Originally Posted by
double_barrel
Thanks, that's very helpful. And as you say, it goes a long way to explain the lethality of CO, I knew its binding to Hb was tenacious, but had no idea it was locked-in like that. I think I will take a look at the underlying biochemistry out of interest.
Thanks to
PDR1 for his definitive answers.
I am not an expert, but also curious about the reversibility of COHb binding. Wikipedia gives some clues:
https://en.wikipedia.org/wiki/Carboxyhemoglobin
COHb has a half-life in the blood of 4 to 6 hours.
Supplemental oxygen takes advantage of Le Chatelier's principle to quicken the decomposition of carboxyhemoglobin back to hemoglobin:
HbCO + O2 ⇌ Hb + CO + O2 ⇌ HbO2 + CO
My interpretation would be:
1. At body temperature in a living being, CO poisoning is slowly reversible through the circulation.
2. The absence of oxygen and blood circulation, and/or low temperatures would "freeze" the binding process.