Joseph 2019 Abstract IOC139
|Joseph V, Arias-Reyes C, Soliz J (2019) Plasticity of brain mitochondrial respiration rates during acclimatization to chronic hypoxia in mice. Mitochondr Physiol Network 24.01.|
Several lines of evidence suggest that hypoxia decreases mitochondrial respiration rates, but some results show an opposite effect in rodents adapted to life at high altitude. In the present study we used FVB mice and SD rats, as two models showing divergent responses at high altitude or during short-term exposure to hypoxia at sea level. We assessed mitochondrial respiration rates in permeabilized brain cortex samples by high resolution respirometry (Oroboros-2k) during acclimatization to hypoxia. Rats and mice were exposed to room air (controls), short-term (6 and 24 hours), or long-term (7 and 21 days) hypoxia (12% O2). Brain samples were rapidly dissected and permeabilized in saponin before measurements of O2 consumption rates with a standard protocol to assess NADH-, FADH2-, or NADH+FADH2-linked respiration. During short-term hypoxic exposure, NADH and FADH2-linked respiration increased in mice, but remained stable in rats. During long-term hypoxia in mice, while NADH-linked respiration remained elevated compared to controls, NADH+FADH2-linked respiration returned to control levels while FADH2-respiration decreased below control levels. Furthermore, in mice, H+ leak after rotenone and oligomycin (state 4 - FADH2-linked) increased during short-term hypoxia, then declined during long-term hypoxia. None of these changes occurred in rats. Our results suggest specific plasticity of complexes I and II of the electron transport chain during acclimatization to chronic hypoxia in mice, but not in rats. These divergent responses might contribute to a more efficient acclimatization to hypoxia in the central nervous system in mice.
Labels: MiParea: Respiration, Comparative MiP;environmental MiP
Stress:Hypoxia Organism: Mouse, Rat Tissue;cell: Nervous system Preparation: Permeabilized tissue
- Inst Univ Cardiology Pneumology Québec, Univ Laval, Québec, QC, Canada