Corticosteroid hormones Androgens

Steroid hormones can be subdivided into sex hormones (androgens, estrogens, and progestins) and corticosteroids (glucocorticoids and mineralocorticoids). 

The interaction between the adrenal cortex of the foetus and the placenta in production of steroid hormones is complex. In outline, the placenta produces progesterone from cholesterol (which is available from the maternal blood) whereas the foetal adrenal cortex produces corticosteroids and androgens from the progesterone produced in the placenta. The placenta then converts some of these androgens into oestrogens. The interplay between the placenta and the foetal adrenal cortex is acknowledged by the use of the term foeto-placental unit to describe steroido-... 

Steroid hormones are secreted on demand from their tissues of origin in response to hormonal signals. The corticosteroids and androgens are made in different regions of the adrenal cortex, and are secreted into blood in response to different signals. 

The mechanisms of action of steroid hormones on lymphoid, mammary, and prostatic cancer have been partially clarified. Specific cell surface receptors have been identified for estrogen, progesterone, corticosteroids, and androgens in neoplastic cells in these tissues. As in normal cells, steroid hormones also form an intracellular steroid-receptor complex that ultimately binds directly to nuclear proteins associated with DNA to activate transcription of a broad range of cellular genes involved in cell growth and proliferation (see Chapter 39 Adrenocorticosteroids Adrenocortical Antagonists). 

Some of the most important steroid derivatives are the steroid icohols, or sterols. Other steroids include the bile acids, which aid digestion of fats in the intestine the sex hormones ( androgens and oestrogens) and the corticosteroid hormones, produced by the adrenal cortex. Vitamin D is also based on the steroid structure. 

An intermediate in the biosynthesis of a number of steroid hormones including corticosteroids and androgens. 

A steroid female sex-hormone secreted by the corpus luteum during the second half of the menstrual cycle when it prepares the uterus for the implantation of the embryo. It is also secreted by the placenta during pregnancy. The adrenals and testes also secrete small amounts of progesterone since it is an intermediate in the biosynthesis of corticosteroids and androgens. The major urinary metabolite of progesterone is pregnanediol. 

Anabolic Androgenic Steroids/Corticosteroids/Hormone Antagonists and Modulators... 

Steroid hormones Estrogens Androgens Gestagens Corticosteroids... 

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