Somatotropic hormone
(refers to polypeptides) is produced in the pituitary gland and affects the growth and development of the human body. Its production depends on the activity of the hypothalamus, which produces neurohormones - somatoliberins and somatostatins. Somatoliberins enhance the production of growth hormone by the pituitary gland, and somatostatins inhibit it.
Neurohormones ensure the production of growth hormone not only in a certain amount, but also at a certain time, regulating daily fluctuations in its level in the blood.
Somatotropic hormone is anabolic, i.e. it promotes synthesis processes in the body and activates protein, lipid, carbohydrate and mineral metabolism.
Under the influence of somatotropic hormone, the processes of formation of protein, glycogen, and DNA proceed more intensively, and fats are extracted from the depot and broken down to fatty acids. In addition, somatotropic hormone enhances lactation, increases the rate of bone growth, and helps maintain blood glucose levels at a certain level. Somatotropic hormone has a biological effect on the body through somatomedin C.
The hypothalamus and pituitary gland are the regulatory center for all endocrine glands, and their activities are carried out according to the principle feedback- how more hormone highlights endocrine organ (thyroid, ovaries, etc.), the less hormones the pituitary gland secretes.
Excessive production of somatotropic hormone by the pituitary gland leads to gigantism, and insufficient production leads to dwarfism. If growth hormone begins to be produced in excess in adults, acromegaly develops. With this disease, the end parts of the body (nose, lower jaw, hands, feet, high growth is noted).
Determination of the level of somatotropic hormone in the blood is carried out in cases of excessive growth or growth retardation, disproportionate development of the body (with acromegaly), decreased muscle tone, as well as diabetes mellitus with uncontrolled metabolic disorders.
In some cases, it is difficult to determine a violation of the production of somatotropic hormone, then provocative tests are performed using medicines, suppressing or enhancing the production of this hormone.
The blood test requires patient preparation. 10-12 hours before blood sampling, it is recommended to limit physical activity and do not eat food. Before blood collection, the patient must wait 30 minutes. lie quietly, as stress and physical activity are accompanied by an additional release of somatotropic hormone into the blood.
The test tube with blood for analysis is stored in the refrigerator (2-8 °C).
The content of somatotropic hormone in the blood of adults and children is presented below.
Level of GH in blood serum
Serum GH levels in children
| Age | Floor | |
| 1-7 days | Men | 11,8 |
| Women | 13 | |
| Age | Floor | Average normal value, ng/ml |
| 8-15 days | Men | 4,8 |
| Women | 5 | |
| 1-3 years | Men | 1,23 |
| Women | 1,28 | |
| 4-6 years | Men | 0,38 |
| Women | 0,71 | |
| 7-8 years | Men | 0,68 |
| Women | 1,2 | |
| 9-10 years | Men | 0,56 |
| Women | 0,56 | |
| 11 years | Men | 0,88 |
| Women | 0,37 | |
| 12 years | Men | 0,69 |
| Women | 0,65 | |
| Age | Floor | Average normal value, ng/ml |
| 13 years | Men | 1,1 |
| Women | 2,2 | |
| 14 years | Men | 0,46 |
| Women | 0,73 | |
| 15 years | Men | 1,3 |
| Women | 1,25 | |
| 16 years | Men | 1 |
| Women | 2,4 | |
| 17 years | Men | 2,4 |
| Women | 1,75 | |
| 18-19 years old | Men | 1,6 |
| Women | 1 |
An increase in the level of somatotropic hormone in the blood occurs during treatment with bromocriptine (in healthy people), ultrasound blockers, clonidine, glucagon, estrogens, adrenocorticotropic hormone, insulin, oral contraceptives, levodopa, nicotinic acid and vasopressin.
A decrease in the level of somatotropic hormone in the blood is observed during treatment with bromocriptine (for acromegaly), glucocorticosteroids, phenothiazides, probucol and glucose.
The analysis reveals a decrease in pituitary function and thyroid gland, tumors of the hypothalamus and pituitary gland, distinguish gigantism from acromegaly in adults, monitor treatment with somatotropic hormone.
