Methemoglobin British English methaemoglobin pronounced met hemoglobin is a form of the oxygen carrying metalloprotein hemoglobin , in which the iron in the heme group is in the Fe sup 3 sup ferric state, not the Fe sup 2 sup ferrous of normal hemoglobin. Methemoglobin cannot bind oxygen, unlike oxyhemoglobin . It is a impossible colors bluish chocolate brown in color. In human blood a trace amount of methemoglobin is normally produced spontaneously. But when it is present in excess the blood becomes abnormally dark bluish brown. The NADH dependent enzyme methemoglobin reductase diaphorase I is responsible for converting methemoglobin back to hemoglobin. Normally one to two percent of people s hemoglobin is methemoglobin a higher percentage than this can be genetic or caused by exposure to various chemicals and depending on the level can cause health problems known as methemoglobinemia . A higher level of methemoglobin will tend to cause a pulse oximeter to read closer to 85 regardless of the true level of oxygen saturation. ref cite web url http www.emedicine.com med TOPIC1466.HTM accessdate 2008 03 31 last Denshaw Burke first Mary date 2006 11 07 title Methemoglobinema ref Common causes Reduced cellular defense mechanisms Children younger than 4 months exposed to various environmental ... of the Fughate family in Kentucky, due to a recessive gene, had blue skin from an excess of methemoglobin ... to methemoglobin, which allows for the binding of cyanide and the formation of non toxic cyanomethemoglobin ... pages 37 38 ref Methemoglobin saturation Methemoglobin saturation is expressed as the percentage of hemoglobin in the methemoglobin state That is MetHb as a proportion of Hb. 1 2 Normal Less than 10 metHb ... Death See also blue baby syndrome References reflist 1 External links MeshName Methemoglobin http books.google.ca ... respiration Category Hemoproteins interwiki cs Methemoglobin da M th moglobin de Meth moglobin es Metahemoglobina ... fi Methemoglobiini sv Methemoglobin zh ... more details
Blue skin may refer to Argyria , caused by the ingestion of elemental silver, silver dust or silver compounds Methemoglobinemia , the presence of excessive levels of Methemoglobin in the blood Cyanosis , caused by the presence of deoxygenated hemoglobin in blood vessels near the skin surface Blue baby syndrome Purpura Bruise Petechia See also Blue people disambiguation disambig ... more details
enzyme Name cytochrome b5 reductase EC number 1.6.2.2 CAS number 9032 25 1 IUBMB EC number 1 6 2 2 GO code 0004128 image NADH cytochrome B5 reductase 1UMK.png width caption Ribbon diagram of red blood cell erythrocytic methemoglobin reductase with FAD bound. From PDB 1UMK . Cytochrome b sub 5 sub reductase also known as methemoglobin reductase is a NADH dependent enzyme that converts methemoglobin to hemoglobin . It contains FAD and catalyzes the reaction center NADH H sup sup 2 ferricytochrome b sub 5 sub NAD sup sup 2 ferrocytochrome b sub 5 sub center The following four human genes encode cytochrome b sub 5 sub reductases CYB5R1 CYB5R2 CYB5R3 CYB5R4 See also Cytochrome b5 Methemoglobinemia Reductase External links MeshName Cytochrome B 5 Reductase PDB 1IB0 crystal structure of rat CBR complexed with NAD PDB 1NDH crystal structure of pig liver CBR PDB 1UMK crystal structure of human erythrocyte CBR InterPro IPR001834 InterPro entry for CBR NADH or NADPH oxidoreductases Flavoproteins Category EC 1.6.2 de Cytochrom b5 Reduktasen it Citocromo b5 reduttasi ja b5 zh b5 ... more details
is a disorder characterized by the presence of a higher than normal level of methemoglobin metHb in the blood . Methemoglobin is an oxidized form of hemoglobin that has a decreased affinity for oxygen ... curve is therefore shifted to the left. When methemoglobin concentration is elevated in red blood cells , tissue hypoxia can occur. Overview Normally, methemoglobin levels are 1 , as measured by the co oximetry test. Elevated levels of methemoglobin in the blood are caused when the mechanisms ... ferric state Fe sup 3 sup . This converts hemoglobin to methemoglobin, resulting in a reduced ... brown color. Spontaneous formation of methemoglobin is normally reduced via electron donation by protective enzyme systems, e.g., NADH methemoglobin reductase cytochrome b5 reductase major pathway , NADPH methemoglobin reductase minor pathway and to a lesser extent the ascorbic acid and glutathione ... recessive pattern of inheritance. Due to a deficiency of the enzyme diaphorase I NADH methemoglobin reductase , methemoglobin levels rise and the blood of met Hb patients has reduced oxygen ... 