Nitrite
描述
Nitrite is a nitrite compound is either a salt or an ester of nitrous acid. Sodium nitrite is used for the curing of meat because it prevents bacterial growth and, in a reaction with the meat's myoglobin, gives the product a desirable dark red color. Nitrite can be reduced to nitric oxide or ammonia by many species of bacteria. Under hypoxic conditions, nitrite may release nitric oxide, which causes potent vasodilation. Several mechanisms for nitrite conversion to NO have been described including enzymatic reduction by xanthine oxidoreductase, the mitochondria, and NO synthase (NOS), as well as nonenzymatic acidic disproportionation. -- Wikipedia.
类别
"Pesticide", "Food Toxin", "Natural Toxin"
同义词
"Nitrite anion", "Nitrite ion", "Nitrogen dioxide", "Nitrogen dioxide ion", "Nitrogen peroxide ion"
InChI 标识符
InChI=1S/HNO2/c2-1-3/h(H,2,3)/p-1
键
InChIKey=IOVCWXUNBOPUCH-UHFFFAOYSA-M
化合物类型
Inorganic compounds
大分类
Homogeneous non-metal compounds
类型
Non-metal oxoanionic compounds
另外分类
"Inorganic nitrites", "Inorganic oxides"
取代基
"Inorganic nitrite", "Inorganic oxide", "Non-metal nitrite"
地位
Detected and Not Quantified
蜂窝位置
"Cytoplasm", "Extracellular"
组织位置
"Bladder", "Brain", "Erythrocyte", "Fibroblasts", "Heart", "Intestine", "Kidney", "Leukocyte", "Liver", "Lung", "Neutrophil", "Oesophagus", "Placenta", "Platelet", "Skeletal Muscle", "Spleen", "Testes"
暴露途径
Oral (L1137) ; inhalation (L1137)
毒性机制
Nitrite causes the autocatalytic oxidation of oxyhemoglobin to hydrogen peroxide and methemoglobin. This elevation of methemoglobin levels is a condition known as methemoglobinemia, and is characterized by tissue hypoxia, as methemoglobin cannot bind oxygen. (A2450, L1613)
代谢
Intake of some amount of nitrates and nitrites is a normal part of the nitrogen cycle in humans. In vivo conversion of nitrates to nitrites can occur in the gastrointestional tract under the right conditions, significantly enhancing nitrates' toxic potency. The major metabolic pathway for nitrate is conversion to nitrite, and then to ammonia. Nitrites, nitrates, and their metabolites are excreted in the urine. (L1137)
致死剂量
10 to 100 mg/kg for an adult human. (L1618)
致癌性
Ingested nitrate or nitrite under conditions that result in endogenous nitrosation is probably carcinogenic to humans (Group 2A). (L135)
用途/来源
Nitrates and nitrites are naturally produced and may also be found in pesticides. Exposure usually occurs from contact with contaminated soil, food water. Nitrates may also be found in certain drugs. (L1137)
健康影响
Nitrite poisoning causes methemoglobinemia. Nitrites may cause pregnancy complications and developmental effects. They may also be carcinogenic. (L1137)
症状
Nitrite poisoning causes methemoglobinemia. Symptoms include cyanosis, cardiac dysrhythmias and circulatory failure, and progressive central nervous system (CNS) effects. CNS effects can range from mild dizziness and lethargy to coma and convulsions. (L1137)
治疗
Methemoglobinemia can be treated with supplemental oxygen and methylene blue 1% solution administered intravenously slowly over five minutes followed by IV flush with normal saline. Methylene blue restores the iron in hemoglobin to its normal (reduced) oxygen-carrying state. (L1613)
维基百科链接
http://en.wikipedia.org/wiki/Nitrite
创建于
2009-03-06 18:58:17 UTC
更新于
2014-12-24 20:21:20 UTC