Ultrafast Spectroscopic Study of Pheomelanin:  Implications on the Mechanism of Superoxide Anion Formation

2002 ◽  
Vol 106 (24) ◽  
pp. 6133-6135 ◽  
Author(s):  
Tong Ye ◽  
John D. Simon
Keyword(s):  
Spectroscopic Study ◽  
Superoxide Anion ◽  
Anion Formation

scholarly journals Constituents of the Fruits of Citrus medica L. var. sarcodactylis and the Effect of 6,7-Dimethoxy-coumarin on Superoxide Anion Formation and Elastase Release

Molecules ◽  
2017 ◽  
Vol 22 (9) ◽  
pp. 1454
Author(s):  
Yu-Yi Chan ◽  
Tsong-Long Hwang ◽  
Ping-Chung Kuo ◽  
Hsin-Yi Hung ◽  
Tian-Shung Wu
Keyword(s):  
Superoxide Anion ◽  
Anion Formation ◽  
Citrus Medica

Increased superoxide anion generation and altered vasoreactivity in rabbits on low-potassium diet

1998 ◽  
Vol 274 (6) ◽  
pp. H1955-H1961 ◽  
Author(s):  
B. C. Yang ◽  
D. Y. Li ◽  
Y. F. Weng ◽  
J. Lynch ◽  
C. S. Wingo ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carotid Artery ◽  
Superoxide Anion ◽  
Control Diet ◽  
Calcium Ionophore ◽  
Potassium Depletion ◽  
Anion Formation ◽  
Urinary Potassium ◽  
Low Potassium

Potassium reduces blood pressure in populations at high risk of developing hypertension, which suggests that potassium depletion may increase vascular resistance. This study was designed to examine the effect of potassium depletion on thel-arginine-nitric oxide pathway in arterial tissues. New Zealand White rabbits were fed either a control diet, containing a normal amount of potassium, or a low-potassium diet for 1–3 wk. As expected, the low-potassium diet resulted in reduced serum and urinary potassium levels. Carotid arteries were excised, and their contractile and relaxant responses were determined in vitro. Carotid arterial ring contractile response to norepinephrine was enhanced, and relaxation in response to the endothelium-dependent vasodilators acetylcholine and calcium ionophore A-23187 was attenuated, in rabbits fed low-potassium diet (all P < 0.01 compared with responses in rabbits fed control diet). The vasomotor responses were similarly altered in rabbits fed low-potassium diet for 1 or 3 wk. Both the enhanced contraction and attenuated relaxation were abolished by treatment of arterial rings with superoxide dismutase but not by treatment with l-arginine or indomethacin. Carotid artery rings from rabbits fed the low-potassium diet showed ∼100% greater superoxide anion formation than those from rabbits fed control diet ( P < 0.01), whereas plasma and urinary nitrite levels were similar in both groups of rabbits. These observations indicate that low-potassium diet enhances the sensitivity of the carotid artery to vasoconstrictor stimuli and reduces the sensitivity to endothelium-dependent stimuli. Attenuation of endothelium-dependent relaxation appears to be secondary to increased free radical generation, which may degrade nitric oxide. Altered vasoreactivity may underlie the genesis of hypertension in populations consuming diets low in potassium.

Methyl Mercury, Mercuric Chloride, and Silver Lactate Decrease Superoxide Anion Formation and Chemotaxis in Human Polymorphonuclear Leucocytes

1993 ◽  
Vol 12 (5) ◽  
pp. 361-364 ◽  
Author(s):  
Niels Obel ◽  
Birte Hansen ◽  
Margot M. Christensen ◽  
Søren Lyhne Nielsen ◽  
Jørgen Rungby
Keyword(s):  
Mercuric Chloride ◽  
Superoxide Anion ◽  
Methyl Mercury ◽  
Polymorphonuclear Leucocytes ◽  
Response Curves ◽  
Metal Compounds ◽  
Anion Formation ◽  
Functional Deficits ◽  
Dose Dependent Fashion ◽  
Dose Dependent

Cytotoxic effects of mercuric chloride, methyl mercury, and silver lactate on polymorphonuclear leucocytes have been examined by assaying superoxide anion formation capability and chemotaxis of metal-exposed cells. Both superoxide anion formation and chemotaxis were negatively affected by all three metal compounds. Both bacteriotoxic functions were affected in a dose-dependent fashion, the functional deficits were seen at doses not affecting cell viability. Dose-response curves were remarkably similar for all three compounds. The bacteriotoxic capacity of polymorphonuclear leucocytes may be hampered by mercury and silver.

Increased superoxide anion formation in endothelial cells during hyperglycemia: an adaptive response or initial step of vascular dysfunction?

1999 ◽  
Vol 45 (2-3) ◽  
pp. 153-160 ◽  
Author(s):  
Wolfgang F. Graier ◽  
Karla Posch ◽  
Eleonore Fleischhacker ◽  
Thomas C. Wascher ◽  
Gert M. Kostner
Keyword(s):  
Endothelial Cells ◽  
Adaptive Response ◽  
Superoxide Anion ◽  
Vascular Dysfunction ◽  
Initial Step ◽  
Anion Formation

scholarly journals Superoxide anion formation from lucigenin: an electron spin resonance spin-trapping study

FEBS Letters ◽  
1997 ◽  
Vol 403 (2) ◽  
pp. 127-130 ◽  
Author(s):  
Jeannette Vásquez-Vivar ◽  
Neil Hogg ◽  
Kirkwood A. Pritchard ◽  
Pavel Martasek ◽  
B. Kalyanaraman
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Superoxide Anion ◽  
Spin Trapping ◽  
Anion Formation ◽  
Spin Resonance ◽  
Resonance Spin
Sign in / Sign up

Export Citation Format

Share Document