Biological Pathway: Reactome:R-HSA-9707564

Water

H2O (18.0105642)

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

O2 (31.98983)

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

Hydrogen peroxide

H2O2 (34.0054792)

Hydrogen peroxide (H2O2) is a very pale blue liquid that appears colourless in a dilute solution. H2O2 is slightly more viscous than water and is a weak acid. H2O2 is unstable and slowly decomposes in the presence of light. It has strong oxidizing properties and is, therefore, a powerful bleaching agent that is mostly used for bleaching paper. H2O2 has also found use as a disinfectant and as an oxidizer. H2O2 in the form of carbamide peroxide is widely used for tooth whitening (bleaching), both in professionally- and in self-administered products. H2O2 is a well-documented component of living cells and is a normal metabolite of oxygen in the aerobic metabolism of cells and tissues. A total of 31 human cellular H2O2 generating enzymes has been identified so far (PMID: 25843657). H2O2 plays important roles in host defence and oxidative biosynthetic reactions. At high levels (>100 nM) H2O2 is toxic to most cells due to its ability to non-specifically oxidize proteins, membranes and DNA, leading to general cellular damage and dysfunction. However, at low levels (<10 nM), H2O2 functions as a signalling agent, particularly in higher organisms. In plants, H2O2 plays a role in signalling to cause cell shape changes such as stomatal closure and root growth. As a messenger molecule in vertebrates, H2O2 diffuses through cells and tissues to initiate cell shape changes, to drive vascular remodelling, and to activate cell proliferation and recruitment of immune cells. H2O2 also plays a role in redox sensing, signalling, and redox regulation (PMID: 28110218). This is normally done through molecular redox “switches” such as thiol-containing proteins. The production and decomposition of H2O2 are tightly regulated (PMID: 17434122). In humans, H2O2 can be generated in response to various stimuli, including cytokines and growth factors. H2O2 is degraded by several enzymes including catalase and superoxide dismutase (SOD), both of which play important roles in keeping the amount of H2O2 in the body below toxic levels. H2O2 also appears to play a role in vitiligo. Vitiligo is a skin pigment disorder leading to patchy skin colour, especially among dark-skinned individuals. Patients with vitiligo have low catalase levels in their skin, leading to higher levels of H2O2. High levels of H2O2 damage the epidermal melanocytes, leading to a loss of pigment (PMID: 10393521). Accumulating evidence suggests that hydrogen peroxide H2O2 plays an important role in cancer development. Experimental data have shown that cancer cells produce high amounts of H2O2. An increase in the cellular levels of H2O2 has been linked to several key alterations in cancer, including DNA changes, cell proliferation, apoptosis resistance, metastasis, angiogenesis and hypoxia-inducible factor 1 (HIF-1) activation (PMID: 17150302, 17335854, 16677071, 16607324, 16514169). H2O2 is found in most cells, tissues, and biofluids. H2O2 levels in the urine can be significantly increased with the consumption of coffee and other polyphenolic-containing beverages (wine, tea) (PMID: 12419961). In particular, roasted coffee has high levels of 1,2,4-benzenetriol which can, on its own, lead to the production of H2O2. Normal levels of urinary H2O2 in non-coffee drinkers or fasted subjects are between 0.5-3 uM/mM creatinine whereas, for those who drink coffee, the levels are between 3-10 uM/mM creatinine (PMID: 12419961). It is thought that H2O2 in urine could act as an antibacterial agent and that H2O2 is involved in the regulation of glomerular function (PMID: 10766414). A - Alimentary tract and metabolism > A01 - Stomatological preparations > A01A - Stomatological preparations > A01AB - Antiinfectives and antiseptics for local oral treatment D - Dermatologicals > D08 - Antiseptics and disinfectants > D08A - Antiseptics and disinfectants S - Sensory organs > S02 - Otologicals > S02A - Antiinfectives > S02AA - Antiinfectives It is used in foods as a bleaching agent, antimicrobial agent and oxidising agent C254 - Anti-Infective Agent > C28394 - Topical Anti-Infective Agent D009676 - Noxae > D016877 - Oxidants > D010545 - Peroxides D000890 - Anti-Infective Agents

Copper

Cu (62.929599)