5&spage 265 ref The protective enzyme systems normally present in red blood cells maintain methemoglobin ... the rate of formation of methemoglobin up to one thousandfold, overwhelming the protective enzyme systems and acutely increasing methemoglobin levels. Other classical drug causes of methemoglobi include ... methemoglobin reductase RBCs usually don t have one the presence of methylene blue allows the enzyme to function at 5x normal levels ref Yubisui T Takeshita M Yoneyama Y. Reduction of methemoglobin .... Symptoms Signs and symptoms of methemoglobinemia methemoglobin 1 include shortness of breath, cyanosis .... Arterial blood with elevated methemoglobin levels has a characteristic chocolate brown color ... 13 ref Severe methemoglobinemia methemoglobin 50 patients have dysrhythmias, seizures, coma and death 70 . ref name emedmed1466 Healthy people may not have many symptoms with methemoglobin levels 15 , however ... more details
Distinguish 4 Dimethylaminopyridine chembox verifiedrevid 443352465 ImageFile 4 Dimethylaminophenol.svg ImageSize 75px IUPACName OtherNames Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 20816 InChI 1 C8H11NO c1 9 2 7 3 5 8 10 6 4 7 h3 6,10H,1 2H3 InChIKey JVVRCYWZTJLJSG UHFFFAOYAU StdInChI Ref stdinchicite correct chemspider StdInChI 1S C8H11NO c1 9 2 7 3 5 8 10 6 4 7 h3 6,10H,1 2H3 StdInChIKey Ref stdinchicite correct chemspider StdInChIKey JVVRCYWZTJLJSG UHFFFAOYSA N CASNo Ref cascite correct ?? CASNo 619 60 3 PubChem 22174 UNII Ref fdacite correct FDA UNII X387L5559O SMILES Oc1ccc N C C cc1 ATCCode prefix V03 ATCCode suffix AB27 Section2 Chembox Properties Formula C sub 8 sub H sub 11 sub NO MolarMass 137.179 g mol Appearance Density MeltingPt BoilingPt 165 C 0.040 bar Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition 4 Dimethylaminophenol abbreviated in medical practice as DMAP is an aromatic compound containing both phenol and amine functional groups. It has the molecular formula C sub 8 sub H sub 11 sub NO. Uses 4 Dimethylaminophenol has been used as an antidote for cyanide poisoning . ref name pmid11121929 cite journal author Kampe S, Iffland R, Korenkov M, Diefenbach C title Survival from a lethal blood concentration of cyanide with associated alcohol intoxication journal Anaesthesia volume 55 issue 12 pages 1189 91 year 2000 month December pmid 11121929 doi 10.1046 j.1365 2044.2000.01628.x url http www3.interscience.wiley.com resolve openurl?genre article&sid nlm pubmed&issn 0003 2409&date 2000&volume 55&issue 12&spage 1189 ref It works by generating methemoglobin . ref name pmid8956097 cite journal author Vick JA, Von Bredow JD title Effectiveness of intramuscularly administered cyanide antidotes on methemoglobin formation and survival journal J Appl Toxicol volume 16 issue 6 pages 509 16 year 1996 pmid 8956097 doi 10.1002 SICI 1099 1263 199611 16 6 509 AID JAT382 3.0.CO 2 V url ref This is ... more details
Image Co monitor.JPG thumb Finger tip carboxyhemoglobin saturation monitor. A CO oximeter is a device for detecting Hypoxia medical hypoxia , a medical condition relating to oxygen deficiency at tissue level . The device measures absorption at several wavelengths to distinguish oxyhemoglobin from carboxyhemoglobin and determine the oxyhemoglobin saturation the percentage of oxygenated Hb compared to the total amount of hemoglobin Hb , including carboxy Hb, met Hb, oxy Hb, and reduced Hb. When a patient presents with carbon monoxide poisoning CO , the CO oximeter will detect this Hb and will report the oxyhemoglobin saturation as markedly reduced. Measurement Traditionally, this measurement is made from Arterial blood gas arterial blood processed in a blood gas analyzer with a CO oximeter. ref name pmid455674 cite journal author Rodkey