HORMONAL DRUGS Hormones are biologically active substances, produced by the endocrine glands and special cell groups in various tissues. They play the most important role in the humoral regulation of various functions of the body. Moreover, some hormones are neuromodulators.

The importance of hormonesis particularly evident when there is a hypofunction of the endocrine glands. For example, failure of the pancreatic islet cells leads to the development of diabetes mellitus, parathyroid gland failure which causes hypocalcaemia (associated with convulsions) and insufficiency of the antidiuretic hormone of the posterior pituitary lobe – diabetes insipidus. At the same time there are diseases, associated with increased production of hormones. Thus, hyperfunction of the thyroid gland causes hyperthyroidism (Basedow, s disease), excessive production of the somatotropic hormone of the anterior pituitary lobe – gigantism, acromegalia.

Failure of the endocrine glands is usually treated with hormones. In such cases so- called replacement therapy is required; the duration of the administration of replacement hormones is determined by the duration of the endocrine gland hypofunction. Drugs that stimulate hormone production can also be used for the treatment of these conditions.

Hormonal drugs are obtained via synthetic routes as well as from the organs and urine of animals (in the latter case the activity of a number of drugs is evaluated by biologic standardization and measured in action units). Currently, genetic engineering methods are widely used to obtain hormones. In addition, a considerable number of natural hormone derivatives and their synthetic substitutes have been synthesized, and some of them are different from the natural hormones in their structure.

When hyperhormonism use hormone antagonists, which block the respective receptors or inhibit the synthesis of hormones. The primary action of hormones is localized at the level of the cytoplasmic membrane or intracellular. Some hormones (group of peptides and proteins) interact with specific receptors on the outer surface of cell membranes. Many of these receptors linked to adenylate cyclase, activity change which largely determines the content of intracellular cAMP. Most hormones stimulate adenylate cyclase and increases cAMP. CAMP can also increase due to inhibition of phosphodiesterase. However, because of the hormones three-iodothyronine only, and then only at very high concentrations. CAMP in turn activates protein kinase that influences during different intracellular processes. In this way the effect of corticotropin, thyrotropin, pituitary gonadotropins, melanotsitstimuliruyushie hormones, parathyroid hormone, calcitonin, glucagon.

Hormones may affect the grip and release of the intracellular distribution of calcium ions, which may also act as a "mediator" between membrane receptors and intracellular processes. Furthermore, certain relationships established between cAMP and kinetics of calcium ions. Several hormones (proteins and peptides) act on membrane receptors, adenylate cyclase is not associated with (HGH lactotropic hormone). The question of "mediator" in this case is still open. Certain hormones can affect fosfatidilinozitolny cycle, increasing the production of inositol three-phosphate and diacylglycerol (for example, a hormone of the hypothalamus, which stimulates the height gonadotropin-releasing hormone, vasopressin). Effect of hormones on cell membranes may also occur that they change their permeability to other endogenous substances (e.g., insulin facilitates entry of glucose into cells).

Several hormones penetrating the cell membrane act intracellularly (e.g., steroids, thyroid hormones). Steroids are an ¬ form a complex with the sytoplasmic receptors and are then transported into the cell nucleus, where it appears their main effect. In the cell nucleus it is activated DNA and mRNA, which leads to the induction of protein synthesis.

DRUGS hormone from the hypothalamus and pituitary gland The pituitary gland is composed of three shares: front, back and middle Just noticeable. The front and middle lobes contain glandular cells and grouped under the name "anterior pituitary." Anterior lobe produces adrenocorticotrop, growth, thyroid, follicle-stimulating, luteinizing hormone and lactotrop. Their education and liberation are regulated by special ¬ releasing challenging (English to release-exempt), hormones and hormone depressing (factors) of the hypothalamus. The average share of some mammalian melanocyte secretes hormones (α, β, γ) and also under the control of the hypothalamus.

Synthesis and secretion of hormones regulated by the hypothalamus and anterior pituitary of feedback. This is manifested in the fact that the activity of the centers of the hypothalamus and the pituitary gland is dependent on the concentration of circulating hormones ¬ new. Decreasing the amount of hormones in the blood stimulates hypotalamo-hypophysar system, and is accompanied by a rise depressing effect.