steroid

Biochem any of a large group of fat-soluble organic compounds containing a characteristic chemical ring system. The majority, including the sterols, bile acids, many hormones, and the D vitamins, have important physiological action

Steroid

Any of a group of organic compounds belonging to the general class of biochemicals called lipids, which are easily soluble in organic solvents and slightly soluble in water. Additional members of the lipid class include fatty acids, phospholipids, and triacylglycerides. The unique structural characteristic of steroids is a four-fused ring system. Members of the steroid family are ubiquitous, occurring, for example, in plants, yeast, protozoa, and higher forms of life. Steroids exhibit a variety of biological functions, from participation in cell membrane structure to regulation of physiological events. Naturally occurring steroids and their synthetic analogs are used extensively in medical practice.

Each steroid contains three fused cyclohexane (six-carbon) rings plus a fourth cyclopentane ring (see illustration). Naturally occurring steroids have an oxygen-containing group at carbon-3. Shorthand formulas for steroids indicate the presence of double bonds, as well as the structure and position of oxygen-containing or other organic groups.

Steroid skeleton

The most abundant steroid in mammalian cells is cholesterol. The levels and locations of planar cholesterol molecules, embedded in the phospholipid bilayers that form cell and organelle membranes, are known to influence the structure and function of the membranes. A second major function of cholesterol is to serve as a precursor of steroids acting as physiological regulators (such as the steroid hormones). Enzyme systems present in a hormone-secreting gland convert cholesterol to the hormone specific for that gland. For example, the ovary produces estrogens (such as estradiol and progesterone); the testis produces androgens (such as testosterone); the adrenal cortex produces hormones that regulate metabolism (such as cortisol) and sodium ion transport (such as aldosterone). A third major function of cholesterol is to serve as a precursor of the bile acids. These detergentlike molecules are produced in the liver and stored in the gall bladder until needed to assist in the absorption of dietary fat and fat-soluble vitamins and in the digestion of dietary fat by intestinal enzymes. See Cell membranes, Cholesterol, Sterol

Some examples of diseases treated with naturally occurring or synthetic steroids are allergic reactions, arthritis, some malignancies, and diseases resulting from hormone deficiencies or abnormal production. In addition, synthetic steroids that mimic an action of progesterone are widely used oral contraceptive agents. Other synthetic steroids are designed to mimic the stimulation of protein synthesis and muscle-building action of naturally occurring androgens. See Hormone, Lipid

Steroid

a group of organic compounds belonging by virtue of their chemical nature to the isoprenoids. The various types of steroids are widely distributed throughout the biological world and are encountered in microorganisms, plants, and animals. One of the main directions in the chemical evolution of steroids has been that toward specialization as biological regulators —hormones and other substances.

In a formal sense, all steroids are derivatives of the hypothetical hydrocarbon sterane (I, where R = H); biogenetically, the steroids derive from squalene, which is converted into the immediate polycyclic steroid precursors lanosterol (in animals) or cy-cloartenol (in plants). These precursors contain 30 carbon atoms (C₃₀). Nearly all steroids are crystalline substances that possess optical activity and dissolve more readily in organic solvents than in water.

The classification of steroids is based on chemical structure and on the nature of the physiological effect or function. There are eight groups of steroids.

The first group comprises the sterols, which contain a branched side chain R made up of 8–10 carbon atoms. Sterols are components of plant and animal lipids, and the most important sterol—cholesterol—participates in the biosynthesis of steroid hormones.

The second group—D vitamins—is made up of unsaturated isomers of sterols (with ring B open). These isomers act to regulate calcium metabolism and the formation of the skeleton in vertebrates.

The third group includes the bile alcohols and bile acids, which contain a hydroxyl or carboxylic group in the side chain (consisting of eight or five carbon atoms). These substances aid in the digestion of food in the intestines of vertebrates.

The fourth group is that of the aglycones (genins) of steroid saponins and steroid glycoalkaloids. Typical representatives of this group are diosgenin (II, where X = O) and solasodine (II, where X = NH). Both groups of aglycones are characteristic of plants of the Liliaceae, Scrophulariaceae, and Solanaceae families, and in the form of glycosides, they have surface-active and hemolytic properties.

The fifth group comprises steroid alkaloids of other types. Among them are C₂₇ alkaloids with modified steroid skeletons (jerveratrum, ceveratrum), which stimulate the contraction of striated muscle, C₂₁ alkaloids, which possess bactericidal and amebicidal action, and modified C₂₁ alkaloids from the glands of amphibians (samandarine, “toad poisons”), which are cardiotox-ic, as well as highly toxic to the central nervous system.

The sixth group is that of the cardiac genins, containing a side chain in the form of an unsaturated five-membered ring (C₂₃ car-denolides) or six-membered lactone ring (C₂₄ bufodienolides). These substances can strengthen the contraction of cardiac muscles by inhibiting the enzyme ATPase in the membrane of the heart cells. Cardenolides are found in many plants, while bufodienolides are found primarily in the venom from the cutaneous glands of toads.

