03:12,3,Oct,2006 | (1633/0/0) | Original

cyanide poisoning mechanism

Medical HEALTH "> Pharmacy>> subjects of drugs and medicines>> Summary of cyanide poisoning mechanism of procaine antagonistic download full-text collection of reviews Recommended acoustic Yang Jiang article [1] Liu Zushun   Department of Toxicology, Medical College of Nantong [2] Department of Pharmacology, Nantong Medical College "Nantong Medical College," 1996, Volume 16 No. 2 fast-food prizes Report Summary: procaine has a role in antagonizing cyanide poisoning. Mouse neural cells by measuring intracellular calcium concentration, methemoglobin concentration in peripheral blood and different time-fang potassium levels in blood to study the mechanism of action. The results showed: procaine antagonistic antagonistic mechanism of cyanide poisoning caused by cyanide poisoning, nerve cells elevated intracellular calcium concentration, thus preventing calcium homeostasis due to disorder caused by cell damage. Number of pages: 2 pages :160-161 range Key words: cyanide methemoglobin procaine neuronal calcium subject classification: R971.2 [medicine, HEALTH "Pharmacy> Drugs> nervous system drugs> anesthetics] Related Articles: Topics related citations (1)
cyanide poisoning mechanism

Cyanide is a class of highly toxic cyanide introduced material, a common hydrogen cyanide, sodium cyanide, potassium cyanide, calcium cyanide and cyanogen bromide and other inorganic and acetonitrile, C eye, acrylonitrile, butyl eyes, etc. organic, the other fruits of certain plants such as almond, peach kernel, Lizi Ren, loquat kernels, nuts and cherries all contain cyanogenic glycosides of cassava, the decomposition can produce hydrogen cyanide. Cyanide can be divided into inorganic cyanide, such as hydrogen cyanide, potassium cyanide (sodium), cyanogen chloride, etc., organic cyanides, such as acetonitrile, acrylonitrile, butadiene, etc. are able to precipitate ions in the body very quickly, are is highly toxic. Many of cyanide, where in Canada
Injection of cyanide poisoning, heat or with acid in the air or after the release of hydrogen cyanide with the organization or cyanide and hydrogen cyanide ions have the same toxic effect. Cyanide is widely used in industry. Such as in electroplating, cleaning injection, paints, dyes, rubber and other industry personnel access to many opportunities. Daily life, peach, plum, apricot, loquat and other acid containing hydrogen and oxygen, in which the highest content of bitter almond, cassava also contain hydrocyanic acid. Cyanide in the community is also useful for suicide or homicide case. Occupational cyanide poisoning mainly through the respiratory tract, followed by the high concentration is also absorbed through the skin. Life of cyanide poisoning by oral-based. Oral mucosa and digestive tract can be fully absorbed. Most are highly toxic cyanide or highly toxic, may, skin, eyes or gastrointestinal tract rapidly absorbe
d, oral sodium cyanide can cause sudden death in 50 ~ 100mg. A way to cyanide poisoning cyanide can be rapidly fatal blood of the poison, the death penalty had been used as gas chambers and the murder weapon during the war. Cyanide may be some natural bacteria, fungi and algae production, and in some plant foods such as almonds, cherries, plums, peaches, ginkgo (Ginkgo), dried pear, apple and pear seeds, cassava and special bamboo shoots, and vitamin B12 to obtain. Cyanide present in the naturally occurring plant sugar or other organic compounds and become part of it. Its chemical structure, the cyanide containing carbon and nitrogen triple bond (C ≡ N) is usually compounds (a combination of two or more chemical substances to form) the form of the existence of colorless gases such as hydrogen cyanide (HCN ) or cyanogen chloride (CNCl), white powder or crystals of sodium cyanide (NaCN) or potassium cyanide (KCN), and organic compounds. In addition to general to be deliberately poisoned, but also may be nitrile (nitriles) class of objects, such as acetonitrile (acetonitrile), nitrosylation of iron cyanide salts (nitroprussid) and other chemical substances into the human body can be metabolized to cyanide, which may lead poisoning. Peach, apricot, loquat approved, plums, bayberry, cherry nucleolus both contain amygdalin and amygdalin enzyme. Amygdalin amygdalin water in under the action of the enzyme, broken down into hydrogen cyanide, benzaldehyde and glucose. Therefore, hydrocyanic acid poisoning can occur overdose (hydrocyanic acidpoisoning). Bitter peach kernel, sweet almond high toxicity than the number of times, a few grains of raw food can be symptoms. Prussic acid poisoning is the principle of cyanate ion (CN-) is easy and trivalent iron (Fe) binding, but not with divalent iron (Fe) binding, when it was absorbed into the bloodstream, the result of hemoglobin with ferrous iron, it is not with the combination, and with the blood flow throughout the organization transported to the cell, quickly and Cytochrome and cytochrome oxidase ferric combination of the cytochrome and cytochrome oxidase lost the role of electron transfer, and place cells asphyxia with normal body build thiocyanate enzyme that changes a small amount of CN-sulfur non-toxic cyanide by renal excretion, but this reaction is relatively slow detoxification of the body, when not enough to relieve the toxicity of hydrogen