Figure 10.

Inhibitors of mitochondrial complexes I and III block cystamine relaxation in rat mesenteric arteries. (A) Original recordings showing contractions induced by extracellular KPSS (100 mM) in the presence of vehicle, a superoxide scavenger, tempol, and an inhibitor of complex I, rotenone, and of complex III, antimycin, followed by addition of cystamine and the NO donor, SNP. U46619 was added to increase contraction in preparations incubated with rotenone and antimycin. The bar corresponds to a tension (ΔT) of 4 Nm⁻¹ in the upper traces and of 3 Nm⁻¹ in the lower traces. (B–E) Average relaxation induced by (B, D) cystamine (10⁻⁴ M) or (C, E) SNP in preparations incubated with rotenone, antimycin, tempol or the mitochondrial superoxide scavenger, mito‐tempo, in preparations contracted with (D, E) KPSS or in case the incubation affected the contraction level by (B,C) KPSS plus U46619. Data are means ± SEM of vessel segments from 10 animals. *P < 0.05 versus control.