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CYP1A1
Cytochrome P450, family 1, subfamily A, polypeptide 1 is a protein that in humans is encoded by the ''CYP1A1'' gene. The protein is a member of the cytochrome P450 superfamily of enzymes. Function Metabolism of xenobiotics and drugs CYP1A1 is involved in phase I xenobiotic and drug metabolism (one substrate of it is theophylline). It is inhibited by hesperetin (a flavonoid found in lime, sweet orange), fluoroquinolones and macrolides and induced by aromatic hydrocarbons. CYP1A1 is also known as AHH (aryl hydrocarbon hydroxylase). It is involved in the metabolic activation of aromatic hydrocarbons (polycyclic aromatic hydrocarbons, PAH), for example, benzo yrene (BaP), by transforming it to an epoxide. In this reaction, the oxidation of benzo yrene is catalysed by CYP1A1 to form BaP-7,8-epoxide, which can be further oxidized by epoxide hydrolase (EH) to form BaP-7,8-dihydrodiol. Finally, CYP1A1 catalyses this intermediate to form BaP-7,8-dihydrodiol-9,10-epoxide, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzo(a)pyrene
Benzo 'a''yrene (B''a''P or B ) is a polycyclic aromatic hydrocarbon and the result of incomplete combustion of organic matter at temperatures between and . The ubiquitous compound can be found in coal tar, tobacco smoke and many foods, especially grilled meats. The substance with the formula C20H12 is one of the benzopyrenes, formed by a benzene ring fused to pyrene. Its diol epoxide metabolites (more commonly known as BPDE) react with and bind to DNA, resulting in mutations and eventually cancer. It is listed as a Group 1 carcinogen by the IARC. In the 18th century a scrotal cancer of chimney sweepers, the chimney sweeps' carcinoma, was already known to be connected to soot. Description Benzo 'a''yrene (B''a''P) is a polycyclic aromatic hydrocarbon found in coal tar with the formula C20H12. The compound is one of the benzopyrenes, formed by a benzene ring fused to pyrene, and is the result of incomplete combustion at temperatures between and . Sources The main source ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxygenase
Epoxygenases are a set of membrane-bound, heme-containing cytochrome P450 (CYP P450 or just CYP) enzymes that metabolize polyunsaturated fatty acids to epoxide products that have a range of biological activities. The most thoroughly studied substrate of the CYP epoxylgenases is arachidonic acid. This polyunsaturated fatty acid is metabolized by cyclooxygenases to various prostaglandin, thromboxane, and prostacyclin metabolites in what has been termed the first pathway of eicosanoid production; it is also metabolized by various lipoxygenases to hydroxyeicosatetraenoic acids (e.g. 5-Hydroxyeicosatetraenoic acid, 12-Hydroxyeicosatetraenoic acid, 15-hydroxyicosatetraenoic acid) and leukotrienes (e.g. leukotriene B4, leukotriene C4) in what has been termed the second pathway of eicosanoid production. The metabolism of arachidonic acid to epoxyeicosatrienoic acids by the CYP epoxygenases has been termed the third pathway of eicosanoid metabolism. Like the first two pathways of eic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome P450
Cytochromes P450 (CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance (pharmacology), clearance of various compounds, as well as for hormone synthesis and breakdown. In 1963, Ronald W. Estabrook, Estabrook, David Y. Cooper, Cooper, and Otto Rosenthal, Rosenthal described the role of CYP as a catalyst in steroid hormone synthesis and drug metabolism. In plants, these proteins are important for the biosynthesis of secondary metabolite, defensive compounds, fatty acids, and hormones. CYP enzymes have been identified in all kingdom (biology), kingdoms of life: animals, plants, fungus, fungi, protists, bacteria, and archaea, as well as in viruses. However, they are not omnipresent; for example, they have not been found in ''Escherichia coli''. , more than 300,000 distinct CYP proteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aryl Hydrocarbon Receptor
The aryl hydrocarbon receptor (also known as AhR, AHR, ahr, ahR, or dioxin receptor) is a protein that in humans is encoded by the AHR gene. The aryl hydrocarbon receptor is a transcription factor that regulates gene expression. It was originally thought to function primarily as a sensor of xenobiotic chemicals and also as the regulator of enzymes such as cytochrome P450s that metabolize these chemicals. The most notable of these xenobiotic chemicals are aromatic (aryl) hydrocarbons from which the receptor derives its name. More recently, it has been discovered that AhR is activated (or deactivated) by a number of endogenous indole derivatives such as kynurenine. In addition to regulating metabolism enzymes, the AhR has roles in regulating immunity, stem cell maintenance, and cellular differentiation. The aryl hydrocarbon receptor is a member of the family of basic helix-loop-helix transcription factors. AHR binds several exogenous ligands such as natural plant flavonoids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxyeicosatetraenoic Acid
Epoxyeicosatetraenoic acids (EEQs or EpETEs) are a set of biologically active epoxides that various cell types make by metabolizing the omega 3 fatty acid, eicosapentaenoic acid (EPA), with certain cytochrome P450 epoxygenases. These epoxygenases can metabolize EPA to as many as 10 epoxides that differ in the site and/or stereoisomer of the epoxide formed; however, the formed EEQs, while differing in potency, often have similar bioactivities and are commonly considered together. Structure EPA is a straight-chain, 20 carbon omega-3 fatty acid containing cis (see Cis–trans isomerism) double bonds between carbons 5 and 6, 8 and 9, 11 and 12, 14 and 15, and 17 and 18; each of these double bonds is designated with the notation ''Z'' to indicate its cis configuration in the IUPAC Chemical nomenclature used here. EPA is therefore 5''Z'',8''Z'',11''Z'',14''Z'',17''Z''-eicosapentaenoic acid. Certain cytochrome P450 epoxygenases metabolize EPA by converting one of these double bounds to an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycyclic Aromatic Hydrocarbons
