Toxicity of nitrous oxide.

摘要: Abstract Nitrous oxide interacts with vitamin B 12 resulting in selective inhibition of methionine synthase, a key enzyme and folate metabolism. Thus, nitrous may alter one-carbon methyl-group transfer most important for DNA, purine thymidylate synthesis. Long-term exposure to high concentrations cause megaloblastic bone-marrow depression neurological symptoms. Exposure higher doses less than 6 hours, as clinical anaesthesia, are considered harmless. Recent studies seem suggest correlation between anaesthesia hyperhomocysteinaemia which is accepted be an independent risk factor coronary artery disease. As today, available data do not support the notion that trace amounts associated impaired fertility or increased developing cancer. Emission from medical use estimated contribute 0·05% total annual greenhouse gas emission.