|
Potassium Channel Opener
A potassium channel opener is a type of drug which facilitates ion transmission through potassium channels. Examples Some examples include: *Diazoxide vasodilator used for hypertension, smooth muscle relaxing activity *Minoxidil vasodilator used for hypertension, also used to treat hair loss *Nicorandil vasodilator used to treat angina *Pinacidil *Retigabine, an anticonvulsant * Flupirtine, analgesic with muscle relaxant and anticonvulsant properties See also * Potassium channel blocker Potassium channel blockers are agents which interfere with conduction through potassium channels. Medical uses Arrhythmia Potassium channel blockers used in the treatment of cardiac arrhythmia are classified as class III antiarrhythmic age ... References {{pharmacology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insufflation (medicine), inhalation, drug injection, injection, smoking, ingestion, absorption (skin), absorption via a dermal patch, patch on the skin, suppository, or sublingual administration, dissolution under the tongue. In pharmacology, a drug is a chemical substance, typically of known structure, which, when administered to a living organism, produces a biological effect. A pharmaceutical drug, also called a medication or medicine, is a chemical substance used to pharmacotherapy, treat, cure, preventive healthcare, prevent, or medical diagnosis, diagnose a disease or to promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nimesulide
Nimesulide is a nonsteroidal anti-inflammatory drug (NSAID) with pain medication and fever reducing properties. Its approved indications are the treatment of acute pain, the symptomatic treatment of osteoarthritis, and primary dysmenorrhoea in adolescents and adults above 12 years old. Side effects may include liver problems. It has a multifactorial mode of action and is characterized by a fast onset of action. It works by blocking the production of prostaglandins (a chemical associated with pain), thereby relieving pain and inflammation. Medical uses It may be used for pain, including period pains. Nimesulide is not recommended long-term, as for chronic conditions such as arthritis. This is due to its association with an increased risk of liver toxicity, including liver failure. Despite its risk of hepatotoxicity, a 2012 evaluation by the European Medicines Agency (EMA) concluded that the overall benefit/risk profile of nimesulide is favourable and in line with that of the ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levcromakalim
Cromakalim (INN) is a potassium channel-opening vasodilator. The active isomer is levcromakalim. It acts on ATP-sensitive potassium channels and so causes membrane hyperpolarization. It can be used to treat hypertension as it will relax vascular smooth muscle to lower blood pressure. Hyperpolarisation of smooth muscle cell membranes pulls their membrane potential away from the threshold, so making it more difficult to excite them and thereby cause relaxation. Synthesis Reaction of 4-cyanophenol (4-Hydroxybenzonitrile) with 2-hydroxy-2-methyl-3-butyne under PTC probably proceeds to initial formation of a propargyl carbocation. The course of the reaction can be envisaged by assuming that this then attacks the aromatic ring; the resulting allylic cation can then capture the adjacent phenol oxygen and thus form the observed product (3). Treatment of that product with aqueous NBS leads to the addition of the elements of hypobromous acid and formation of the bromohydrin (4) as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cromakalim
Cromakalim (INN) is a potassium channel-opening vasodilator. The active isomer is levcromakalim. It acts on ATP-sensitive potassium channels and so causes membrane hyperpolarization. It can be used to treat hypertension as it will relax vascular smooth muscle to lower blood pressure. Hyperpolarisation of smooth muscle cell membranes pulls their membrane potential away from the threshold, so making it more difficult to excite them and thereby cause relaxation. Synthesis Reaction of 4-cyanophenol (4-Hydroxybenzonitrile) with 2-hydroxy-2-methyl-3-butyne under PTC probably proceeds to initial formation of a propargyl carbocation. The course of the reaction can be envisaged by assuming that this then attacks the aromatic ring; the resulting allylic cation can then capture the adjacent phenol oxygen and thus form the observed product (3). Treatment of that product with aqueous NBS leads to the addition of the elements of hypobromous acid and formation of the bromohydrin (4) as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bimakalim
Bimakalim is a potassium channel opener A potassium channel opener is a type of drug which facilitates ion transmission through potassium channels. Examples Some examples include: *Diazoxide vasodilator used for hypertension, smooth muscle relaxing activity *Minoxidil vasodilator u .... References Potassium channel openers 2-Pyridones Benzopyrans Nitriles {{Cardiovascular-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATP-sensitive K+ Channels
An ATP-sensitive potassium channel (or KATP channel) is a type of potassium channel that is gated by intracellular nucleotides, ATP and ADP. ATP-sensitive potassium channels are composed of Kir6.x-type subunits and sulfonylurea receptor (SUR) subunits, along with additional components. KATP channels are found in the plasma membrane; however some may also be found on subcellular membranes. These latter classes of KATP channels can be classified as being either sarcolemmal ("sarcKATP"), mitochondrial ("mitoKATP"), or nuclear ("nucKATP"). Discovery and structure KATP channels were first identified in cardiac myocytes by the Akinori Noma group in Japan. They have also been found in pancreas where they control insulin secretion, but are in fact widely distributed in plasma membranes. SarcKATP are composed of eight protein subunits (octamer). Four of these are members of the inward-rectifier potassium ion channel family Kir6.x (either Kir6.1 or Kir6.2), while the other fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPCR
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related proteins that are cell surface receptors that detect molecules outside the cell and activate cellular responses. Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times. Text was copied from this source, which is available under Attribution 2.5 Generic (CC BY 2.5) license. Ligands can bind either to extracellular N-terminus and loops (e.g. glutamate receptors) or to the binding site within transmembrane helices (Rhodopsin-like family). They are all activated by agonists although a spontaneous auto-activation of an empty receptor can also be observed. G protein-coupled receptors are found only in eukaryotes, including yeast, choanoflagellates, and an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G Protein-coupled Inwardly-rectifying Potassium Channel
The G protein-coupled inwardly-rectifying potassium channels (GIRKs) are a family of lipid-gated inward-rectifier potassium ion channels which are activated (opened) by the signaling lipid PIP2 and a signal transduction cascade starting with ligand-stimulated G protein-coupled receptors (GPCRs). GPCRs in turn release activated G-protein βγ- subunits ( Gβγ) from inactive heterotrimeric G protein complexes (Gαβγ). Finally, the Gβγ dimeric protein interacts with GIRK channels to open them so that they become permeable to potassium ions, resulting in hyperpolarization of the cell membrane. G protein-coupled inwardly-rectifying potassium channels are a type of G protein-gated ion channels because of this direct interaction of G protein subunits with GIRK channels. The activation likely works by increasing the affinity of the channel for PIP2. In high concentration PIP2 activates the channel absent G-protein, but G-protein does not activate the channel absent PIP2. GIRK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ROMK
The renal outer medullary potassium channel (ROMK) is an ATP-dependent potassium channel (Kir1.1) that transports potassium out of cells. It plays an important role in potassium recycling in the thick ascending limb (TAL) and potassium secretion in the cortical collecting duct (CCD) of the nephron. In humans, ROMK is encoded by the ''KCNJ1'' (potassium inwardly-rectifying channel, subfamily J, member 1) gene. Multiple transcript variants encoding different isoforms have been found for this gene. Function Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. It is inhibited by internal ATP and probably plays an important role in potassium homeostasis. The encoded protein has a greater tendency to allow potassium to flow into a cell rather than out of a cell, which has (hence the term "inwardly rectif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
