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Metribolone
Metribolone (developmental code R1881, also known as methyltrienolone) is a synthetic and orally active anabolic–androgenic steroid (AAS) and a 17α-alkylated nandrolone (19-nortestosterone) derivative which was never marketed for medical use but has been widely used in scientific research as a hot ligand in androgen receptor (AR) ligand binding assays (LBAs) and as a photoaffinity label for the AR. More precisely, metribolone is the 17α-methylated derivative of trenbolone. It was investigated briefly for the treatment of advanced breast cancer in women in the late 1960s and early 1970s, but was found to produce signs of severe hepatotoxicity at very low dosages, and its development was subsequently discontinued. Medical uses Metribolone was never approved for medical use, a situation unlikely to change given its liver toxicity even at low doses. It was studied for the potential treatment of advanced breast cancer in women but development was abandoned. Side effects Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anabolic–androgenic Steroid
Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects to testosterone. They increase protein within cells, especially in skeletal muscles, and also have varying degrees of virilizing effects, including induction of the development and maintenance of masculine secondary sexual characteristics such as the growth of facial and body hair. The word ''anabolic'', referring to anabolism, comes from the Greek ἀναβολή ''anabole'', "that which is thrown up, mound". Androgens or AAS are one of three types of sex hormone agonists, the others being estrogens like estradiol and progestogens like progesterone. AAS were synthesized in the 1930s, and are now used therapeutically in medicine to stimulate muscle growth and appetite, induce male puberty and treat chronic wasting conditions, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anabolic Steroid
Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects to testosterone. They increase protein within cells, especially in skeletal muscles, and also have varying degrees of virilizing effects, including induction of the development and maintenance of masculine secondary sexual characteristics such as the growth of facial and body hair. The word ''anabolic'', referring to anabolism, comes from the Greek ἀναβολή ''anabole'', "that which is thrown up, mound". Androgens or AAS are one of three types of sex hormone agonists, the others being estrogens like estradiol and progestogens like progesterone. AAS were synthesized in the 1930s, and are now used therapeutically in medicine to stimulate muscle growth and appetite, induce male puberty and treat chronic wasting conditions, such as cancer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nandrolone
Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate (brand name Durabolin). Nandrolone esters are used in the treatment of anemias, cachexia (muscle wasting syndrome), osteoporosis, breast cancer, and for other indications. They are not used by mouth and instead are given by injection into muscle or fat. Side effects of nandrolone esters include symptoms of masculinization like acne, increased hair growth, voice changes, and decreased sexual desire due to its ability to suppress endogenous testosterone synthesis while not being a sufficient androgen itself. They are synthetic androgens and anabolic steroids and hence are agonists of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT). Nandrolone has strong anabolic effects and weak androgenic eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyltestosterone
Methyltestosterone, sold under the brand names Android, Metandren, and Testred among others, is an androgen and anabolic steroid (AAS) medication which is used in the treatment of low testosterone levels in men, delayed puberty in boys, at low doses as a component of menopausal hormone therapy for menopausal symptoms like hot flashes, osteoporosis, and low sexual desire in women, and to treat breast cancer in women. It is taken by mouth or held in the cheek or under the tongue. Side effects of methyltestosterone include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire. It can also cause estrogenic effects like fluid retention, breast tenderness, and breast enlargement in men and liver damage. The drug is a synthetic androgen and anabolic steroid and hence is an agonist of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT). It has moderate androgenic effects a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virilization
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens. Virilization is most commonly used in three medical and biology of sex contexts: prenatal biological sexual differentiation, the postnatal changes of typical chromosomal male (46, XY) puberty, and excessive androgen effects in typical chromosomal females (46, XX). It is also the intended result of androgen replacement therapy in males with delayed puberty and low testosterone. Prenatal virilization In the prenatal period, virilization refers to closure of the perineum, thinning and wrinkling (rugation) of the scrotum, growth of the penis, and closure of the urethral groove to the tip of the penis. In this context, ''masculinization'' is synonymous with ''virilization.'' Prenatal virilization of genetic females and undervirilization of genetic males are common causes of ambiguous genitalia and inters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology From the Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive Types of agonists Receptors can be activated by either agonists (such as[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anabolic
Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-down aspect. Anabolism is usually synonymous with biosynthesis. Pathway Polymerization, an anabolic pathway used to build macromolecules such as nucleic acids, proteins, and polysaccharides, uses condensation reactions to join monomers. Macromolecules are created from smaller molecules using enzymes and cofactors. Energy source Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in cellular respiration. Many anabolic processes are powered by the cleavage of adenosine triphosphate (ATP). Anabolism usually involves reduction and decreases entropy, making it unfavorable without energy input. The starting materials, called the precursor molecules, are joined using the chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") 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 hormones, females also have them, but at lower levels: they function in libido and sexual arousal. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potency (pharmacology)
In the field of pharmacology Pharmacology is a branch of medicine, biology and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemi ..., potency is a measure of drug activity expressed in terms of the amount required to produce an effect of given intensity. A highly potent drug (e.g., fentanyl, alprazolam, risperidone, bumetanide, bisoprolol) evokes a given response at low concentrations, while a drug of lower potency ( meperidine, diazepam, ziprasidone, furosemide, metoprolol) evokes the same response only at higher concentrations. Higher potency does not necessarily mean greater effectiveness or more side effects. The IUPHAR has stated that 'potency' is ''"an imprecise term that should always be further defined"'', for instance as EC_, IC_, ED_, LD_ and so on. See also * Reaction inhibitor § Potency References F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oral Administration
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are intended to have a systemic effect, reaching different parts of the body via the bloodstream, for example. Oral administration can be easier and less painful than other routes, such as injection. However, the onset of action is relatively low, and the effectiveness is reduced if it is not absorbed properly in the digestive system, or if it is broken down by digestive enzymes before it can reach the bloodstream. Some medications may cause gastrointestinal side effects, such as nausea or vomiting, when taken orally. Oral administration can also only be applied to conscious patients, and patients willing and able to swallow. Terminology ''Per os'' (; ''P.O.'') is an adverbial phrase meaning literally from Latin "through the mouth" or "by mouth ... [...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 ''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 of lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatotoxicity
Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn from the market after approval. The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses (e.g. paracetamol) and sometimes even when introduced within therapeutic ranges (e.g. halothane), may injure the organ. Other chemical agents, such as those used in laboratories and industries, natural chemicals (e.g., microcystins), and herbal remedies (two prominent examples being kava, mechanism unknown, and comfrey, through its pyrrolizidine alkaloid content) can also induce hepatotoxicity. Chemicals that cause liver injury are called hepatotoxins. More than 900 drugs have been implicated in causing liver injury (see LiverTox, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
