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5α-Dihydroethisterone
5α-Dihydroethisterone (5α-DHET; developmental code name HE-3562) is an active metabolite of the formerly clinically used but now-discontinued progestin ethisterone and the experimental and never-marketed hormonal antineoplastic agent ethynylandrostanediol (HE-3235). Its formation from its parent drugs is catalyzed by 5α-reductase in tissues that express the enzyme in high amounts like the liver, skin, hair follicles, and prostate gland. 5α-DHET has significant affinity for steroid hormone receptors and may contribute importantly to the activities of its parent drugs. Pharmacology Pharmacodynamics The affinity of 5α-DHET for the androgen receptor (AR) is relatively high, in the range of 38 to 100% of that of dihydrotestosterone (DHT). A study found that, similarly to norethisterone and its 5α-reduced metabolite 5α-dihydronorethisterone, 5α-DHET showed increased affinity for the AR but decreased androgenic potency relative to ethisterone (Ki = 16.1 nM for 5α-DHE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethisterone
Ethisterone, also known as ethinyltestosterone, pregneninolone, and anhydrohydroxyprogesterone and formerly sold under the brand names Proluton C and Pranone among others, is a progestin medication which was used in the treatment of gynecological disorders but is now no longer available. It was used alone and was not formulated in combination with an estrogen (medication), estrogen. The medication is taken oral administration, by mouth. Side effects of ethisterone include virilization, masculinization among others. Ethisterone is a progestin, or a synthetic compound, synthetic progestogen (medication), progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. It has some androgenic and anabolic activity and no other important hormonal agent, hormonal activity. Ethisterone was discovered in 1938 and was introduced for medical use in Germany in 1939 and in the United States in 1945. It was the second progestogen ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progestin
A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural female sex hormone progesterone in the body. A progestin is a '' synthetic'' progestogen. Progestogens are used most commonly in hormonal birth control and menopausal hormone therapy. They can also be used in the treatment of gynecological conditions, to support fertility and pregnancy, to lower sex hormone levels for various purposes, and for other indications. Progestogens are used alone or in combination with estrogens. They are available in a wide variety of formulations and for use by many different routes of administration. Examples of progestogens include natural or bioidentical progesterone as well as progestins such as medroxyprogesterone acetate and norethisterone. Side effects of progestogens include menstrual irregularities, headaches, nausea, breast tenderness, mood changes, acne, increased hair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Affinity (pharmacology)
In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from Latin ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a molecule which produces a signal by binding to a site on a target protein. The binding typically results in a change of conformational isomerism (conformation) of the target protein. In DNA-ligand binding studies, the ligand can be a small molecule, ion, or protein which binds to the DNA double helix. The relationship between ligand and binding partner is a function of charge, hydrophobicity, and molecular structure. Binding occurs by intermolecular forces, such as ionic bonds, hydrogen bonds and Van der Waals forces. The association or docking is actually reversible through dissociation. Measurably irreversible covalent bonding between a ligand and target molecule is atypical in biological systems. In contrast to the definition o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves ." '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, beta b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiandrogen
Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the androgen receptor (AR) and/or inhibiting or suppressing androgen production. They can be thought of as the functional opposites of AR agonists, for instance androgens and anabolic steroids (AAS) like testosterone, DHT, and nandrolone and selective androgen receptor modulators (SARMs) like enobosarm. Antiandrogens are one of three types of sex hormone antagonists, the others being antiestrogens and antiprogestogens. Antiandrogens are used to treat an assortment of androgen-dependent conditions. In men, antiandrogens are used in the treatment of prostate cancer, enlarged prostate, scalp hair loss, overly high sex drive, unusual and problematic sexual urges, and early puberty. In women, antiandrogens are used to treat acne, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Agonist