Copper is an essential nutrient to all higher plants and animals. Physiologically, it exists as an ion in the body. In animals, it is found primarily in the bloodstream, as a cofactor in various enzymes, and in copper-based pigments. In the body, copper shifts between the cuprous (Cu1+) and cupric (Cu2+) forms, though the majority of the bodys copper is in the Cu2+ form. The ability of copper to easily accept and donate electrons explains its important role in oxidation-reduction (redox) reactions and in scavenging free radicals. Copper is a critical functional component of a number of essential enzymes known as cuproenzymes. For instance, the copper-dependent enzyme, cytochrome c oxidase, plays a critical role in cellular energy production. By catalyzing the reduction of molecular oxygen (O2) to water (H2O), cytochrome c oxidase generates an electrical gradient used by the mitochondria to create the vital energy-storing molecule, ATP. Another cuproenzyme, lysyl oxidase, is required for the cross-linking of collagen and elastin, which are essential for the formation of strong and flexible connective tissue. Another cuproeznyme, Monoamine oxidase (MAO), plays a role in the metabolism of the neurotransmitters norepinephrine, epinephrine, and dopamine. MAO also functions in the degradation of the neurotransmitter serotonin, which is the basis for the use of MAO inhibitors as antidepressants. One of the most important cuproenzymes is Superoxide dismutase (SOD). SOD functions as an antioxidant by catalyzing the conversion of superoxide radicals (free radicals or ROS) to hydrogen peroxide, which can subsequently be reduced to water by other antioxidant enzymes. Two forms of SOD contain copper: 1) copper/zinc SOD is found within most cells of the body, including red blood cells, and 2) extracellular SOD is a copper-containing enzyme found at high levels in the lungs and low levels in blood plasma. In sufficient amounts, copper can be poisonous or even fatal to organisms. Copper is normally bound to cuproenzymes (such as SOD, MOA) and is thus only toxic when unsequestered and unmediated. It is believed that zinc and copper compete for absorption in the digestive tract so that a diet that is excessive in one of these minerals may result in a deficiency in the other. An imbalance of zinc and copper status might be involved in human hypertension. Furthermore, copper is found to be associated with hyperzincaemia and hypercalprotectinaemia and Wilsons disease, which are inborn errors of metabolism. Copper(2+), also known as copper, ion (cu2+) or copper (ii) ion, is a member of the class of compounds known as homogeneous transition metal compounds. Homogeneous transition metal compounds are inorganic compounds containing only metal atoms,with the largest atom being a transition metal atom. Copper(2+) can be found in a number of food items such as common grape, black cabbage, loquat, and spelt, which makes copper(2+) a potential biomarker for the consumption of these food products. Copper(2+) can be found primarily in blood, cerebrospinal fluid (CSF), saliva, and urine, as well as throughout most human tissues. Copper(2+) exists in all living species, ranging from bacteria to humans. In humans, copper(2+) is involved in several metabolic pathways, some of which include tyrosine metabolism, disulfiram action pathway, riboflavin metabolism, and histidine metabolism. Copper(2+) is also involved in several metabolic disorders, some of which include monoamine oxidase-a deficiency (MAO-A), hawkinsinuria, tyrosinemia type I, and alkaptonuria. Moreover, copper(2+) is found to be associated with alzheimers disease, wilsons disease, hyperzincaemia and hypercalprotectinaemia, and multiple sclerosis. Copper(2+) is a non-carcinogenic (not listed by IARC) potentially toxic compound. In cases of suspected copper poisoning, penicillamine is the drug of choice, and dimercaprol, a heavy metal chelating agent, is often administered. Vinegar is not recommended, as it assists in solubilizing insoluble copper salts (T3DB). G - Genito urinary system and sex hormones > G02 - Other gynecologicals > G02B - Contraceptives for topical use > G02BA - Intrauterine contraceptives D018977 - Micronutrients > D014131 - Trace Elements

Carbon monoxide

CO (27.994915)

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

Nitric oxide

NO (29.997989)

