Question

Cyanide is very fast-acting poison that functions by binding irreversible to cytochrome c oxidase and inactivating complex IV. initial autopsy reports in case of cyanide poisoning usually indicate the immediate cause of death as hypoxia? A) why then are the blood oxygen level in autopsy reports usually slightly above normal? b). At the time of death, what would you expect the measured levels of mitochondrial ATP, NADH, and A (CoA) to be (answer for each of these compounds as being above normal, normal or below normal) and why?

Answer 1

A). Blood oxygen level usually slightly above normal in case of cyanide poisoning death, because hemoglobin dissociates from O2 and binds with cyanide to form methmoglobin. Increase in dissociation of oxygenated Hb, increases the blood oxygen levels.

B). Inactivation of complex IV: the mitochondrial ATP will be below normal because there will be less H+ gradient, less ATP synthesis.

NADH levels will be above normal because electron doesn't reach to its final acceptor. So, electron from NADH not received and it will not convert into NAD+.

CoA should be normal because it utilized in one step and released from other step.