- Plural of steroid
A steroid is a terpenoid lipid characterized by a carbon skeleton with four fused rings, generally arranged in a 6-6-6-5 fashion.
Steroids vary by the functional groups attached to these rings and the oxidation state of the rings. Hundreds of distinct steroids are found in plants, animals, and fungi. All steroids are made in cells either from the sterol lanosterol (animals and fungi) or the sterol cycloartenol (plants). Both sterols are derived from the cyclization of the triterpene squalene.
OriginSteroids include estrogen (US spelling) or oestrogen (UK/AUS spelling), progesterone and testosterone. Estrogen and progesterone are made primarily in the ovary and in the placenta during pregnancy and testosterone in the testes. Testosterone is also converted into estrogen to regulate the supply of each, in the bodies of both females and males. Certain neurons and glia in the central nervous system (CNS) express the enzymes that are required for the local synthesis of pregnane neurosteroids, either de novo or from peripherally derived sources. The rate limiting step of steroid synthesis is the conversion of cholesterol to pregnenolone which occurs inside the mitochondrion.
Taxonomical/FunctionalSome of the common categories of steroids:
- Animal steroids
- Ecdysteroids such as ecdysterone
- Sex steroids are a subset of sex hormones that produce sex differences or support reproduction. They include androgens, estrogens, and progestagens.
- Corticosteroids include glucocorticoids and mineralocorticoids. Glucocorticoids regulate many aspects of metabolism and immune function, whereas mineralocorticoids help maintain blood volume and control renal excretion of electrolytes.
- Anabolic steroids are a class of steroids that interact with androgen receptors to increase muscle and bone synthesis. There are natural and synthetic anabolic steroids. In popular language the word "steroids" usually refers to anabolic steroids.
- Cholesterol which modulates the fluidity of cell membranes and is the principle constituent of the plaques implicated in atherosclerosis.
- Steroid hormones
- Insect steroids
- Plant steroids
- Fungus steroids
StructuralIt is also possible to classify steroids based upon their chemical composition. One example of how MeSH performs this classification is available at the Wikipedia MeSH catalog. Examples from this classification include:
- Michael W. King's Medical Biochemistry. Steroids and retinoids are both terpenes which are hydrophobic, pass through cell membranes and bind to intracellular receptors. However, retinoic acid is not a steroid because it does not have the defining ring structure. See: [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Search&db=books&doptcmdl=GenBookHL&term=retinoids+AND+stryer%5Bbook%5D+AND+217301%5Buid%5D&rid=stryer.section.4466#4467 Steroids and Related Hydrophobic Molecules].
- "Biochemistry" by Jeremy M. Berg, John L. Tymoczko and Lubert Stryer (2002) W. H. Freeman and Co. steroid topics in this
- Steroids, Rage and Criminal Activity -- Video: Insidermedicine.com's Maria Radina on Anabolic Androgenic Steroids, as presented in a study in Archives of General Psychiatry.
- Nomenclature of Steroids Home Page at Queen Mary University of London.
- href="http://il-st-acad-sci.org/steroid0.html">http://il-st-acad-sci.org/steroid0.html Steroid abbreviations at ISAS (page now defunct, web archive version)
steroids in Arabic: ستيرويد
steroids in Bulgarian: Стероид
steroids in Catalan: Esteroide
steroids in Czech: Steroidy
steroids in German: Steroide
steroids in Spanish: Esteroide
steroids in Esperanto: Steroido
steroids in French: Stéroïde
steroids in Korean: 스테로이드
steroids in Croatian: Steroidi
steroids in Italian: Steroide
steroids in Hebrew: סטרואיד
steroids in Malay (macrolanguage): Steroid
steroids in Dutch: Steroïde
steroids in Japanese: ステロイド
steroids in Norwegian: Steroid
steroids in Occitan (post 1500): Esteroïd
steroids in Polish: Steroidy
steroids in Portuguese: Esteróide
steroids in Romanian: Steroid
steroids in Russian: Стероиды
steroids in Simple English: Steroid
steroids in Slovak: Steroid
steroids in Serbian: Стероиди
steroids in Serbo-Croatian: Steroidi
steroids in Finnish: Steroidi
steroids in Swedish: Steroid
steroids in Thai: สเตอรอยด์
steroids in Turkish: Steroid
steroids in Chinese: 類固醇