The biologically active molecule nitric oxide (NO) is a simple, membrane-permeable gas with unique chemistry. It is formed by the conversion of L-arginine to L-citrulline, with the release of NO. The enzymatic oxidation of L-arginine to L-citrulline takes place in the presence of oxygen and NADPH using flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), heme, thiol, and tetrahydrobiopterin as cofactors. The enzyme responsible for the generation of NO is nitric oxide synthase (E.C. 1.7.99.7; NOS). Three NOS isoforms have been described and shown to be encoded on three distinct genes: neuronal NOS (nNOS, NOS type I), inducible NOS (NOS type II), and endothelial NOS (eNOS, NOS type III). Two of them are constitutively expressed and dependent on the presence of calcium ions and calmodulin to function (nNOS and eNOS), while iNOS is considered non-constitutive and calcium-independent. However, experience has shown that constitutive expression of nNOS and eNOS is not as rigid as previously thought (i.e. either present or absent), but can be dynamically controlled during development and in response to injury. Functionally, NO may act as a hormone, neurotransmitter, paracrine messenger, mediator, cytoprotective molecule, and cytotoxic molecule. NO has multiple cellular molecular targets. It influences the activity of transcription factors, modulates upstream signaling cascades, mRNA stability and translation, and processes the primary gene products. In the brain, many processes are linked to NO. NO activates its receptor, soluble guanylate cyclase by binding to it. The stimulation of this enzyme leads to increased synthesis of the second messenger, cGMP, which in turn activates cGMP-dependent kinases in target cells. NO exerts a strong influence on glutamatergic neurotransmission by directly interacting with the N-methyl-D-aspartate (NMDA) receptor. Neuronal NOS is connected to NMDA receptors (see below) and sharply increases NO production following activation of this receptor. Thus, the level of endogenously produced NO around NMDA synapses reflects the activity of glutamate-mediated neurotransmission. However, there is recent evidence showing that non-NMDA glutamate receptors (i.e. AMPA and type I metabotropic receptors) also contribute to NO generation. Besides its influence on glutamate, NO is known to have effects on the storage, uptake and/or release of most other neurotransmitters in the CNS (acetylcholine, dopamine, noradrenaline, GABA, taurine, and glycine) as well as of certain neuropeptides. Finally, since NO is a highly diffusible molecule, it may reach extrasynaptic receptors at target cell membranes that are some distance away from the place of NO synthesis. NO is thus capable of mediating both synaptic and nonsynaptic communication processes. NO is a potent vasodilator (a major endogenous regulator of vascular tone), and an important endothelium-dependent relaxing factor. NO is synthesized by NO synthases (NOS) and NOS are inhibited by asymmetrical dimethylarginine (ADMA). ADMA is metabolized by dimethylarginine dimethylaminohydrolase (DDAH) and excreted in the kidneys. Lower ADMA levels in pregnant women compared to non-pregnant controls suggest that ADMA has a role in vascular dilatation and blood pressure changes. Several studies show an increase in ADMA levels in pregnancies complicated with preeclampsia. Elevated ADMA levels in preeclampsia are seen before clinical symptoms have developed; these findings suggest that ADMA has a role in the pathogenesis of preeclampsia. In some pulmonary hypertensive states such as ARDS, the production of endogenous NO may be impaired. Nitric oxide inhalation selectively dilates the pulmonary circulation. Significant systemic vasodilation does not occur because NO is inactivated by rapidly binding to hemoglobin. In an injured lung with pulmonary hypertension, inhaled NO produces local vasodilation of well-ventilated lung units and may "steal" blood flow away from unventil... D002317 - Cardiovascular Agents > D014665 - Vasodilator Agents > D045462 - Endothelium-Dependent Relaxing Factors D019141 - Respiratory System Agents > D018927 - Anti-Asthmatic Agents > D001993 - Bronchodilator Agents D018373 - Peripheral Nervous System Agents > D001337 - Autonomic Agents D018377 - Neurotransmitter Agents > D064426 - Gasotransmitters D000975 - Antioxidants > D016166 - Free Radical Scavengers D020011 - Protective Agents > D000975 - Antioxidants R - Respiratory system

Superoxide

O2- (31.98983)

