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Mefway
Mefway is a serotonin 5-HT1A receptor antagonist used in medical research, usually in the form of mefway ( 18F) as a positron emission tomography (PET) radiotracer. Chemistry Mefway is closely related to the research compound WAY-100,635. The compound adds a fluoromethyl group to the cyclohexyl ring of WAY-100,635 and it is effectively prepared with automation module. There are two isomers with regard to the cyclohexane ring, of which the ''trans'' conformation has the higher 5-HT1A specificity. Animal PET studies In one study the uptake and retention of mefway (18F) was found to be similar to that found for 11C-WAY-100,635. Head-to-head comparison of mefway (18F) and 11C-WAY-100,635 have been evaluated. Since 11C-WAY-100,635 is the current 'gold standard' and difficult to synthesize, a suitable fluorine-18 replacement as in mefway is highly desired. In addition, mefway (18F) showed comparable brain uptake and the target-to-reference ratios compared to fcway(18F) The ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mefway Cis-trans Comparison
Mefway is a serotonin 5-HT1A receptor antagonist used in medical research, usually in the form of mefway ( 18F) as a positron emission tomography (PET) radiotracer. Chemistry Mefway is closely related to the research compound WAY-100,635. The compound adds a fluoromethyl group to the cyclohexyl ring of WAY-100,635 and it is effectively prepared with automation module. There are two isomers with regard to the cyclohexane ring, of which the ''trans'' conformation has the higher 5-HT1A specificity. Animal PET studies In one study the uptake and retention of mefway (18F) was found to be similar to that found for 11C-WAY-100,635. Head-to-head comparison of mefway (18F) and 11C-WAY-100,635 have been evaluated. Since 11C-WAY-100,635 is the current 'gold standard' and difficult to synthesize, a suitable fluorine-18 replacement as in mefway is highly desired. In addition, mefway (18F) showed comparable brain uptake and the target-to-reference ratios compared to fcway(18F) The ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT1A
The serotonin 1A receptor (or 5-HT1A receptor) is a subtype of serotonin receptor, or 5-HT receptor, that binds serotonin, also known as 5-HT, a neurotransmitter. 5-HT1A is expressed in the brain, spleen, and neonatal kidney. It is a G protein-coupled receptor (GPCR), coupled to the Gi protein, and its activation in the brain mediates hyperpolarisation and reduction of firing rate of the postsynaptic neuron. In humans, the serotonin 1A receptor is encoded by the HTR1A gene. Distribution The 5-HT1A receptor is the most widespread of all the 5-HT receptors. In the central nervous system, 5-HT1A receptors exist in the cerebral cortex, hippocampus, septum, amygdala, and raphe nucleus in high densities, while low amounts also exist in the basal ganglia and thalamus. The 5-HT1A receptors in the raphe nucleus are largely somatodendritic autoreceptors, whereas those in other areas such as the hippocampus are postsynaptic receptors. Function Neuromodulation 5-HT1A receptor ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positron Emission Tomography
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in Metabolism, metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body. For example, 18F-FDG, -FDG is commonly used to detect cancer, Sodium fluoride#Medical imaging, NaF is widely used for detecting bone formation, and Isotopes of oxygen#Oxygen-15, oxygen-15 is sometimes used to measure blood flow. PET is a common medical imaging, imaging technique, a Scintigraphy#Process, medical scintillography technique used in nuclear medicine. A radiopharmaceutical, radiopharmaceutical — a radioisotope attached to a drug — is injected into the body as a radioactive tracer, tracer. When the radiopharmaceutical undergoes beta plus decay, a positron is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WAY-100,635
WAY-100635 is a piperazine drug and research chemical widely used in scientific studies. It was originally believed to act as a selective 5-HT1A receptor antagonist, but subsequent research showed that it also acts as potent full agonist at the D4 receptor. It is sometimes referred to as a silent antagonist at the former receptor. It is closely related to WAY-100135. In light of its only recently discovered dopaminergic activity, conclusions drawn from studies that employed WAY-100635 as a selective 5-HT1A antagonist may need to be re-evaluated. Human PET studies In human PET studies WAY-100635 shows high binding in the cerebral cortex, hippocampus, raphe nucleus and amygdaloid nucleus, while lower in thalamus and basal ganglia. One study described a single case with relatively high binding in the cerebellum. In relating its binding to subject variables one Swedish study found WAY-100635 binding in raphe brain region correlating with self-transcendence and spiritual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Antagonist
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.Pharmacology Guide: In vitro pharmacology: concentration-response curves " '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, |
