Biphasic oxygen kinetics of cellular respiration and linear oxygen dependence of antimycin A inhibited oxygen consumption.
Oxygen kinetics in fibroblasts was biphasic. This was quantitatively explained by a major mitochondrial hyperbolic component in the low-oxygen range and a linear increase of rotenone- and antimycin A-inhibited oxygen consumption in the high-oxygen range. This suggests an increased production of reactive oxygen species and oxidative stress at elevated, air-level oxygen concentrations. The high oxygen affinity of mitochondrial respiration provides the basis for the maintenance of a high aerobic scope at physiological low-oxygen levels, whereas further pronounced depression of oxygen pressure induces energetic stress under hypoxia.
Hütter
Eveline
E
Institute for Biomedical Aging Research, Austrian Academy of Sciences, Innsbruck.
Renner
Kathrin
K
Jansen-Dürr
Pidder
P
Gnaiger
Erich
E
D000968:Antimycin A / Q000494:pharmacology*; D019069:Cell Respiration / Q000502:physiology*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D009840:Oligomycins / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D012402:Rotenone / Q000494:pharmacology; D014475:Uncoupling Agents / Q000494:pharmacology
D009840:Oligomycins; D014475:Uncoupling Agents; D012402:Rotenone; D000968:Antimycin A; D010100:Oxygen