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HC-3 Insignia
Hemicholinium-3 (HC3), also known as hemicholine, is a drug which blocks the reuptake of choline by the high-affinity choline transporter (ChT; encoded in humans by the gene ''SLC5A7'') at the presynapse. The reuptake of choline is the rate-limiting step in the synthesis of acetylcholine; hence, hemicholinium-3 decreases the synthesis of acetylcholine. It is therefore classified as an indirect acetylcholine antagonist. Acetylcholine is synthesized from choline and a donated acetyl group from acetyl-CoA, by the action of choline acetyltransferase (ChAT). Thus, decreasing the amount of choline available to a neuron will decrease the amount of acetylcholine produced. Neurons affected by hemicholinium-3 must rely on the transport of choline from the soma (cell body), rather than relying on reuptake of choline from the synaptic cleft. Toxicity Hemicholinium-3 is highly toxic because it interferes with cholinergic neurotransmission. The LD50 of hemicholinium-3 for mice is about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl-CoA
Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production. Coenzyme A (CoASH or CoA) consists of a β-mercaptoethylamine group linked to the vitamin pantothenic acid (B5) through an amide linkage and 3'-phosphorylated ADP. The acetyl group (indicated in blue in the structural diagram on the right) of acetyl-CoA is linked to the sulfhydryl substituent of the β-mercaptoethylamine group. This thioester linkage is a "high energy" bond, which is particularly reactive. Hydrolysis of the thioester bond is exergonic (−31.5 kJ/mol). CoA is acetylated to acetyl-CoA by the breakdown of carbohydrates through glycolysis and by the breakdown of fatty acids through β-oxidation. Acetyl-CoA then enters the citric acid cycle, where the acetyl group is oxidized to carbon dioxide and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Ammonium Compounds
In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds (called quaternary amines in oilfield parlance) are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule. Quats are used in consumer applications including as antimicrobials (such as detergents and disinfectants), fabric softeners, and hair conditioners. As an antimicrobial, they are able to inactivate enveloped viruses (such as SARS-CoV-2). Quats tend to be gentler on surfaces than bleach-based disinfectants, and are generally fabric-safe. Synthesis Quaternary ammonium compou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenylmorpholines
Substituted phenylmorpholines, or substituted phenmetrazines alternatively, are chemical derivatives of phenylmorpholine or of the psychostimulant drug phenmetrazine. Most such compounds act as releasers of monoamine neurotransmitters, and have stimulant effects. Some also act as agonists at serotonin receptors, and compounds with an N-propyl substitution act as dopamine receptor agonists. A number of derivatives from this class have been investigated for medical applications, such as for use as anorectics or medications for the treatment of ADHD. Some compounds have also become subject to illicit use as designer drugs. See also * Substituted amphetamine * Substituted benzofuran * Substituted cathinone * Substituted methylenedioxyphenethylamine * List of aminorex analogues * List of methylphenidate analogues This is a list of methylphenidate (MPH or MPD) Analog (chemistry), analogues, or Phenidates. The most well known compound from this family, methylphenidate, is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesamicol
Vesamicol is an experimental drug, acting presynaptically by inhibiting acetylcholine (ACh) uptake into synaptic vesicles and reducing its release. Vesamicol may have applications for the treatment of adenocarcinoma in situ of the lung. Mechanism of action Vesamicol can be broadly categorized as a cholinergic physiological antagonist, because it reduces the apparent activity of cholinergic neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...s, but does not act at the postsynaptic ACh receptor. Vesamicol causes a non-competitive and reversible block of the intracellular transporter VAChT responsible for carrying newly synthesized ACh into secretory vesicles in the presynaptic nerve terminal. This transport process is driven by a proton gradient between cell organelles and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triethylcholine
Triethylcholine is a drug which mimics choline, and causes failure of cholinergic transmission by interfering with synthesis of acetylcholine in nerve endings. Effects Triethylcholine produces a slowly developing neuromuscular weakness that is exacerbated by exercise, resembling the symptoms of myasthenia gravis. It also has ganglionic blocking effects, causing transient autonomic symptoms such as hypotension. Muscles stimulated at a high contraction rate are much more affected than those stimulated at a low rate. The muscle weakness typically lasts for 80 to 120 minutes; it is partially relieved by rest. High doses may result in death from respiratory failure, particularly after exercise. Triethylcholine seems to interfere with the synthesis of acetylcholine in the presynaptic nerve endings, since its effects are reversed by choline but not by acetylcholinesterase inhibitors. However the mechanism of action is not definitely known. Animal experiments revealed a relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soma (biology)
