Sex steroids, also known as
gonadal steroids, are
steroid hormones that interact with
vertebrate androgen or
estrogen receptors. Their effects are mediated by slow genomic mechanisms through
nuclear receptors as well as by fast nongenomic mechanisms through membrane-associated receptors and
signaling cascades. The term
sex hormone nearly always is synonymous with
sex steroid.
Production
Natural sex steroids are made by the
gonads (
ovaries or
testes), by
adrenal glands, or by conversion from other sex steroids in other tissue such as liver or fat.
Functions
Sex steroids play important roles in inducing the body changes known as
primary sex characteristics and
secondary sex characteristics.
The development of both primary and secondary sexual characteristics is controlled by sex hormones after the initial fetal stage where the presence or absence of the Y-chromosome and/or the SRY gene determine development.
Synthetic sex steroids
There are also many synthetic sex steroids. Synthetic androgens are often referred to as
anabolic steroids. Synthetic estrogens and progestins are used in methods of
hormonal contraception.
Ethinylestradiol is a semi-synthetic estrogen.
Types
In many contexts, the two main classes of sex steroids are androgens and estrogens, of which the most important human derivatives are
testosterone and
estradiol, respectively. Other contexts will include
progestagen as a third class of sex steroids, distinct from androgens and estrogens.
Progesterone is the most important and only naturally-occurring human progestagen. In general, androgens are considered "male sex hormones", since they have masculinizing effects, while estrogens and progestagens are considered "female sex hormones although all types are present in each gender, albeit at different levels.
Sex steroids include:
See also
References
External links
