scholarly journals Copper-phenanthroline-induced site-specific oxygen-radical damage to DNA. Detection of loosely bound trace copper in biological fluids

1984 ◽  
Vol 218 (3) ◽  
pp. 983-985 ◽  
Author(s):  
J M C Gutteridge
Keyword(s):  
Oxygen Radicals ◽  
Biological Fluids ◽  
Thiobarbituric Acid ◽  
Oxygen Radical ◽  
Body Fluids ◽  
Reducing Agent ◽  
Reactive Material ◽  
Site Specific ◽  
Radical Damage ◽  
Micromolar Range

Copper(II) ions, in the presence of 1,10-phenanthroline, O2 and a reducing agent, degrade DNA with the release of thiobarbituric-acid-reactive material. This reaction, dependent on the formation of oxygen radicals, was made the basis of a sensitive and specific assay for loosely bound copper in body fluids. When applied to certain extracellular fluids, trace amounts of copper could be detected in the lower micromolar range.

scholarly journals Antioxidant protection by haemopexin of haem-stimulated lipid peroxidation

1988 ◽  
Vol 256 (3) ◽  
pp. 861-865 ◽  
Author(s):  
J M Gutteridge ◽  
A Smith
Keyword(s):  
Lipid Peroxidation ◽  
Protoporphyrin Ix ◽  
Thiobarbituric Acid ◽  
Iron Chelator ◽  
Oxygen Radical ◽  
Butylated Hydroxytoluene ◽  
Radical Reactions ◽  
Antioxidant Protection ◽  
Reactive Material ◽  
Chain Breaking

Haem (ferrous protoporphyrin IX) is a reactive low-molecular-mass form of iron able to participate in oxygen-radical reactions that can lead to the degradation of proteins, lipids, carbohydrates and DNA. Oxygen-radical reactions are likely to occur upon tissue damage. Extracellular fluids rely on antioxidant mechanisms different from those found inside the cell, and circulating proteins limit radical reactions by converting pro-oxidant forms of iron into less-reactive forms. Of the compounds tested, only apohaemopexin and the chain-breaking antioxidant butylated hydroxytoluene inhibited (by more than 90%) haemin-stimulated peroxidation as measured by formation of conjugated dienes, thiobarbituric acid-reactive material from linolenic acid or peroxidation-induced phospholipid fluorescence. Haptoglobin, the haemoglobin-binding serum protein, was ineffective. Conversely, only haptoglobin significantly inhibited haemoglobin-stimulated lipid peroxidation. Iron-salt-induced lipid peroxidation was inhibited only by apotransferrin and the iron-chelator desferrioxamine. All lipid peroxidations were inhibited by the radical scavengers butylated hydroxytoluene and propyl gallate. These findings support the concept that transport and conservation of body iron stores are closely linked to antioxidant protection.

scholarly journals Lens Lipid Peroxides and Glutathione Concentrations in Diabetic Cataract

1997 ◽  
Vol 34 (2) ◽  
pp. 190-192 ◽  
Author(s):  
D Özmen ◽  
I Mutaf ◽  
B Özmen ◽  
J Mentes ◽  
O Bayindir
Keyword(s):  
G Protein ◽  
Lipid Peroxide ◽  
Lipid Peroxides ◽  
Thiobarbituric Acid ◽  
Thiobarbituric Acid Reactive Substances ◽  
Diabetic Cataract ◽  
Free Radical Damage ◽  
Significant Difference ◽  
Radical Damage

This study aims to explore the role of reactive oxygen radicals in the genesis of diabetic cataract. Lipid peroxide (LPO) concentrations in senile ( n = 30) and diabetic ( n = 14) cataractous lenses, were determined as thiobarbituric acid-reactive substances (TBARS) by a method modified from Satoh and Yagi, and reduced glutathione (GSH) concentrations were measured according to Beutler. Lens LPO levels (mean, SD; nmol TBARS/g protein) were significantly higher in diabetics (107·54, 18·12) than senile cataractous subjects (53·54, 15·48) ( P < 0·0001). Lens GSH levels (mean, SD; nmol/g protein) showed no significant difference between diabetics (4·29, 2·05) and senile cataractous subjects (4·68, 3·12). These results suggest that free radical damage is more effective in the genesis of diabetic cataract than in senile cataract.