In pharmacology, partial agonists are drugs that bind to and activate a given Receptor (biochemistry), receptor, but have only partial Intrinsic activity, efficacy at the receptor relative to a full agonist. They may also be considered Ligand (biochemistry), ligands which display both agonistic and Receptor antagonist, antagonistic effects—when both a full agonist and partial agonist are present, the partial agonist actually acts as a competitive antagonist, competing with the full agonist for receptor occupancy and producing a net decrease in the receptor activation observed with the full agonist alone. Clinically, partial agonists can be used to activate receptors to give a desired submaximal response when inadequate amounts of the endogenous ligand are present, or they can reduce the overstimulation of receptors when excess amounts of the endogenous ligand are present. Some currently common drugs that have been classed as partial agonists at particular receptors include buspi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selective Androgen Receptor Modulator
Selective androgen receptor modulators (SARMs) are a class of drugs that tissue selectivity, selectively activate the androgen receptor in specific tissue (biology), tissues, promoting muscle and bone growth while having less effect on male reproductive system, male reproductive tissues like the prostate gland. Non-selective steroidal drugs, called anabolic androgenic steroids (AAS), have been used for various medical purposes, but their side effects limit their use. In 1998, researchers discovered a new class of non-steroidal compounds, the SARMs. These compounds selectively stimulate the androgen receptor, offering potent effects on bone and muscle to increase bone density and lean body mass while having minimal impact on reproductive tissues. SARMs have been investigated in human studies for the treatment of osteoporosis, cachexia (wasting syndrome), benign prostatic hyperplasia, stress urinary incontinence, and breast cancer. , there are no SARMs which have been approved b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist
An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an Receptor antagonist, antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology The word originates from the Ancient Greek, Greek word (''agōnistēs''), "contestant; champion; rival" < (''agōn''), "contest, combat; exertion, struggle" < (''agō''), "I lead, lead towards, conduct; drive." Types of agonists Receptor (biochemistry), Receptors can be activated by either endogenous agonists (such as hormones and neurotransmitters) or exogenous agonists (such as medication, drugs), resulting in a biological response. A physiological agonism an ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Efficacy
Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as '' effectiveness'', and it has often been used synonymously, although in pharmacology a distinction is now often made between efficacy and effectiveness. The word ''efficacy'' is used in pharmacology and medicine to refer both to the maximum response achievable from a pharmaceutical drug in research settings, and to the capacity for sufficient therapeutic effect or beneficial change in clinical settings. Pharmacology In pharmacology, efficacy () is the maximum response achievable from an applied or dosed agent, for instance, a small molecule drug. Intrinsic activity is a relative term for a drug's efficacy relative to a drug with the highest observed efficacy. It is a purely descriptive term that has little or no mechanistic interpretation. In order for a drug to have an effect, it needs to bind to its target, and then to affect the function of this tar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potency (pharmacology)
In pharmacology, potency or biological potency is a measure of a drug's biological activity expressed in terms of the dose required to produce a pharmacological effect of given intensity. A highly potent drug (e.g., fentanyl, clonazepam, risperidone, benperidol, bumetanide) evokes a given response at low concentrations, while a drug of lower potency (e.g. morphine, alprazolam, ziprasidone, haloperidol, furosemide) evokes the same response only at higher concentrations. Higher potency does not necessarily mean greater effectiveness nor more side effects nor less side effects. Types of potency The International Union of Basic and Clinical Pharmacology (IUPHAR) has stated that "potency is an imprecise term that should always be further defined", and lists of types of potency as follows: Miscellaneous Lysergic acid diethylamide (LSD) is one of the most potent psychoactive drug A psychoactive drug, psychopharmaceutical, mind-altering drug, consciousness-altering drug, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androgen
An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes the embryological development of the primary male sex organs, and the development of male secondary sex characteristics at puberty. Androgens are synthesized in the testes, the ovaries, and the adrenal glands. Androgens increase in both males and females during puberty. The major androgen in males is testosterone. Dihydrotestosterone (DHT) and androstenedione are of equal importance in male development. DHT ''in utero'' causes differentiation of the penis, scrotum and prostate. In adulthood, DHT contributes to balding, prostate growth, and sebaceous gland activity. Although androgens are commonly thought of only as male Sex steroids, sex hormones, females also have them, but at lower levels: they function in libido and sexual arousal. An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
