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Alpha-3 Beta-2 Nicotinic Receptor
The alpha-3 beta-2 nicotinic receptor, also known as the α3β2 receptor, is a type of nicotinic acetylcholine receptor, consisting of α3 and β2 subunits. It occurs alongside the more common α3β4 nicotinic receptor in autonomic ganglia, and as an facilitatory presynaptic autoreceptor at the neuromuscular junction (NMJ). At the NMJ, it is involved in upregulation of ACh release during high-frequency stimulation. Nicotine, a component of tobacco, a common stimulate of the receptor has been found to increase the concentration of this receptor. Blockage of this receptor in the presence of a partial postsynaptic neuromuscular block is thought to produce the characteristic tetanic fade caused by non-depolarizing neuromuscular blockers. The receptor is classified as an allosteric enzyme that is generally activated by the natural agonist acetylcholine, however it may also be activated by external agonists such as nicotine and blocked by toxins such as bungarus toxin 3.1. The main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Acetylcholine Receptor
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms. At the neuromuscular junction they are the primary receptor in muscle for motor nerve-muscle communication that controls muscle contraction. In the peripheral nervous system: (1) they transmit outgoing signals from the presynaptic to the postsynaptic cells within the sympathetic and parasympathetic nervous system, and (2) they are the receptors found on skeletal muscle that receive acetylcholine released to signal for muscular contraction. In the immune system, nAChRs regulate inflammatory processes and signal through distinct intracellular pathways. In insects, the cholinergic system is limited to the central nervous system. The nicotinic receptors are considered cholinergi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varenicline
Varenicline (trade name Chantix and Champix) is a medication used for smoking cessation. Varenicline is also used for the treatment of dry eye disease. The most common side-effects include nausea (feeling sick), insomnia (difficulty sleeping), abnormal dreams, headache and nasopharyngitis (inflammation of the nose and throat). It is a high-affinity partial agonist for the α4β2 nicotinic acetylcholine receptor subtype (nACh) that leads to the release of the neurotransmitter dopamine in the nucleus accumbens reward center of the brain when activated, and therefore, has the capacity to reduce the feelings of craving and withdrawal caused by smoking cessation. In this respect it is similar to cytisine and different from the nicotinic antagonist bupropion and nicotine replacement therapies (NRTs) like nicotine patches and nicotine gum. It is estimated that varenicline successfully helps one of every eleven people who smoke remain abstinent from tobacco at six months. It is on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-7 Nicotinic Receptor
The alpha-7 nicotinic receptor, also known as the α7 receptor, is a type of nicotinic acetylcholine receptor implicated in long-term memory, consisting entirely of α7 subunits.Pharmacology, (Rang, Dale, Ritter & Moore, , 5th ed., Churchill Livingstone 2003) p. 138. As with other nicotinic acetylcholine receptors, functional α7 receptors are pentameric .e., (α7)5 stoichiometry">stoichiometry.html" ;"title=".e., (α7)5 stoichiometry">.e., (α7)5 stoichiometry It is located in the brain, spleen, and lymphocytes of lymph nodes where activation yields Excitatory postsynaptic potential, post- and excitatory presynaptic potential, presynaptic excitation, mainly by increased Ca2+ permeability. Further, recent work has implicated this receptor as being important for generation of adult mammal neurons in the retina. Functional α7 receptors are present in the submucous plexus neurons of the guinea-pig ileum. Medical relevance Recent work has demonstrated a potential role in red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-4 Beta-2 Nicotinic Receptor
The alpha-4 beta-2 nicotinic receptor, also known as the α4β2 receptor, is a type of nicotinic acetylcholine receptor implicated in learning, consisting of α4 and β2 subunits. It is located in the brain, where activation yields post- and presynaptic excitation, mainly by increased Na+ and K+ permeability. Stimulation of this receptor subtype is also associated with growth hormone secretion. People with the inactive CHRNA4 mutation Ser248Phe are an average of 10 cm (4 inches) shorter than average and predisposed to obesity. A 2015 review noted that stimulation of the α4β2 nicotinic receptor in the brain is responsible for certain improvements in attentional performance; among the nicotinic receptor subtypes, nicotine has the highest binding affinity at the α4β2 receptor (ki=1 ), which is also the primary biological target that mediates nicotine's addictive properties. The receptors exist in the two stoichiometries: *(α4)2(β2)3 receptors have high sensitivi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-3 Beta-4 Nicotinic Receptor
The alpha-3 beta-4 nicotinic receptor, also known as the α3β4 receptor and the ganglion-type nicotinic receptor,Pharmacology, (Rang, Dale, Ritter & Moore, , 5th ed., Churchill Livingstone 2003) p. 138. is a type of nicotinic acetylcholine receptor, consisting of α3 and β4 subunits. It is located in the autonomic ganglia and adrenal medulla, where activation yields post- and/or presynaptic excitation, mainly by increased Na+ and K+ permeability. As with other nicotinic acetylcholine receptors, the α3β4 receptor is pentameric α3)m(β4)n where m + n = 5 The exact subunit stoichiometry is not known and it is possible that more than one functional α3β4 receptor assembles in vivo with varying subunit stoichiometries. Ligands which inhibit the α3β4 receptor have been shown to modulate drug-seeking behavior, making α3β4 a promising target for the development of novel antiaddictive agents. Ligands Agonists * Acetylcholine (endogenous neurotransmitter that binds non- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubocurarine
