methaemoglobin


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Related to methaemoglobin: carboxyhemoglobin, Blue baby syndrome

methaemoglobin

(mɛtˌhiːməˈɡləʊbɪn; mɛˌθiːmə-) or

methemoglobin

n
(Biochemistry) a brown compound of oxygen and haemoglobin formed in the blood by the action of certain drugs
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References in periodicals archive ?
Inverse relationship between age - dependent erythrocyte activity of methaemoglobin reductase and prilocaine-induced methaemoglobinaemia during infancy.
Methaemoglobin has got decreased affinity for oxygen and so decreased availability of oxygen to the tissues.
It stains negatively charged components, such as DNA, and can be used to treat both cyanide poisoning and low levels of methaemoglobin (3).
Furthermore, [Pb.sup.2+] effect may be seen in the increased production of reactive oxygen species (ROS) by accelerating of oxidation of oxyhaemoglobin to methaemoglobin and thus induces oxidative stress by generating imbalance between production of free radicals in tissues and cellular components and their ability to detoxify the extremely reactive intermediates that causing damage to membranes, DNA and proteins [1].
Brooks, "The oxidation of haemoglobin to methaemoglobin by oxygen.
Wilson, "Redox cycling of human methaemoglobin by H2O2 yields persistent ferryl iron and protein based radicals," Free Radical Research, vol.
In humans, high contents of nitrate can cause methaemoglobinaemia, as a consequence of the reaction of nitrite with haemoglobin in the red blood cells to form methaemoglobin, which binds oxygen tightly and does not release it, thus blocking oxygen transport.
Other deleterious effects include protein nitrosylation and nitration, convertion of haemoglobin (Hb) to methaemoglobin (MetHb) which leads to red blood cell lysis and thus iron availability to the pathogens, and enhance the production of IL-6 and IL-8 and activation of NF-kB [26, 51] (Table 2).
Long-term exposure to even low levels of [H.sub.2]S at the workplace has been reported to raise mean methaemoglobin and sulfhaemoglobin levels [72].
Hemoglobin test used coulter ACT series analyzer; the blood sample was hydrolyzed with drubkins solution (photonium ferricynide) to methaemoglobin that got converted by cyanide to stable haemoglobincyanide (HICN).
NaN[O.sub.2] can oxidize the iron moiety of normal haemoglobin from the ferrous to the ferric state to form methaemoglobin. The inability of methaemoglobin to adequately transport oxygen produces symptoms typical of hypoxia, including tachypnoea, lactic acidosis, convulsions, cognitive disorder, coma and death (Tanen et al., 2000).