Hypothermia augments reactive oxygen species detected in the guinea pig isolated perfused heart

Hypothermic perfusion of the heart decreases oxidative phosphorylation and increases NADH. Because O2 and substrates remain available and respiration (electron transport system, ETS) may become impaired, we examined whether reactive oxygen species (ROS) exist in excess during hypothermic perfusion. A fiberoptic probe was placed on the left ventricular free wall of isolated guinea pig hearts to record intracellular ROS, principally superoxide (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}{\cdot}\) \end{document}), and an extracellular reactive nitrogen reactant, principally peroxynitrite (ONOO–), a product of nitric oxide (NO·) + \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}{\cdot}\) \end{document}. Hearts were loaded with dihydroethidium (DHE), w...