Steroid Hormones: Progestogens, Androgens, Estrogens, and Corticosteroids

Progestogens are a class of steroid hormones with progesterone as the major and most potent hormone.
Progesterone has 100% potency, referring to its high binding affinity to the progesterone receptor.
Other progestogens, such as 17 alpha-hydroxyprogesterone (40-70%) and 20 alpha-hydroxyprogesterone(5%), have lower potency.
Progestogens prepare the body for gestation. "Pro" means "for," and "gestogen/gesturone" relates to gestation - pregnancy
Progesterone maintains the secretory function of the endometrial glands in the uterus to provide nutrition for a potentially implanting conceptus.
Progesterone also affects glandular tissue in the breast.
It has negative feedback effects on the anterior pituitary, regulating LH and FSH secretion.

Androgens are a class of steroid hormones with testosterone as one of the hormones within this class.
Five alpha-dihydrotestosterone (DHT) is the most potent androgen. DHT has 100% potency at the androgen receptor, whereas testosterone has 50% potency.
Testosterone is converted to DHT by the enzyme five alpha-reductase, increasing its potency in specific target tissues, such as developing genitalia.
Weaker androgens include androstenedione (8% potency) and dihydroepiandosterone (DHEA) - weak androgen.
Androgens are secreted by Leydig cells of the testis.
They are secreted from the adrenal glands and have effects early in puberty.
Androgens (specifically testosterone) are produced by thecal cells in the female ovary and then converted to estrogen in the ovarian follicle.
Androgens, specifically DHT, cause the development of male secondary sexual characteristics (male genitalia, effects on the larynx, body hair, pubic hair, axillary hair) during fetal development.
Androgens play a role in sexual behavior in both sexes.

Males treated with testosterone showed increased sexual activity, frequency of sexual thoughts, and perceived energy.
Females treated with androgens showed increased levels of sexual desire, frequency of sexual fantasies, and level of sexual arousal.
Androgens have an anabolic effect, stimulating the building of lean tissue, particularly muscle mass.
Androgens have a negative feedback effect on the anterior pituitary and hypothalamus, regulating gonadotrophins FSH and LH.

Estrogens are a class of hormones, with estradiol (specifically estradiol 17 beta) as the major estrogen having 100% potency at the estrogen receptor.
All estrogens must be aromatized from androgens.
Estriol is weaker (10% potency) and is one of the main estrogens produced during pregnancy.
Estrone is a very weak estrogen.
Estrogens increase fat deposition and ductal development in the breast during puberty and cause changes in the menstrual cycle.
Estrogens proliferate the endometrium of the uterus.
Estrogens increase the water content of cervical mucus, facilitating sperm transport through the cervix.
Estrogens can have negative and positive feedback effects.
Estrogen plays a role in sexual behavior in some species, particularly non-primate species, such as rats and mice. In some primates, like baboons, estrogen facilitates interactions between sexes.

Corticosteroids are a group of hormones broadly classified as glucocorticoids, with cortisol and Aldosterone as the major one in humans.
Cortisol is important for maturation of organ systems in the developing fetus, particularly the lungs.
Mothers at risk of preterm labor are often given glucocorticoids to aid in fetal lung maturation.
In some species (e.g., sheep), cortisol is important for the onset of parturition/ child birth - not really in humans
Cortisol may play a role in maternal behaviors and maternal-fetal interactions.
Cortisol is a major stress hormone, and elevated stress levels can profoundly affect fertility.
Abnormal cortisol levels during prenatal life are believed to influence aspects of health/ill-health.