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5-HT4 Agonists
5-Hydroxytryptamine receptor 4 is a protein that in humans is encoded by the ''HTR4'' gene. Function This gene is a member of the family of human serotonin receptors, which are G protein-coupled receptors that stimulate cyclic adenosine monophosphate, cAMP production in response to serotonin (5-hydroxytryptamine). The gene product is a glycosylated transmembrane protein that functions in both the peripheral and central nervous system to modulate the release of various neurotransmitters. Multiple transcript variants encoding proteins with distinct C-terminal sequences have been described, but the full-length nature of some transcript variants has not been determined. Location The receptor is located in the alimentary tract, urinary bladder, heart and adrenal gland as well as the central nervous system (CNS). In the CNS the receptor appears in the putamen, caudate nucleus, nucleus accumbens, globus pallidus, and substantia nigra, and to a lesser extent in the neocortex, raph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raphe Nuclei
The raphe nuclei (, "seam") are a moderate-size cluster of nuclei found in the brain stem. They have 5-HT1 receptors which are coupled with Gi/Go-protein-inhibiting adenyl cyclase. They function as autoreceptors in the brain and decrease the release of serotonin. The anxiolytic drug Buspirone acts as partial agonist against these receptors. Selective serotonin reuptake inhibitor (SSRI) antidepressants are believed to act in these nuclei, as well as at their targets. Anatomy The raphe nuclei are traditionally considered to be the medial portion of the reticular formation, and appear as a ridge of cells in the center and most medial portion of the brain stem. In order from caudal to rostral, the raphe nuclei are known as the '' nucleus raphe obscurus'', the '' nucleus raphe pallidus'', the '' nucleus raphe magnus'', the '' nucleus raphe pontis'', the '' median raphe nucleus'', ''dorsal raphe nucleus'', ''caudal linear nucleus''. In the first systematic examination of the raph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ML-10302
ML-1 was an experimental nuclear reactor built as part of the US Army Nuclear Power Program between 1961 and 1965. It was intended to provide truck-mounted nuclear power that could accompany troops from place to place and provide power to command and communication centers, evacuation hospitals, depots, and radar and weapons systems. Unlike the other seven reactors of this program, it did not use a steam turbine, but instead used a nitrogen coolant at to drive a closed-cycle gas turbine. It was designed to produce 3.3 MWthermal of heat and 400 kW of shaft horsepower with an outlet temperature of . Though the concept of a nitrogen closed cycle gas turbine was strong, the design failed to live up to expectations, and was abandoned with the closure of ML-1 in 1965 after several major refits and with only a few hundred hours of testing completed in all. Similar concepts have been more recently proposed as part of the PBMR program as derivatives thereof. A 1964 economic anal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felcisetrag
Felcisetrag (TAK-954, TD-8954) is a drug which acts as a potent and highly selective agonist for the serotonin receptor 5-HT4. It is in clinical trials for the treatment of gastroparesis Gastroparesis (gastro- from Ancient Greek – gaster, "stomach"; and -paresis, πάρεσις – "partial paralysis") is a medical disorder of ineffective neuromuscular contractions (peristalsis) of the stomach, resulting in food and l .... References {{Serotonergics Alkyl groups Carbamates Benzamides Benzimidazoles Piperidines Methyl esters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CJ-033,466
CJ-033466 is a drug which acts as a potent and selective 5-HT4 serotonin receptor partial agonist. In animal tests it stimulated gastrointestinal motility with 30 times the potency of cisapride, and with lower affinity for the hERG channel. See also * Imidazopyridine An imidazopyridine is a nitrogen containing heterocycle that is also a class of medication, drugs that contain this same chemical substructure. In general, they are GABAA receptor, GABAA receptor receptor_agonist, agonists, however recently proto ... References Amines Carboxamides Chloroarenes Imidazoles Piperidines Pyridines Serotonin receptor agonists Isobutyl compounds {{gastrointestinal-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisapride
Cisapride is a gastroprokinetic agent, a drug that increases motility in the upper gastrointestinal tract. It acts directly as a serotonin 5-HT4 receptor agonist and indirectly as a parasympathomimetic. Stimulation of the serotonin receptors increases acetylcholine release in the enteric nervous system. It has been sold under the trade names Prepulsid (Janssen-Ortho) and Propulsid (in the United States). It was discovered by Janssen Pharmaceuticals in 1980. In many countries, it has been either withdrawn from the market or had its indications limited due to incidence of serious cardiac side-effects. Propulsid was linked to children's deaths. The commercial preparations of this drug are the racemic mixture of both enantiomers of the compound. The (+) enantiomer itself has the major pharmacologic effects and does not induce many of the detrimental side-effects of the mixture. Medical uses Cisapride has been used for the treatment of gastroesophageal reflux disease (GERD). There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIMU-8
