Mitochondria are proposed to play an important role in hypoxic cell signaling. One currently accepted signaling paradigm is that the mitochondrial generation of reactive oxygen species (ROS) increases in hypoxia. This is paradoxical, because oxygen is a substrate for ROS generation. Although the response of isolated mitochondrial ROS generation to [O(2)] has been examined previously, such inves...

Recent studies demonstrating a close relationship between postprandial hyperglycemia and the incidence of atherosclerotic cardiovascular disease prompted us to investigate the generation and source of reactive oxygen species (ROS) in endothelial cells stimulated by short-term exposure to a high glucose concentration. In addition, we investigated the effect of insulin on ROS production induced b...

Myogenic vasoconstriction, an intrinsic response to elevated transmural pressure (TMP), requires the activation of sphingosine kinase (Sk1) and the generation of reactive oxygen species (ROS). We hypothesized that pressure-induced Sk1 signaling and ROS generation are functionally linked. Using a model of cannulated resistance arteries isolated from the hamster gracilis muscle, we monitored vess...

Dear Editor, The O2-generating enzyme NADPH oxidase, plays a crucial role in host defense against microbial infection through the production of reactive oxygen species (ROS).1The multisubunit NADPH oxidase complex can be detected in vitro by the nitroblue tetrazolium test (NBT).2The NBT test is used for the diagnosis of chronic granulomatous disease.3 However, several factors, such as some cyto...

Oxidative stress and the generation of reactive oxygen species (ROS) can lead to mitochondrial dysfunction, DNA damage, protein misfolding, programmed cell death with apoptosis and autophagy, and the promotion of aging -dependent processes. Mitochondria control the processing of redox energy that yields adenosine triphosphate (ATP) through the oxidation of glucose, pyruvate, and nicotinamide ad...

Oxidative modification of cellular components may contribute to tissue dysfunction during aging. In skeletal muscle, contractile activity increases the generation of reactive oxygen and nitrogen species (ROS). The question of whether contraction-induced ROS generation is further increased in skeletal muscle of the elderly is important since this influences recommendations on their exercise part...

Rationale: Although premenopausal females have a lower risk for cardiovascular disease, the mechanism(s) are poorly understood. Objective: We tested the hypothesis that cardioprotection in females is mediated by altered mitochondrial protein levels and/or posttranslational modifications. Methods and Results: Using both an in vivo and an isolated heart model of ischemia and reperfusion (I/R), we...

RATIONALE Although premenopausal females have a lower risk for cardiovascular disease, the mechanism(s) are poorly understood. OBJECTIVE We tested the hypothesis that cardioprotection in females is mediated by altered mitochondrial protein levels and/or posttranslational modifications. METHODS AND RESULTS Using both an in vivo and an isolated heart model of ischemia and reperfusion (I/R), w...

Katakam PV, Gordon AO, Sure VN, Rutkai I, Busija DW. Diversity of mitochondria-dependent dilator mechanisms in vascular smooth muscle of cerebral arteries from normal and insulin-resistant rats. Am J Physiol Heart Circ Physiol 307: H493–H503, 2014. First published June 14, 2014; doi:10.1152/ajpheart.00091.2014.—Mitochondrial depolarization following ATP-sensitive potassium (mitoKATP) channel ac...

Reactive oxygen species are oxygen derivates and play an active role in vascular biology. These compounds are generated within the vascular wall, at the level of endothelial and vascular smooth muscle cells, as well as by adventitial fibroblasts. In healthy conditions, ROS are produced in a controlled manner at low concentrations and function as signaling molecules regulating vascular contracti...