Tubocurarine (also known as ''d''-tubocurarine or DTC) is a toxic alkaloid historically known for its use as an arrow poison. In the mid-1900s, it was used in conjunction with an anesthetic to provide skeletal muscle relaxation during surgery or mechanical ventilation. It is now rarely used as an adjunct for clinical anesthesia because safer alternatives, such as cisatracurium and rocuronium, are available. History Tubocurarine is a naturally occurring mono-quaternary alkaloid obtained from the bark of the Menispermaceae, Menispermaceous South American plant ''Chondrodendron tomentosum'', a climbing vine known to the European world since the Spanish conquest of South America. Curare had been used as a source of arrow poison by South American natives to hunt animals, and they were able to eat the animals' contaminated flesh subsequently without any adverse effects because tubocurarine cannot easily cross mucous membranes. Thus, tubocurarine is effective only if given parenterally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Medicinal Chemistry
A journal, from the Old French ''journal'' (meaning "daily"), may refer to: *Bullet journal, a method of personal organization *Diary, a record of what happened over the course of a day or other period *Daybook, also known as a general journal, a daily record of financial transactions *Logbook, a record of events important to the operation of a vehicle, facility, or otherwise *Record (other) *Transaction log, a chronological record of data processing *Travel journal In publishing, ''journal'' can refer to various periodicals or serials: *Academic journal, an academic or scholarly periodical **Scientific journal, an academic journal focusing on science **Medical journal, an academic journal focusing on medicine **Law review, a professional journal focusing on legal interpretation *Magazine, non-academic or scholarly periodicals in general **Trade magazine, a magazine of interest to those of a particular profession or trade **Literary magazine, a magazine devoted to literat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyllycaconitine
Methyllycaconitine (MLA) is a diterpenoid alkaloid found in many species of ''Delphinium'' (larkspurs). In common with many other diterpenoid alkaloids, it is toxic to animals, although the acute toxicity varies with species. Early research was focused on identifying, and characterizing the properties of methyllycaconitine as one of the principal toxins in larkspurs responsible for livestock poisoning in the mountain rangelands of North America. Methyllycaconitine has been explored as a possible therapeutic agent for the treatment of spastic paralyses in man, and it has been shown to have insecticidal properties. Most recently, it has become an important molecular probe for studying the pharmacology of the nicotinic acetylcholine receptor. Isolation The first isolation of MLA, from ''Delphinium brownii ''Delphinium glaucum'', known by the common names Sierra larkspur, mountain larkspur, and glaucous larkspur, is a species of wildflower in the genus ''Delphinium'', which belongs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memantine
Memantine is a medication used to slow the progression of moderate-to-severe Alzheimer's disease. It is taken by mouth. Common side effects include headache, constipation, sleepiness, and dizziness. Severe side effects may include blood clots, psychosis, and heart failure. It is believed to work by acting on NMDA receptors, working as pore blockers of these ion channels. Memantine was approved for medical use in the United States in 2003. It is available as a generic medication. In 2020, it was the 152nd most commonly prescribed medication in the United States, with more than 3million prescriptions. Medical use Alzheimer's disease and dementia Memantine is used to treat moderate-to-severe Alzheimer's disease, especially for people who are intolerant of or have a contraindication to AChE (acetylcholinesterase) inhibitors.NICE review of technology appraisal guidance 111 January 18, 201Alzheimer's disease - donepezil, galantamine, rivastigmine and memantine (review): final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mecamylamine
Mecamylamine (INN, BAN; or mecamylamine hydrochloride (USAN); brand names Inversine, Vecamyl) is a non-selective, non-competitive antagonist of the nicotinic acetylcholine receptors (nAChRs) that was introduced in the 1950s as an antihypertensive drug. In the United States, it was voluntarily withdrawn from the market in 2009 but was brought to market in 2013 as Vecamyl and eventually was marketed by Turing Pharmaceuticals. Chemically, mecamylamine is a secondary aliphatic amine, with a pKaH of 11.2 Pharmacology and clinical applications Mecamylamine has been used as an orally-active ganglionic blocker in treating autonomic dysreflexia and hypertension, but, like most ganglionic blockers, it is more often used now as a research tool. Mecamylamine is also sometimes used as an antiaddictive drug to help people stop smoking tobacco, and is now more widely used for this application than it is for lowering blood pressure. This effect is thought to be due to its blocking α3β4 nic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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