Figure 2. Complex I-stimulated oxygen consumption through pyruvate and malate oxidation measurementin control and PRKN-PD fibroblasts. No statistically significant differences were obtained between groups. In glucose, downward trends in CI-stimulated oxygen was shown in PRKN-PD compared to control fibroblasts. Exposure to galactose trended to reduce CI-stimulated oxygen consumption in control fibroblasts when compared to glucose, but not in PRKN-PD cells. The results are expressed as means and standard error of the mean (SEM). CTL= Control fibroblasts. GAL= 10 mM galactose medium. GLC= 25 mM glucose medium. NS= not significant. PRKN-PD= Parkin-associated PD fibroblasts. Oxygen consumption values were normalized by citrate synthase activity as a marker of mitochondrial content.