An increased level of somatotropic hormone in the blood is detected in pituitary gigantism, Laron dwarfism, acromegaly, somatotropin-producing tumors of the lungs and stomach, and malnutrition. A similar result is observed in liver cirrhosis, anorexia of neurogenic origin, renal failure, uncontrolled diabetes, stress, physical activity and prolonged fasting.
A decrease in the level of somatotropic hormone in the blood is observed with pituitary dwarfism, increased function adrenal cortex, hypopituitarism, during chemotherapy and under the influence of radiation.
A test with stimulation of growth hormone secretion or a study for somatotropic insufficiency (low levels of growth hormone in the blood) is aimed at identifying low level somatotropic hormone. This test is usually performed after the patient has been given a drug that stimulates the production of GH.
This test also detects dysfunction of the pituitary gland, the organ that produces growth hormone.
Preparation
There are not many precautions that should be taken before undergoing this test: it is recommended to tell your doctor about liver or kidney disease and medications you are taking, and to avoid food and physical activity for 12 hours before the procedure.
Your doctor may also ask you to avoid taking certain medications for a few days.
Reasons for the analysis
The procedure is carried out as follows: First, in the morning, a control blood sample is taken from a vein, then a catheter is inserted into the vein and an infusion of arginine, an amino acid that stimulates the production of growth hormone, is administered. After this, a blood sample is taken through the catheter after a half-hour break. A total of five samples need to be taken.
results
Arginine increases the level of growth hormone. The norms for its increase are as follows:
- Men – above 10 ng/ml. (more than 10 µg/l.).
- Women – more than 15 ng/ml. (above 15 µg/l.).
- Children – above 48 ng/ml. (more than 48 µg/l.).
If there is no increase in growth hormone levels after arginine infusion, then its secretion is reduced. If it is below 10 ng/ml, you need to retest.
Abnormally low test results indicate a deficiency of growth hormone. In adults, it can cause a disease known as panhypopituitarism.
The level of somatotropin changes throughout the day. It is maximum at night.
Video
Main in laboratory diagnostics acromegaly is the study of growth hormone secretion on an empty stomach. To correctly interpret the results obtained, it is advisable to take blood samples 2-3 times over 2-3 days with a break of 1-2 days and evaluate the average value of the samples.
In healthy individuals aged 20 to 50 years, fasting growth hormone levels range from 0 to 10 ng/ml. In patients with acromegaly, fasting growth hormone levels tend to be elevated. However, 30 - 53% of patients have a moderate or slight increase in this indicator. Moreover, in almost 17% of patients, growth hormone levels are within normal limits.
Research on the circadian rhythm of growth hormone
For a number of conditions and diseases (stress, insulin-dependent diabetes, chronic diseases kidneys, prolonged fasting) there may be a “false” increase in the level of growth hormone on an empty stomach. Therefore, it is necessary to study the daily rhythm of growth hormone secretion, as well as perform functional tests.
When studying the circadian rhythm, blood samples are taken every 30 or 60 minutes for 24 hours using an intravenous catheter. Normally, in 75% of samples the growth hormone content is at the lower limit of the sensitivity of the method, and in 25% of samples (midnight, early morning hours) high values growth hormone levels. The normal daily average secretion of growth hormone is 4.9 ng/ml. During the active stage of acromegaly, serum growth hormone levels are persistently elevated. Integrated daily levels of growth hormone in patients exceed normal values 2-100 times, and sometimes more.
If it is impossible to study the circadian rhythm, it is necessary to conduct functional tests - with stimulation and suppression of growth hormone secretion. Stimulation tests include insulin hypoglycemia, a test with thyrotropin-releasing hormone and somatoliberin.
Insulin test
Insulin is administered intravenously at a dose of 0.15-0.2 U/kg body weight. The test results are considered reliable if glycemia falls below 2 mmol/l. Blood sampling is carried out 15 minutes before insulin administration, immediately before administration (0 minutes), and also 15, 30, 60, 90, 120 minutes after it.