The seventh group comprises the steroid sex hormones and the products of the hormones’ conversions. These substances determine the development and operation of the sexual system in animals. They include progesterone and related C₂₁ compounds, in which the side chain R contains two carbon atoms, as well as the male sex hormones—androgens—which contain 19 carbon atoms, and the female sex hormones—estrogens—which contain 18 carbon atoms. A hydroxyl or carbonylic group replaces the side chain in androgens and estrogens.

The last group includes the hormones of the adrenal cortex—corticosteroids (where R = COCH₂OH)—which regulate the balance of electrolytes and the metabolism of carbohydrates in vertebrates. Certain triterpene antibiotics (fusidic acid, cephalosporin P]) and other triterpenes are similar to steroids.

The biosynthesis of steroids is an operation more characteristic of higher vertebrates. Insects do not produce steroids and instead obtain these compounds from their food. However, the critical function of molting is controlled by a special type of C₂₇ sterol known as ecdysone. Derivatives of progesterone serve as a means of chemical protection for a number of species of insects. Sexual reproduction in certain lower fungi (Achlya) is also induced by steroids. Steroids may participate in the morphogenesis of vascular plants. Inhibitors of the biosynthesis of steroids prevent the reproduction of certain fungi and the flowering of higher plants.

The chemistry, biochemistry, and physiological activity of steroids are under intense study in light of the great importance of steroids in medicine, veterinary science, and animal husbandry. In industry, chemical and microbiological methods have been introduced for the partial synthesis of steroid hormones from available raw materials (sterols, bile acids, saponins), and in the 1960’s and 1970’s methods have been introduced for complete chemical synthesis from the simplest starting materials. The synthesis of “artificial” steroid hormones with specialized physiological effects (contraceptive, anabolic), in particular, fluorine-containing and nitrogen-containing analogs, is acquiring increasing importance.

REFERENCES

Trudy V Mezhdunarodnogo biokhimicheskogo kongressa [vol. 7]: Biosintez lipidov. Moscow, 1962.
Fieser, L., and M. Fieser. Steroidy. Moscow, 1964. (Translated from English.)
Bersin, T. Biokhimiia gormonov. Moscow, 1964. (Translated from German.)
Heftmann, E. M. Biokhimiia steroidov. Moscow, 1972. (Translated from English.)
Akhrem, A. A., and Iu. A. Titov. Poleznyisintezsteroidov. Moscow, 1967.
Akhrem, A. A., and Iu. A. Titov. Steroidy i mikroorganizmy. Moscow, 1970.
Heftmann, E. “Biochemistry of Plant Steroids.” Annual Review of Plant Physiology, 1963, vol. 14, pp. 225–48.
Krüskemper, H. L. Anabolic Steroids. New York, 1968.
The Sex Steroids. Edited by K. W. McKerns. New York, 1971.

E. P. SEREBRIAKOV

steroid

[′sti‚rȯid] (biochemistry) A member of a group of compounds, occurring in plants and animals, that are considered to be derivatives of a fused, reduced ring system, cyclopenta[α]-phenanthrene, which consists of three fused cyclohexane rings in a nonlinear or phenanthrene arrangement.

steroid

[ster´oid] any of a group of lipids with a complex molecule containing carbon atoms in four interlocking rings forming a hydrogenated cyclopentophenanthrene-ring system; three of the rings contain six carbon atoms each and the fourth contains five. Steroids are important in body chemistry and include steroid hormones such as the gonadal or steroids" >sex steroids, corticosteroids, glucocorticoids, and mineralocorticoids; vitamins" >vitamins of the D group; and the sterols, including cholesterol, the main building block of the steroid hormones in the body. The glycosides" >cardiac glycosides, a group of compounds derived from certain plants, are partly steroids.anabolic steroid any of a group of synthetic derivatives of testosterone having pronounced anabolic properties and relatively weak androgenic properties; they are used clinically mainly to promote growth and repair of body tissues in diseases or states promoting catabolism or tissue wasting.gonadal steroid (sex steroid) a steroid hormone produced by a gonad, such as an androgen, estrogen, or progestational agent.

ster·oid

(stēr'oyd, ster'oyd), Avoid using the simple word steroid in a special sense, such as adrenal corticosteroid (or corticoid) or anabolic steroid, unless the meaning is clear from the context.1. Pertaining to the steroids. Synonym(s): steroidal Compare: steroids. 2. One of the steroids (for example, sterols, bile acids, cardiac glycosides, androgens, estrogens, corticosteroids, precursors of the D vitamins). Synonym(s): sterid3. Generic designation for compounds closely related in structure to the steroids, such as sterols, bile acids, cardiac glycosides, androgens, estrogens, corticosteroids, and precursors of the D vitamins. [G. stereos, solid; solid lipids vs oils]

steroid

(stĕr′oid′, stîr′-)n.1. Any of numerous fat-soluble organic compounds that have a core structure of 17 carbon atoms arranged in four rings, found naturally in animals, plants, and fungi, or produced synthetically. Steroids include the sterols (such as cholesterol), sex hormones (such as estrogen and testosterone), corticosteroid hormones (such as cortisol), bile acids, and anabolic steroids.2. Informal An anabolic steroid.

