Accumulation of Exogenous Amyloid-Beta Peptide in Hippocampal Mitochondria Causes Their Dysfunction: A Protective Role for Melatonin
Figure 7
The hydrolytic activity of ATPase did not respond to melatonin. Enzymatic ATP hydrolysis was determined by a colorimetric reaction measuring the release of free orthophosphate (Pi), based on the formation of a phosphomolybdate complex in an acid medium followed by a reduction or complexation with basic dyes that yield colored complexes. When electron transport ceases, the inner-membrane potential is developed at the expense of ATP hydrolysis by the mitochondrial ATP synthase. However, in the presence of Aβ the hydrolytic activity of ATPase decreases significantly as compared to intact brains () and did not show any recovery in melatonin-treated animals (fAβ = fAβ Mel), which may imply a different mechanism of damage by Aβ. In fact, another report explores the possibility of a direct interaction of Aβ with the alpha subunit of the F1Fo-ATP synthase complex [42].
