Total protein was isolated from hippocampus following 24 h exposure to 17β-oestradiol (E2, 30 μg/kg), PPT (30 μg/kg), DPN (100 μg/kg) or corn oil vehicle control (OVX). All immunoblot data were normalised to β-tubulin or β-actin loading control and compared relative to OVX as 100%. Western blots were analysed to determine protein expression for: A. pyruvate dehydrogenase, subunit E1α of the PDH complex, the key enzyme linking glycolysis to the tricarboxylic acid cycle, responsible for catalysing the formation of acetyl-CoA and carbon dioxide from pyruvate within the mitochondria; B. complex I, subunit NDUFB8, accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase which functions in the transfer of electrons from NADH to the respiratory chain; C. complex II, subunit SDHB, one of the four subunits of succinate dehydrogenase located on the inner mitochondrial membrane and participates in both the tricarboxylic acid cycle and the respiratory chain; D. complex III, core II subunit, necessary for the formation of the complex, a component of the respiratory chain responsible for transferring electrons from coenzyme Q to cytochrome c; E. cytochrome c oxidase, subunit I (COXI), one of three mtDNA-encoded subunits of respiratory complex IV, located within the mitochondrial inner membrane and is the third and final enzyme of the electron transport chain of mitochondrial oxidative phosphorylation; F. cytochrome c oxidase, subunit IV (COXIV), one of ten nucDNA-encoded subunits of the enzyme complex IV; and G. complex V, subunit α, contained within the extramembraneous catalytic core of the complex that produces ATP from ADP in the presence of a proton gradient across the inner mitochondrial membrane. Panels B, C, D, E and G were blotted and analyzed simultaneously with a “mito-cocktail” antibody kit as described in the Methods section. Bars represent mean relative expression ± SEM from four to five animals per group (*=P<0.05 vs. OVX; n=4–5).