Increased reactive oxygen species production and functional alterations in antioxidant enzymes in human failing myocardium.

Background: The nature of oxidative stress and the activity of antioxidant enzyme systems are incompletely characterized in the failing human heart.

Methods And Results: We obtained ventricular myocardium from failing, explanted human hearts in patients with nonischemic dilated cardiomyopathy at the time of heart transplant to examine whether reactive oxygen species (ROS) production and antioxidant enzyme activity or expression were altered in end-stage human heart failure. Nonfailing myocardium was obtained from organ donors who were not eligible for transplantation.

Mice lacking osteopontin exhibit increased left ventricular dilation and reduced fibrosis after aldosterone infusion.

Background: Osteopontin, also known as cytokine Eta-1, plays an important role in postmyocardial infarction remodeling by regulating collagen accumulation. Aldosterone promotes collagen synthesis and structural remodeling of the heart. The role of osteopontin in aldosterone-induced fibrosis and myocardial remodeling is unknown.