Figure 5. Chronic ISO infusion in vivo increased mPTP openings in the intact heart of mt-cpYFP transgenic mice and induced cardiac hypertrophy.

(a) Representative images and traces showing the onset of mitochondrial flashes (white boxes) accompanied by loss of Δψ_m (TMRM signal) in intact and Langendorff perfused heart. Scale bar, 10 μm. The mice were under ISO infusion (15 mg kg⁻¹ d⁻¹ for 2 weeks, ISO 2W) by a mini-osmotic pump implanted subcutaneously. (b) Summarized data showing the increase in flash frequency by ISO infusion and its blockade by KN93 (10 μM kg⁻¹ administered together with ISO). N=33, 27 and 25 serial scanning images from 4 to 6 mice in the groups of Vehicle, ISO and KN93+ISO, respectively. (c–e) ISO-induced cardiac hypertrophy was measured by heart weight to body weight ratio (c, N=5) and quantitative real-time PCR for ANP (d, N=4) and BNP (e, N=6). KN93 or β-blocker (Prop, 10 mg kg⁻¹) were administered together with ISO. Data in b–e are mean±s.e.m. *P<0.05 versus Vehicle group, ^#P<0.05 versus ISO group. The data were analysed using One-way ANOVA followed by Turkey post test in b–e.