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5α-Dihydrodeoxycorticosterone
5α-Dihydrodeoxycorticosterone (abbreviated as DHDOC), also known as 21-hydroxy-5α-pregnan-20-one, is an endogenous progestogen and neurosteroid. It is synthesized from the adrenal hormone deoxycorticosterone (DOC) by the enzyme 5α-reductase type I. DHDOC is an agonist of the progesterone receptor, as well as a positive allosteric modulator of the GABAA receptor, and is known to have anticonvulsant effects. Chemistry See also * Tetrahydrodeoxycorticosterone (THDOC) * 5α-Dihydroprogesterone (DHP) * Hydroxydione Hydroxydione, as hydroxydione sodium succinate (, , ) (brand names Viadril, Predion, and Presuren), also known as 21-Hydroxy-5β-pregnane-3,20-dione, is a neuroactive steroid which was formerly used as a general anesthetic, but was discontinued ... References {{GABAAR PAMs Neurosteroids Pregnanes Progestogens GABAA receptor positive allosteric modulators ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endogenous
Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, estradiol is an endogenous estrogen hormone produced within the body, whereas ethinylestradiol Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. In the past, EE was widely used for various indications such as the treatment of menopausal symptoms, gynecological disord ... is an exogenous synthetic estrogen, commonly used in birth control pills. References External links *{{Wiktionary-inline, endogeny Biology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor
The GABAA receptor (GABAAR) is an ionotropic receptor and ligand-gated ion channel. Its endogenous ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Upon opening, the GABAA receptor on the postsynaptic cell is selectively permeable to chloride ions (Cl−) and, to a lesser extent, bicarbonate ions (HCO3−). Depending on the membrane potential and the ionic concentration difference, this can result in ionic fluxes across the pore. If the membrane potential is higher than the equilibrium potential (also known as the reversal potential) for chloride ions, when the receptor is activated Cl− will flow into the cell. This causes an inhibitory effect on neurotransmission by diminishing the chance of a successful action potential occurring at the postsynaptic cell. The reversal potential of the GABAA-mediated inhibitory postsynaptic potential (IPSP) in normal solution is −70 mV, contrasting the GABAB IPSP (-100 mV). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pregnanes
Pregnane, also known as 17β-ethylandrostane or as 10β,13β-dimethyl-17β-ethylgonane, is a C21 steroid and, indirectly, a parent of progesterone. It is a parent hydrocarbon for two series of steroids stemming from 5α-pregnane (originally allopregnane) and 5β-pregnane (17β-ethyletiocholane). It has a gonane core. 5β-Pregnane is the parent of pregnanediones, pregnanolones, and pregnanediols, and is found largely in urine as a metabolic product of 5β-pregnane compounds. Pregnanes Pregnanes are steroid derivatives with carbons present at positions 1 through 21. Most biologically significant pregnane derivatives fall into one of two groups: pregnenes and pregnadienes. Another class is pregnatrienes. Pregnenes Pregnenes have a double bond. Examples include: * Cortisone * Hydrocortisone * Progesterone Pregnadienes Pregnadienes have two double bonds. Examples include: * Cyproterone acetate * Danazol * Fluocinonide See also * 5β-Pregnane * Pregnanedione * Pregna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurosteroids
Neurosteroids, also known as neuroactive steroids, are endogenous or exogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. The term ''neurosteroid'' was coined by the French physiologist Étienne-Émile Baulieu and refers to steroids synthesized in the brain. The term, ''neuroactive steroid'' refers to steroids that can be synthesized in the brain, or are synthesized by an endocrine gland, that then reach the brain through the bloodstream and have effects on brain function. The term neuroactive steroids was first coined in 1992 by Steven Paul and Robert Purdy. In addition to their actions on neuronal membrane receptors, some of these steroids may also exert effects on gene expression via nuclear steroid hormone receptors. Neurosteroids have a wide range of potential clinical applications from sedation to treatment of epilepsy and traumatic brain injury. Ganaxolone, a synthetic analog of the end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxydione
Hydroxydione, as hydroxydione sodium succinate (, , ) (brand names Viadril, Predion, and Presuren), also known as 21-Hydroxy-5β-pregnane-3,20-dione, is a neuroactive steroid which was formerly used as a general anesthetic, but was discontinued due to incidence of thrombophlebitis in patients. It was introduced in 1957, and was the first neuroactive steroid general anesthetic to be introduced for clinical use, an event which was shortly preceded by the observation in 1954 of the sedative properties of progesterone in mice. Chemistry Related compounds include alfadolone, alfaxolone, dihydrodeoxycorticosterone, ganaxolone, minaxolone, pregnanolone, and renanolone Renanolone ( INN), or 11-ketopregnanolone, also known as 5β-pregnan-3α-ol-11,20-dione, is a synthetic neuroactive steroid which is described as a general anesthetic but was never introduced for clinical use. Its isomers, alfaxolone and alfadolon .... References {{GABAA receptor positive modulators 5β-Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5α-Dihydroprogesterone
