Reaction Process: Reactome:R-TGU-189483
Heme degradation related metabolites
find 13 related metabolites which is associated with chemical reaction(pathway) Heme degradation
Oxygen + TPNH + heme ⟶ BV + CO + Fe2+ + H2O + TPN
Bilirubin
Bilirubin is a yellow bile pigment that is a degradation product of heme. It occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the bodys clearance of waste products that arise from the destruction of aged or abnormal red blood cells. Bilirubin has been found in all vertebrates and in certain plants including Strelitzia nicolai (PMID: 28573242). Bilirubin levels in humans are elevated in certain diseases such as jaundice and liver disease and it is responsible for the yellow color of bruises and the yellow discoloration in jaundice. Bilirubin breakdown products, such as stercobilin, cause the brown color of feces. A different breakdown product, urobilin, is the main component of the straw-yellow color in urine. Bilirubin consists of an open chain of four pyrroles (tetrapyrrole). It is formed by oxidative cleavage of a porphyrin in heme, which leads to biliverdin, a green tetrapyrrolic bile pigment that is also a product of heme catabolism. Biliverdin is then reduced to bilirubin via biliverdin reductase. After conjugation with glucuronic acid, bilirubin can be excreted in the urine. Bilirubin is structurally similar to the pigment phycobilin used by certain algae to capture light energy, and to the pigment phytochrome used by plants to sense light. Elevated bilirubin levels in humans are associated with Crigler-Najjar syndrome type I, which is an inborn error of metabolism. Crigler-Najjar syndrome is a rare genetic disorder characterized by an inability to properly convert and clear bilirubin from the body. Affected individuals cannot convert unconjugated bilirubin to the conjugated form because they lack a specific liver enzyme required to break down (metabolize) bilirubin. Since they cannot convert bilirubin, they develop abnormally high levels of unconjugated bilirubin in the blood (hyperbilirubinemia). Crigler-Najjar syndrome is caused by mutations in the UGT1A1 gene. The hallmark finding of Crigler-Najjar syndrome is a persistent yellowing of the skin, mucous membranes and whites of the eyes (jaundice). Elevation of both alanine aminotransferase and bilirubin levels in serum or plasma can be indicative of serious liver injury. High levels of bilirubin are indicative of jaundice, which is easily recognizable due to a yellowing of the skin and eyes. Bilirubin is also an antioxidant. Bilirubins antioxidant activity may be particularly important in the brain, where it prevents excitotoxicity and neuronal death by scavenging superoxide during N-methyl-D-aspartic acid neurotransmission (PMID: 31353321). Bilirubin is a bile pigment that is a degradation product of heme. In particular, bilirubin is a yellow breakdown product of normal heme catabolism. Its levels are elevated in certain diseases and it is responsible for the yellow color of bruises. Bilirubin is an excretion product, and the body does not control levels. Bilirubin levels reflect the balance between production and excretion. Thus, there is no "normal" level of bilirubin. Bilirubin consists of an open chain of four pyrroles (tetrapyrrole); by contrast, the heme molecule is a closed ring of four pyrroles, called porphyrin. -- Wikipedia [HMDB]. Bilirubin is found in many foods, some of which are barley, mustard spinach, other bread, and sesbania flower. Bilirubin (BR) (from the Latin for "red bile") is a red-orange compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from the destruction of aged or abnormal red blood cells.[3] In the first step of bilirubin synthesis, the heme molecule is stripped from the hemoglobin molecule. Heme then passes through various processes of porphyrin catabolism, which varies according to the region of the body in which the breakdown occurs. For example, the molecules excreted in the urine differ from those in the feces.[4] The production of biliverdin from heme is the first major step in the catabolic pathway, after which the enzyme biliverdin reductase performs the second step, producing bilirubin from biliverdin.[5][6] Ultimately, bilirubin is broken down within the body, and its metabolites excreted through bile and urine; elevated levels may indicate certain diseases.[7] It is responsible for the yellow color of healing bruises and the yellow discoloration in jaundice. The bacterial enzyme bilirubin reductase is responsible for the breakdown of bilirubin in the gut.[8] One breakdown product, urobilin, is the main component of the straw-yellow color in urine.