Oxygen therapy (OT) with hyperbaric oxygen (HBO) or normobaric hyperoxia (NBO) improves the oxygenation of penumbral tissue in experimental ischemic stroke. However, whether this results in the improvement of energy metabolism is unclear. We investigated the effect of both OTs on tissue acidosis and on ATP production. Beginning 25 min after filament middle cerebral artery occlusion (MCAO), mice...

PURPOSE To investigate whether nitric oxide (NO) regulates retinal circulation during and after induction of hyperoxia in cats. METHODS Hyperoxia was induced for 10 minutes with 100% oxygen. The vessel diameter and blood velocity were measured simultaneously in second-order retinal arterioles by laser Doppler velocimetry; the retinal blood flow (RBF) and wall shear rate (WSR) were calculated ...

Acute brain injury is associated with depressed aerobic metabolism. Below a critical mitochondrial pO2 cytochrome c oxidase, the terminal electron acceptor in the mitochondrial respiratory chain, fails to sustain oxidative phosphorylation. After acute brain injury, this ischaemic threshold might be shifted into apparently normal levels of tissue oxygenation. We investigated the oxygen dependenc...

TO THE EDITOR: The review by Matute-Bello et al. (15) has misleading and potentially dangerous statements concerning the role of hyperoxia in human acute lung injury (ALI). Table 4 states “in normal human lungs, 100% oxygen has not induced lung injury . . . ” The text states that most mammalian species develop respiratory distress and die with exposure to 100% oxygen, but the “same findings hav...

Recent studies suggest that normobaric hyperoxia (HO) protects the rat brain from ischemia reperfusion (IR) injury. Protein kinase C (PKC) is a key signaling molecule involved in protection against IR injury but its role in protective effect of HO in brain injury in unknown. In this study we attempted to see if PKC is involved in the effect of HO. Rats were divided into four main experimental g...

Hyperoxic ventilation induces detrimental effects on the respiratory system, and ambient oxygen may be harmful unless compensated by physiological anti-oxidants, such as vitamin C. Here we investigate the changes in electrolyte transport of airway epithelium in mice exposed to normobaric hyperoxia and in gulonolacton oxidase knock-out (gulo[-/-]) mice without vitamin C (Vit-C) supplementation. ...

Exposure of preterm infants to hyperoxia impairs vascular growth, contributing to the development of bronchopulmonary dysplasia and retinopathy of prematurity. Disruption of vascular endothelial growth factor (VEGF)-nitric oxide (NO) signaling impairs vascular growth. Endothelial progenitor cells (EPCs) may play an important role in vascular growth. Endothelial colony-forming cells (ECFCs), a t...

Hyperoxia prolongs the postantibiotic effect (PAE) of the aminoglycoside tobramycin in Pseudomonas aeruginosa. We tested the hypothesis that the PAE is prolonged because hyperoxia increases free radical flux while tobramycin inhibits the induction of antioxidant defenses. Exposure of P. aeruginosa to hyperoxia (100% O2) for 1 h increased superoxide dismutase, catalase, and glutathione levels. I...

BACKGROUND AND PURPOSE Normobaric hyperoxia (NBO) has been shown to exert neuroprotective effects against cerebral ischemia and to restore penumbral oxygenation. Inspired by recent reports on postconditioning with intermittent occlusions of cerebral artery, we tested the hypothesis that intermittent NBO (iNBO) may cause oscillation of cerebral oxygenation and thereby elicit repetitive interrupt...

Numerous clinical trials of thrombolytic and neuroprotective drugs for stroke have been conducted over the last 2 decades. The NINDS trial of intravenous tissue plasminogen activator remains the most notable success. Intra-arterial thrombolysis appears promising, but in the absence of phase III clinical trial data, this approach remains investigational. Numerous pharmaceutical drugs targeting 1...