5α-Dihydroprogesterone (5α-DHP, allopregnanedione, or 5α-pregnane-3,20-dione) is an endogenous progestogen and neurosteroid that is synthesized from progesterone. It is also an intermediate in the synthesis of allopregnanolone and isopregnanolone from progesterone. 5α-DHP is metabolized by the aldo-keto reductases (AKRs) AKR1C1, AKR1C2, and AKR1C4 with high catalytic efficiency. AKR1C1 preferentially forms 20α-hydroxy-5α-pregnane-3-one while AKR1C2 preferentially forms allopregnanolone. Similarly AKR1C1 reduces and consequently inactivates allopregnanolone into 5α-pregnane-3α,20α-diol. In contrast to the other AKRs, AKR1C3 has low catalytic efficiency for reduction of 5α-DHP. These AKRs are highly expressed in the human liver and mammary gland but have relatively modest expression in the human brain and uterus. 5α-DHP is an agonist of the progesterone receptor and a positive allosteric modulator of the GABAA receptor (albeit with an affinity for this receptor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydrodeoxycorticosterone
Tetrahydrodeoxycorticosterone (abbreviated as THDOC; 3α,21-dihydroxy-5α-pregnan-20-one), also referred to as ''allotetrahydrocorticosterone'', is an endogenous neurosteroid. It is synthesized from the adrenal hormone deoxycorticosterone by the action of two enzymes, 5α-reductase type I and 3α-hydroxysteroid dehydrogenase. THDOC is a potent positive allosteric modulator of the GABAA receptor, and has sedative, anxiolytic and anticonvulsant effects. Changes in the normal levels of this steroid particularly during pregnancy and menstruation may be involved in some types of epilepsy ( catamenial epilepsy) and premenstrual syndrome, as well as stress, anxiety and depression. Chemistry See also * Allopregnanolone * Dihydrodeoxycorticosterone (DHDOC) * Tetrahydrocorticosterone 3α,5α-Tetrahydrocorticosterone (3α,5α-THB), or simply tetrahydrocorticosterone (THB or THCC), is an endogenous glucocorticoid hormone. See also * 5α-Dihydrocorticosterone * Tetrahydrodeoxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticonvulsant
Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder and borderline personality disorder, since many seem to act as mood stabilizers, and for the treatment of neuropathic pain. Anticonvulsants suppress the excessive rapid firing of neurons during seizures. Anticonvulsants also prevent the spread of the seizure within the brain. Conventional antiepileptic drugs may block sodium channels or enhance γ-aminobutyric acid ( GABA) function. Several antiepileptic drugs have multiple or uncertain mechanisms of action. Next to the voltage-gated sodium channels and components of the GABA system, their targets include GABAA receptors, the GAT-1 GABA transporter, and GABA transaminase. Additional targets include voltage-gated calcium channels, SV2A, and α2δ. By blocking sodium or ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive Allosteric Modulator
In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allosteric modulator binds to (i.e., an ''allosteric site'') is not the same one to which an endogenous agonist of the receptor would bind (i.e., an ''orthosteric site''). Modulators and agonists can both be called receptor ligands. Allosteric modulators can be 1 of 3 types either: positive, negative or neutral. Positive types increase the response of the receptor by increasing the probability that an agonist will bind to a receptor (i.e. affinity), increasing its ability to activate the receptor (i.e. efficacy), or both. Negative types decrease the agonist affinity and/or efficacy. Neutral types don't affect agonist activity but can stop other modulators from binding to an allosteric site. Some modulators also work as allosteric agonists. The term "allosteric" derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. The progestogens are named for their function in maintaining pregnancy (i.e., ''progestational''), although they are also present at other phases of the estrous and menstrual cycles. The progestogens are one of three types of sex hormones, the others being estrogens like estradiol and androgens/anabolic steroids like testosterone. In addition, they are one of the five major classes of steroid hormones, the others being the androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as the neurosteroids. All endogenous progestogens are characterized by their basic 21-carbon skeleton, called a pregnane skeleton (C21). In similar manner, the estrogens possess an estrane skeleton (C18), and androgens, an androstane skeleton (C19). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progesterone Receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene residing on chromosome 11q22, it has two isoforms, PR-A and PR-B, that differ in their molecular weight. The PR-B is the positive regulator of the effects of progesterone, while PR-A serve to antagonize the effects of PR-B. Mechanism Progesterone is necessary to induce the progesterone receptors. When no binding hormone is present the carboxyl terminal inhibits transcription. Binding to a hormone induces a structural change that removes the inhibitory action. Progesterone antagonists prevent the structural reconfiguration. After progesterone binds to the receptor, restructuring with dimerization follows and the complex enters the nucleus and binds to DNA. There transcription takes place, resulting in formation of messenger RNA that is tra ... [...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 can be activated by either endogenous agonists (such as |