Superoxide is the anionic form O2. It is important as the product of the one-electron reduction of dioxygen (oxygen gas), which occurs widely in nature. With one unpaired electron, the superoxide ion is a free radical. It is also paramagnetic. The biological toxicity of superoxide is due to its capacity to inactivate iron-sulfur cluster containing enzymes (which are critical in a wide variety of metabolic pathways), thereby liberating free iron in the cell, which can undergo fenton-chemistry and generate the highly reactive hydroxyl radical. In its HO2 form, superoxide can also initiate lipid peroxidation of polyunsaturated fatty acids. It also reacts with carbonyl compounds and halogenated carbons to create toxic peroxy radicals. As such, superoxide is a main cause of oxidative stress. Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to Methemoglobin. Because superoxide is toxic, nearly all organisms living in the presence of oxygen contain isoforms of the superoxide scavenging enzyme, superoxide dismutase, or SOD. SOD is an extremely efficient enzyme; it catalyzes the neutralization of superoxide nearly as fast as the two can diffuse together spontaneously in solution. Genetic inactivation ("knockout") of SOD produces deleterious phenotypes in organisms ranging from bacteria to mice. The latter species dies around 21 days after birth if the mitochondrial variant of SOD (Mn-SOD) is inactivated, and suffers from multiple pathologies, including reduced lifespan, liver cancer, muscle atrophy, cataracts and female infertility when the cytoplasmic (Cu, Zn -SOD) variant is inactivated. With one unpaired electron, the superoxide ion is a free radical and therefore paramagnetic. In living organisms, superoxide dismutase protects the cell from the deleterious effects of superoxides. Superoxide is the anionic form O2. It is important as the product of the one-electron reduction of dioxygen (oxygen gas), which occurs widely in nature. With one unpaired electron, the superoxide ion is a free radical. It is also paramagnetic. The biological toxicity of superoxide is due to its capacity to inactivate iron-sulfur cluster containing enzymes (which are critical in a wide variety of metabolic pathways), thereby liberating free iron in the cell, which can undergo fenton-chemistry and generate the highly reactive hydroxyl radical. In its HO2 form, superoxide can also initiate lipid peroxidation of polyunsaturated fatty acids. It also reacts with carbonyl compounds and halogenated carbons to create toxic peroxy radicals. As such, superoxide is a main cause of oxidative stress.; Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to Methemoglobin. D009676 - Noxae > D016877 - Oxidants > D013481 - Superoxides D009676 - Noxae > D016877 - Oxidants > D010545 - Peroxides

Hydroxide

HO- (17.0027396)

In chemistry, hydroxide is the most common name for the diatomic anion OH, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest diatomic ions known. Hydroxide ion is a kind of ligand. It donates one pair of electrons, behaving as a Lewis base. Examples include the aluminate ion [Al(OH)4]- and aurate ion [Au(OH)4]-. [HMDB] In chemistry, hydroxide is the most common name for the diatomic anion OH, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest diatomic ions known. Hydroxide ion is a kind of ligand. It donates one pair of electrons, behaving as a Lewis base. Examples include the aluminate ion [Al(OH)4]- and aurate ion [Au(OH)4]-.

Hydrogen Ion

H+ (1.0078246)

Hydrogen ion, also known as proton or h+, is a member of the class of compounds known as other non-metal hydrides. Other non-metal hydrides are inorganic compounds in which the heaviest atom bonded to a hydrogen atom is belongs to the class of other non-metals. Hydrogen ion can be found in a number of food items such as lowbush blueberry, groundcherry, parsley, and tarragon, which makes hydrogen ion a potential biomarker for the consumption of these food products. Hydrogen ion exists in all living organisms, ranging from bacteria to humans. In humans, hydrogen ion is involved in several metabolic pathways, some of which include cardiolipin biosynthesis cl(i-13:0/a-25:0/a-21:0/i-15:0), cardiolipin biosynthesis cl(a-13:0/a-17:0/i-13:0/a-25:0), cardiolipin biosynthesis cl(i-12:0/i-13:0/a-17:0/a-15:0), and cardiolipin biosynthesis CL(16:1(9Z)/22:5(4Z,7Z,10Z,13Z,16Z)/18:1(11Z)/22:5(7Z,10Z,13Z,16Z,19Z)). Hydrogen ion is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis TG(20:3(8Z,11Z,14Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)/22:5(7Z,10Z,13Z,16Z,19Z)), de novo triacylglycerol biosynthesis TG(18:2(9Z,12Z)/20:0/20:4(5Z,8Z,11Z,14Z)), de novo triacylglycerol biosynthesis TG(18:4(6Z,9Z,12Z,15Z)/18:3(9Z,12Z,15Z)/18:4(6Z,9Z,12Z,15Z)), and de novo triacylglycerol biosynthesis TG(24:0/20:5(5Z,8Z,11Z,14Z,17Z)/24:0). A hydrogen ion is created when a hydrogen atom loses or gains an electron. A positively charged hydrogen ion (or proton) can readily combine with other particles and therefore is only seen isolated when it is in a gaseous state or a nearly particle-free space. Due to its extremely high charge density of approximately 2×1010 times that of a sodium ion, the bare hydrogen ion cannot exist freely in solution as it readily hydrates, i.e., bonds quickly. The hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions . Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions. Under aqueous conditions found in biochemistry, hydrogen ions exist as the hydrated form hydronium, H3O+, but these are often still referred to as hydrogen ions or even protons by biochemists. [Wikipedia])