cyanide, that is poisoning. Another little mentioned in the novel and film unnatural sources of cyanide, including electroplating, metal surface treatment, electronic scrap recycling precious metals (gold stripping agents), chemical synthesis, nylon (nylon) intermediate, photos developing, poisoning, fire scene and so on. It is worth special mention is the scene of the fire of cyanide. Why has a relationship with the fire scene it? Because some cyanide (nitrile) is the petrochemical industry, raw materials and intermediate products, the current number of non-wrinkle clothing and petrochemical products are likely to be so easy to have cyanide produced during combustion, while the fire scene wool, silk clothing is burning the source of cyanide. Mechanism of cyanide and cyanide poisoning via oral, inhalation and skin and mucous membranes are absorbed into the body. Since cyanide can inhibit a variety of enzymes, is absorbed and the mitochondria (mitochondria) on the cytochrome oxidase (cytochrome oxidase) complex with ferric ions, inhibit oxidative phosphorylation (oxidative phosphylation), blocked energy of ATP (adenosine triphosphate) formation, and makes hypoxia suffocation. In general, for trace amounts of cyanide and denatured human hemoglobin can be by (methemoglobin) role, rather than with the cytochrome oxidase as the way, and to exclude toxic effects. The cyanide methemoglobinemia (Cyanomethemoglobin) with a sulfide transferase after - thiocyanate generation enzyme (rhodanese), the formation of ammonium thiocyanate (thiocyanate) complexes. Ammonium thiocyanate excretion by the kidneys (that is, from the urine.) When too much of cyanide into the body can not load the above reaction mechanism, resulting in toxicity. Detection of cyanide poisoning cyanide poisoning was not, in addition to the aforementioned "almond" flavor can be when there is a possible sign, the final verification test, or to traditional colorimetric titration. Colorimetry in the spectrophotometer, in solution of pH <8   cyanide with chloramine-T (Chloramine-T) reaction into cyanogen chloride (CNCl), when the reaction is complete, add Pyridine - Barbituric acid agent (Pyridine-barbituric acid reagent) coloring, then the resulting complexes spectrophotometer at a wavelength of 578 nm absorbance was measured to determine its concentration. In the titration method, the sample must be keen to add to the silver class of compounds by measuring the indicator, then use the calibrated standard solution of silver nitrate as titrant to determine the concentration of cyanide. More accurate detection method for meteorological chromatography with nitrogen detector analyzer (Nitrogen Phosphrous Detection, NPD) or electron capture detector (Electron-Capture detection, ECD) for analysis and detection. Patients with first aid immediately move to fresh air, oxygen. Breathing has stopped artificial respiration should be (but avoid using mouth to mouth artificial respiration method), cardiac arrest, should immediately be closed chest cardiac compression. Conditions were amyl nitrite immediately wrapped in a handkerchief in two crushed nose and mouth before inhaling home patients can be repeatedly applied 2 to 3 times. No matter what route of exposure, give oxygen, if when the food poisoning, do not induce vomiting! Cyanide has been listed on the box set which contains an antidote: sodium nitrite (Sodium Nitrite), sodium thiosulfate (Sodium Thiosulfate) and amyl nitrite (Amyl Nitrite) inhalation. The detoxification mechanism is as follows: the role of sodium nitrite and heme formation methemoglobinemia (Methemoglobin). Methemoglobinemia from various organizations to remove the cyanide ion. And and their relatively low toxicity of cyanide into methemoglobinemia (Cyanmethemoglobin), the function of sodium thiosulfate is generated by the thiocyanate enzyme (rhodanese) into thio cyanide cyanide (Thiocyanate). The combination of the mechanisms listed in the following chemical formula: NaNO2 Hemoglobin = Methemoglobin type (1) HCN Methemoglobin = Cyanomethemoglobin type (2) Na2S2O3 Cyanomethemoglobin = SCN Methemoglobin-style (3) detoxification measures: a nitrite sodium thiosulfate therapy: first with the sub- sodium nitrate, amyl nitrite to quickly generate methemoglobin. Methemoglobin can be cytochrome oxidase from cyanide to cytochrome oxidase in the displace, thereby restoring activity. CN-residual cleaning with sodium thiosulfate to produce non-toxic thiocyanate excreted. Second, methylene blue (methylene blue): low-dose methylene blue can be used to methemoglobinemia; large dose of the Syrians first aid for cyanide poisoning. Oral lethal dose of sodium cyanide was 150 ~ 250mg, (if the adult oral amygdalin 40 ~ 60g that can cause poisoning or death.) Cyanide poisoning due to the history of celebrities and their real-life wife of Hitler, the German Air Marshal Hermann Goering, are all taking potassium cyanide to commit suicide. Recent notable are September 29, 1982 within 48 hours, the U.S. Johnson
(A) the cause of poisoning
Organic and inorganic cyanide is widely used in industrial and agricultural production, particularly common cyanide electroplating industry, it is easy to obtain, are often used to commit suicide or homicide. People often consume large amounts of improper handling or untreated almond, cassava Erzhi accidental poisoning.
