|
Gabazine
Gabazine (SR-95531) is a drug that acts as an antagonist at GABAA receptors. It is used in scientific research and has no role in medicine, as it would be expected to produce convulsions if used in humans. Gabazine binds to the GABA recognition site of the receptor-channel complex and acts as an allosteric inhibitor of channel opening. The net effect is to reduce GABA-mediated synaptic inhibition by inhibiting chloride The term chloride refers to a compound or molecule that contains either a chlorine anion (), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (). The pr ... flux across the cell membrane, and thus inhibiting neuronal hyperpolarization. While phasic (synaptic) inhibition is gabazine-sensitive, tonic (extrasynaptic) inhibition is relatively gabazine-insensitive. Gabazine has been found to bind to and antagonize α4βδ subunit-containing GABAA receptors, which may rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convulsants
A convulsant is a drug which induces convulsions or epileptic seizures, the opposite of an anticonvulsant. These drugs generally act as stimulants at low doses, but are not used for this purpose due to poor therapeutic index, therapeutic indices. Most convulsants are Receptor antagonist, antagonists (or inverse agonists) at either the GABA-A receptor, GABAA or/and glycine receptors (e.g the pesticide fipronil), or Ligand-gated ion channel, ionotropic glutamate receptor agonists (e.g the marine toxin domoic acid). Many other drugs may cause convulsions as a side effect at high doses (e.g. bupropion, tramadol, pethidine, dextropropoxyphene, clomipramine) but only drugs whose primary action is to cause convulsions are known as convulsants. Nerve agents such as sarin, which were developed as chemical weapons, produce convulsions as a major part of their toxidrome, but also produce a number of other effects in the body and are usually classified separately. Dieldrin which was developed a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GHB Receptor
The γ-hydroxybutyrate (GHB) receptor (GHBR), originally identified as GPR172A, is an excitatory G protein-coupled receptor (GPCR) that binds the neurotransmitter and psychoactive drug γ-hydroxybutyric acid (GHB). As solute carrier family 52 member 2 (SLC52A2), it is also a transporter for riboflavin. History The existence of a specific GHB receptor was predicted by observing the action of GHB and related compounds that primarily act on the GABAB receptor, but also exhibit a range of effects which were found not to be produced by GABAB activity, and so were suspected of being produced by a novel and at the time unidentified receptor target. Following the discovery of the "orphan" G-protein coupled receptor GPR172A, it was subsequently found to be the GHB receptor whose existence had been previously predicted. The rat GHB receptor was first cloned and characterised in 2003, followed by the human receptor in 2007. Due to its many functions, this gene has a history of multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains. Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm. Natural occurrence Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper. Formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Subunit
In structural biology, a protein subunit is a polypeptide chain or single protein molecule that assembles (or "''coassembles''") with others to form a protein complex. Large assemblies of proteins such as viruses often use a small number of types of protein subunits as building blocks. A subunit is often named with a Greek or Roman letter, and the numbers of this type of subunit in a protein is indicated by a subscript. For example, ATP synthase has a type of subunit called α. Three of these are present in the ATP synthase molecule, leading to the designation α3. Larger groups of subunits can also be specified, like α3β3-hexamer and c-ring. Naturally occurring proteins that have a relatively small number of subunits are referred to as oligomeric.Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridazines
Pyridazine is an aromatic, heterocyclic, organic compound with the molecular formula . It contains a six-membered Ring (chemistry), ring with two adjacent nitrogen atoms. It is a colorless liquid with a boiling point of 208 °C. It is Structural isomer, isomeric with two other diazine () rings, pyrimidine and pyrazine. Occurrence Pyridazines are rare in nature, possibly reflecting the scarcity of naturally occurring hydrazines, common building blocks for the synthesis of these heterocycles. The pyridazine structure is a popular pharmacophore which is found within a number of herbicides such as credazine, pyridafol and pyridate. It is also found within the structure of several drugs such as cefozopran, cadralazine, minaprine, pipofezine, and hydralazine. Synthesis In the course of his classic investigation on the Fischer indole synthesis, Emil Fischer prepared the first pyridazine via the condensation of phenylhydrazine and levulinic acid. The parent heterocycle was first pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA-rho Receptor Antagonists
