Figure 6.

Biological effects of helium-conditioned serum on mitochondrial function. All assays utilized serum collected 24 h post exposure. (A) L6 muscle cells were treated with serum (5%) from control or helium-exposed mice. Seahorse Bioscience mitochondrial stress was assessed. Oxygen consumption rate (OCR) was measured before and after the addition of inhibitors (oligomycin, a complex V inhibitor; FCCP, a protonophore; and antimycin A and rotenone, complex III and I inhibitors, respectively) to derive parameters of mitochondrial respiration. (B) After addition of serum mean OCR was calculated after normalizing for baseline OCR of the L6 cells. (C) High-resolution respirometry analysis was performed using the Oroboros O2k-Respirometer. Serum from control and helium-exposed animals was incubated with naïve mouse heart ventricular tissue. Respiratory function of complex I and II activity (CI, CII), maximum oxidative phosphorylation capacity (mOX) and maximum uncoupled capacity (mUC) are shown after addition of complex I substrates glutamate and malate. (D) Electron paramagnetic resonance (EPR) with a DEPMPO spin probe was used to assess superoxide formation in isolated mouse heart mitochondria exposed to serum from control and helium-exposed animals under state 3 and 4 conditions with complex I substrates. All assays utilized n = 4–6 samples/group.