In the active stage of acromegaly, 50% of patients experience a hyperergic reaction of growth hormone. Due to the non-specificity of this test, false negative results are possible.
Thyroliberin test
The test with thyrotropin-releasing hormone is carried out as follows. In the morning, on an empty stomach, the patient, who is in a horizontal position, is administered intravenously 500 mcg of thyrotropin-releasing hormone. Blood sampling is carried out at the same time intervals as during the insulin test. With acromegaly, especially in its active stage, there is an increase in the level of growth hormone by 50-100% or more from the initial level. The maximum increase, as a rule, is observed at the 30-60th minute of the test.
Normally, there is no reaction to thyrotropin-releasing hormone. False Positives possible in the presence of kidney disease, mental depression, anorexia nervosa, serious illnesses liver, false negative results can be obtained when the adenoma is autonomous or in cases where the secretion of growth hormone is regulated not by dopaminergic, but by other mechanisms.
Test with somatoliberin
When conducting a test with somatoliberin, the latter is administered intravenously at a dose of 100 mcg in the morning on an empty stomach.
Blood is taken at the same time intervals as for other samples. In acromegaly, a hyperergic response of growth hormone to somatoliberin is observed.
Tests with suppression of growth hormone secretion
Tests that suppress growth hormone secretion include oral glucose tolerance test(OPT) and a test with parlodel. When performing a glucose load test, blood is taken on an empty stomach, as well as every 30 minutes for 2.5-3 hours after taking glucose.
Normally, hyperglycemia is accompanied by a significant decrease in growth hormone levels.
In the active phase of acromegaly, the test is considered positive if this level does not fall below 2 ng/ml within 2.5-3 hours. Such a GH reaction is observed in most patients (up to 70%). Moreover, often (up to 25-30% of cases) a “paradoxical” release of the hormone is observed in response to a glucose load.
The parlodel (bromocriptine) test is carried out as follows. In the morning on an empty stomach, blood is taken 30 minutes before and before taking the drug. After taking 2.5 mg (1 tablet) of parlodel, repeated blood samples are taken after 2 and 4 hours. The patient remains hungry throughout the test.
The test is considered positive if after 4 hours there is a decrease in the level of growth hormone by 50% or more compared to the basal level. Normally, taking parlodel causes the opposite effect. The test simultaneously allows you to determine the possibility of subsequent long-term therapy parloder.
IN everyday practice OPT is most often used as the most accessible, easily portable, and highly informative. The only contraindication for its implementation is the presence of diabetes mellitus in the patient.
N.Molitvoslovova, V.Peterkova, O.Fofanova
"Research on growth hormone" and other articles from the section
General information about the study
The analysis determines the amount of growth hormone in the blood. Growth hormone is produced by the pituitary gland, a grape-sized gland located at the base of the brain behind the bridge of the nose. The hormone is usually secreted into the blood in waves throughout the day with a peak concentration, usually at night.
Somatotropic hormone is necessary for the normal growth and development of children, since it helps to increase bones in length from the very birth of the child until the end of puberty. If there is a lack of growth hormone production, the child grows more slowly. Excessive growth hormone production is often observed with a pituitary tumor (usually benign). Excessive synthesis of the hormone contributes to excessive elongation of bones and continued growth even after puberty, which can lead to gigantism (height above 2 meters). Also, with an excess of somatotropic hormone, rough facial features may be observed, general weakness, slow sexual development and headaches.
Although growth hormone partially loses activity in adults, it continues to play a role in regulating bone density, maintaining muscle mass and fatty acid metabolism: hormone deficiency can lead to decreased bone density, decreased muscle mass, and changes in lipid levels. However, growth hormone testing is not a common practice for evaluating patients with low bone density, underdeveloped muscles and increased content lipids - a lack of somatotropic hormone is quite rarely the cause of these disorders.
