Chapter 6 - Molecular mechanism of action of estrogens, progestins, and androgens

Abstract

The lipophilic steroid sex hormones are central to major regulators for paracrine and endocrine responses for various biological processes, including the development of sexual characteristics, pregnancy maintenance, etc. The slight imbalance in the concentration of steroid hormones, estrogens, progesterone, and androgens, could disastrously affect normal cellular functioning and physiology of the human body, such as hypogonadism, irregular menstruation, and cancer. These hormones in synthetic form could be utilized as pharmaceutical agents to treat hormonal disorders and diseases, including cancers. Different classes of synthetic estrogens, progestins, and androgens exert similar therapeutic but also few side effects. Synthetic hormones and their derivatives structurally resemble endogenous testosterone that acts at the molecular level just like endogenous hormones. The effects of synthetic sex steroids mainly occur through penetrating target cells, binding to receptors, steroid–receptor complex, interaction with the targeted regulatory DNA sequence, regulation of RNA synthesis, and mediating proteins. Synthetic hormones regulate endogenous hormones via a negative feedback mechanism and suppress the secretion of gonadotropin-releasing hormone, luteinizing hormone, and follicle-stimulating hormone from the anterior pituitary. In light of this concept of mechanism, synthetic estrogens, progestins, and androgens control the target cells, organs, and systems for complex steroid hormones–related functions. This chapter aims to bring insights into the molecular and cellular mechanism of actions of different drug classes of synthetic estrogens, progestins, and androgens drugs.