A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. PAHs are uncharged, non-polar and planar. Many are colorless. Many of them are found in coal and in oil deposits, and are also produced by the combustion of organic matter—for example, in engines and incinerators or when biomass burns in forest fires. Polycyclic aromatic hydrocarbons are discussed as possible starting materials for abiotic syntheses of materials required by the earliest forms of life. Nomenclature and structure The terms polyaromatic hydrocarbon or polynuclear aromatic hydrocarbon are also used for this concept. By definition, polycyclic aromatic hydrocarbons have multiple rings, precluding benzene from being considered a PAH. Some sources, such as the US EPA and CDC, consider naphthalene to be the simplest PAH. Other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxydocosapentaenoic Acid
Epoxide docosapentaenoic acids (epoxydocosapentaenoic acids, EDPs, or EpDPEs) are metabolites of the 22-carbon straight-chain omega-3 fatty acid, docosahexaenoic acid (DHA). Cell types that express certain cytochrome P450 (CYP) epoxygenases metabolize polyunsaturated fatty acid's (PUFAs) by converting one of their double bonds to an epoxide. In the best known of these metabolic pathways, cellular CYP epoxygenases metabolize the 20-carbon straight-chain omega-6 fatty acid, arachidonic acid, to epoxyeicosatrienoic acids (EETs); another CYP epoxygenase pathway metabolizes the 20-carbon omega-3 fatty acid, eicosapentaenoic acid (EPA), to epoxyeicosatetraenoic acids (EEQs). CYP epoxygenases similarly convert various other PUFAs to epoxides (see epoxygenase) These epoxide metabolites have a variety of activities. However, essentially all of them are rapidly converted to their corresponding, but in general far less active, Vicinal (chemistry) dihydroxy fatty acids by ubiquitous cellu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiogenesis
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting. Vasculogenesis is the embryonic formation of endothelial cells from mesoderm cell precursors, and from neovascularization, although discussions are not always precise (especially in older texts). The first vessels in the developing embryo form through vasculogenesis, after which angiogenesis is responsible for most, if not all, blood vessel growth during development and in disease. Angiogenesis is a normal and vital process in growth and development, as well as in wound healing and in the formation of granulation tissue. However, it is also a fundamental step in the transition of tumors from a benign state to a malignant one, leading to the use of angiogenesis inhibitors in the treatment of cancer. The essential role of angiogenesis in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
20-Hydroxyeicosatetraenoic Acid
20-Hydroxyeicosatetraenoic acid, also known as 20-HETE or 20-hydroxy-5''Z'',8''Z'',11''Z'',14''Z''-eicosatetraenoic acid, is an eicosanoid metabolite of arachidonic acid that has a wide range of effects on the vascular system including the regulation of vascular tone, blood flow to specific organs, sodium and fluid transport in the kidney, and vascular pathway remodeling. These vascular and kidney effects of 20-HETE have been shown to be responsible for regulating blood pressure and blood flow to specific organs in rodents; genetic and preclinical studies suggest that 20-HETE may similarly regulate blood pressure and contribute to the development of stroke and heart attacks. Additionally the loss of its production appears to be one cause of the human neurological disease, Hereditary spastic paraplegia. Preclinical studies also suggest that the overproduction of 20-HETE may contribute to the progression of certain human cancers, particularly those of the breast. Biosynthesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arteriole
An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the primary site of vascular resistance. The greatest change in blood pressure and velocity of blood flow occurs at the transition of arterioles to capillaries.This function is extremely important because it prevents the thin, one-layer capillaries from exploding upon pressure. The arterioles achieve this decrease in pressure, as they are the site with the highest resistance (a large contributor to total peripheral resistance) which translates to a large decrease in the pressure. Structure Microanatomy In a healthy vascular system the endothelium lines all blood-contacting surfaces, including arteries, arterioles, veins, venules, capillaries, and heart chambers. This healthy condition is promoted by the ample production of nitric oxide by the end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omega-3 Fatty Acid
Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chemical structure. They are widely distributed in nature, being important constituents of animal lipid metabolism, and they play an important role in the human diet and in human physiology. The three types of omega−3 fatty acids involved in human physiology are α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA can be found in plants, while DHA and EPA are found in algae and fish. Marine algae and phytoplankton are primary sources of omega−3 fatty acids. DHA and EPA accumulate in fish that eat these algae. Common sources of plant oils containing ALA include walnuts, edible seeds, and flaxseeds as well as hempseed oil, while sources of EPA and DHA include fish and fish oils, and algae oil. Mammals a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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