Excess growth hormone production in adults can cause acromegaly, characteristic which is not elongation of bones, but their excessive thickness. Although symptoms such as thickening of the skin, sweating, fatigue, headaches and joint pain are not severe at the onset of the disease, further increases in hormone levels can lead to enlarged hands and feet, carpal tunnel syndrome ( painful sensation in the wrist) and pathological enlargement internal organs. Because of higher level growth hormone sometimes causes papillomas on the body and polyps in the intestines. Without treatment, acromegaly and gigantism often lead to complications: type 2 diabetes, increased risk cardiovascular diseases, increased blood pressure, arthritis and a general reduction in life expectancy.
To diagnose abnormalities of growth hormone, the test for its stimulation and suppression is most often performed. Because growth hormone is released by the pituitary gland in waves throughout the day, spontaneous measurement of hormone concentrations is not usually used in clinical practice.
What is the research used for?
Growth hormone testing is not recommended for general examination body. In general, it is carried out only when problems associated with its production are suspected, and is prescribed after tests for other hormones have been performed or to help study the function of the pituitary gland.
The test is performed to check for excess or insufficient production of growth hormone and to provide information about how severe the disease is. He is part diagnostic examination when determining the causes of abnormal synthesis of growth hormone, and in addition can be used to assess the effectiveness of treatment for acromegaly or gigantism.
Along with the growth hormone test, an insulin-like factor test is often performed. The latter also reflects an excess or deficiency of growth hormone, but its level remains stable throughout the day, thereby making it an indicator of the average level of growth hormone.
Diagnosis of SG abnormalities often includes stimulation and suppression tests, which are used to assess pituitary function and changes in growth hormone levels.
- Stimulation test helps diagnose growth hormone deficiency and hypopituitarism. To do this, blood is taken from a vein from the patient after 10-12 hours of abstinence from food, then, under medical supervision, a solution of insulin or arginine is administered intravenously. Next, blood samples are collected at certain intervals, at each of which the level of growth hormone is detected to determine whether insulin (or arginine) acts on the pituitary gland, producing the expected level of the hormone. In addition, clonidine and glucagon are used to stimulate growth hormone.
- Suppression test helps diagnose hormone excess and, together with other blood tests and scintigraphy, help identify and localize pituitary tumors. To carry out this test, blood is also taken after 10-12 hours of abstaining from food. The patient then takes orally standard solution glucose, after which blood tests are done at certain intervals, in which the content of growth hormone is determined to check whether the pituitary gland is sufficiently suppressed by the dose of glucose taken.
Other tests are often used to check the functioning of the pituitary gland, such as T4 (thyroxine), thyroid-stimulating hormone, cortisol, follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (in men). They are usually performed before a growth hormone test to ensure that their levels are normal or under the control of medications taken. For example, hypothyroidism in children must be treated before testing for growth hormone deficiency, otherwise the results may be falsely low. The blood sample taken for the growth hormone suppression test is also used for the glucose test to ensure that the patient's body is sufficiently suppressed by the glucose solution taken.
Because exercise usually temporarily increases growth hormone levels, deficiency is sometimes assessed after intense exercise over a period of time.
Tests for somatotropic hormone and insulin-like growth factor may be periodically prescribed to children exposed to radioactive treatment central nervous system or radiation before stem cell transplantation. This is quite common in acute lymphoblastic leukemia, where radiation can affect the hypothalamus and pituitary gland and thus affect growth.
When is the study scheduled?
A growth hormone stimulation test is performed if the child has following symptoms deficiency of this hormone:
- growth slowdown in early childhood– at the same time, the child is much shorter than his peers;
- diagnosis of the thyroid gland (for example, determination of free T4) indicates the absence of hypothyroidism (since insufficient thyroid function can also slow down growth);
- fluoroscopy indicates delayed bone growth;
- there is a suspicion that the pituitary gland has reduced activity.
