Difference between revisions of "Talk:Hypoxia"
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== Systematic definition of normoxia as a reference for hypoxia == | == Systematic definition of normoxia as a reference for hypoxia == | ||
=== Categories of normoxia === | === Categories of normoxia === | ||
:::: 1. Environmental conditions | :::: For explaining normoxia and deviations from normoxia, we distinguish environmental, compartmental, and functional definitions of normoxia. These definitions provide a reference for distinguishing corresponding causes for deviations from normoxia or normoxic function. | ||
::::: 1. Environmental conditions | |||
::::::* Normoxia may be defined arbitrarily (like altitude relative to sealevel) as air-level ''p''<sub>O<sub>2</sub></sub> at sealevel in air or in the aqueous extra-organismic environment. | ::::::* Normoxia may be defined arbitrarily (like altitude relative to sealevel) as air-level ''p''<sub>O<sub>2</sub></sub> at sealevel in air or in the aqueous extra-organismic environment. | ||
:::: 2. Compartmental respiratory cascade | ::::: 2. Compartmental respiratory cascade | ||
::::::* Normoxia may be defined arbitrarily as the ''p''<sub>O<sub>2</sub></sub> in any given compartment of a living organism (alveolar, arterial, venous, mixed-venous, intracellular) obtained under environmental normoxia in a steady state of physiological routine activity (here ‘routine’ is organismic physiological, whereas ‘ROUTINE’ is cellular physiological). | ::::::* Normoxia may be defined arbitrarily as the ''p''<sub>O<sub>2</sub></sub> in any given compartment of a living organism (alveolar, arterial, venous, mixed-venous, intracellular) obtained under environmental normoxia in a steady state of physiological routine activity (here ‘routine’ is organismic physiological, whereas ‘ROUTINE’ is cellular physiological). | ||
:::: 3. Biological response | ::::: 3. Biological response | ||
::::::* For any function, normoxic performance is defined as the biological response that does not deviate from the physiological function measured under environmental or compartmental normoxia. | ::::::* For any function, normoxic performance is defined as the biological response that does not deviate from the physiological function measured under environmental or compartmental normoxia. | ||
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:::: Starting from definitions of categories environmental normoxia, compartmental normoxia, and normoxic function, the causes for deviations from normoxia are considered: | :::: Starting from definitions of categories environmental normoxia, compartmental normoxia, and normoxic function, the causes for deviations from normoxia are considered: | ||
:::: 1. Environmental hypoxia and hyperoxia | ::::: 1. Environmental hypoxia and hyperoxia | ||
::::::* Hypobaric conditions: high altitude or low-pressure chamber with air | ::::::* Hypobaric conditions: high altitude or low-pressure chamber with air | ||
::::::* Hyperbaric conditions: high-pressure chamber, diving with air | ::::::* Hyperbaric conditions: high-pressure chamber, diving with air | ||
::::::* Normobaric: O<sub>2</sub> deprivation in the environment (environmental normobaric hypoxia), O<sub>2</sub> supplementation (environmental normobaric hyperoxia) | ::::::* Normobaric: O<sub>2</sub> deprivation in the environment (environmental normobaric hypoxia), O<sub>2</sub> supplementation (environmental normobaric hyperoxia) | ||
:::: 2. Compartmental hypoxia and hyperoxia | ::::: 2. Compartmental hypoxia and hyperoxia | ||
::::::* Environmentally induced hypoxia or hyperoxia on the compartmental level (living organism) | ::::::* Environmentally induced hypoxia or hyperoxia on the compartmental level (living organism) | ||
::::::* Physiologically induced hypoxia on the compartmental level: tissue-work related (living organism at high work load of a tissue) | ::::::* Physiologically induced hypoxia on the compartmental level: tissue-work related (living organism at high work load of a tissue) | ||
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::::::* Experimental for isolated organs, tissues, cells, and organelles: deviations of incubation O<sub>2</sub> levels of experimental preparations from compartmental or biological normoxia in the intact organism | ::::::* Experimental for isolated organs, tissues, cells, and organelles: deviations of incubation O<sub>2</sub> levels of experimental preparations from compartmental or biological normoxia in the intact organism | ||
