Steroid hormones: aldosteron, cortisol, androgens and estrogen

1.Aldosteron.

• It iss mineralokortikoidy.
• He stimulates exchange of ions of K+ for Na ions + in kidney tubules.
• Na+ reabsorption ↑, secretion of K+ ↓, secretion of H+ ↑

2.Cortisol

• It is a glucocorticoid.
• Catabolic steroid hormone.
• He stimulates gluconeogenesis, lipoliz and disintegration of proteins of fabrics

3.Androgens

• Anabolic steroid hormones.
• Stimulate synthesis of proteins and development of secondary male sexual characters

4.Estrogen

• Promote development of female secondary sexual characteristics

There are four main types of steroid hormones: mineralokortikoida, glucocorticoids, male sex hormones (androgens) and female sex hormones (estrogen). Notice that androstendion is the predecessor both androgens, and estrogen. Really, on someone's well-aimed observation, Romeo and Juliette differ only in keto-group at the 3rd atom of carbon and metal group at the 10th atom of carbon of steroid kernel.

Giperaldosteronizm

Primary giperaldosteronizm (Conn's syndrome) is the rare disease caused by a tumor of bark of adrenal glands, sekretiruyushchy àëüäîñòåðîí. Because of it the organism loses ions of potassium and hydrogen which are removed with urine. Develop gipokaltsiyemiya, metabolic alcaloz. The secondary giperaldosteronizm which develops because of damage of kidneys or a liver meets more often.

Chronic insufficiency of bark of adrenal glands (Addison's disease)

Addison's disease is a rare disease with a possible lethal outcome. An etiology atrophy of adrenal glands which leads to reduced secretion of an aldosteron and cortisol. The disease is characterized by the low arterial pressure, loss of ions of sodium with urine, decrease in body weight and pigmentation of mucous membranes. Insufficiency of bark of adrenal glands develops also because of violation of functioning of the hypothesis which is followed by violation of formation of adrenokortikotrop hormone (AKTG). Please pay attention to Kristagen.

Giperkortitsizm: Cushing's syndrome

Cortisol is developed by bark of adrenal glands in response to a stress and starvation. It stimulates splitting of fats, and also formation of glucose from the amino acids which are formed in case of disintegration of proteins of fabrics. Thus, cortisol is catabolic steroid hormone which is developed in case of starvation. Natural steroids of this type or their synthetic analogs (in particular, dexamethasone) are called glucocorticoids. Secretion of cortisol is regulated by gipotalamo-hypophysial system. At first the hypothalamus sekretirut which stimulates secretion of AKTG of a forward share of hypothesis. Then AKTG stimulates secretion of cortisol with bark of adrenal glands. In case of excessive products of cortisol Cushing's syndrome develops. Cushing's syndrome can arise for four reasons: yatrogenno, in case of hypothesis adenoma, in case of adenoma or a carcinoma of adrenal glands, and also in case of ektopichesky formation of AKTG.

• The most widespread is the iatrogenic syndrome of Cushing. (An iatrogenic syndrome of Cushing also call an exogenous or medicinal syndrome of Cushing as it is caused by prolonged treatment by glucocorticoids or other steroids.)
• For the first time the syndrome was described by Cushing at the patient with the infrequent primary adenoma of a pituitary body cosecreting AKTG. Such state is called Cushing's illness.
• Further patients with primary tumor of an adrenal good-quality (adenoma) or malignant were described (carcinoma) at which hydrocortisone level in a blood was increased, but the AKTG level was lowered.
• Ectopic formation of AKTG happens, for example, at cancer of a lung.

At Cushing's syndrome patients have characteristic appearance a lunar face, thin legs and arms at a gross obesity of a trunk, and their figure reminds a pear on legs matches. It is caused by accumulation of visceral fat at this illness. At first can seem that development of obesity at the high level of catabolic hormone (hydrocortisone) contradicts any common sense. However it is necessary to remember that the hydrocortisone stimulates glucose-genesis, and in blood glucose level increases that, in turn, causes insulin secretion intensifying. At Cushing's syndrome hydrocortisone level in a blood is high so that even the increased content of insulin can't reduce concentration of a glucose in a blood. But in visceral fatty tissue effect of insulin appears stronger, than action of a hydrocortisone, and insulin stimulates a lipoprotein lipase gene expression. It promotes fat accumulation, and first of all visceral, but not hypodermic: obesity occurs where rate of a blood flow is higher and where the number of adiposities is higher.

Sex hormones

Disturbance of synthesis of androgens: failure of 5-a-reductase

Dihydrotestosterone is formed of Testosteron under the influence of enzyme of 5-a-reductase. At a failure of a 5-a-reductase reaction is blocked, and in a blood the ratio Testosteron-Depotum/dihydrotestosterone raises. Dihydrotestosterone is 4 times more active, than Testosteron therefore newborn boys at a failure of a 5-a-reductase have genitals of critical accessory. The main task in such cases — the correct sex determination.

Inhibitors of 5-a-reductase

Finasterid also minoksidit are used for treatment of an androgenic alopecia. Finasterid is also applied at a good-quality prostatauxe to decrease of its sizes. Flutamid blocks a receptor of Testosteron and is used in treatment of a carcinoma of a prostate.

Aromatase inhibitors: new drugs against a breast cancer

Aromatase inhibitors, for example anastrozol, letrozole and ecsemestan, block synthesis of estrogens from androstendion. These are the new drugs developed for cancer therapy of a mammary gland. Clinical tests of letrozole turned out so successful that they had to be stopped: doctors counted unethical to continue to give placebo to volunteers from control group.