Carbon monoxide-mediated brain lipid peroxidation in the rat.

Clinical and animal data suggest that the pathogenesis of CO poisoning extends beyond the inhibition of hemoglobin function, but no mechanism has been identified. Evidence of neurological compromise, particularly loss of consciousness, has been implicated as a marker for increased mortality and morbidity in clinical reports. Experiments were carried out with rats to assess whether CO exposure may cause brain lipid peroxidation. With the use of two methods, measurement of conjugated dienes and thiobarbituric acid reactivity, brain lipid peroxidation could be documented as a result of exposure to CO at a concentration sufficient to cause unconsciousness. Products of lipid peroxidation were increased by 75% over the base-line values 90 min after CO exposure. Unconsciousness was associated with a brief period of hypotension, so brief that in itself it caused no apparent insult. Lipid peroxidation occurred only after the animals were returned to CO-free air, and there was no direct correlation with the carboxyhemoglobin level. This work may provide an explanation for a number of currently poorly understood clinical observations regarding CO poisoning.