Maria A Linarte
Forum Senior
Topics: 50
Posts: 112
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Where did you read that?
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| Anno Domini
Moderator
Topics: 293
Posts: 727
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Brs physiology
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| MIG
Forum Junior
Topics: 6
Posts: 63
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P50 defined as the partial pressure of O2 necessary to bind 50% of available Hemoglobin. CO will decrease P50 of Hb for O2 . CO bind Hb with greater affinity than does O2 and by that left-shift the curve and make more difficult to unload O2 in tissue. For example , in carbon monoxide poisoning : O2 decrease, this will lead to decrease in saturation and as a result left-shift of O2 curve ( in this case by inhibiting cytochrome oxidase). I hope i answered your question.
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| Ouli Maty
Forum Elite
Topics: 33
Posts: 275
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CO has basically two effects on O2-hemoglobin.
It decreases the O2 content of blood, by binding almost all the sites in hemoglobin( grater affinity> 200 times that of O2 for Hb) , leaving a very little place for O2. So the PO2 to produce 50% Hb saturation (P50) is lower. That shifts the curve to the left. practice on a curb, you will see it clear.
And the remaining sites on the Hb will have a grater affinity for O2. So the little O2 that is bound to Hb will have hard time leaving it once in the tissues resulting in hypoxia. (You like something, you want to keep it)
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deep breathing...
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