| methemoglobin | Haemoglobin in a form incapable of carrying oxygen. (12 Dec 1998) |
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| methemoglobin reductase | <enzyme> An erythrocyte enzyme which catalyses the reduction of methemoglobin (ferrihemoglobin) to haemoglobin (ferrohemoglobin). Deficiency produces the inherited disease familial methemoglobinaemia. In the absence of methemoglobin, the enzyme can also reduce methylene blue. Registry number: EC 1.6.- (12 Dec 1998) |
| methemoglobinaemia | The presence of methemoglobin in the blood, resulting in cyanosis. A small amount of methemoglobin is present in the blood normally, but injury or toxic agents convert a larger proportion of haemoglobin into methemoglobin, which does not function reversibly as an oxygen carrier. Methemoglobinaemia may be due to a defect in the enzyme NADH methemoglobin reductase (an autosomal recessive trait) or to an abnormality in haemoglobin m (an autosomal dominant trait). (12 Dec 1998) |
| methemoglobinuria | The presence of methemoglobin in the urine. Origin: methemoglobin + G. Ouron, urine (05 Mar 2000) |
| cyanide methemoglobin | A relatively nontoxic compound of cyanide with methemoglobin, which is formed when methylene blue is administered in cases of cyanide poisoning. Synonym: cyanide methemoglobin. (05 Mar 2000) |
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