Fig. 2

Effects of PQQ administration on ATP, NAD, mitochondrial membrane potential levels and mitochondrial function in vitro. A ATP and B NAD content in dissociated mouse brain cortical cells incubated with different doses of PQQ (0.1, 0.5, 1, 5, 10, 50 µM) for 2 h. n = 4 different cell suspensions from different hemispheres. C ATP content in dissociated retinal and superior colliculus cells and in isolated optic nerves incubated with 50 µM PQQ for 2 h. The red inset shows a zoom of the graph related to the ATP content in superior colliculus. n = 5 retinal replicates made by 2 pooled retinas, 5 optic nerve replicates made of isolated segments cut to 3 mm length, 5 superior colliculus replicates. D Mitochondrial membrane potential (ΔΨ) levels in dissociated brain cortical cells incubated with several concentrations of PQQ (0.5, 5, 50 µM) for 2 h. n = 4 different cell suspensions from different hemispheres. E ΔΨ levels in dissociated retinal and superior colliculus cells and in isolated optic nerves incubated with 50 µM PQQ for 2 h. n = 8 retinal replicates made by 2 pooled retinas, 5 optic nerve replicates made of isolated segments cut to 3 mm length, 5 superior colliculus replicates. F–I Mitochondrial Complex (C) II (F), III (G), IV (H) and citrate synthase (CS; I) activity in dissociated cortical cells incubated with 50 µM PQQ for 2 h. n = 6 different cell suspensions from different hemispheres. *p < 0.05, **p < 0.01 and ***p < 0.001 versus control