A stimulation test in adult patients may be required for symptoms of growth hormone deficiency or hypopituitarism: decreased bone density, fatigue, impairment lipid metabolism, reduced resistance to physical exercise. Typically, tests for other hormones are done first to see if other diseases are causing these symptoms. Insufficiency of growth hormone production is a fairly rare phenomenon among both children and adults. Hormone deficiency in adults can occur due to genetic predisposition to disease of the hypothalamus or pituitary gland.
A growth hormone suppression test is performed if a child has signs of gigantism or an adult has signs of acromegaly. Such an analysis may also be required when a pituitary tumor is suspected; sometimes the test is performed in conjunction with an insulin-like factor-1 test and tests for other hormones to monitor the effectiveness of treatment of the disease.
Growth hormone and insulin-like factor 1 tests may be performed regularly at regular intervals over many years to monitor for possible recurrences of growth hormone abnormalities.
The content of the article:
Growth hormone is increasingly used by athletes today. If just a few years ago it was available exclusively to professional bodybuilders, now the situation is gradually changing. Probably, many will be interested in learning not only how to determine the quality of growth hormone in practice, but also getting acquainted with the history of obtaining the drug.
I would also like to draw your attention to the fact that somatotropin can only be effective in bodybuilding. The drug is not able to influence physical parameters. Its main properties used in sports are a powerful fat-burning effect, as well as activation of the processes of hyperplasia and hypertrophy of muscle tissue. These are the problems that are solved in bodybuilding.
How was growth hormone created?
It’s worth starting a conversation on the topic of how to determine the quality of growth hormone in practice with a brief history of the creation of this drug. It all started in the twenties of the last century. However, the first drug was obtained only in 1944 from the pituitary gland of animals. It is quite obvious that it was not suitable for human use, but the first step was taken.
Twelve years later, scientists managed to create an artificial human growth hormone. For this, the pituitary gland of corpses was used, since no other technologies existed. The cost of the drug was extremely high, but at the same time it represented serious danger for good health. There are two explanations for this:
- It was not possible to obtain three milligrams of the drug from one pituitary gland, but the child needed seven to carry out therapy for a week.
- Together with growth hormone, a virus could enter the body, causing the development of Creutzfeldt-Jacob disease.
In the early nineties, Creutzfeldt-Jacob disease was discovered in seven more children, and the drug was banned from use. Here it should be noted one more feature of the disease caused by the use of cadaveric somatotropin - the first symptoms may appear only several years after infection. However, the ban only pushed scientists to further research in this area.
People have been trying to find the Holy Grail since the beginning of time. Of course, artificial growth hormone is not capable of giving a person eternal life, but it is quite capable of slowing down the aging process. As a result, scientists managed to discover a recombinant technology for the production of this drug. Bacteria are used to synthesize the substance coli T.Coli containing the somatotropin gene.
Note that insulin is produced in a similar way today, which is also actively used by bodybuilders. Moreover, the bacterium can be placed in intestinal tract, and she will be able to synthesize hormones directly in the body. The question arises, why is this not done today? The answer is simple - profit. None pharmaceutical company does not want to lose the huge money that the production of insulin or growth hormone brings her.
However, let's return to our topic - how to determine the quality of growth hormone in practice. It should be remembered that the process of synthesis of growth hormone by bacteria was not always of high quality. Until recently, the body, after a certain period of time, adapted to the administered drug and began to produce antibodies. As a result, growth hormone became ineffective.
The Chinese pharmaceutical company GeneScience was able to make a breakthrough in this direction. Its scientists tried to obtain chains of amines directly from E. coli. Other manufacturers crushed the E.Coli and then purified the final product. Today, the fifth generation drug Jintropin, created by a Chinese company, is the purest and most perfect.
What does the concept of “quality” mean when applied to growth hormone?
Let's start with the fact that not every drug can be called a growth hormone. Some unscrupulous sellers can sell anything under the guise of somatotropin, say, gonadotropin or albumin. Although such situations are now extremely rare, they should not be ruled out. But at the same time, real drugs can be of low quality.