H2O

H2O (18.0105642)

An oxygen hydride consisting of an oxygen atom that is covalently bonded to two hydrogen atoms. Water. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=7732-18-5 (retrieved 2024-10-17) (CAS RN: 7732-18-5). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).

Coenzyme II

C21H25N7O17P3-3 (740.051977)

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Ferrous cation

Fe+2 (55.934939)

Copper

Cu (62.929599)

G - Genito urinary system and sex hormones > G02 - Other gynecologicals > G02B - Contraceptives for topical use > G02BA - Intrauterine contraceptives D018977 - Micronutrients > D014131 - Trace Elements Copper (pronounced /?k?p?r/, KOP-?r) is a chemical element with the symbol Cu (Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable and a freshly-exposed surface has a pinkish or peachy color. It is used as a thermal conductor, an electrical conductor, a building material, and a constituent of various metal alloys.; Copper can be found as native copper in mineral form (for example, in Michigans Keewenaw Peninsula). It is a polycrystal, with the largest single crystals measuring 4.4x3.2x3.2 cm3. Minerals such as the sulfides: chalcopyrite (CuFeS2), bornite (Cu5FeS4), covellite (CuS), chalcocite (Cu2S) are sources of copper, as are the carbonates: azurite (Cu3(CO3)2(OH)2) and malachite (Cu2CO3(OH)2) and the oxide: cuprite (Cu2O).; Copper compounds are known in several oxidation states, usually 2+, where they often impart blue or green colors to natural minerals such as turquoise and have been used historically widely as pigments. Copper as both metal and pigmented salt, has a significant presence in decorative art. Copper 2+ ions are soluble in water, where they function at low concentration as bacteriostatic substances and fungicides. For this reason, copper metal can be used as an anti-germ surface that can add to the anti-bacterial and antimicrobial features of buildings such as hospitals. In sufficient amounts, copper salts can be poisonous to higher organisms as well. However, despite universal toxicity at high concentrations, the 2+ copper ion at lower concentrations is an essential trace nutrient to all higher plant and animal life. In animals, including humans, it is found widely in tissues, with concentration in liver, muscle, and bone. It functions as a co-factor in various enzymes and in copper-based pigments.; Copper has a reddish, orangish, or brownish color because a thin layer of tarnish (including oxides) gradually forms on its surface when gases (especially oxygen) in the air react with it. But pure copper, when fresh, is actually a pinkish or peachy metal. Copper, caesium and gold are the only three elemental metals with a natural color other than gray or silver. The usual gray color of metals depends on their "electron sea" that is capable of absorbing and re-emitting photons over a wide range of frequencies. Copper has its characteristic color because of its unique band structure. By Madelungs rule the 4s subshell should be filled before electrons are placed in the 3d subshell but copper is an exception to the rule with only one electron in the 4s subshell instead of two. The energy of a photon of blue or violet light is sufficient for a d band electron to absorb it and transition to the half-full s band. Thus the light reflected by copper is missing some blue/violet components and appears red. This phenomenon is shared with gold which has a corresponding 5s/4d structure. In its liquefied state, a pure copper surface without ambient light appears somewhat greenish, a characteristic shared with gold. When liquid copper is in bright ambient light, it retains some of its pinkish luster. When copper is burnt in oxygen it gives off a black oxide.; Copper is a finite resource, but, unlike oil, it is not destroyed and therefore can be recycled. Recycling is a major source of copper in the modern world.; Copper is malleable and ductile and is a good conductor of both heat and electricity.; Copper, as native copper, is one of the few metals to occur naturally as an un-compounded mineral. Copper was known to some of the oldest civilizations on record, and has a history of use that is at least 10,000 years old. Some estimates of coppers discovery place this event around 9000 BC in the Middle East. A copper pendant was found in what is now northern Iraq that dates to 8700 BC. It is probable that gold and meteoritic iron were the only metals used by humans before copper. By 5000 BC, there are signs of copper smelting: the re...