[9] Another breakdown product, stercobilin, causes the brown color of feces. Although bilirubin is usually found in animals rather than plants, at least one plant species, Strelitzia nicolai, is known to contain the pigment.[10] Bilirubin is created by the activity of biliverdin reductase on biliverdin, a green tetrapyrrolic bile pigment that is also a product of heme catabolism. Bilirubin, when oxidized, reverts to become biliverdin once again. This cycle, in addition to the demonstration of the potent antioxidant activity of bilirubin,[14] has led to the hypothesis that bilirubin's main physiologic role is as a cellular antioxidant.[15][16] Consistent with this, animal studies suggest that eliminating bilirubin results in endogenous oxidative stress.[17] Bilirubin's antioxidant activity may be particularly important in the brain, where it prevents excitotoxicity and neuronal death by scavenging superoxide during N-methyl-D-aspartic acid neurotransmission.[18] Bilirubin in plasma is mostly produced by the destruction of erythrocytes. Heme is metabolized into biliverdin (via heme oxygenase) and then into bilirubin (via biliverdin reductase) inside the macrophages. [11] Bilirubin is then released into the plasma and transported to the liver bound by albumin, since it is insoluble in water in this state. In this state, bilirubin is called unconjugated (despite being bound by albumin). [11] In the liver, unconjugated bilirubin is up-taken by the hepatocytes and subsequently conjugated with glucuronic acid (via the enzyme uridine diphosphate–glucuronyl transferase). In this state, bilirubin is soluble in water and it is called conjugated bilirubin. [11] Conjugated bilirubin is excreted into the bile ducts and enters the duodenum. During its transport to the colon, it is converted into urobilinogen by the bacterial enzyme bilirubin reductase.[8] Most of the urobilinogen is further reduced into stercobilinogen and is excreted through feces (air oxidizes stercobilinogen to stercobilin, which gives feces their characteristic brown color). [11] A lesser amount of urobilinogen is re-absorbed into portal circulation and transferred to the liver. For the most part, this urobilinogen is recycled to conjugated bilirubin and this process closes the enterohepatic circle. There is also an amount of urobilinogen which is not recycled, but rather enters the systemic circulation and subsequently the kidneys, where it is excreted. Air oxidizes urobilinogen into urobilin, which gives urine its characteristic color.[11][19] In parallel, a small amount of conjugated billirubin can also enter the systemic circulation and get excreted through urine. This is exaggerated in various pathological situations.[19]
Nicotinamide adenine dinucleotide phosphate
NADPH is the reduced form of NADP+, and NADP+ is the oxidized form of NADPH. Nicotinamide adenine dinucleotide phosphate (NADP) is a coenzyme composed of ribosylnicotinamide 5-phosphate (NMN) coupled with a pyrophosphate linkage to 5-phosphate adenosine 2,5-bisphosphate. NADP serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). NADP is formed through the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage (Dorland, 27th ed). This extra phosphate is added by the enzyme NAD+ kinase and removed via NADP+ phosphatase. NADP is also known as TPN (triphosphopyridine nucleotide) and it is an important cofactor used in anabolic reactions in all forms of cellular life. Examples include the Calvin cycle, cholesterol synthesis, fatty acid elongation, and nucleic acid synthesis (Wikipedia). Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5-phosphate (NMN) coupled by pyrophosphate linkage to the 5-phosphate adenosine 2,5-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed.) [HMDB]. NADPH is found in many foods, some of which are american pokeweed, rice, ginseng, and ostrich fern. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Uridine diphosphate glucuronic acid
Uridine diphosphate glucuronic acid, also known as udpglucuronate or udp-D-glucuronic acid, is a member of the class of compounds known as pyrimidine nucleotide sugars. Pyrimidine nucleotide sugars are pyrimidine nucleotides bound to a saccharide derivative through the terminal phosphate group. Uridine diphosphate glucuronic acid is soluble (in water) and a moderately acidic compound (based on its pKa). Uridine diphosphate glucuronic acid can be synthesized from alpha-D-glucuronic acid. Uridine diphosphate glucuronic acid can also be synthesized into UDP-2,3-diacetamido-2,3-dideoxy-alpha-D-glucuronic acid. Uridine diphosphate glucuronic acid can be found in a number of food items such as parsley, chervil, black mulberry, and malabar plum, which makes uridine diphosphate glucuronic acid a potential biomarker