Testosterone is the main human sex hormone, which is a steroid in nature. Testosterone is produced by special formations in the body: Leydig and Sertoli bodies in the testes, as well as in the reticular area of the adrenal glands. At its core, testosterone, produced primarily, is just a prohormone that has practically no activity. Once in cells, testosterone reacts with a specific enzyme — reductase, resulting in the formation of its extremely active metabolite — dihydrotestosterone. I have done a number of studies to determine the effect of growth hormone on testosterone levels.
Changes in the body during exercise
Muscle tissues contain a huge number of androgen receptors, which are simple monomeric proteins, approximately 400-600 amino acid residues in size. These receptors are located inside the cell and have a nuclear type of reception. This means that the acceleration of the synthesis of new proteins and nucleic acids, which takes place on the mRNA of the cell, occurs only when the sex hormone interacts with the androgen receptor. This also happens while taking a course on growth hormone. At the same time, the control group that took part in the testing noted the positive effect of injections during physical activity.
It should be noted that super-intense physical exercises significantly damage the muscles: there are numerous tears and microtraumas. To start restoring their integrity in their previous form, the body needs a significant amount of "scarce" plastic materials: amino acids, oligopeptides, nucleotides, nucleosides, and the above-mentioned growth hormone. The formation of these substances in the cell in the most direct way depends on the density of androgen receptors in each myocyte. It follows that damage to muscle cells during exercise stimulates the formation of new androgen receptors. At the same time, injections of growth hormone significantly accelerate this process.
The effect of testosterone
After taking growth hormone (in combination with exercise), the number of receptors for androgens in myocytes becomes much higher. As a result, more testosterone enters the myocytes, triggering anabolic processes there. The endocrine system performs its work according to the feedback principle: when the pituitary gland is washed with blood with an extremely low amount of androgens, the processes of stimulating the formation of releasing hormone (factor) in the hypothalamus are immediately triggered.
From all that has been presented, we can conclude: an increase in the secretion of androgenic hormones occurs delayed, according to a feedback mechanism, and immediately after heavy loads or injection of growth hormone, the level of androgens is very low.