Is this true? - What is it considered hypoxia? (May/23/2007 )

Hello everyone. I came across this paper in Nature Methods and discussing with my very experience physiologist supervisor, he told me that what it says it isn't true. He is sure that levels of oxygen in tissue aren't as low as they say. He saw a good physiology text book which supported his point of view. He convinced me, however I would like to hear other opinions.

http://www.nature.com/nmeth/journal/v4/n5/...th0507-386.html


What do you think? Are cell lines many times in hyperoxia conditions? What are the real levels of oxygen in tissue/blood, etc?


All opinions welcome.

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It has to do with the fact that the vast majority of oxygen molecules in the body (at least in higher organisms) are bound by hemoglobin. Very little oxygen is left free. You can see this in the classic Hgb-oxygen dissociation curves in any physiology book. The hemoglobin is tuned to hold on to oxygen at higher partial pressures; it is virtually saturated at atmospheric oxygen partial pressures (i.e. in the lungs) and releases maximally in areas of relatively lower partial pressure (i.e. the peripheral tissues).

So the concept that mammalian cells would prefer to be cultured at a lower oxygen partial pressure actually makes complete sense physiologically... I wonder why it hasn't been commented on before... It makes you wonder about the validity of a whole lot of the scientific literature using in vitro cell culture models.

-jb

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