FL, Hill TA, Pitts LL, Robertson RF title Spectrophotometric measurement of carboxyhemoglobin and methemoglobin in blood journal Clinical Chemistry volume 25 issue 8 pages 1388 93 year 1979 month August pmid 455674 doi url http www.clinchem.org cgi pmidlookup?view long&pmid 455674 accessdate 2009 07 17 ref ref name pmid7361284 cite journal author Rees PJ, Chilvers C, Clark TJ title Evaluation of methods used to estimate inhaled dose of carbon monoxide journal Thorax volume 35 issue 1 pages 47 51 year 1980 month January pmid 7361284 pmc 471219 doi 10.1136 thx.35.1.47 url http thorax.bmj.com cgi pmidlookup?view long&pmid 7361284 accessdate 2009 07 17 ref More recently, pulse CO oximeters have made it possible to estimate carboxyhemoglobin with non invasive technology similar to a Pulse oximeter . ref name pmid18500075 cite journal author Coulange M, Barthelemy A, Hug F, Thierry AL, De Haro L title Reliability of new pulse CO oximeter in victims of carbon monoxide poisoning journal Undersea & Hyperbaric Medicine volume 35 issue 2 pages 107 11 year 2008 pmid 18500075 doi url http archive.rubicon foundation.org 8084 accessdate 2009 07 17 re ... more details
provides Adenosine triphosphate ATP for membrane ion pumps and NADH for reduction of methemoglobin ... rates of oxidation of hemoglobin to methemoglobin that also weakens the cell wall. Glutathione ... more details
from the ferrous state to the ferric state, converting the hemoglobin into methemoglobin . Citation needed date May 2010 Treatment with alkyl nitrite nitrite s is not innocuous as methemoglobin cannot ... bonds to methemoglobin rather than the cytochrome oxidase , converting methemoglobin into cyanmethemoglobin ... the cells to combat cyanide intoxication. This versatility contrasts with methemoglobin, which acts ... mg kg of 4 DMAP produces 35 percent methemoglobin levels within 1 minute. Reportedly, 4 DMAP is part ... an antidote effect more quickly than formation of methemoglobin, but a clear superiority to methemoglobin ... more details
Image Streptococcal hemolysis.jpg thumb Hemolyses of Streptococcus spp. BR left &alpha hemolysis S. mitis BR middle &beta hemolysis S. pyogenes BR right &gamma hemolysis non hemolytic, S. salivarius Hemolysis or haemolysis in British English is the breakdown of red blood cells . The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms . This is particularly useful in classifying Streptococcus streptococcal species. A substance that causes hemolysis is a hemolysin . Types of hemolysis Alpha When alpha hemolysis hemolysis is present, the agar under the colony is dark and greenish. Streptococcus pneumoniae and a group of oral streptococci Streptococcus viridans Streptococcus viridans or viridans streptococci display alpha hemolysis. This is sometimes called green hemolysis because of the color change in the agar. Other synonymous terms are incomplete hemolysis and partial hemolysis . Alpha hemolysis is caused by hydrogen peroxide produced by the bacterium, oxidizing hemoglobin to green methemoglobin . Beta Beta hemolysis hemolysis , sometimes called complete hemolysis , is a complete lysis of red cells in the media around and under the colonies the area appears lightened yellow and transparent. Streptolysin, an exotoxin, is the enzyme produced by the bacteria which causes the complete lysis of red blood cells. There are two types of streptolysin Streptolysin O SLO and streptolysin S SLS . Streptolysin O is an oxygen sensitive cytotoxin, secreted by most Group A streptococcus GAS , and interacts with cholesterol in the membrane of eukaryotic cells mainly red and white blood cells, macrophages, and platelets , and usually results in hemolysis under the surface of blood agar. Streptolysin S is an oxygen stable cytotoxin also produced by most GAS strains which results in clearing on the surface of blood agar. SLS affects immune cells, including polymorphonuclear leukocytes and lymphocytes, and is though ... more details
of nitrate than others. The cytochrome b5 reductase methemoglobin reductase enzyme may be under ... url http www.doh.wa.gov ehp dw Programs nitrate.htm ref Such individuals cannot break down methemoglobin as rapidly as those that do have the enzyme, leading to increased circulating levels of methemoglobin ... more details
