Growth hormone (somatropin) is produced by the cells of the pituitary gland and its secretion depends on age and gender. Its main function is to stimulate weight gain and growth. Abnormal levels of growth hormone may be associated with growth disturbances.
What is Growth Hormone?
Growth hormone, GH, is a polypeptide (protein) hormone that stimulates the growth of long bones and organs. It stimulates the synthesis of nucleic acids and enhances the processes of cell division and protein synthesis. The pituitary gland (anterior lobe) is responsible for the production of growth hormone and its dysfunction is often the result of the development of a tumor in this gland. GH secretion is pulsatile and is related to sex, time of day and age of the patient. Human growth hormone consists of 191 amino acid residues. The amount of somatropin entering the body is regulated by somatostatin (inhibiting its production) and somatoliberin (increasing its secretion). The abnormal concentration of somatropin may be due to, inter alia, about gigantism and acromegaly, which is why doctors often refer patients for a growth hormone measurement test. Growth hormone is secreted most intensively at night, during deep sleep.
The importance of growth hormone
The growth of the organism would not be possible without the growth hormone. Thanks to GH, cartilage in long bones widens and bones lengthen. It is accompanied by weight gain. Other tasks of somatotropin are also (as already mentioned) the synthesis of proteins, fats and carbohydrates. As a result, valuable substances, such as phosphorus ions, are retained in the body. In addition, growth hormone accelerates and stimulates glycogenolysis and glucose secretion. As a result, the lipolysis process (breakdown of triglycerides into fatty acids and glycerol) in adipose tissues is much greater. And finally – growth hormone has a positive effect on the appearance and thickness of our skin. It improves concentration and promotes a good mood.
When do we do the growth hormone test?
Growth hormone testing consists of drawing blood from a vein in the arm several times. The test is used in the diagnosis of excess or deficiency of GH in the body. The test material is serum. The patient should be fasting for at least eight hours:
in the stimulation test – on an empty stomach and after administration of insulin, arginine or dopamine;
in the inhibition test – on an empty stomach and after administration of glucose.
About 12 hours without food, a blood sample is taken from the patient and then given orally a glucose solution or an intravenous arginine or insulin solution. The next step (in the case of both tests) is to monitor the effect of the applied substances on the somatropin by examining the collected blood samples.
We measure the concentration of growth hormone in the case of:
diagnosis of short stature in children,
suspicion of the presence of a growth hormone producing tumor, gigantism and acromegaly,
to evaluate the effectiveness of growth hormone treatment.
The normal concentration of growth hormone: 1-12 µg / l, higher values in newborns and children (10-30 µg / l).