Table 1.
Comparison of the O2 levels defining physiological and pathological hypoxia in mammals
| Condition | PO2 (mmHg) | PO2 (%) | Reference |
|---|---|---|---|
| Atmosphere | 150 | 21.1 | Reviewed by Carreau et al. (2011) |
| Lungs (tissue) | 42 | 5.6 | |
| Arterial blood | 100 | 13.2 | |
| Venous blood | 40 | 5.3 | |
| Physiological hypoxia (mammalian brain): | |||
| Fetus | <7.6 | ≤1 | Lee et al. (2001), Zhang et al. (2011) |
| Fetal subventricular zone | 18–24 | 2.5–3 | Santilli et al. (2010) |
| Adult subventricular zone | 8–48 | 1–6 | Panchision (2009), Mohyeldin et al. (2010), Zhang et al. (2011) |
| Human adult brain | 6–33 | 0.5–8 | Erecinska and Silver (2001), Ivanovic (2009), Carreau et al. (2011) |
| Pathological hypoxia: | |||
| Stroke (penumbral region in rats) | 30–1.2 | 3.5–0 | Liu et al. (2004, 2006), Zhang et al. (2011) |
| Brain trauma (risk of death in humans) | 15 | 2 | van den Brink et al. (2000) |
| Atmospheric hypoxia | <160 | <21.1 | |
| Mild hypoxia “in vitro” | 19–40 | 2.5–5 | Pistollato et al. (2007), Santilli et al. (2010), De Filippis and Delia (2011) |
| Severe hypoxia/anoxia | <8 | 0–1 | Ivanovic (2009), De Filippis and Delia (2011) |