for the consumption of these food products. Uridine diphosphate glucuronic acid can be found primarily in human liver tissue. Uridine diphosphate glucuronic acid exists in all living species, ranging from bacteria to humans. In humans, uridine diphosphate glucuronic acid is involved in several metabolic pathways, some of which include etoposide metabolism pathway, estrone metabolism, tamoxifen action pathway, and androgen and estrogen metabolism. Uridine diphosphate glucuronic acid is also involved in several metabolic disorders, some of which include porphyria variegata (PV), glycogenosis, type III. cori disease, debrancher glycogenosis, 17-beta hydroxysteroid dehydrogenase III deficiency, and hereditary coproporphyria (HCP). Uridine diphosphate glucuronic acid is made from UDP-glucose by UDP-glucose 6-dehydrogenase (EC 1.1.1.22) using NAD+ as a cofactor. It is the source of the glucuronosyl group in glucuronosyltransferase reactions . Uridine diphosphate glucuronic acid is a nucleoside diphosphate sugar which serves as a source of glucuronic acid for polysaccharide biosynthesis. It may also be epimerized to UDP Iduronic acid, which donates Iduronic acid to polysaccharides. In animals, UDP glucuronic acid is used for formation of many glucosiduronides with various aglycones. The transfer of glucuronic acid from UDP-alpha-D-glucuronic acid onto a terminal galactose residue is done by beta1,3-glucuronosyltransferases, responsible for the completion of the protein-glycosaminoglycan linkage region of proteoglycans and of the HNK1 epitope of glycoproteins and glycolipids. In humans the enzyme galactose-beta-1,3-glucuronosyltransferase I completes the synthesis of the common linker region of glycosaminoglycans (GAGs) by transferring glucuronic acid (GlcA) onto the terminal galactose of the glycopeptide primer of proteoglycans. The GAG chains of proteoglycans regulate major biological processes such as cell proliferation and recognition, extracellular matrix deposition, and morphogenesis. (PMID:16815917). Acquisition and generation of the data is financially supported in part by CREST/JST.
Uridine 5'-diphosphate
Uridine 5-diphosphate, also known as 5-UDP, UDP or uridine diphosphoric acid, belongs to the class of organic compounds known as pyrimidine ribonucleoside diphosphates. These are pyrimidine ribonucleotides with diphosphate group linked to the ribose moiety. UDP is also classified as a nucleotide diphosphate. It is an ester of pyrophosphoric acid with the nucleoside uridine. UDP consists of a pyrophosphate group, a pentose sugar ribose, and the nucleobase uracil. UDP exists in all living species, ranging from bacteria to plants to humans. In mammals UDP is an important factor in glycogenesis or the formation of glycogen in the liver. Before glucose can be stored as glycogen in the liver and muscles, the enzyme UDP-glucose pyrophosphorylase forms a UDP-glucose unit by combining glucose 1-phosphate with uridine triphosphate, cleaving a pyrophosphate ion in the process. Then, the enzyme glycogen synthase combines UDP-glucose units to form a glycogen chain. UDP is also an important extracellular pyrimidine signaling molecule that mediates diverse biological effects via P1 and P2 purinergic receptors, such as the uptake of thymidine and proliferation of gliomas. UDP plays a key role in the function of Uridine 5-diphospho-glucuronosyltransferases (UDP-glucuronosyltransferases, UGTs) which catalyze the transfer of the glucuronic acid component of UDP-glucuronic acid to a small hydrophobic molecule. UDP-Glucuronosyltransferases are responsible for the process of glucuronidation, a major part of phase II metabolism. The reaction catalyzed by UGT enzymes involves the addition of a glucuronic acid moiety to xenobiotics and is the most important pathway for the human bodys elimination of the most frequently prescribed drugs. It is also the major pathway for foreign chemical (dietary, environmental, pharmaceutical) removal for most drugs, dietary substances, toxins and endogenous substances. UGT is present in humans, other animals, plants, and bacteria. Famously, UGT enzymes are not present in the genus Felis (PMID: 10862526) and this accounts for a number of unusual toxicities in the cat family. Uridine-5-diphosphate, also known as udp or uridine 5-diphosphoric acid, is a member of the class of compounds known as pyrimidine ribonucleoside diphosphates. Pyrimidine ribonucleoside diphosphates are pyrimidine ribonucleotides with diphosphate group linked to the ribose moiety. Uridine-5-diphosphate is slightly soluble (in water) and a moderately acidic compound (based on its pKa). Uridine-5-diphosphate can be found in a number of food items such as napa