Polymorphonuclear Oxygen Free Radical Production and Complement Activation Induced by Dialysis Membranes as Assayed in an Experimental Model

1989 ◽  
Vol 7 (6) ◽  
pp. 293-300 ◽  
Author(s):  
Gianni Cappelli ◽  
Leonardo Lucchi ◽  
Decenzio Bonucchi ◽  
Anna Maria Cenci ◽  
Giuliano Montagnani ◽  
...  
Keyword(s):  
Free Radical ◽  
Experimental Model ◽  
Complement Activation ◽  
Oxygen Free Radical ◽  
Free Radical Production ◽  
Radical Production ◽  
Dialysis Membranes

Control of oxidative stress in microcirculation of spontaneously hypertensive rats

2005 ◽  
Vol 288 (2) ◽  
pp. H805-H812 ◽  
Author(s):  
F. A. DeLano ◽  
R. Balete ◽  
G. W. Schmid-Schönbein
Keyword(s):  
Free Radical ◽  
Spontaneously Hypertensive Rats ◽  
Oxygen Free Radical ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Free Radical Production ◽  
Wky Rats ◽  
Arterial Blood ◽  
Radical Production ◽  
Tetrazolium Reduction

One mechanism for organ damage in individuals with arterial hypertension may be due to oxygen free radical production. This study was designed to localize free radicals in a microvascular network of mature spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats. Because glucocorticoids play a role in pressure elevation of SHRs, we investigated their role in microvascular free radical formation. Oxygen radical production in mesentery was detected by tetranitroblue tetrazolium reduction to formazan aided by digital light-absorption measurements. Formazan deposits were observed in the endothelial cells and lumens of all microvessels and in lymphatic endothelia but were fewer in tissue parenchyma. The formazan distribution in younger (14–16 wk old) WKY rats and SHRs was heterogeneous with low values in capillaries and small arterioles/venules (<30 μm) but enhanced deposits in larger venules. Adrenalectomy served to reduce the formazan density in SHRs to the level of WKY rats, whereas dexamethasone supplementation of the adrenalectomized rats caused elevation in the larger venules of SHRs. In older (40 wk old) SHRs, formazan levels were elevated in all hierarchies of microvessels. After pressure reduction was employed with chronic hydralazine treatment, the formazan deposits were reduced in all locations of the microcirculation in both WKY rats and SHRs. Elevated formazan deposits were also found in lymphatic endothelium. These results suggest that oxygen free radical production is elevated in both high- and low-pressure regions of SHR microcirculation via a process that is controlled by glucocorticoids. Older SHRs have higher formazan levels than younger SHRs in all microvessels. Chronic hydralazine treatment, which serves to reduce arterial blood pressure, attenuates tetranitroblue tetrazolium reduction in WKY rats and SHRs even in venules of the microcirculation, which has no micropressure elevation. Free radical production may be a more global condition in SHRs and may not be limited to arteries and arterioles.

Amlodipine Decreases Iron Uptake and Oxygen Free Radical Production in the Heart of Chronically Iron Overloaded Mice

2002 ◽  
Vol 3 (4) ◽  
pp. 189-197 ◽  
Author(s):  
Sarah Crowe ◽  
Wally J. Bartfay
Keyword(s):  
Free Radical ◽  
Iron Metabolism ◽  
Iron Uptake ◽  
Hereditary Hemochromatosis ◽  
Antioxidant Properties ◽  
Oxygen Free Radical ◽  
Cardiac Complications ◽  
Channel Blockers ◽  
Free Radical Production ◽  
Radical Production

Hereditary hemochromatosis is a disorder of iron metabolism, which is currently the most prevalent autosomal recessive disorder in the world, with an expression of the homozygous form occurring in approximately 1 in 200 individuals of European descent. Approximately one third of patients with hemochromatosis die of iron-induced cardiac complications. Although the exact mechanism is not known, it is believed that the toxicity of excess iron in biological systems is due to its ability to catalyze the generation of harmful reactive oxygen free radical species (ROS), which can damage proteins, lipids, and DNA. There is preliminary evidence to suggest that nontransferrinbound iron uptake in the myocardium may occur through voltage-dependent L-type calcium channels, and that calcium channel blockers (CCBs) may possess antioxidant properties. Accordingly, the authors hypothesized that the administration of amlodipine besylate would (1) decrease iron uptake in the myocardium and (2) decrease oxygen free radical production as measured by cytotoxic aldehyde–derived peroxidation products in a murine model of iron overload cardiomyopathy. The findings show that the CCB amlodipine is partially effective in limiting iron uptake in the heart and significantly inhibits the production of ROS in chronically iron-loaded mice. These are important preliminary findings because they suggest that CCBs may have significance in the clinical management of genetic disorders of iron metabolism.

Heterogeneity in the Effect of Albumin and Other Resuscitation Fluids on Intracellular Oxygen Free Radical Production

2004 ◽  
Vol 56 (3) ◽  
pp. 548-559 ◽  
Author(s):  
Cuthbert O. Simpkins ◽  
Donnie Little ◽  
Andrew Brenner ◽  
January A. Hill ◽  
John A. Griswold
Keyword(s):  
Free Radical ◽  
Oxygen Free Radical ◽  
Free Radical Production ◽  
Radical Production

CARDIAC SURGICAL PATIENTS PLASMA ENHANCES OXYGEN FREE RADICAL PRODUCTION IN NEUTROPHILS

1991 ◽  
Vol 75 (3) ◽  
pp. A95-A95
Author(s):  
H. Nakamura ◽  
J. V. Bonventre ◽  
E. Inada ◽  
F. deBros ◽  
O. Shibata ◽  
...  
Keyword(s):  
Free Radical ◽  
Oxygen Free Radical ◽  
Surgical Patients ◽  
Free Radical Production ◽  
Radical Production
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