Figure 2.

Effects of resveratrol on F0F1-ATPase/ATP synthase activity of rat brain mitochondrial preparations. (A) Typical examples of spectrophotometric read-out showing the absorbance change at 340 nm induced by 20 μl digitonin-solubilized brain mitochondrial preparation (51 μg protein) in the presence of ethanol vehicle, methanol vehicle, 7 μg ml⁻¹ oligomycin in methanol, 7 μM diethylstilbestrol in ethanol and 14 μM resveratrol in ethanol. Resveratrol itself and, to a lesser degree, diethylstilbestrol and oligomycin, had extinction at 340 nm, so the starting point had higher absorbance. Diethylstilbestrol was included here as a comparison. Oligomycin and efrapeptin (see below and text) were included for determination of the F0F1-ATPase activity in the preparations. (B) The concentration-dependent effect of 0.7–70 μM resveratrol on digitonin- and CHAPS-solubilized rat brain mitochondrial preparations. Data are expressed as means (s.d.) from three experiments. Also shown is the concentration-dependent effect of oligomycin and efrapeptin. For studying the effect of efrapeptin on ATPase activity, efrapeptin was pre-incubated at 26°C with the solubilized preparation for 6 min to allow for binding. The F0F1-ATPase activity in 0.7% vehicle (this and following figures) was defined as 100%. (C) Effect of resveratrol on ATP synthesis and hydrolysis catalysed by rat brain submitochondrial preparations. F0F1-ATPase activity of rat brain submitochondrial preparations was determined similarly as solubilized mitochondrial preparation except that 2 μg ml⁻¹ antimycin A was present. Data are expressed as means (s.d.) from three experiments. The F0F1-ATPase/ATP synthase activity in vehicle was defined as 100%.