Growth hormone inhibits the ability of insulin The principles of action of insulin - the science of saving lives   stimulate glucose uptake by peripheral tissues and cells to stimulate the synthesis of glucose in the liver. It may look like a paradox, but the receiving growth hormone stimulates the secretion of insulin and can lead to a state as hyperinsulinemia.

Control of growth hormone secretion

Growth hormone is caused by many factors, including stress How to beat stress? Create an oasis , Exercise, nutrition, sleep Dreams: how to understand our dreams And the activity of the growth hormone. However, it is a primary controllers hormone three, two of which are produced in the hypothalamus and one - in the stomach:

• Somatoliberin or growth hormone-releasing hormone (AWG) - hypothalamic peptide that stimulates the synthesis and secretion of growth hormone.
• Somatostatin - a peptide that is produced in several tissues of the body, including the hypothalamus. Somatostatin inhibits the secretion of growth hormone in response to the AWG and other stimulating factors, such as low glucose Glucose: The energy source   in blood.
• Ghrelin - a hormone that vyrabatyaetsya stomach. Ghrelin receptor binds somatotrophs and stimulates growth hormone secretion.

The secretion of growth hormone also occurs as a result of negative feedback, which is involved IGF. High levels of IGF in the blood reduces the secretion of growth hormone not only by directly inhibiting the activity somatotrophs, and stimulating production of somatostatin hypothalamus.

The combination of all these factors produces a pulsating pattern of growth hormone secretion. Meanwhile, the base concentration of growth hormone in the blood is very low.

Diseases associated with growth hormone

Gigantism - a disease resulting from excessive secretion of growth hormone in children and adolescents. This is a very rare disorder that develops because of a tumor. One of the most famous patients gigantism was Robert Wadlow. At birth, he weighed 3, 8 kg, but in five years, his weight was 47 kg and height - 160 cm. Before his death at age 22, he weighed 222 kg, and its growth was equal to 247 cm.

Acromegaly results from excessive secretion of growth hormone in adults caused by a benign tumor of the pituitary. The disease develops slowly, its symptoms gradually. Its main features are exaggerated limbs, abnormal growth of soft tissue and heart disease.

Insufficient production of growth hormone leads to a slowing of growth.

Use of growth hormone in the pharmaceutical and biotechnology

Growth hormone, which is released from the pituitary glands of human corpses, has long been used to treat severe stunting. Recombinant DNA technology today allows to obtain the growth hormone in any amount, so it is widely used in various types of treatment, both humans and animals.

For example, growth hormone is used to treat children of pathologically short stature. Some experts have expressed fears that there was an opportunity to give growth hormone to children with normal growth - just to a certain extent, increase the growth.

Growth hormone is also used to improve athletic performance. Although growth hormone therapy is generally safe, it is associated with unpredictable health risks. The increase in the already healthy growth with the help of this therapy - one of the ways to use potentially dangerous hormone.

The role of growth hormone in a natural process of aging is not well studied, but the results of many tests, it can be used to eliminate some cosmetic signs of aging. Research in this area is ongoing.

Growth hormone is also used as an agent for improving milk production in dairy cattle. The milk obtained from animals treated with growth hormone, is not dangerous for human health.

Furthermore, growth hormone give pigs - proved that it stimulates the growth of muscle tissue, and significantly reduces body fat in animals.

Insulin - a hormone secreted by the beta cells of the pancreas Diabetes and pancreas - the things you need to know . It is involved in the processing of carbohydrates, lipids and proteins. Insulin - a condition in which the body's cells become resistant to insulin The principles of action of insulin - the science of saving lives That is, when a certain amount of hormone release is not peculiar to perform their mission. As a result, to make cells perform the same tasks as the body has to produce more insulin.

Causes

It is assumed that insulin resistance may lead to genetic predisposition to this violation and taking certain drugs. Furthermore, causes insulin resistance may be:

• Metabolic syndrome;
• Obesity;
• Pregnancy;
• Infection or serious illness;
• Stress;
• Steroids.

Diseases associated with insulin resistance

• Type 2 diabetes

Insulin resistance often precedes the development of Type II diabetes. It can also be accompanied by increased levels of cholesterol, overweight, hypertension.

• Fatty liver

The accumulation of fat in the liver may be one of the manifestations of metabolic disorders, which occurs when insulin resistance. The consequences can be a fatty liver cirrhosis, and in some cases of liver cancer.

• Atherosclerosis

Atherosclerosis - a disorder in which the walls of medium and large arteries progressively compacted and lose their elasticity. Atherosclerosis may lead to coronary artery disease, stroke and peripheral vascular disease.

• Problems with the female reproductive system

Insulin resistance can lead to problems such as menstrual irregularities, including the cessation of menses, and infertility. For unknown reasons, insulin resistance in men does not cause disruption to the reproductive system.

• Polycystic ovaries

Polycystic ovaries - a common problem of young women, which may be associated with insulin resistance.

• Hyperandrogenism

High levels of male hormones is often observed in insulin resistance; often found in patients with polycystic ovaries Polycystic ovaries - watch their menstruation .

• Dysplasia

Since insulin is anabolic, elevated levels of this hormone, which occurs when insulin resistance can start the growth of certain tissues, even if the phase of active growth in a patient has long been completed.

Risk factors

The following factors increase the chance of developing insulin resistance:

• Body mass index greater than 25;
• Age more than forty years;
• Gestational diabetes history of;
• Hypertension;
• Elevated levels of triglycerides.

Treatment

The primary goal of treatment for insulin resistance is to prevent, or at least slow down the development of insulin resistance. To do this, the patient should change their lifestyle - start to eat healthy and lead an active life. A diet rich in fiber, complex carbohydrates and unsaturated fats, as well as regular exercise can help keep blood sugar levels Blood sugar - one of the main indicators of human health   at normal levels and slow the progression of insulin resistance.