cabbage, lichee, tea leaf willow, and parsnip, which makes uridine-5-diphosphate a potential biomarker for the consumption of these food products. Uridine-5-diphosphate can be found primarily in blood, as well as in human placenta, prostate and thyroid gland tissues. Uridine-5-diphosphate exists in all living species, ranging from bacteria to humans. In humans, uridine-5-diphosphate is involved in several metabolic pathways, some of which include morphine action pathway, androgen and estrogen metabolism, estrone metabolism, and amino sugar metabolism. Uridine-5-diphosphate is also involved in several metabolic disorders, some of which include 17-beta hydroxysteroid dehydrogenase III deficiency, acute intermittent porphyria, beta ureidopropionase deficiency, and g(m2)-gangliosidosis: variant B, tay-sachs disease. Acquisition and generation of the data is financially supported in part by CREST/JST. COVID info from COVID-19 Disease Map, WikiPathways Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Biliverdin
Biliverdin is a green pigment formed as a byproduct of hemoglobin breakdown. It consists of four linearly connected pyrrole rings (a tetrapyrrole). Biliverdin is formed when the heme group in hemoglobin is cleaved at its alpha-methene bridge. The resulting biliverdin is then reduced to bilirubin, a yellow pigment, by the enzyme biliverdin reductase. The changing color of a bruise from deep purple to yellow over time is a graphical indicator of this reaction. Biosynthesized from hemoglobin as a precursor of bilirubin. Occurs in the bile of amphibia and of birds, but not in normal human bile or serum. [HMDB] Biliverdin is a green pigment formed as a byproduct of hemoglobin breakdown. It consists of four linearly connected pyrrole rings (a tetrapyrrole). Biliverdin is formed when the heme group in hemoglobin is cleaved at its alpha-methene bridge. The resulting biliverdin is then reduced to bilirubin, a yellow pigment, by the enzyme biliverdin reductase. The changing color of a bruise from deep purple to yellow over time is a graphical indicator of this reaction. Biliverdin occurs in the bile of amphibia and of birds, but not in normal human bile or serum. Biliverdin. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=114-25-0 (retrieved 2024-07-01) (CAS RN: 114-25-0). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).
NADP+
[C21H29N7O17P3]+ (744.0832754)
[Spectral] NADP+ (exact mass = 743.07545) and NAD+ (exact mass = 663.10912) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Water
Water is a chemical substance that is essential to all known forms of life. It appears colorless to the naked eye in small quantities, though it is actually slightly blue in color. It covers 71\\% of Earths surface. Current estimates suggest that there are 1.4 billion cubic kilometers (330 million m3) of it available on Earth, and it exists in many forms. It appears mostly in the oceans (saltwater) and polar ice caps, but it is also present as clouds, rain water, rivers, freshwater aquifers, lakes, and sea ice. Water in these bodies perpetually moves through a cycle of evaporation, precipitation, and runoff to the sea. Clean water is essential to human life. In many parts of the world, it is in short supply. From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances. It carries out this role by allowing organic compounds to react in ways that ultimately allow replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the bodys solutes dissolve and as an essential part of many metabolic processes within the body. Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed from molecules (through energy requiring enzymatic chemical reactions) in order to grow larger molecules (e.g. starches, triglycerides and proteins for storage of fuels and information). In catabolism, water is used to break bonds in order to generate smaller molecules (e.g. glucose, fatty acids and amino acids to be used for fuels for energy use or other purposes). Water is thus essential and central to these metabolic processes. Water is also central to photosynthesis and respiration. Photosynthetic cells use the suns energy to split off waters hydrogen from oxygen. Hydrogen is combined with CO2 (absorbed from air or water) to form glucose and release oxygen. All living cells use such fuels and oxidize the hydrogen and carbon to capture the suns energy and reform water and CO2 in the process (cellular respiration). Water is also central to acid-base neutrality and enzyme function. An acid, a hydrogen ion (H+, that is, a proton) donor, can be neutralized by a base, a proton acceptor such as hydroxide ion (OH-) to form water. Water is considered to be neutral, with a pH (the negative log of