Figure 6.

Panel (a) Time course of Δψ_m changes in mouse hepatocytes exposed to APAP (6.6 mM) alone or in combination with 50 μM NCX-1000 or UDCA. NCX-1000 induces a long-lasting Δψ_m hyperpolarization while APAP causes hyperpolarization followed by depolarization. Data are mean±s.e. of six experiments. ^*P<0.05 versus control. Panel (b) NCX-1000 prevents cytochrome c translocation caused by APAP. Hepatocytes were treated with APAP (6.6 mM) with or without 50 μM NCX-1000 and UDCA for 8 h and subsequently lysed as described in Methods. Lysates equivalent to 1 × 10⁷ cells were subjected to 10–12% SDS–PAGE and immunoblotted with the cytochrome c antibody. Lane 1: control. Lane 2: APAP 6.6 μM alone. Lane 3, APAP plus NCX-1000 50 μM. Lane 4, APAP plus UDCA 40 μM. Each blot is representative of at least three others. Panel (c) Cytochome c concentration in the mitochondrial and cytosolic fractions of hepatocytes exposed to 6.6 mM alone or in combination with 50 μM NCX-1000 and UDCA. Data are mean±s.e. of six experiments. ^*P<0.05 versus control. ^**P<0.05 versus APAP alone. Panels (d) and (e) Cyclosporine and trifluoperazine protect against Δψ_m collapse and apoptosis induced by APAP. Hepatocytes were incubated for 12 h with cyclosporine and/or trifluoperazine with or without APAP (6.6 mM) and Δψ_m changes and percent of apoptotic cells (annexin V⁺/PI⁻) measured as described in Methods. Data are mean±s.e. of six experiments. ^*P<0.05 versus control. ^**P<0.05 versus APAP.