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Bradykinin Receptor B2
Bradykinin receptor B2 is a G-protein coupled receptor for bradykinin, encoded by the BDKRB2 gene in humans. Mechanism The B2 receptor is a G protein-coupled receptor, probably coupled to Gq and Gi. Gq stimulates phospholipase C to increase intracellular free calcium and Gi inhibits adenylate cyclase. Furthermore, the receptor stimulates the mitogen-activated protein kinase pathways. It is ubiquitously and constitutively expressed in healthy tissues. The B2 receptor forms a complex with angiotensin converting enzyme (ACE), and this is thought to play a role in cross-talk between the renin-angiotensin system (RAS) and the kinin–kallikrein system (KKS). The heptapeptide angiotensin (1-7) also potentiates bradykinin action on B2 receptors. Kallidin also signals through the B2 receptor. An antagonist for the receptor is Hoe 140 (icatibant). Function The 9 amino acid bradykinin peptide elicits several responses including vasodilation, edema, smooth muscle spasm and nocicepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-protein Coupled Receptor
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 protein family, evolutionarily-related proteins that are cell surface receptors that detect molecules outside the cell (biology), 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 y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiotensin (1-7)
Angiotensin (1-7) (; Molecular weight = 899.02 g/mol; H- Asp-Arg- Val- Tyr-Ile-His-Pro-OH) is an active heptapeptide of the renin–angiotensin system (RAS). In 1988, Santos ''et al'' demonstrated that angiotensin (1-7) was a main product of the incubation of angiotensin I with brain micropunches and Schiavone ''et al'' reported the first biological effect of this heptapeptide. Angiotensin (1-7) is a vasodilator agent affecting cardiovascular organs, such as heart, blood vessels and kidneys, with functions frequently opposed to those attributed to the major effector component of the RAS, angiotensin II (Ang II). Synthesis The polypeptide Ang I can be converted into Ang (1-7) by the actions of neprilysin (NEP) and thimet oligopeptidase (TOP) enzymes. Also, Ang II can be hydrolyzed into Ang (1-7) through the actions of angiotensin-converting enzyme 2 (ACE2). Ang (1-7) binds and activates the G-protein coupled receptor Mas receptor leading to opposite effects of those of Ang II. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nociception
Nociception (also nocioception, from Latin ''nocere'' 'to harm or hurt') is the sensory nervous system's process of encoding noxious stimuli. It deals with a series of events and processes required for an organism to receive a painful stimulus, convert it to a molecular signal, and recognize and characterize the signal in order to trigger an appropriate defense response. In nociception, intense chemical (e.g., capsaicin present in Chili pepper or Cayenne pepper), mechanical (e.g., cutting, crushing), or thermal (heat and cold) stimulation of sensory neurons called nociceptors produces a signal that travels along a chain of nerve fibers via the spinal cord to the brain. Nociception triggers a variety of physiological and behavioral responses to protect the organism against an aggression and usually results in a subjective experience, or perception, of pain in sentient beings. Detection of noxious stimuli Potentially damaging mechanical, thermal, and chemical stimuli are detected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smooth Muscle
Smooth muscle is an involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit muscle, the whole bundle or sheet of smooth muscle cells contracts as a syncytium. Smooth muscle is found in the walls of hollow organs, including the stomach, intestines, bladder and uterus; in the walls of passageways, such as blood, and lymph vessels, and in the tracts of the respiratory, urinary, and reproductive systems. In the eyes, the ciliary muscles, a type of smooth muscle, dilate and contract the iris and alter the shape of the lens. In the skin, smooth muscle cells such as those of the arrector pili cause hair to stand erect in response to cold temperature or fear. Structure Gross anatomy Smooth muscle is grouped into two types: single-unit smooth muscle, also known as visceral smooth muscle, and multiunit smooth muscle. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edema
Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's Tissue (biology), tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels tight, the area may feel heavy, and joint stiffness. Other symptoms depend on the underlying cause. Causes may include Chronic venous insufficiency, venous insufficiency, heart failure, kidney problems, hypoalbuminemia, low protein levels, liver problems, deep vein thrombosis, infections, angioedema, certain medications, and lymphedema. It may also occur after prolonged sitting or standing and during menstruation or pregnancy. The condition is more concerning if it starts suddenly, or pain or shortness of breath is present. Treatment depends on the underlying cause. If the underlying mechanism involves Hypernatremia, sodium retention, decreased salt intake and a diuretic may be used. Elevating the legs and support stockings may be useful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasodilation
Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure. The response may be intrinsic (due to local processes in the surrounding tissue) or extrinsic (due to hormones or the nervous system). In addition, the response may be localized to a specific organ (depending on the metabolic needs of a particular tissue, as during strenuous exercise), or it may be systemic (seen throughout the entire systemic circulation). Endogenous substances and drugs that cause vasodilation are termed vasodilators. Such vasoactivity is necessary for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icatibant
Icatibant, sold under the brand name Firazyr, is a medication for the symptomatic treatment of acute attacks of hereditary angioedema (HAE) in adults with C1-esterase-inhibitor deficiency. It is not effective in angioedema caused by medication from the ACE inhibitor class. It is a peptidomimetic consisting of ten amino acids, which is a selective and specific antagonist of bradykinin B2 receptors. Mechanism of action Bradykinin is a peptide-based hormone that is formed locally in tissues, very often in response to a trauma. It increases vessel permeability, dilates blood vessels and causes smooth muscle cells to contract. Bradykinin plays an important role as the mediator of pain. Surplus bradykinin Bradykinin (BK) (Greek brady-, slow; -kinin, kīn(eîn) to move) is a peptide that promotes inflammation. It causes arterioles to dilate (enlarge) via the release of prostacyclin, nitric oxide, and endothelium-derived hyperpolarizing factor and ... is responsible for the typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kallidin
Kallidin is a bioactive kinin formed in response to injury from kininogen precursors through the action of kallikreins. Kallidin is a decapeptide whose sequence is H-Lys-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg-OH. It can be converted to bradykinin by the aminopeptidase enzyme. It can be a substrate for carboxypeptidase M and N. Kallidin is identical to bradykinin with an additional lysine residue added at the N-terminal end and signals through the bradykinin receptor The bradykinin receptor family is a group of G-protein coupled receptors whose principal ligand is the protein bradykinin. There are two Bradykinin receptors: the B1 receptor and the B2 receptor. B1 receptor Bradykinin receptor B1 (B1) is a .... References Peptides Kinin–kallikrein system {{Biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinin–kallikrein System
The kinin–kallikrein system or simply kinin system is a poorly understood hormonal system with limited available research. It consists of blood proteins that play a role in inflammation, blood pressure control, coagulation and pain. Its important mediators bradykinin and kallidin are vasodilators and act on many cell types. Clinical symptoms include marked weakness, tachycardia, fever, leukocytosis and acceleration of ESR. History The system was discovered in 1909 when researchers discovered that injection with urine (high in kinins) led to hypotension (low blood pressure). The researchers Emil Karl Frey, Heinrich Kraut and Eugen Werle discovered high-molecular weight kininogen in urine around 1930. Etymology kinin kkīn(eîn) to move, set in motion. kallikrein k kalli~ sweet and krein = kreos, flesh, named for the pancreatic extracts where it was first discovered Members The system consists of a number of large proteins, some small polypeptides and a group of enzymes that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bradykinin
Bradykinin (BK) (Greek brady-, slow; -kinin, kīn(eîn) to move) is a peptide that promotes inflammation. It causes arterioles to dilate (enlarge) via the release of prostacyclin, nitric oxide, and endothelium-derived hyperpolarizing factor and makes veins constrict, via prostaglandin F2, thereby leading to leakage into capillary beds, due to the increased pressure in the capillaries. Bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids. A class of drugs called angiotensin converting enzyme inhibitors (ACE inhibitors) increase bradykinin levels by inhibiting its degradation, thereby increasing its blood pressure lowering effect. ACE inhibitors are FDA approved for the treatment of hypertension and heart failure. Structure Bradykinin, sometimes referred to as BK, is a 9-amino acid peptide chain. The amino acid sequence of bradykinin is: Arg-Pro-Pro-Gly- Phe-Ser-Pro- Phe- Arg (RPPGFSPFR). Its empi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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