ORIGINAL RESEARCH—BASIC SCIENCE: Superoxide Anion Production in the Rat Penis Impairs Erectile Function in Diabetes: Influence of In Vivo Extracellular Superoxide Dismutase Gene Therapy

2005 ◽  
Vol 2 (2) ◽  
pp. 187-198 ◽  
Author(s):  
Trinity J. Bivalacqua ◽  
Mustafa F. Usta ◽  
Muammer Kendirci ◽  
Leena Pradhan ◽  
Xavier Alvarez ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Superoxide Dismutase ◽  
Basic Science ◽  
Superoxide Anion ◽  
Original Research ◽  
Extracellular Superoxide Dismutase ◽  
Superoxide Anion Production ◽  
Anion Production ◽  
Superoxide Dismutase Gene

Mitochondrial Adenosine Triphosphate–regulated Potassium Channel Opening Acts as a Trigger for Isoflurane-induced Preconditioning by Generating Reactive Oxygen Species

2003 ◽  
Vol 98 (4) ◽  
pp. 935-943 ◽  
Author(s):  
Katsuya Tanaka ◽  
Dorothee Weihrauch ◽  
Lynda M. Ludwig ◽  
Judy R. Kersten ◽  
Paul S. Pagel ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Infarct Size ◽  
Adenosine Triphosphate ◽  
Superoxide Anion ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Superoxide Anion Production ◽  
Channel Opening ◽  
Anion Production

Background Whether the opening of mitochondrial adenosine triphosphate-regulated potassium (K(ATP)) channels is a trigger or an end effector of anesthetic-induced preconditioning is unknown. We tested the hypothesis that the opening of mitochondrial K(ATP) channels triggers isoflurane-induced preconditioning by generating reactive oxygen species (ROS) in vivo. Methods Pentobarbital-anesthetized rabbits were subjected to a 30-min coronary artery occlusion followed by 3 h reperfusion. Rabbits were randomly assigned to receive a vehicle (0.9% saline) or the selective mitochondrial K(ATP) channel blocker 5-hydroxydecanoate (5-HD) alone 10 min before or immediately after a 30-min exposure to 1.0 minimum alveolar concentration (MAC) isoflurane. In another series of experiments, the fluorescent probe dihydroethidium was used to assess superoxide anion production during administration of 5-HD or the ROS scavengers N-acetylcysteine or N-2-mercaptopropionyl glycine (2-MPG) in the presence or absence of 1.0 MAC isoflurane. Myocardial infarct size and superoxide anion production were measured using triphenyltetrazolium staining and confocal fluorescence microscopy, respectively. Results Isoflurane (P < 0.05) decreased infarct size to 19 +/- 3% (mean +/- SEM) of the left ventricular area at risk as compared to the control (38 +/- 4%). 5-HD administered before but not after isoflurane abolished this beneficial effect (37 +/- 4% as compared to 24 +/- 3%). 5-HD alone had no effect on infarct size (42 +/- 3%). Isoflurane increased fluorescence intensity. Pretreatment with N-acetylcysteine, 2-MPG, or 5-HD before isoflurane abolished increases in fluorescence, but administration of 5-HD after isoflurane only partially attenuated increases in fluorescence produced by the volatile anesthetic agent. Conclusions The results indicate that mitochondrial K(ATP) channel opening acts as a trigger for isoflurane-induced preconditioning by generating ROS in vivo.

Exposure of surfactant protein A to ozone in vitro and in vivo impairs its interactions with alveolar cells

1992 ◽  
Vol 262 (1) ◽  
pp. L63-L68 ◽  
Author(s):  
R. S. Oosting ◽  
J. F. Van Iwaarden ◽  
L. Van Bree ◽  
J. Verhoef ◽  
L. M. Van Golde ◽  
...  
Keyword(s):  
Superoxide Anion ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Alveolar Type ◽  
Type Ii ◽  
Superoxide Anion Production ◽  
Anion Production

This study focused on the question of whether exposure of surfactant protein A (SP-A) to ozone affected properties of this protein that may be involved in regulating alveolar type II cell and alveolar macrophage functions. In vitro exposure of human or canine SP-A to ozone reduced the ability of this protein to inhibit phorbol-ester induced secretion of [3H]phosphatidylcholine by alveolar type II cells in culture. Ozone-exposed human SP-A showed a decreased ability to enhance phagocytosis of herpes simplex virus and to stimulate superoxide anion production by alveolar macrophages. Experiments with elastase showed that ozone-exposed canine SP-A was more susceptible to proteolysis. A conformational change of the protein could underlie this phenomenon. Surfactant isolated from ozone-exposed rats (0.4 ppm ozone for 12 h) was also less able to stimulate superoxide anion production by alveolar macrophages than surfactant from control rats, which suggested that SP-A in vivo was also susceptible to ozone. The results of this study suggest that SP-A-alveolar cell interactions can be inhibited by ozone exposure, which may contribute to the toxicity of ozone in the lungs.

