Brain carbon monoxide toxicity

The model of carbon monoxide toxicity proposed by Kao and Nanagas (2006) combines the cascade of changes resulting from three primary events - binding to HB, direct cellular injury, and increased NO activity. CO is not a radical but many of the injuries produced by it are those that are caused by oxidative stress, which is secondary to hypoxia. In the model of Kao and Nanagas (2006), the oxidant is NO, which contributes to oxidative damage to the brain and produces the clinical syndrome of delayed neurologic sequelae (Thom et al, 1997). 

Prockop LD, Naidu KA Brain CT and MRI findings after carbon monoxide toxicity. J Neuroimaging 9 175-181, 1999... 

Some inhalants show toxicity to blood and bone marrow. Benzene is a solvent that is very toxic to bone marrow. It can cause leukemia and severe anemia. Nitrous oxide does damage to bone marrow in chronic users. Another chemical in inhalants, methylene chloride, is converted to carbon monoxide in the body. Carbon monoxide can prevent the transport of oxygen in the blood and result in brain damage. 

Carbon monoxide - carbon monoxide (CO) is an odourless, colourless and toxic gas. It is a narcotic gas that quickly induces sleep and because it is impossible to see, taste or smell the fumes are particular dangerous. Exposure to CO can result in angina, impaired vision and reduced brain function. At higher concentrations, CO exposure can be fatal. While the direct effect on the environment is minimal CO assists in the creation of smog or ground level ozone. 

Degradation of Heme. Two enzymes in heme degradation require reduction equivalents from NADPH. These are heme oxygenase (HO) and biliverdin reductase. HO metabolizes heme to biliverdin, iron, and carbon-monoxide (CO). The latter one acts as a neurotransmitter. Biliverdin reductase, on the other hand, reduces biliverdin to bilirubin. While, bilirubin is toxic for the brain of newborns, NADPH-dependent recycling of bilirubin by biliverdin reductase plays some antioxidative role in the cells [20, 23]. 

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