We designed experiments to study the interaction of activated rat peritoneal neutrophils with aortas from spontaneously hypertensive rats (SHR) compared with those from normotensive rats. In aortic rings precontracted with phenylephrine, neutrophils obtained from normotensive rats caused a cell number-dependent relaxation of normotensive rat aorta with or without endothelium, whereas relaxation...

Our goal was to determine whether exercise training (ExT) alleviates impaired nitric oxide synthase (NOS)-dependent dilation of pial arterioles during chronic exposure to nicotine. We measured dilation of cerebral (pial) arterioles in sedentary and exercised control and nicotine-treated (2 mg·kg(-1)·day(-1) for 4 wk via an osmotic minipump) rats to an endothelial NOS (eNOS)-dependent (ADP), a n...

Eosinophils, which may be associated with allergic, parasitic, or neoplastic disease, have a potent oxidative burst that may be activated by particulate or soluble stimuli. Eosinophils from normal persons and patients with hypereosinophilia were compared with respect to their ability to produce the active oxygen product, superoxide anion. Normal eosinophils produced large amounts of superoxide ...

Increased production of superoxide anion may contribute to impaired bioactivity of endothelium-derived nitric oxide in hypertension. Ascorbic acid is capable of scavenging superoxide anion; however, experimental studies have shown that high physiological concentrations (.1 mmol/L) of ascorbic acid are required to prevent superoxide-mediated vascular dysfunction. To seek kinetic evidence that su...

Increase in intracellular superoxide anion level has been found to inhibit Fas-mediated apoptosis. However, not much has been studied on the relationship between intracellular superoxide and caspases. In response to incubation with TNF ligand over a period of time, caspases-2, -3, -8, and -9 activities of M14TF cells showed increasing caspase activity, meaning apoptosis was triggered. However, ...

Targeting of the antioxidant enzyme catalase to endothelial cells protects against vascular oxidative stress induced by hydrogen peroxide (H(2)O(2))(Am J Physiol 285:L283-L292, 2003; Nat Biotechnol 21:392-398, 2003; Am J Physiol 293:L162-L169, 2007). However, another reactive oxygen species, superoxide anion, is also involved in many forms of vascular oxidative stress, including ischemia/reperf...

Idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) are thought to involve lung injury induced by reactive oxygen species (ROS), in particular superoxide anion. The enzyme, superoxide dismutase (SOD) catalyses the dismutation of superoxide anion to hydrogen peroxide. Lecithinized SOD (PC-SOD) has overcome a number of previous clinical limitations of SOD, includi...