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(Redirected from
Steroids)
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This article is about the chemical family of steroids in general.
For discussion of performance-enhancing steroids and their effects,
please see
Anabolic steroid.
A steroid is a
lipid
characterized by a
carbon
skeleton with four fused rings. Different steroids vary in the
functional groups attached to these rings. Hundreds of distinct
steroids have been identified in
plants,
animals,
and fungi.
Their most important role in most living systems is as
hormones.
In human physiology and medicine, the most important steroids are
cholesterol, the
steroid hormones, and their
precursors and
metabolites.
In conversations, the term steroid is often used more
restrictively in specific contexts. For instance, steroid in common
medical usage by non-endocrinologists usually refers to
corticosteroids, nearly always
glucocorticoids. In an athletic or body-building context, steroid
commonly refers to
anabolic steroids.
Cholesterol is an important
steroid
alcohol, being a common component of animal
cell membranes. However, a high level of it can cause various
conditions and
diseases,
such as
atherosclerosis. Most other steroids are synthesized from cholesterol.
Also, various hormones, including
vertebrate
sex
hormones, are steroids created from cholesterol.
There are also various specific categories of steroids, including:
Steroid hormones produce their physiological effects by binding to
steroid hormone
receptor proteins. The binding of steroid hormones to their receptors
causes changes in gene
transcription and cell function.
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