Technische Universität München

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In general, hormones are derivatives of cholesterol (steroid hormones) or amino acids (thyroid hormones, adrenaline) and polypeptide derivatives. Depending on the nature and size of the hormone molecule, hormones bind to specific receptors that are either on the surface or in the cytoplasm/the nucleus of target cells, triggering sequences of intracellular changes that produce their physiological effects. As all peptide hormones, the hormones included in section S2 of the Prohibited List, bind to receptors located on the plasma membrane, many of them triggering the release of intracellular mediators (second messengers) that initiate changes in the cell function.

  1. EPO acts on the bone marrow to stimulate production of erythrocytes. The increase of erythrocytes improves the amount of oxygen the blood can transport to the skeletal muscles and other tissues. Recombinant (rh) EPO has a legitimate use in the treatment of anaemia in patients with kidney disease, cancer and AIDS. Endurance athletes may use EPO to improve their aerobic working capacity.
  2. The major actions of hGH are to stimulate protein synthesis and body growth, and to increase secretion of IGF-1 in target tissues. In addition hGH mobilizes fat by direct lipolytic action and has a hyperglycemic effect. IGF-1 has also an anabolic effect and plays a key role in bone and muscle growth, but it has a weaker lipolytic action and hypoglycemic effect. MGF is a local type of IGF-1 and promotes muscle growth and muscle tissue repair after resistance training. Deficiency in hGH before puberty results in pituitary dwarfism; in medical practice (“recombinant”) hGH is used to treat GH-deficient patients. In sport hGH is used for its anabolic and lipolytic effects.
  3. In men LH stimulates the testosterone production by the Leydig cells. As hCG mediates its biological activity through the same receptor as LH it has the same effects on the reproductive system as LH. Gonadotrophins and GnRH are used for diagnosis and treatment of some type of hypogonadism, amenorrhea, and infertility. hCG is used by athletes to increase the endogenous testosterone production especially during and after steroid cycles.
  4. Insulin has anabolic, lipogenic and hypoglycemic effects. It lowers blood glucose concentrations because it stimulates the translocation of glucose transporters from the cytoplasm of muscle and adipose tissue to the cell membrane thus increasing the rate of glucose uptake, glycogenesis, and the intramuscular energy reserves. In medical practice insulin is used to treat type 1 diabetes mellitus. Some athletes may use insulin to increase muscle growth and improve muscle endurance.
  5. ACTH increases mainly the secretion of glucocorticosteroids and adrenal androgens from the adrenal cortex. ACTH is used for diagnosis of some type of adrenal insufficiency and as an anti-inflammatory agent. Some athletes may use ACTH to increase the secretion of endogenous glucocorticosteroids.