Fig. 4

Percent change in mitochondrial swelling following incubation of isolated mitochondria 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 taurourso auroursodeoxycholate (TUDC) or 5 µM cyclosprine A (CsA) in respiration buffer as described in “Materials and Methods.” At 5 min, the apoptotic agent was added and the percent change in mitochondrial swelling from 5 to 10 min was determined by monitoring the absorbance at 540 nm. In the coincubation experiments, mitochondria were pretreated with UDC, TUDC, or CsA for 5 min. The results are means ± standard error of the mean (SEM) of at least three separate experiments. ^†p < 0.05, *p < 0.001 from control; ^§p < 0.05, ^¶p < 0.01, ^‡p < 0.001 from toxic stimuli alone.