Acute infusion of nicotine impairs nNOS-dependent reactivity of cerebral arterioles via an increase in oxidative stress

2007 ◽  
Vol 103 (6) ◽  
pp. 2062-2067 ◽  
Author(s):  
Denise M. Arrick ◽  
William G. Mayhan
Keyword(s):  
Oxidative Stress ◽  
Superoxide Anion ◽  
Potential Role ◽  
Acute Exposure ◽  
Cerebral Microcirculation ◽  
Superoxide Anion Production ◽  
Anion Production ◽  
Cerebral Arterioles ◽  
Oxide Synthase

Our goals were to determine whether acute exposure to nicotine alters neuronal nitric oxide synthase (nNOS)-dependent reactivity of cerebral arterioles and to identify a potential role for oxidative stress in nicotine-induced impairment in nNOS-dependent responses of cerebral arterioles. We measured in vivo diameter of cerebral arterioles to nNOS-dependent ( N-methyl-d-aspartate and kainate) and -independent (nitroglycerin) agonists before and during acute treatment with nicotine. We found that nNOS-dependent, but not -independent, vasodilatation was impaired during treatment with nicotine. In addition, treatment of the cerebral microcirculation with tempol (1 h before infusion of nicotine) prevented nicotine-induced impairment in nNOS-dependent vasodilatation. Furthermore, the production of superoxide anion (lucigenin chemiluminescence) was increased in parietal cortex tissue of rats by treatment with nicotine, and this increase in superoxide anion production could be inhibited by tempol. Our findings suggest that acute exposure to nicotine impairs nNOS-dependent dilatation of cerebral arterioles by a mechanism that appears to be related to the formation of superoxide anion.

scholarly journals Mechanism of Preconditioning by Isoflurane in Rabbits: A Direct Role for Reactive Oxygen Species

2002 ◽  
Vol 97 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Katsuya Tanaka ◽  
Dorothee Weihrauch ◽  
Franz Kehl ◽  
Lynda M. Ludwig ◽  
John F. LaDisa ◽  
...  
Keyword(s):  
Infarct Size ◽  
Superoxide Anion ◽  
Myocardial Infarct ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Myocardial Infarct Size ◽  
Oxygen Species ◽  
Superoxide Anion Production ◽  
Anion Production

Background Reactive oxygen species (ROS) contribute to myocardial protection during ischemic preconditioning, but the role of the ROS in protection against ischemic injury produced by volatile anesthetics has only recently been explored. We tested the hypothesis that ROS mediate isoflurane-induced preconditioning in vivo. Methods Pentobarbital-anesthetized rabbits were instrumented for measurement of hemodynamics and were subjected to a 30 min coronary artery occlusion followed by 3 h reperfusion. Rabbits were randomly assigned to receive vehicle (0.9% saline), or the ROS scavengers N-acetylcysteine (NAC; 150 mg/kg) or N-2-mercaptopropionyl glycine (2-MPG; 1 mg. kg(-1).min(-1)), in the presence or absence of 1.0 minimum alveolar concentration (MAC) isoflurane. Isoflurane was administered for 30 min and then discontinued 15 min before coronary artery occlusion. A fluorescent probe for superoxide anion production (dihydroethidium, 2 mg) was administered in the absence of the volatile anesthetic or 5 min before exposure to isoflurane in 2 additional groups (n = 8). Myocardial infarct size and superoxide anion production were assessed using triphenyltetrazolium staining and confocal fluorescence microscopy, respectively. Results Isoflurane (P < 0.05) decreased infarct size to 24 +/- 4% (mean +/- SEM; n = 10) of the left ventricular area at risk compared with control experiments (43 +/- 3%; n = 8). NAC (43 +/- 3%; n = 7) and 2-MPG (42 +/- 5%; n = 8) abolished this beneficial effect, but had no effect on myocardial infarct size (47 +/- 3%; n = 8 and 46 +/- 3; n = 7, respectively) when administered alone. Isoflurane increased superoxide anion production as compared with control experiments (28 +/- 12 -6 +/- 9 fluorescence units; P < 0.05). Conclusions The results indicate that ROS produced following administration of isoflurane contribute to protection against myocardial infarction in vivo.

Superoxide anion production by rabbit thoracic aorta: effect of endothelium-derived nitric oxide

1993 ◽  
Vol 265 (2) ◽  
pp. H707-H712 ◽  
Author(s):  
P. J. Pagano ◽  
K. Tornheim ◽  
R. A. Cohen
Keyword(s):  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Thoracic Aorta ◽  
Superoxide Anion ◽  
Rabbit Aorta ◽  
Superoxide Anion Production ◽  
Mechanical Removal ◽  
Anion Production ◽  
Cuzn Superoxide Dismutase ◽  
Synthase Inhibitor

Rabbit thoracic aorta was assessed for the influence of the endothelium and nitric oxide (NO) on superoxide anion (SO) levels in the presence and absence of an inhibitor of superoxide dismutase. Aortic rings (0.5 cm) were incubated for 30 min at 37 degrees C in the presence or absence of diethyldithiocarbamate (DDC, 10 mM), a CuZn superoxide dismutase inhibitor. Rings were then placed in a solution containing lucigenin (250 microM) at 37 degrees C, and changes in amounts of SO over 10 min were determined by measuring chemiluminescence under basal and acetylcholine-stimulated conditions. Treatment with DDC markedly enhanced basal levels of SO, and the DDC-evoked levels were significantly reduced by the SO scavenger, Tiron (10 mM). Addition of acetylcholine (10 microM) to the assay did not significantly affect the levels of SO in either control or DDC-treated rings. Also, mechanical removal of the endothelium or pretreatment of the rings with the NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) (300 microM), did not significantly affect the levels of SO in DDC-treated rings. In contrast, exogenous NO at 1 and 10 microM reduced the DDC-evoked SO levels by 54 and 77%, respectively. These data imply that the predominant sources of SO in the rabbit aorta are vascular components other than the endothelium and that endogenous superoxide dismutase modulates the level of SO. Although exogenous NO reduced aortic SO levels, neither basal nor acetylcholine-stimulated production of endogenous NO appears sufficient to reduce SO levels.

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