Fig. 5

Cytochrome c release following membrane permeabilization in isolated mitochondria incubated with UCB and Aβ peptide. Mitochondria were isolated and incubated with either no addition (control), 4.3 µM unconjugated bilirubin (UCB), 125 µM amyloid-β (Aβ) peptide (25–35), or a combination of toxic agent plus 500 µM ursodeoxycholate (UDC), 500 µM tauroursodeoxycholate (TUDC) or 5 µM (CsA) in respiration buffer as described in “Materials and Methods.” Mitochondrial pellets and supernatants were examined for cytochrome c levels by Western blot analysis. Following SDS-PAGE and transfer, the nitrocellulose membranes were incubated with the monoclonal antibody to cytochrome c and the 15 kDa protein was detected using enhanced chemiluminescent light (ECL) reagent cyclosporine A. Representative Western blots (top) and densitometric means ± standard error of the mean (SEM) relative to controls (bottom) of at least three separate experiments. *p < 0.01 from control; ^†p < 0.05 from toxic stimuli alone.