|
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-s ... [...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 choline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbachol
Carbachol, also known as carbamylcholine and sold under the brand name Miostat among others, is a cholinomimetic drug that binds and activates acetylcholine receptors. Thus it is classified as a cholinergic agonist. It is primarily used for various ophthalmic purposes, such as for treating glaucoma, or for use during ophthalmic surgery. It is generally administered as an ophthalmic solution (i.e., eye drops). Carbachol produces effects comparable to those of sarin if a massive overdose is administered (as may occur following industrial and shipping accidents) and therefore it is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities. It is on the World Health Organization's List of Essential Medicines. Chemistry and pharmacology Carbach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imipramine
Imipramine, sold under the brand name Tofranil, among others, is a tricyclic antidepressant (TCA) mainly used in the treatment of depression. It is also effective in treating anxiety and panic disorder. The drug is also used to treat bedwetting. Imipramine is taken by mouth. Common side effects of imipramine include dry mouth, drowsiness, dizziness, low blood pressure, rapid heart rate, urinary retention, and electrocardiogram changes. Overdose of the medication can result in death. Imipramine appears to work by increasing levels of serotonin and norepinephrine and by blocking certain serotonin, adrenergic, histamine, and cholinergic receptors. Imipramine was discovered in 1951 and was introduced for medical use in 1957. It was the first TCA to be marketed. Imipramine and the other TCAs have decreased in use in recent decades, due to the introduction of the selective serotonin reuptake inhibitors (SSRIs), which have fewer side effects and are far safer in overdose. Medical u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexamethonium
Hexamethonium is a non-depolarising ganglionic blocker, a nicotinic (nAChR) receptor antagonist that acts in autonomic ganglia by binding mostly in or on the nAChR receptor, and not the acetylcholine binding site itself. It does not have any effect on the muscarinic acetylcholine receptors ( mAChR) located on target organs of the parasympathetic nervous system but acts as antagonist at the nicotinic acetylcholine receptors located in sympathetic and parasympathetic ganglia (nAChR). Pharmacology It can act on receptors at pre-ganglionic sites in both the sympathetic and parasympathetic nervous systems, which are both regulated by nicotinic ligand-gated ionotropic acetylcholine receptors. Postganglionic sympathetic systems are usually regulated by norepinephrine (noradrenaline) (adrenergic receptors), whereas parasympathetic systems are acetylcholine-based, and instead rely on muscarinic receptors (some post-ganglionic sympathetic neurons, such as those stimulating sweat glan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dextropropoxyphene
Dextropropoxyphene is an analgesic in the opioid category, patented in 1955 and manufactured by Eli Lilly and Company. It is an optical isomer of levopropoxyphene. It is intended to treat mild pain and also has antitussive (cough suppressant) and local anaesthetic effects. The drug has been taken off the market in Europe and the US due to concerns of fatal overdoses and heart arrhythmias. It is still available in Australia, albeit with restrictions after an application by its manufacturer to review its proposed banning. Its onset of analgesia (pain relief) is said to be 20–30 minutes and peak effects are seen about 1.5–2.0 hours after oral administration. Dextropropoxyphene is sometimes combined with acetaminophen. Trade names include Darvocet-N, Di-Gesic, and Darvon with APAP (for dextropropoxyphene and paracetamol). The British approved name (i.e. the generic name of the active ingredient) of the paracetamol/dextropropoxyphene preparation is co-proxamol (sold under a va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dextrorphan
Dextrorphan (DXO) is a psychoactive drug of the morphinan class which acts as an antitussive or cough suppressant and dissociative hallucinogen. It is the dextrorotatory enantiomer of racemorphan; the levorotatory enantiomer is levorphanol. Dextrorphan is produced by O-demethylation of dextromethorphan by CYP2D6. Dextrorphan is an NMDA antagonist and contributes to the psychoactive effects of dextromethorphan. Pharmacology Pharmacodynamics The pharmacology of dextrorphan is similar to that of dextromethorphan (DXM). However, dextrorphan is much more potent as an NMDA receptor antagonist as well much less active as a serotonin reuptake inhibitor, but retains DXM's activity as a norepinephrine reuptake inhibitor. It also has more affinity for the opiod receptors than dextromethorphan, significantly so at high doses. Pharmacokinetics Dextrorphan has a notably longer elimination half-life than its parent compound, and therefore has a tendency to accumulate in the blood after r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dextromethorphan
Dextromethorphan (DXM) is a medication most often used as a cough suppressant in over-the-counter cold and cough medicines. It is sold in syrup, tablet, spray, and lozenge forms. In 2022, the FDA approved a formulation of it combined with bupropion named Auvelity to serve as a rapid acting antidepressant in patients with major depressive disorder. It is in the morphinan class of medications with sedative, dissociative, and stimulant properties (at lower doses). Dextromethorphan does not have a significant affinity for the mu-opioid receptor activity typical of morphinan compounds and exerts its therapeutic effects through several other receptors. In its pure form, dextromethorphan occurs as a white powder. Dextromethorphan is also used recreationally. When exceeding approved dosages, dextromethorphan acts as a dissociative hallucinogen. It has multiple mechanisms of action, including actions as a nonselective serotonin reuptake inhibitor and a sigma-1 receptor agonis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RJR-2429
RJR-2429 is a drug that acts as an agonist at neural nicotinic acetylcholine receptors, binding to both the α3β4 and the α4β2 subtypes. RJR-2429 is stronger than nicotine Nicotine is a naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used fo ... but weaker than epibatidine in most assays, and with high affinity for both α3β4 and α4β2 subtypes, as well as the less studied α1βγδ subtype. References Nicotinic agonists Nitrogen heterocycles {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotine
Nicotine is a naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and '' Duboisia hopwoodii'') and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for smoking cessation to relieve withdrawal symptoms. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors (nAChRs), except at two nicotinic receptor subunits ( nAChRα9 and nAChRα10) where it acts as a receptor antagonist. Nicotine constitutes approximately 0.6–3.0% of the dry weight of tobacco. Nicotine is also present at ppb-concentrations in edible plants in the family Solanaceae, including potatoes, tomatoes, and eggplants, though sources disagree on whether this has any biological significance to human consumers. It functions as an antiherbivore toxin; consequently, nicotine was widely used as an insecticide in the past, and neonicotinoids (structurally similar to nicotine), such as imidaclopri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobeline
Lobeline is a pyridine alkaloid found in a variety of plants, particularly those in the genus '' Lobelia'', including Indian tobacco ('' Lobelia inflata''), Devil's tobacco ('' Lobelia tupa''), great lobelia ('' Lobelia siphilitica''), '' Lobelia chinensis'', and ''Hippobroma longiflora''. In its pure form, it is a white amorphous powder which is freely soluble in water. Potential uses Lobeline has been sold, in tablet form, for use as a smoking cessation aid, but scientific research has not provided supporting evidence for this use. Lobeline has also been studied for the treatment of other drug addictions such as addiction to amphetamines, cocaine, or alcohol; however, there is limited clinical evidence of any efficacy. Toxicity Ingestion of lobeline may cause nausea, vomiting, diarrhea, coughing, dizziness, visual disturbances, hearing disturbances, mental confusion, weakness, slowed heart rate, increased blood pressure, increased breathing rate, tremors, and seizures. Lobe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_with_tube_model.png "Click for more on -> Alpha-3 Beta-4 Nicotinic Receptor")
