Figure 2

NE stimulates proton-ATPase activity of mitochondrial complex V in BA. (a–g) Fluorescence of AT1.03-based ratiometric measurements of mitochondrial and cytoplasmic ATP. (a and b) Show fluorescence images of mitAT1.03- and AT1.03-transfected BA before and after 0.1 μM NE treatment, respectively. Scale bar, 20 μm. (c and d) Show raw data plots (c) and an average plot (d) of mitochondrial ATP changes (n=16) in 0.1 μM NE-treated BA. Each colored trace represents the ATP change of a single BA (c). (e) Shows the raw data plots of cytoplasmic ATP (n=29) after NE treatment. Each colored trace represents the ATP change of a single BA. (f) Shows the raw data plots of cytoplasmic ATP (n=23) after co-treatment of NE and oligomycin A. Each colored trace represents the ATP change of a single BA. (g) Compares the averaged changes in cytoplasmic ATP after NE treatment (n=29) or NE and oligomycin A co-treatment (n=23), which show that the inhibitor (oligomycin A) of mitochondrial complex V mitigates the ATP consumption induced by NE stimulation. (h) Shows a representative scatter plot of pH changes versus MMP changes induced by 0.1 μM NE with (red, n=75) or without (black, n=75) 10 μg ml⁻¹ oligomycin A pretreatment, which demonstrates that the inhibitor of mitochondrial complex V blocks the activity of the proton pump. All data points in d and g represent mean±s.e.m.