Most important indicator The characteristics of any somatotropin preparation is the degree of its purification from foreign protein compounds. These are so-called related substances, which are waste products of the E.Coli bacterium. If this indicator is low, then the body quickly adapts to it by establishing the synthesis of antibodies. It is quite obvious that after this the effectiveness of the drug will be zero.
If the manufacturer has purified his product, then the content of foreign protein compounds in it will not exceed two percent. The amount of liquid in the dry powder is also an important indicator. In high-quality growth hormone it does not exceed three percent. In conclusion, we note that some drugs may contain a smaller amount of active ingredient compared to the declared one.
How to check the quality of growth hormone yourself?
Undoubtedly, best choice will contact the laboratory. However, not every person has such an opportunity. During laboratory research after a certain amount of time from the moment of drug administration, the concentration of insulin-like growth factor is measured. The lower this indicator, the lower quality the drug is.
You probably thought that the answer to the question of how to determine the quality of growth hormone in practice would be found. After all, what could be simpler - after the injection of growth hormone, you can go and take the appropriate test. Of course, such a solution has the right to life, but it is not the best. There are several explanations for this fact:
- The test must be taken within a maximum of four hours from the moment of injection. Although the half-life of the synthetic substance is eight hours, after the first four its concentration in the body begins to decrease. However, this is not the most difficult thing in this matter and, in fact, is only a recommendation.
- Assuming that you got a dummy drug, then the level of insulin-like factor should remain at the same level. However, if at the time of taking the test there was a natural release of growth hormone in the body, then instead of negative, the result will be positive.
- This method of determining the quality of a drug cannot indicate the presence of the amount of the active component declared by the manufacturer.
- Quality of the drug this method cannot be determined. As a result, you will continue to use it, being satisfied with the test results, but after a couple of weeks it will stop working.
The second option is quite effective, but we cannot recommend it. You should fill the syringe with solvent and insert the needle into the vial. All the liquid should be absorbed into the container with the powder almost effortlessly. If this does not happen, then there is air in the bottle and the quality of the powder can no longer be considered high.
If you feel pain in your joints, then after just a few injections of a high-quality drug they should decrease significantly. Many athletes claim that a similar effect is observed after the first injection. If you take the injection shortly before going to bed, you will fall asleep quickly, and the sleep itself will be deep and of high quality. In turn, when administering the drug before class, you should feel good effect pumping.
High-quality somatropin (note that it is not Somatrem) does not cause severe fluid retention in the body. If after several injections your body begins to swell, then the purchased drug is of low quality. On the other hand, much in this matter depends on the dosages used and the characteristics of your body. But if you have already used growth hormone, and there was no swelling before, then the conclusion suggests itself.
A low-quality drug at the time of administration can cause itching. And sometimes severe irritation skin at the puncture site. There is also a risk that you bought not just a low-quality drug, but an extract from the pituitary gland of corpses or animals. In this case, it can quickly develop carpal tunnel syndrome, the joints of the hands will begin to swell, and the muscles will become stiff. I want to believe. That something like this will never happen to you.
Myths about the rules for storing growth hormone
Having answered the question of how to determine the quality of growth hormone in practice, a few words should be said about the most popular myths associated with the rules for storing the drug.
- Myth No. 1- somatropin should only be stored in the refrigerator. It all depends on the form of the drug that you are going to store. If the bottle has not yet been opened, the active ingredient may be room temperature within a month without losing its properties. If you open the cap, we recommend storing the drug in the refrigerator at a temperature of 2 to 8 degrees.
- Myth No. 2- the prepared solution must be used immediately. Modern high-quality drugs, say, Jintropin, even in the form of a solution, can be stored in the refrigerator for about 14 days. This is very convenient, because it is not always possible to use the prepared solution immediately.
- Myth No. 3- somatropin cannot be stored in liquid form for more than two weeks. If you used bactericidal water as a solvent and stored it at room temperature, then the answer is yes. If you place the solution in a refrigerator with a temperature of 2 to 8 degrees, then when the bottle is closed, the drug will last about two years, and after opening - a couple of months.
How to check growth hormone for quality, see below:
Loading...