beans . Citation needed date June 2010 . Normally, through the NADH or NADPH dependent methemoglobin reductase enzymes, methemoglobin is reduced back to hemoglobin. When large amounts of methemoglobin ... group from methemoglobin to hemoglobin . Methylene blue can reduce the half life of methemoglobin ... more details
PBB geneid 1727 NADH cytochrome b5 reductase 3 is an enzyme that in humans is encoded by the CYB5R3 gene . ref name pmid2479590 cite journal author Tomatsu S, Kobayashi Y, Fukumaki Y, Yubisui T, Orii T, Sakaki Y title The organization and the complete nucleotide sequence of the human NADH cytochrome b5 reductase gene journal Gene volume 80 issue 2 pages 353 61 year 1989 month Dec pmid 2479590 pmc doi 10.1016 0378 1119 89 90299 0 ref ref name pmid3268037 cite journal author Bull PC, Shephard EA, Povey S, Santisteban I, Phillips IR title Cloning and chromosomal mapping of human cytochrome b5 reductase DIA1 journal Ann Hum Genet volume 52 issue Pt 4 pages 263 8 year 1989 month Nov pmid 3268037 pmc doi 10.1111 j.1469 1809.1988.tb01105.x ref The PBB Summary template is automatically maintained by Protein Box Bot. See Template PBB Controls to Stop updates. PBB Summary section title summary text Two forms of NADH cytochrome b5 reductase are known, a membrane bound form in somatic cells anchored in the endoplasmic reticulum, mitochondrial and other membranes and a soluble form in erythrocytes. The former exists mainly on the cytoplasmic side of the endoplasmic reticulum and functions in desaturation and elongation of fatty acids, in cholesterol biosynthesis, and in drug metabolism. The erythrocyte form is located in a soluble fraction of circulating erythrocytes and is involved in methemoglobin reduction. The membrane bound form has both membrane binding and catalytic domains. The soluble form has only the catalytic domain. This gene encodes both forms of the enzyme which arise from tissue specific alternative transcripts that differ in the first exon. Mutations in this gene cause methemoglobinemias. ref name entrez cite web title Entrez Gene CYB5R3 cytochrome b5 reductase 3 url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 1727 accessdate ref References reflist Further reading refbegin 2 PBB Further reading citations cite journal author Nar ... more details
to attempt pharmacologic intervention in sickle cell disease by increasing methemoglobin levels ref name Beutler E 1871 Beutler E. The effect of methemoglobin formation in sickle cell disease. J Clin ... more details
or in the Fe sup 3 sup state, but ferrihemoglobin methemoglobin Fe sup 3 sup cannot bind oxygen. ref ... how much methemoglobin is too much? journal Artif Cells Blood Substit Immobil Biotechnol volume ... oxidized and incapable to bind oxygen. In such cases, the enzyme cytochrome b5 reductase methemoglobin reductase will be able to eventually reactivate methemoglobin by reducing the iron center. In adult ... shift of 5 eV between Deoxyhemoglobin and Oxyhemoglobin, as for all the Methemoglobin species ... oxidation state III as methemoglobin , when not accompanied by superoxide . O sub 2 sub sup ... or methemoglobin pronounced MET hemoglobin , which cannot bind oxygen. Hemoglobin in normal red ... of converting a small fraction of hemoglobin to methemoglobin in red blood cells. The latter reaction ... more details
cases. This is where higher than normal levels of methemoglobin a form of hemoglobin that can not carry ... intravenous fluids. ref name Lampe Monitoring of biochemical parameters such as methemoglobin levels ... more details
can be eliminated by the kidneys. This method has the advantage of avoiding the formation of methemoglobin ... respiration energy production for cyanide. The nitrite s oxidize hemoglobin to methemoglobin , which ... more details
that methemoglobin contains ferric Fe sup 3 sup iron rather than the ferrous Fe sup 2 sup of normal hemoglobin, and therefore that, unlike oxyhemoglobin, methemoglobin cannot bind oxygen. He investigated ... more details
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