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Histamine H4 Receptor
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. Discovery Unlike the histamine receptors discovered earlier, H4 was found in 2000 through a search of the human genomic DNA data base. Tissue distribution H4 is highly expressed in bone marrow and white blood cells and regulates neutrophil release from bone marrow and subsequent infiltration in the zymosan-induced pleurisy mouse model. It was also found that H4R exhibits a uniform expression pattern in the human oral epithelium. Function The Histamine H4 receptor has been shown to be involved in mediating eosinophil shape change and mast cell chemotaxis. This occurs via the βγ subunit acting at phospholipase C to cause actin polymerization and eventually chemotaxis. Structure The 3D structure of the H4 receptor has not been solved yet due to the difficulties of GPCR crystallization. Some attempts have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histamine Receptors
The histamine receptors are a class of G protein–coupled receptors which bind histamine as their primary endogenous ligand. There are four known histamine receptors: * H1 receptor * H2 receptor * H3 receptor * H4 receptor Comparison There are several splice variants of H3 present in various species. Though all of the receptors are 7-transmembrane g protein coupled receptors, H1 and H2 are quite different from H3 and H4 in their activities. H1 causes an increase in PIP2 hydrolysis, H2 stimulates gastric acid secretion, and H3 mediates feedback inhibition An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a sp ... of histamine. References External links *Holger Stark: Histamine Receptors, BIOTREND Reviews No. 01, November 2007 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JNJ 39758979
Johnson & Johnson (J&J) is an American multinational corporation founded in 1886 that develops medical devices, pharmaceuticals, and consumer packaged goods. Its common stock is a component of the Dow Jones Industrial Average and the company is ranked No. 36 on the 2021 Fortune 500 list of the largest United States corporations by total revenue. Johnson & Johnson is one of the world's most valuable companies, and is one of only two U.S.-based companies that has a prime credit rating of AAA, higher than that of the United States government. Johnson & Johnson is headquartered in New Brunswick, New Jersey, the consumer division being located in Skillman, New Jersey. The corporation includes some 250 subsidiary companies with operations in 60 countries and products sold in over 175 countries. Johnson & Johnson had worldwide sales of $93.8billion during calendar year 2021. Johnson & Johnson's brands include numerous household names of medications and first aid supplies. Among its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histamine H2 Receptor
H2 receptors are positively coupled to adenylate cyclase via Gs. 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. Function Histamine is a ubiquitous messenger molecule released from mast cells, enterochromaffin-like cells, and neurons. Its various actions are mediated by histamine receptors H1, H2, H3 and H4. The histamine receptor H2 belongs to the rhodopsin-like family of G protein-coupled receptors. It is an integral membrane protein and stimulates gastric acid secretion. It also regulates gastrointestinal motility and intestinal secretion and is thought to be involved in regulating cell growth and differentiation. Histamine may play a role in penile erection. Tissue distribution Histamine H2 receptors are expressed in the following tissues: ;Peripheral tissues *Gastric parietal cells (oxyn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histamine H1 Receptor
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. Function The expression of NF-κB, the transcription factor that regulates inflammatory processes, is promoted by the constitutive activity of the H1 receptor as well as by agonists that bind at the receptor. H1-antihistamines have been shown to attenuate NF-κB expression and mitigate certain in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperalgesia
Hyperalgesia ( or ; 'hyper' from Greek ὑπέρ (huper, “over”), '-algesia' from Greek algos, ἄλγος (pain)) is an abnormally increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves and can cause hypersensitivity to stimulus. Prostaglandins E and F are largely responsible for sensitizing the nociceptors. Temporary increased sensitivity to pain also occurs as part of sickness behavior, the evolved response to infection. Types Hyperalgesia can be experienced in focal, discrete areas, or as a more diffuse, body-wide form. Conditioning studies have established that it is possible to experience a learned hyperalgesia of the latter, diffuse form. The focal form is typically associated with injury, and is divided into two subtypes: * ''Primary hyperalgesia'' describes pain sensitivity that occurs directly in the damaged tissues. * ''Secondary hyperalgesia'' describes pain sensitivity that occurs in surrounding undamaged tissues. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-inflammatory
Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs remedy pain by reducing inflammation as opposed to opioids, which affect the central nervous system to block pain signaling to the brain. Nonsteroidal anti-inflammatory drugs Nonsteroidal anti-inflammatory drugs (NSAIDs) alleviate pain by counteracting the cyclooxygenase (COX) enzyme. On its own, COX enzyme synthesizes prostaglandins, creating inflammation. In whole, the NSAIDs prevent the prostaglandins from ever being synthesized, reducing or eliminating the inflammation and resulting pain. Some common examples of NSAIDs are aspirin, ibuprofen, and naproxen. The newer specific COX-inhibitors are not classified together with the traditional NSAIDs, even though they presumably share the same mode of action. On the other hand, there are analgesics that are commonly associat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosinophil
Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells (WBCs) and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. Along with mast cells and basophils, they also control mechanisms associated with allergy and asthma. They are granulocytes that develop during hematopoiesis in the bone marrow before migrating into blood, after which they are terminally differentiated and do not multiply. They form about 2 to 3% of WBCs. These cells are eosinophilic or "acid-loving" due to their large acidophilic cytoplasmic granules, which show their affinity for acids by their affinity to coal tar dyes: Normally transparent, it is this affinity that causes them to appear brick-red after staining with eosin, a red dye, using the Romanowsky method. The staining is concentrated in small granules within the cellular cytoplasm, which contain many chemical mediators, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mast Cell
A mast cell (also known as a mastocyte or a labrocyte) 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 tumours. The mast cell is very similar in both appearance and function to the basophil, another type of white blood cell. Although mast cells were once thought to be tissue-resident basophils, it has been shown that the two cells develop from different hematopoietic lineages and thus cannot be the same cells. Structure Mast cells are very similar to basophil granulocytes (a class of white ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allergy
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note: food intolerances and food poisoning are separate conditions. Common allergens include pollen and certain foods. Metals and other substances may also cause such problems. Food, insect stings, and medications are common causes of severe reactions. Their development is due to both genetic and environmental factors. The underlying mechanism involves immunoglobulin E antibodies (IgE), part of the body's immune system, binding to an allergen and then to a receptor on mast cells or basophils where it triggers the release of inflammatory chemicals such as histamine. Diagnosis is ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. These may occur a few times a day or a few times per week. Depending on the person, asthma symptoms may become worse at night or with exercise. Asthma is thought to be caused by a combination of genetic and environmental factors. Environmental factors include exposure to air pollution and allergens. Other potential triggers include medications such as aspirin and beta blockers. Diagnosis is usually based on the pattern of symptoms, response to therapy over time, and spirometry lung function testing. Asthma is classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate. It may also be classified as atopic or non-atopic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pimozide
Pimozide (sold under the brand name Orap) is an antipsychotic drug of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine (ratio 50-70:1). On a weight basis it is even more potent than haloperidol. It also has special neurologic indications for Tourette syndrome and resistant tics. The side effects include akathisia, tardive dyskinesia, and, more rarely, neuroleptic malignant syndrome and prolongation of the QT interval. Medical uses Pimozide is used in its oral preparation in schizophrenia and chronic psychosis (on-label indications in Europe only), Tourette syndrome, and resistant tics (Europe, United States and Canada). There have been numerous studies showing Pimozide can be used successfully to treat Delusional parasitosis and traditionally was the drug of choice. However, newer medications have become prevalent recently as the preferred medication. In one case a series of 33 patients ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