nitric oxide

NO (29.997989)

D002317 - Cardiovascular Agents > D014665 - Vasodilator Agents > D045462 - Endothelium-Dependent Relaxing Factors A nitrogen oxide which is a free radical, each molecule of which consists of one nitrogen and one oxygen atom. D019141 - Respiratory System Agents > D018927 - Anti-Asthmatic Agents > D001993 - Bronchodilator Agents D018373 - Peripheral Nervous System Agents > D001337 - Autonomic Agents D018377 - Neurotransmitter Agents > D064426 - Gasotransmitters D000975 - Antioxidants > D016166 - Free Radical Scavengers D020011 - Protective Agents > D000975 - Antioxidants R - Respiratory system It is used as a food additive .

NADPH(4-)

C21H26N7O17P3-4 (741.0598016)

Oxidanyl

HO (17.0027396)

D009676 - Noxae > D016877 - Oxidants

[[[(2R,3S,4R,5R)-5-(6-aminopurin-9-yl)-3,4-dihydroxyoxolan-2-yl]methoxy-oxidophosphoryl]oxy-oxidophosphoryl] phosphate

C10H12N5O13P3-4 (502.9644492)

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Adenosine-diphosphate

C10H12N5O10P2-3 (424.0059412)

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Bilirubin(2-)

C33H34N4O6-2 (582.2478224)

3-[(2E,5Z)-2-[[3-(2-carboxyethyl)-5-[(Z)-(3-ethenyl-4-methyl-5-oxopyrrol-2-ylidene)methyl]-4-methyl-1H-pyrrol-2-yl]methylidene]-5-[(4-ethenyl-3-methyl-5-oxopyrrol-2-yl)methylidene]-4-methylpyrrol-3-yl]propanoic acid

C33H32N4O6-2 (580.2321732)

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Ferroprotoporphyrin IX

C34H32FeN4O4-2 (616.1772821999999)

Ferriheme

C34H32FeN4O4+ (616.1772821999999)

hydrogen peroxide

H2O2 (34.0054792)

A - Alimentary tract and metabolism > A01 - Stomatological preparations > A01A - Stomatological preparations > A01AB - Antiinfectives and antiseptics for local oral treatment An inorganic peroxide consisting of two hydroxy groups joined by a covalent oxygen-oxygen single bond. D - Dermatologicals > D08 - Antiseptics and disinfectants > D08A - Antiseptics and disinfectants S - Sensory organs > S02 - Otologicals > S02A - Antiinfectives > S02AA - Antiinfectives C254 - Anti-Infective Agent > C28394 - Topical Anti-Infective Agent D009676 - Noxae > D016877 - Oxidants > D010545 - Peroxides D000890 - Anti-Infective Agents

Carbon monoxide

CO (27.994915)

A one-carbon compound in which the carbon is joined only to a single oxygen. It is a colourless, odourless, tasteless, toxic gas. D018377 - Neurotransmitter Agents > D064426 - Gasotransmitters D009676 - Noxae > D000963 - Antimetabolites V - Various > V04 - Diagnostic agents

Oxygen

O2 (31.98983)

V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AN - Medical gases

Hydroxide

HO- (17.0027396)

Superoxide

O2- (31.98983)

D009676 - Noxae > D016877 - Oxidants > D013481 - Superoxides D009676 - Noxae > D016877 - Oxidants > D010545 - Peroxides

Hydrogen cation

H+ (1.0078246)