the hydrogen ion concentration) of 7. Acids have pH values less than 7 while bases have values greater than 7. Stomach acid (HCl) is useful to digestion. However, its corrosive effect on the esophagus during reflux can temporarily be neutralized by ingestion of a base such as aluminum hydroxide to produce the neutral molecules water and the salt aluminum chloride. Human biochemistry that involves enzymes usually performs optimally around a biologically neutral pH of 7.4. (Wikipedia). Water, also known as purified water or dihydrogen oxide, is a member of the class of compounds known as homogeneous other non-metal compounds. Homogeneous other non-metal compounds are inorganic non-metallic compounds in which the largest atom belongs to the class of other nonmetals. Water can be found in a number of food items such as caraway, oxheart cabbage, alaska wild rhubarb, and japanese walnut, which makes water a potential biomarker for the consumption of these food products. Water can be found primarily in most biofluids, including ascites Fluid, blood, cerebrospinal fluid (CSF), and lymph, as well as throughout all human tissues. Water exists in all living species, ranging from bacteria to humans. In humans, water is involved in several metabolic pathways, some of which include cardiolipin biosynthesis CL(20:4(5Z,8Z,11Z,14Z)/18:0/20:4(5Z,8Z,11Z,14Z)/18:2(9Z,12Z)), cardiolipin biosynthesis cl(i-13:0/i-15:0/i-20:0/i-24:0), cardiolipin biosynthesis CL(18:0/18:0/20:4(5Z,8Z,11Z,14Z)/22:5(7Z,10Z,13Z,16Z,19Z)), and cardiolipin biosynthesis cl(a-13:0/i-18:0/i-13:0/i-19:0). Water is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis tg(i-21:0/i-13:0/21:0), de novo triacylglycerol biosynthesis tg(22:0/20:0/i-20:0), de novo triacylglycerol biosynthesis tg(a-21:0/i-20:0/i-14:0), and de novo triacylglycerol biosynthesis tg(i-21:0/a-17:0/i-12:0). Water is a drug which is used for diluting or dissolving drugs for intravenous, intramuscular or subcutaneous injection, according to instructions of the manufacturer of the drug to be administered [fda label]. Water plays an important role in the world economy. Approximately 70\\% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a major source of food for many parts of the world. Much of long-distance trade of commodities (such as oil and natural gas) and manufactured products is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a wide variety of chemical substances; as such it is widely used in industrial processes, and in cooking and washing. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, and diving .
Oxygen
Oxygen is the third most abundant element in the universe after hydrogen and helium and the most abundant element by mass in the Earths crust. Diatomic oxygen gas constitutes 20.9\\% of the volume of air. All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all living organisms. Green algae and cyanobacteria in marine environments provide about 70\\% of the free oxygen produced on earth and the rest is produced by terrestrial plants. Oxygen is used in mitochondria to help generate adenosine triphosphate (ATP) during oxidative phosphorylation. For animals, a constant supply of oxygen is indispensable for cardiac viability and function. To meet this demand, an adult human, at rest, inhales 1.8 to 2.4 grams of oxygen per minute. This amounts to more than 6 billion tonnes of oxygen inhaled by humanity per year. At a resting pulse rate, the heart consumes approximately 8-15 ml O2/min/100 g tissue. This is significantly more than that consumed by the brain (approximately 3 ml O2/min/100 g tissue) and can increase to more than 70 ml O2/min/100 g myocardial tissue during vigorous exercise. As a general rule, mammalian heart muscle cannot produce enough energy under anaerobic conditions to maintain essential cellular processes; thus, a constant supply of oxygen is indispensable to sustain cardiac function and viability. However, the role of oxygen and oxygen-associated processes in living systems is complex, and they and can be either beneficial or contribute to cardiac dysfunction and death (through reactive oxygen species). Reactive oxygen species (ROS) are a family of oxygen-derived free radicals that are produced in mammalian cells under normal and pathologic conditions. Many ROS, such as the superoxide anion (O2-)and hydrogen peroxide (H2O2), act within blood vessels, altering mechanisms mediating mechanical signal transduction and autoregulation of cerebral blood flow. Reactive oxygen species are believed to be involved in cellular signaling in blood vessels in both normal and pathologic states. The major pathway for the production of ROS is by way of the one-electron reduction of molecular oxygen to