(B) the toxicological effect
Cyanide into the body break down toxic cyanide ion issued (CN-), cyanide ions within the tissue cells can inhibit the activity of 42 enzymes such as cytochrome oxidase, peroxidase, decarboxylase, succinic dehydrogenase and lactate dehydrogenase. Which cytochrome oxidase is most sensitive to cyanide. Cyanide ion can rapidly and oxidized cytochrome oxidase in the combination of ferric iron to prevent its reduction into ferrous iron, so that transmission electron oxidation process is interrupted, cells can not use the oxygen in the blood caused by suffocation. Central nervous system most sensitive to hypoxia, it is first of all the brain damage, leading to central respiratory failure and death. In addition, the release of cyanide in the digestive tract has a corrosive effect of hydroxide ions. Inhalation of high concentrations of cyanide, hydrogen cyanide, or swallow a lot of those in respiratory arrest within 2-3 minutes, was "electric shock-like" death.
(C) the amount of toxic and lethal dose
Oral lethal dose of hydrocyanic acid 0.7 ~ 3.5mg/kg; inhalation of hydrogen cyanide concentration of the air in the 0.5mg / L can be lethal; oral administration of sodium cyanide, potassium cyanide, a lethal dose of 1 ~ 2mg/kg. Adults take one bitter almond 40 60, 10 to 20 children with poisoning and even death can occur. Untreated cassava lethal dose 150 ~ 300g. In addition many cyanide compounds (eg potassium cyanide, sodium cyanide and electroplating, photographic dyes often containing cyanide used in drugs) can cause acute poisoning.
(D) Clinical manifestations
High-dose poisoning often occurs with lightning speed coma and death. A few seconds after the intake screamed, cyanosis, convulsions, respiratory arrest immediately. Low-dose poisoning can occur 15 to 40 minutes of poisoning process: numbness of mouth and throat, salivation, headache, nausea, chest tightness, breathing speed up the deeper, the pulse speed up, arrhythmias, miosis, bright red skin and mucous membranes, convulsions, coma Finally, loss of consciousness and death.
General clinical manifestations of acute poisoning can be divided into four phases:
(1) prodromal phase: oral poisoning with mouth, throat, burning sensation, nausea and vomiting, vomit, bitter almond flavor, accompanied by headache, dizziness, fatigue, tinnitus, chest tightness, stool urgency and so on. Inhalation poisoning may have eyes, throat and upper respiratory tract irritation. After narr
owing the pupil to expand on both sides of the first, then quickly blurred consciousness, coma.
(2) of difficulty breathing: difficulty breathing, rapid pulse, enlarged pupils shrink first, then quickly blurred consciousness, coma.
(3) seizure phase: tonic or paroxysmal convulsions, and even opisthotonus, incontinence, loss of consciousness.
(4) paralysis of: muscle relaxation, reflex, slow shallow breathing, and finally breathing, cardiac arrest.
(E) Autopsy findings
Cyanide in the blood of heme formation, so Shiban, muscle and blood showed a bright red. Those who died quickly, the body organs obvious signs of suffocation. Oral poisoning, digestive tract are visible edema, stomach and duodenal mucosa congestion, erosion, necrosis, stomach and body cavity bitter almond flavor. Inhalation of cyanide poisoning death, brain, hippocampus, striatum, substantia nigra edema, nerve cell degeneration and necrosis, gliosis, heart, liver, cloudy swelling of renal parenchymal cells.
Add a comment
  • Nickname [Register]
  • Password Optional
  • Site URI
  • Email
Enable HTML Enable UBB Enable Emots Hidden Remember