The GABAA-rho receptor (previously known as the GABAC receptor) is a subclass of GABAA receptors composed entirely of rho (ρ) subunits. GABAA receptors including those of the ρ-subclass are ligand-gated ion channels responsible for mediating the effects of gamma-amino butyric acid (GABA), the major inhibitory neurotransmitter in the brain. The GABAA-ρ receptor, like other GABAA receptors, is expressed in many areas of the brain, but in contrast to other GABAA receptors, the GABAA-ρ receptor has especially high expression in the retina. Nomenclature A second type of ionotropic GABA receptor, insensitive to typical allosteric modulators of GABAA receptor channels such as benzodiazepines and barbiturates, was designated GABAС receptor. Native responses of the GABAC receptor type occur in retinal bipolar or horizontal cells across vertebrate species. GABAС receptors are exclusively composed of ρ (rho) subunits that are related to GABAA receptor subunits. Although the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor Antagonists
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. Accurate regulation of GABAergic transmission through appropriate developmental processes, specificity to neural cell types, and responsiveness to activity is crucial for the proper functioning of nearly all aspects of the central nervous system (CNS). Upon opening, the GABAA receptor on the postsynaptic cell is selectively permeable to chloride ions () and, to a lesser extent, bicarbonate ions (). GABAAR are members of the ligand-gated ion channel receptor superfamily, which is a chloride channel family with a dozen or more heterotetrametric subtypes and 19 distinct subunits. These subtypes have distinct brain regional and subcellular localization, age-dependent expression, and the ability to undergo plastic alterations in response to experience, including drug exposure. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloride
The term chloride refers to a compound or molecule that contains either a chlorine anion (), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (). The pronunciation of the word "chloride" is . Chloride salts such as sodium chloride are often soluble in water.Green, John, and Sadru Damji. "Chapter 3." ''Chemistry''. Camberwell, Vic.: IBID, 2001. Print. It is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating liquid flow in and out of cells. Other examples of ionic chlorides include potassium chloride (), calcium chloride (), and ammonium chloride (). Examples of covalent chlorides include methyl chloride (), carbon tetrachloride (), sulfuryl chloride (), and monochloramine (). Electronic properties A chloride ion (diameter 167 pm) is much larger than a chlorine atom (diameter 99 pm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug injection, injection, smoking, ingestion, absorption (skin), absorption via a dermal patch, patch on the skin, suppository, or sublingual administration, dissolution under the tongue. In pharmacology, a drug is a chemical substance, typically of known structure, which, when administered to a living organism, produces a biological effect. A pharmaceutical drug, also called a medication or medicine, is a chemical substance used to pharmacotherapy, treat, cure, preventive healthcare, prevent, or medical diagnosis, diagnose a disease or to promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a limited duration, or on a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Synapse
Chemical synapses are biological junctions through which neurons' signals can be sent to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system to connect to and control other systems of the body. At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis. These molecules then bind to neurotransmitter receptors on the postsynaptic cell. Finally, the neurotransmitters are cleared from the synapse through one of several potential mechanisms including enzymatic degradation or re-uptake by specific transporters either on the presynaptic cell or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allosteric Regulation
In the fields of biochemistry and pharmacology an allosteric regulator (or allosteric modulator) is a substance that binds to a site on an enzyme or receptor distinct from the active site, resulting in a conformational change that alters the protein's activity, either enhancing or inhibiting its function. In contrast, substances that bind directly to an enzyme's active site or the binding site of the endogenous ligand of a receptor are called orthosteric regulators or modulators. The site to which the effector binds is termed the ''allosteric site'' or ''regulatory site''. Allosteric sites allow effectors to bind to the protein, often resulting in a conformational change and/or a change in protein dynamics. Effectors that enhance the protein's activity are referred to as ''allosteric activators'', whereas those that decrease the protein's activity are called ''allosteric inhibitors''. Allosteric regulations are a natural example of control loops, such as feedback from do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