form an oxygen radical, the superoxide anion (O2-). Within the vasculature there are several enzymatic sources of O2-, including xanthine oxidase, the mitochondrial electron transport chain, and nitric oxide (NO) synthases. Studies in recent years, however, suggest that the major contributor to O2- levels in vascular cells is the membrane-bound enzyme NADPH-oxidase. Produced O2- can react with other radicals, such as NO, or spontaneously dismutate to produce hydrogen peroxide (H2O2). In cells, the latter reaction is an important pathway for normal O2- breakdown and is usually catalyzed by the enzyme superoxide dismutase (SOD). Once formed, H2O2 can undergo various reactions, both enzymatic and nonenzymatic. The antioxidant enzymes catalase and glutathione peroxidase act to limit ROS accumulation within cells by breaking down H2O2 to H2O. Metabolism of H2O2 can also produce other, more damaging ROS. For example, the endogenous enzyme myeloperoxidase uses H2O2 as a substrate to form the highly reactive compound hypochlorous acid. Alternatively, H2O2 can undergo Fenton or Haber-Weiss chemistry, reacting with Fe2+/Fe3+ ions to form toxic hydroxyl radicals (-.OH). (PMID: 17027622, 15765131) [HMDB]. Oxygen is found in many foods, some of which are soy bean, watermelon, sweet basil, and spinach. Oxygen is the third most abundant element in the universe after hydrogen and helium and the most abundant element by mass in the Earths crust. Diatomic oxygen gas constitutes 20.9\\% of the volume of air. All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all living organisms. Green algae and cyanobacteria in marine environments provide about 70\\% of the free oxygen produced on earth and the rest is produced by terrestrial plants. Oxygen is used in mitochondria to help generate adenosine triphosphate (ATP) during oxidative phosphorylation. For animals, a constant supply of oxygen is indispensable for cardiac viability and function. To meet this demand, an adult human, at rest, inhales 1.8 to 2.4 grams of oxygen per minute. This amounts to more than 6 billion tonnes of oxygen inhaled by humanity per year. At a resting pulse rate, the heart consumes approximately 8-15 ml O2/min/100 g tissue. This is significantly more than that consumed by the brain (approximately 3 ml O2/min/100 g tissue) and can increase to more than 70 ml O2/min/100 g myocardial tissue during vigorous exercise. As a general rule, mammalian heart muscle cannot produce enough energy under anaerobic conditions to maintain essential cellular processes; thus, a constant supply of oxygen is indispensable to sustain cardiac function and viability. However, the role of oxygen and oxygen-associated processes in living systems is complex, and they and can be either beneficial or contribute to cardiac dysfunction and death (through reactive oxygen species). Reactive oxygen species (ROS) are a family of oxygen-derived free radicals that are produced in mammalian cells under normal and pathologic conditions. Many ROS, such as the superoxide anion (O2-)and hydrogen peroxide (H2O2), act within blood vessels, altering mechanisms mediating mechanical signal transduction and autoregulation of cerebral blood flow. Reactive oxygen species are believed to be involved in cellular signaling in blood vessels in both normal and pathologic states. The major pathway for the production of ROS is by way of the one-electron reduction of molecular oxygen to form an oxygen radical, the superoxide anion (O2-). Within the vasculature there are several enzymatic sources of O2-, including xanthine oxidase, the mitochondrial electron transport chain, and nitric oxide (NO) synthases. Studies in recent years, however, suggest that the major contributor to O2- levels in vascular cells is the membrane-bound enzyme NADPH-oxidase. Produced O2- can react with other radicals, such as NO, or spontaneously dismutate to produce hydrogen peroxide (H2O2). In cells, the latter reaction is an important pathway for normal O2- breakdown and is usually catalyzed by the enzyme superoxide dismutase (SOD). Once formed, H2O2 can undergo various reactions, both enzymatic and nonenzymatic. The antioxidant enzymes catalase and glutathione peroxidase act to limit ROS accumulation within cells by breaking down H2O2 to H2O. Metabolism of H2O2 can also produce other, more damaging ROS. For example, the endogenous enzyme myeloperoxidase uses H2O2 as a substrate to form the highly reactive compound hypochlorous acid. Alternatively, H2O2 can undergo Fenton or Haber-Weiss chemistry, reacting with Fe2+/Fe3+ ions to form toxic hydroxyl radicals (-.OH). (PMID: 17027622, 15765131). V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AN - Medical gases