The soma (pl. ''somata'' or ''somas''), perikaryon (pl. ''perikarya''), neurocyton, or cell body is the bulbous, non-process portion of a neuron or other brain cell type, containing the cell nucleus. The word 'soma' comes from the Greek '' σῶμα'', meaning 'body'. Although it is often used to refer to neurons, it can also refer to other cell types as well, including astrocytes, oligodendrocytes, and microglia. There are many different specialized types of neurons, and their sizes vary from as small as about 5 micrometres to over 10 millimetres for some of the smallest and largest neurons of invertebrates, respectively. The soma of a neuron (i.e., the main part of the neuron in which the dendrites branch off of) contains many organelles, including granules called Nissl granules, which are composed largely of rough endoplasmic reticulum and free polyribosomes. The cell nucleus is a key feature of the soma. The nucleus is the source of most of the RNA that is produced in neuro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choline Acetyltransferase
Choline acetyltransferase (commonly abbreviated as ChAT, but sometimes CAT) is a transferase enzyme responsible for the synthesis of the neurotransmitter acetylcholine. ChAT catalyzes the transfer of an acetyl group from the coenzyme acetyl-CoA to choline, yielding acetylcholine (ACh). ChAT is found in high concentration in cholinergic neurons, both in the central nervous system (CNS) and peripheral nervous system (PNS). As with most nerve terminal proteins, ChAT is produced in the body of the neuron and is transported to the nerve terminal, where its concentration is highest. Presence of ChAT in a nerve cell classifies this cell as a "cholinergic" neuron. In humans, the choline acetyltransferase enzyme is encoded by the ''CHAT'' gene. History Choline acetyltransferase was first described by David Nachmansohn and A. L. Machado in 1943. A German biochemist, Nachmansohn had been studying the process of nerve impulse conduction and utilization of energy-yielding chemical reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl
In organic chemistry, acetyl is a functional group with the chemical formula and the structure . It is sometimes represented by the symbol Ac (not to be confused with the element actinium). In IUPAC nomenclature, acetyl is called ethanoyl, although this term is barely heard. The acetyl group contains a methyl group () single-bonded to a carbonyl (). The carbonyl center of an acyl radical has one nonbonded electron with which it forms a chemical bond to the remainder ''R'' of the molecule. The acetyl moiety is a component of many organic compounds, including acetic acid, the neurotransmitter acetylcholine, acetyl-CoA, acetylcysteine, acetaminophen (also known as paracetamol), and acetylsalicylic acid (also known as aspirin). Acetylation In nature The introduction of an acetyl group into a molecule is called acetylation. In biological organisms, acetyl groups are commonly transferred from acetyl-CoA to other organic molecules. Acetyl-CoA is an intermediate both ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reuptake
Reuptake is the reabsorption of a neurotransmitter by a neurotransmitter transporter located along the plasma membrane of an axon terminal (i.e., the pre-synaptic neuron at a synapse) or glial cell after it has performed its function of transmitting a neural impulse. Reuptake is necessary for normal synaptic physiology because it allows for the recycling of neurotransmitters and regulates the level of neurotransmitter present in the synapse, thereby controlling how long a signal resulting from neurotransmitter release lasts. Because neurotransmitters are too large and hydrophilic to diffuse through the membrane, specific transport proteins are necessary for the reabsorption of neurotransmitters. Much research, both biochemical and structural, has been performed to obtain clues about the mechanism of reuptake. Protein structure The first primary sequence of a reuptake protein was published in 1990. The technique for protein sequence determination relied upon the purification, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholine Antagonist
Anticholinergics (anticholinergic agents) are substances that block the action of the neurotransmitter called acetylcholine (ACh) at synapses in the central and peripheral nervous system. These agents inhibit the parasympathetic nervous system by selectively blocking the binding of ACh to its receptor in nerve cells. The nerve fibers of the parasympathetic system are responsible for the involuntary movement of smooth muscles present in the gastrointestinal tract, urinary tract, lungs, sweat glands, and many other parts of the body. In broad terms, anticholinergics are divided into two categories in accordance with their specific targets in the central and peripheral nervous system and at the neuromuscular junction: antimuscarinic agents, and antinicotinic agents ( ganglionic blockers, neuromuscular blockers). The term "anticholinergic" is typically used to refer to antimuscarinics which competitively inhibit the binding of ACh to muscarinic acetylcholine receptors; suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