:::: 3. Biological hypoxia and hyperoxia | ::::: 3. Biological hypoxia and hyperoxia | ||
::::::* Compartmental: tissue-work related | ::::::* Compartmental: tissue-work related | ||
::::::* Compartmental: pathological | ::::::* Compartmental: pathological | ||
::::::* Genetic: inhibition or acceleration of O<sub>2</sub>-linked pathways (mutations, knockout, knockin) | ::::::* Genetic: inhibition or acceleration of O<sub>2</sub>-linked pathways (mutations, knockout, knockin) | ||
::::::* Pharmacological-toxicological: inhibition or acceleration of O<sub>2</sub>-linked pathways (cyanide, rotenone, NO, ..; doping, ..) | ::::::* Pharmacological-toxicological: inhibition or acceleration of O<sub>2</sub>-linked pathways (cyanide, rotenone, NO, ..; doping, ..) | ||
== Extents of hypoxia == | |||
:::: There is a continuous transition of hypoxia to anoxia, which is best represented on a logarithmic scale of ''p''<sub>O<sub>2</sub></sub>. Only if the transition to anoxia is of interest, then further differentiation of microxia and anoxia is of technical and physiological interest taking into account the limit of detection of a method of determining ''p''<sub>O<sub>2</sub></sub> and different methods to detect functional responses to the presence (microxia) or absence (anoxia) of trace amounts of oxygen. | |||
Revision as of 00:02, 14 December 2021
Systematic definition of normoxia as a reference for hypoxia
Categories of normoxia
- For explaining normoxia and deviations from normoxia, we distinguish environmental, compartmental, and functional definitions of normoxia. These definitions provide a reference for distinguishing corresponding causes for deviations from normoxia or normoxic function.
- 1. Environmental conditions
- Normoxia may be defined arbitrarily (like altitude relative to sealevel) as air-level pO2 at sealevel in air or in the aqueous extra-organismic environment.
- 2. Compartmental respiratory cascade
- Normoxia may be defined arbitrarily as the pO2 in any given compartment of a living organism (alveolar, arterial, venous, mixed-venous, intracellular) obtained under environmental normoxia in a steady state of physiological routine activity (here ‘routine’ is organismic physiological, whereas ‘ROUTINE’ is cellular physiological).
- 3. Biological response
- For any function, normoxic performance is defined as the biological response that does not deviate from the physiological function measured under environmental or compartmental normoxia.
- 1. Environmental conditions
Causes of deviations from normoxia
- Starting from definitions of categories environmental normoxia, compartmental normoxia, and normoxic function, the causes for deviations from normoxia are considered:
- 1. Environmental hypoxia and hyperoxia
- Hypobaric conditions: high altitude or low-pressure chamber with air
- Hyperbaric conditions: high-pressure chamber, diving with air
- Normobaric: O2 deprivation in the environment (environmental normobaric hypoxia), O2 supplementation (environmental normobaric hyperoxia)
- 1. Environmental hypoxia and hyperoxia
- 2. Compartmental hypoxia and hyperoxia
- Environmentally induced hypoxia or hyperoxia on the compartmental level (living organism)
- Physiologically induced hypoxia on the compartmental level: tissue-work related (living organism at high work load of a tissue)
- O2-transport related hypoxia (pathological: ischemia and stroke, anaemia, chronic heart disease, chronic obstructive pulmonary disease, severe COVID-19, obstructive sleep apnea, CO poisoning)
- Experimental for isolated organs, tissues, cells, and organelles: deviations of incubation O2 levels of experimental preparations from compartmental or biological normoxia in the intact organism
- 2. Compartmental hypoxia and hyperoxia
- 3. Biological hypoxia and hyperoxia
- Compartmental: tissue-work related
- Compartmental: pathological
- Genetic: inhibition or acceleration of O2-linked pathways (mutations, knockout, knockin)
- Pharmacological-toxicological: inhibition or acceleration of O2-linked pathways (cyanide, rotenone, NO, ..; doping, ..)
- 3. Biological hypoxia and hyperoxia
Extents of hypoxia
- There is a continuous transition of hypoxia to anoxia, which is best represented on a logarithmic scale of pO2. Only if the transition to anoxia is of interest, then further differentiation of microxia and anoxia is of technical and physiological interest taking into account the limit of detection of a method of determining pO2 and different methods to detect functional responses to the presence (microxia) or absence (anoxia) of trace amounts of oxygen.