Carbon monoxide
Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. It is the product of the incomplete combustion of carbon-containing compounds, notably in internal-combustion engines. It consists of one carbon atom covalently bonded to one oxygen atom. It is a gas at room temperature. Carbon monoxide is a significantly toxic gas and is the most common type of fatal poisoning in many countries. Exposures can lead to significant toxicity of the central nervous system and heart. Carbon monoxide has a higher diffusion coefficient compared to oxygen and the only enzyme in the human body that produces carbon monoxide is heme oxygenase which is located in all cells and breaks down heme. Because it has a higher diffusion coefficient than oxygen the body easily gets rid of any CO made. When CO is not ventilated it binds to hemoglobin, which is the principal oxygen-carrying compound in blood; this produces a compound known as carboxyhemoglobin. The traditional belief is that carbon monoxide toxicity arises from the formation of carboxyhemoglobin, which decreases the oxygen-carrying capacity of the blood and inhibits the transport, delivery, and utilization of oxygen by the body. The affinity between hemoglobin and carbon monoxide is approximately 230 times stronger than the affinity between hemoglobin and oxygen so hemoglobin binds to carbon monoxide in preference to oxygen. Following poisoning, long-term sequelae often occur. Carbon monoxide can also have severe effects on the fetus of a pregnant woman. Despite its serious toxicity, CO is extremely useful and underpins much modern technology, being a precursor to a myriad of useful - even life-saving - products. Carbon monoxide, though thought of as a pollutant today, has always been present in the atmosphere, chiefly as a product of volcanic activity. It occurs dissolved in molten volcanic rock at high pressures in the earths mantle. Carbon monoxide contents of volcanic gases vary from less than 0.01\\% to as much as 2\\% depending on the volcano. It also occurs naturally in bushfires. Because natural sources of carbon monoxide are so variable from year to year, it is extremely difficult to accurately measure natural emissions of the gas. (wikipedia). Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. It is the product of the incomplete combustion of carbon-containing compounds, notably in internal-combustion engines. It consists of one carbon atom covalently bonded to one oxygen atom. It is a gas at room temperature. D018377 - Neurotransmitter Agents > D064426 - Gasotransmitters D009676 - Noxae > D000963 - Antimetabolites V - Various > V04 - Diagnostic agents
Mono(glucosyluronic acid)bilirubin
This compound belongs to the family of Tricarboxylic Acids and Derivatives. These are organic compounds containing three carboxylic acid groups (or salt/ester derivatives thereof).
Bilirubin diglucuronide
Bilirubin diglucuronide is a glucuronidated version of bilirubin, a tetrapyrrole compound produced via heme degradation. Heme is the red pigment in haemoglobin and red blood cells (RBCs). RBCs have a life span of about 120 days. When the RBCs have reached the end of their useful lifespan, the cells are engulfed by macrophages and their constituents recycled or disposed of. Heme is broken down when the heme ring is opened by the enzyme known as heme oxygenase, which is found in the endoplasmic reticulum of the macrophages. The oxidation process produces the linear tetrapyrrole known as biliverdin along with ferric iron (Fe3+), and carbon monoxide (CO). In the next reaction, a second methylene group (located between rings III and IV of the porphyrin ring) is reduced by the enzyme known as biliverdin reductase, producing bilirubin. Bilirubin is significantly less extensively conjugated than biliverdin. This reduction causes a change in the color of the biliverdin molecule from blue-green (vert or verd for green) to yellow-red, which is the color of bilirubin (ruby or rubi for red). In plasma virtually all the bilirubin is tightly bound to plasma proteins, largely albumin, because it is only sparingly soluble in aqueous solutions at physiological pH. In the sinusoids unconjugated bilirubin dissociates from albumin, enters the liver cells across the cell membrane through non-ionic diffusion to the smooth endoplasmatic reticulum. In hepatocytes, bilirubin-UDP-glucuronyltransferase (bilirubin-UGT) adds 2 additional glucuronic acid molecules to bilirubin to produce the more water-soluble version of the molecule known as bilirubin diglucuronide. The bilirubin diglucuronide is transferred rapidly across the canalicular membrane into the bile canaliculi where it is then excreted as bile into the large intestine.