Fluorine-18
Fluorine-18 (18F) is a fluorine radioisotope which is an important source of positrons. It has a mass of 18.0009380(6) u and its half-life is 109.771(20) minutes. It decays by positron emission 96% of the time and electron capture 4% of the time. Both modes of decay yield stable oxygen-18. Natural occurrence is a natural trace radioisotope produced by cosmic ray spallation of atmospheric argon as well as by reaction of protons with natural oxygen: 18O + p → 18F + n.18O">sup>18Oater with high energy protons (typically ~18 MeV). The fluorine produced is in the form of a water solution of 18F.html" ;"title="sup>18F">sup>18F luoride, which is then used in a rapid chemical synthesis of various radio pharmaceuticals. The organic oxygen-18 pharmaceutical molecule is not made before the production of the radiopharmaceutical, as high energy protons destroy such molecules ( radiolysis). Radiopharmaceuticals using fluorine must therefore be synthesized after the fluorine-18 has been p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiotracer
A radioactive tracer, radiotracer, or radioactive label is a chemical compound in which one or more atoms have been replaced by a radionuclide so by virtue of its radioactive decay it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling or radiotracing is thus the radioactive form of isotopic labeling. In biological contexts, use of radioisotope tracers are sometimes called radioisotope feeding experiments. Radioisotopes of hydrogen, carbon, phosphorus, sulfur, and iodine have been used extensively to trace the path of biochemical reactions. A radioactive tracer can also be used to track the distribution of a substance within a natural system such as a cell or tissue, or as a flow tracer to track fluid flow. Radioactive tracers are also used to determine the location of fractures created by hydraulic fracturing in natural gas production.Reis, John C. (1976). ''Environmental Control in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomers
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which ''bonds'' between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" () is a back-form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cis–trans Isomerism
''Cis''–''trans'' isomerism, also known as geometric isomerism or configurational isomerism, is a term used in chemistry that concerns the spatial arrangement of atoms within molecules. The prefixes "''cis''" and "''trans''" are from Latin: "this side of" and "the other side of", respectively. In the context of chemistry, ''cis'' indicates that the functional groups (substituents) are on the same side of some plane, while ''trans'' conveys that they are on opposing (transverse) sides. ''Cis''–''trans'' isomers are stereoisomers, that is, pairs of molecules which have the same formula but whose functional groups are in different orientations in three-dimensional space. ''Cis-trans'' notation does not always correspond to E–Z notation, ''E''–''Z'' isomerism, which is an ''Absolute configuration, absolute'' stereochemical description. In general, ''cis''–''trans'' stereoisomers contain double bonds that do not rotate, or they may contain ring structures, where the rotation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Models Of Parkinson's Disease
Animal models of Parkinson's disease are essential in the research field and widely used to study Parkinson's disease. Parkinson's disease is a neurodegenerative disorder, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). The loss of the dopamine neurons in the brain, results in motor dysfunction, ultimately causing the four cardinal symptoms of PD: tremor, rigidity, postural instability, and bradykinesia. It is the second most prevalent neurodegenerative disease, following Alzheimer's disease. It is estimated that nearly one million people could be living with PD in the United States. There are a variety of models that can be utilized to be able to address important aspects of Parkinson's disease. Researchers can consider disease progression, cell death, behavioral characteristics, and more PD phenotypes. Parkinson's disease animal models are divided into two categories: neurotoxin models and genetic models. Neurotoxin models include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiopharmaceuticals
Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which is different from contrast media which absorb or alter external electromagnetism or ultrasound. Radiopharmacology is the branch of pharmacology that specializes in these agents. The main group of these compounds are the radiotracers used to diagnose dysfunction in body tissues. While not all medical isotopes are radioactive, radiopharmaceuticals are the oldest and still most common such drugs. Drug nomenclature As with other pharmaceutical drugs, there is standardization of the drug nomenclature for radiopharmaceuticals, although various standards coexist. The International Nonproprietary Names (INNs), United States Pharmacopeia (USP) names, and IUPAC names for these agents are usually similar other than trivial style differences. The de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
