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IUPAC name (2S,4R)-N,N-dimethyl-4-phenyl-1,2,3,4-tetrahydronaphthalen-2-amine | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
PubChem CID | |
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Properties | |
C18H21N | |
Molar mass | 251.373 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Phenylaminotetralins are novel histamine receptor ligands. Binding assays determined that (-)-trans-H2-PAT possessed the strongest binding affinity at the histamine H1 receptor. [1]
A mast cell is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems. Mast cells were discovered by Paul Ehrlich in 1877. Although best known for their role in allergy and anaphylaxis, mast cells play an important protective role as well, being intimately involved in wound healing, angiogenesis, immune tolerance, defense against pathogens, and vascular permeability in brain tumors.
Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Discovered in 1910, histamine has been considered a local hormone (autocoid) because it's produced without involvement of the classic endocrine glands; however, in recent years, histamine has been recognized as a central neurotransmitter. Histamine is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues. It consists of an imidazole ring attached to an ethylamine chain; under physiological conditions, the amino group of the side-chain is protonated.
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins. They are sometimes called blockers; examples include alpha blockers, beta blockers, and calcium channel blockers. In pharmacology, antagonists have affinity but no efficacy for their cognate receptors, and binding will disrupt the interaction and inhibit the function of an agonist or inverse agonist at receptors. Antagonists mediate their effects by binding to the active site or to the allosteric site on a receptor, or they may interact at unique binding sites not normally involved in the biological regulation of the receptor's activity. Antagonist activity may be reversible or irreversible depending on the longevity of the antagonist–receptor complex, which, in turn, depends on the nature of antagonist–receptor binding. The majority of drug antagonists achieve their potency by competing with endogenous ligands or substrates at structurally defined binding sites on receptors.
Chlorphenamine (CP, CPM), also known as chlorpheniramine, is an antihistamine used to treat the symptoms of allergic conditions such as allergic rhinitis (hay fever). It is taken orally (by mouth). The medication takes effect within two hours and lasts for about 4–6 hours. It is a first-generation antihistamine and works by blocking the histamine H1 receptor.
The histamine receptors are a class of G protein–coupled receptors which bind histamine as their primary endogenous ligand.
Histamine H3 receptors are expressed in the central nervous system and to a lesser extent the peripheral nervous system, where they act as autoreceptors in presynaptic histaminergic neurons and control histamine turnover by feedback inhibition of histamine synthesis and release. The H3 receptor has also been shown to presynaptically inhibit the release of a number of other neurotransmitters (i.e. it acts as an inhibitory heteroreceptor) including, but probably not limited to dopamine, GABA, acetylcholine, noradrenaline, histamine and serotonin.
The histamine H4 receptor, like the other three histamine receptors, is a member of the G protein-coupled receptor superfamily that in humans is encoded by the HRH4 gene.
The H1 receptor is a histamine receptor belonging to the family of rhodopsin-like G-protein-coupled receptors. This receptor is activated by the biogenic amine histamine. It is expressed in smooth muscles, on vascular endothelial cells, in the heart, and in the central nervous system. The H1 receptor is linked to an intracellular G-protein (Gq) that activates phospholipase C and the inositol triphosphate (IP3) signalling pathway. Antihistamines, which act on this receptor, are used as anti-allergy drugs. The crystal structure of the receptor has been determined (shown on the right/below) and used to discover new histamine H1 receptor ligands in structure-based virtual screening studies.
Astemizole was a second-generation antihistamine drug that has a long duration of action. Astemizole was discovered by Janssen Pharmaceutica in 1977. It was withdrawn from the market globally in 1999 because of rare but potentially fatal side effects.
H2 receptors are a type of histamine receptor found in many parts of the anatomy of humans and other animals. They are positively coupled to adenylate cyclase via Gs alpha subunit. It is a potent stimulant of cAMP production, which leads to activation of protein kinase A. PKA functions to phosphorylate certain proteins, affecting their activity. The drug betazole is an example of a histamine H2 receptor agonist.
Mianserin, sold under the brand name Tolvon among others, is an atypical antidepressant that is used primarily in the treatment of depression in Europe and elsewhere in the world. It is a tetracyclic antidepressant (TeCA). Mianserin is closely related to mirtazapine, both chemically and in terms of its actions and effects, although there are significant differences between the two drugs.
Ciproxifan is an extremely potent histamine H3 inverse agonist/antagonist.
Histamine N-methyltransferase (HNMT) is a protein encoded by the HNMT gene in humans. It belongs to the methyltransferases superfamily of enzymes and plays a role in the inactivation of histamine, a biomolecule that is involved in various physiological processes. Methyltransferases are present in every life form including archaeans, with 230 families of methyltransferases found across species.
Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic drug that can be bought without a prescription and provides relief from nasal congestion, sneezing, or hives caused by pollen, dust mites, or animal allergy with few side effects. Antihistamines are usually for short-term treatment. Chronic allergies increase the risk of health problems which antihistamines might not treat, including asthma, sinusitis, and lower respiratory tract infection. Consultation of a medical professional is recommended for those who intend to take antihistamines for longer-term use.
An H3 receptor antagonist is a type of antihistaminic drug used to block the action of histamine at H3 receptors.
Iodophenpropit is a histamine antagonist which binds selectively to the H3 subtype. Its 125I radiolabelled form has been used for mapping the distribution of H3 receptors in animal studies.
VUF-6002 (JNJ-10191584) is a drug which acts as a potent and selective antagonist at the histamine H4 receptor. It has anti-inflammatory and analgesic effects in animal studies of inflammatory diseases.
GSK-189,254 is a potent and selective H3 histamine receptor inverse agonist developed by GlaxoSmithKline. It has subnanomolar affinity for the H3 receptor (Ki = 0.2nM) and selectivity of over 10,000x for H3 over other histamine receptor subtypes. Animal studies have shown it to possess not only stimulant and nootropic effects, but also analgesic action suggesting a role for H3 receptors in pain processing in the spinal cord. GSK-189,254 and several other related drugs are currently being investigated as a treatment for Alzheimer's disease and other forms of dementia, as well as possible use in the treatment of conditions such as narcolepsy, or neuropathic pain which do not respond well to conventional analgesic drugs.
Pitolisant, sold under the brand name Wakix among others, is a medication used for the treatment of excessive daytime sleepiness in adults with narcolepsy. It is an inverse agonist of the histamine 3 (H3) receptor (an antihistamine drug specific to that kind of receptors). It represents the first commercially available medication in its class, so that the U.S. Food and Drug Administration (FDA) declares it a first-in-class medication. Pitolisant enhances the activity of histaminergic neurons in the brain that function to improve a person's wakefulness. It was approved by the European Medicines Agency (EMA) in March 2016 for narcolepsy with or without cataplexy, and for excessive daytime sleepiness by the FDA in August 2019. The most common side effects include difficulty sleeping, nausea, and feeling worried.
Toreforant (JNJ-38518168) is an orally-dosed selective antagonist of the histamine H4 receptor that has been studied for various health conditions. It is the successor of a number of H4-selective compounds developed by Johnson & Johnson. Phase IIa clinical trials completed as recently as November 2018 continue to suggest that toreforant is safe.