ste′roid′, ste·roi′dal (stĕ-roid′l, stĭ-) adj.

steroid

adjective Pertaining to steroid hormones noun 1. A cholesterol-derived lipid that is the parent compound for steroid hormones of the adrenal gland and gonads.2. Steroid hormone A hormone produced from modified cholesterol Examples Hormones from testis, ovary, adrenal cortex, etc Uses Relief of swelling, inflammation. See Anabolic steroid, Corticosteroid, Glucocorticosteroid, Ketogenic steroid. Cf Peptide hormone.3. Any compound–eg, bile acids, cardiac glycosides, vitamin D precursors, that is struturally similar–ie, has a cyclopentaphenanthrene core–to steroid hormones.

ster·oid

(ster'oyd) 1. Pertaining to the steroids.
Synonym(s): steroidal. 2. Generic designation for compounds closely related in structure to the steroids, such as sterols, bile acids, cardiac glycosides, and precursors of the D vitamins.
Compare: bioregulator
Compare: steroids[G. stereos, solid; solid lipids vs. oils]

steroid

1. Sterol-like. 2. Any member of the class of fat-soluble organic compounds based on a structure of 17 carbon atoms arranged in three connected rings of six, six and five carbons. The steroids include the adrenal cortex hormones, the SEX HORMONES, PROGESTOGENS, BILE SALTS, STEROLS and a wide range of synthetic compounds produced for therapeutic purposes. Anabolic steroids are male sex hormones that stimulate the production of protein.

steroid

an important but unusual type of LIPID, formed of four rings of carbon atoms with various side groups, such as cholesterol, digitoxin (which forms part of the heart-stimulating drug digitalis) and cortisone.

Steroid

A natural body substance that often is given to women before delivering a very premature infant to stimulate the fetal lungs to produce surfactant, hopefully preventing RDS (or making it less severe).Mentioned in: Barbiturate-Induced Coma, Hypersensitivity Pneumonitis, Respiratory Distress Syndrome

steroid

One of a group of hormonal substances produced mainly by the adrenal cortex. They fall into three main groups: glucocorticoids (or glucocorticosteroids), mineralocorticoids and sex hormones. The glucocorticoids have antiinflammatory properties reducing vasodilatation, stabilizing mast cells thus decreasing the release of histamine and maintaining the normal permeability of blood thus preventing oedema. They also inhibit the production of prostaglandins, which mediate some of the effects of inflammation. They are widely used in the treatment of a variety of inflammatory diseases of various organs including the eye (e.g. allergic and vernal conjunctivitis, corneal diseases, iritis, uveitis and sympathetic ophthalmia). The natural glucocorticoids, such as cortisone and hydrocortisone, are effective only at high doses. Synthetic and more potent steroids are used in ophthalmic treatment (when used as ophthalmic preparations they are called corticosteroids). They include, betamethasone, dexamethasone, fluorometholone, prednisolone and triamcinolone. See antiinflammatory drug.

ster·oid

(ster'oyd) 1. Pertaining to the steroids. 2. One of the steroids (e.g., sterols, bile acids, cardiac glycosides, androgens, estrogens, corticosteroids, precursors of the D vitamins). [G. stereos, solid; solid lipids vs. oils]

Patient discussion about steroid

Q. Does steroids make children shorter? My 10 years-old son has asthma, and is treated with a steroid inhaler. Will this treatment cause him to be shorter in the future?A. I don't think so. My cousin had asthma very badly when he was young, and he grew up to be tall, strong and healthy, thank goodness. Sometimes one does outgrow this, sometimes now, but as far as growth goes, I don't think it will stump growth.

Q. what sort of diet should I take to tone up my muscle and to lose fat in my body? Is steroid a good idea? A. as williams41 say- it's a BAD idea... steroids wil damage your body immune system and can get you more prone to bacterial/virus/fungal attacks. it also have unhealthy side effects that one of them is distribution of fat in the face area that can be unpleasant. so consider your steps...

Q. Had FMS for almost twenty years now, tried almost everything. Is Lyrica in the "steroid" family? Any one in this community could help me? I have given my few questions to find out an answer. I Had FMS for almost twenty years now, tried almost everything. I'm considering Lyrica but I'd like more info. Is Lyrica in the "steroid" family? If you go on Lyrica for a while & see no improvement with pain, is going off of it a big deal like with other med's, or can you simply just stop taking it? I take Ambien, will that have any interactions? I'm seeing my Doc about this at the end of the month, but I was hoping to get some personal experiences about it. Thanks for any thoughts! Thanks for your answers, keep them coming!A. according to this-
http://www.drugs.com/drug_interactions.php
there is a moderate interaction. that means you can take them both but be checked regularly for depression of breath.

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Patient discussion about steroid

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Synonyms for steroid

noun any of several fat-soluble organic compounds having as a basis 17 carbon atoms in four rings

Related Words

noun any hormone affecting the development and growth of sex organs

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