BIMU-8 is a drug which acts as a 5-HT4 receptor selective agonist. BIMU-8 was one of the first compounds of this class. The main action of BIMU-8 is to increase the rate of respiration by activating an area of the brain stem known as the pre-Botzinger complex. Use The most obvious practical use of BIMU-8 is to combine it with opioid analgesic drugs in order to counteract the dangerous respiratory depression which can occur when opioids are used in excessive doses. BIMU-8 does not affect the pleasurable or painkilling properties of opiates, which means that if combined with BIMU-8, large therapeutic doses of opiates could theoretically be given to humans without risking a decrease in breathing rate. Studies have shown BIMU-8 to be effective in rats at counteracting the respiratory depression caused by the potent opioid fentanyl Fentanyl is a highly potent synthetic piperidine opioid primarily used as an analgesic (pain medication). It is 30 to 50 times more Potency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropisetron
Tropisetron is a serotonin 5-HT3 receptor antagonist used mainly as an antiemetic to treat nausea and vomiting following chemotherapy, although it has been used experimentally as an analgesic in cases of fibromyalgia. It was patented in 1982 and approved for medical use in 1992. It is on the World Health Organization's List of Essential Medicines. It is marketed by Novartis in Europe, Australia, New Zealand, Japan, South Korea and the Philippines as Navoban, but is not available in the U.S. It is also available from Novell Pharmaceutical Laboratories and marketed in several Asian countries as Setrovel. Pharmacology Tropisetron acts as both a selective 5-HT3 receptor antagonist and α7-nicotinic receptor partial agonist. Tropisetron have been shown to sensitise human α7-nicotinic receptors to low concentrations of acetylcholine, indicative of a possible co-agonist or other modulatory action of tropisetron at these receptors. Adverse effects Tropisetron is a well-tol ... [...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 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, such as: * Fluorodeoxyglucose ( 18F">sup>18FDG or FDG) is commonly used to detect cancer; * 18Fodium fluoride">sup>18Fodium fluoride (Na18F) is widely used for detecting bone formation; * Oxygen-15 (15O) is sometimes used to measure blood flow. PET is a common imaging technique, a medical scintillography technique used in nuclear medicine. A radiopharmaceutical—a radioisotope attached to a drug—is injected into the body as a tracer. When the radiopharmaceutical undergoes beta plus decay, a positron is emitted, and when the positron interacts with an ordinary electron, the tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioligand
A radioligand is a microscopic particle which consists of a Radiopharmaceutical, therapeutic radioactive isotope and the cell-targeting compound - the ligand. The ligand is the target binding site, it may be on the surface of the targeted cancer cell for therapeutic purposes. Radioisotopes can occur naturally or be synthesized and produced in a cyclotron/nuclear reactor. The different types of radioisotopes include Y-90, H-3, C-11, Lu-177, Ac-225, Ra-223, In-111, I-131, I-125, etc. Thus, radioligands must be produced in special nuclear reactors for the radioisotope to remain stable. Radioligands can be used to analyze/characterize receptors, to perform binding assays, to help in diagnostic imaging, and to provide targeted cancer therapy. Radiation is a novel method of treating cancer and is effective in short distances along with being unique/personalizable and causing minimal harm to normal surrounding cells. Furthermore, radioligand binding can provide information about receptor-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-11
Carbon (6C) has 14 known isotopes, from to as well as , of which only and are stable nuclide, stable. The longest-lived radionuclide, radioisotope is , with a half-life of years. This is also the only carbon radioisotope found in nature, as trace quantities are formed cosmogenic nuclide, cosmogenically by the reaction + → + . The most stable artificial radioisotope is , which has a half-life of . All other radioisotopes have half-lives under 20 seconds, most less than 200 milliseconds. The least stable isotope is , with a half-life of . Light isotopes tend to decay into isotopes of boron and heavy ones tend to decay into isotopes of nitrogen. List of isotopes , -id=Carbon-8 , , style="text-align:right" , 6 , style="text-align:right" , 2 , , [] , proton emission, 2p , Also immediately emits two protons for the net reaction of → + 4 , 0+ , , , -id=Carbon-9 , rowspan=3, , rowspan=3 style="text-align:right" , 6 , rowspan=3 style="text-align ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