Conversion of xanthine dehydrogenase to oxidase in ischemic rat intestine: a reevaluation

1988 ◽  
Vol 254 (5) ◽  
pp. G768-G774 ◽  
Author(s):  
D. A. Parks ◽  
T. K. Williams ◽  
J. S. Beckman
Keyword(s):  
Small Intestine ◽  
Oxygen Radicals ◽  
Total Activity ◽  
Xanthine Dehydrogenase ◽  
Oxygen Radical ◽  
Morphological Evidence ◽  
Cellular Injury ◽  
Rat Intestine ◽  
Entire Small Intestine ◽  
Ischemic Intestine

Oxygen radicals derived from xanthine oxidase (XO) are important mediators of the cellular injury associated with reperfusion of ischemic intestine, stomach, liver, kidney, and pancreas. XO exists in nonischemic tissue predominantly as xanthine dehydrogenase (XDH) and converts to oxygen radical-producing XO with ischemia. Grinding intestine under liquid nitrogen and placing the powder in phosphate buffer (pH 7.0) containing thiol reductants and protease inhibitors adequately preserved total XDH + XO activity and the percentage in the oxidase form (%XO) for 24 h. Total activity in nonischemic intestine ranged from 374 nmol.min-1.g-1 in duodenum to 138 nmol.min-1.g-1 in ileum, while XO activity was approximately 19% of total activity throughout the entire small intestine. The rate of XDH conversion to XO during normothermic ischemia varied only slightly throughout the intestine, increasing 13% per hour to 34, 46, and 61% XO after 1, 2, and 3 h of ischemia, respectively. Our results contrast with previous reports where XDH conversion to XO occurred within 60 s ischemia but are consistent with physiological and morphological evidence of ischemic injury and provide further support for involvement of XO in intestinal injury associated with ischemia.

Reactivity of Oxygen Radicals [HO•, RO•, HOO•, ROO-, and RC(O)O•]

1992 ◽  
Author(s):  
Donald T. Sawyer ◽  
R. J. P. Williams
Keyword(s):  
Oxygen Atom ◽  
Hydroxyl Radical ◽  
Gas Phase ◽  
Oxygen Radicals ◽  
Oxygen Radical ◽  
Superoxide Ion ◽  
Radical Reactivity ◽  
The Family ◽  
Hydrocarbon Substrates

Oxygen radicals are defined as those molecules that contain an oxygen atom with an unpaired, nonbonding electron (e.g., HO·). Although triplet dioxygen (·O2·) and superoxide ion (O2 - ·) come under this definition, their nonradical chemistry dominates their reactivity, which is discussed in Chapters 6 (·O2·) and 7 (O2-·). The hydroxyl radical (HO·) is the most reactive member of the family of oxygen radicals [HO·, RO·, ·O·, HOO·, ROO·, and RC(O)O·], and is the focus of most oxygen radical research. In the gas phase the dramatic example of oxygen radical reactivity with hydrocarbon substrates is combustion, which is initiated by HO· (or RO· or MO·) and propagated by ·O2· and ·O·.

293 EFFECT OF GUAIAZULENE ON IN VITRO BOVINE EMBRYO PRODUCTION

2007 ◽  
Vol 19 (1) ◽  
pp. 262 ◽  
Author(s):  
I. Dimitriadis ◽  
E. A. Rekka ◽  
E. Vainas ◽  
G. S. Amiridis ◽  
C. A. Rekkas
Keyword(s):  
Lipid Peroxidation ◽  
Embryo Development ◽  
Antioxidant Properties ◽  
Thiobarbituric Acid ◽  
Early Embryo ◽  
Bovine Embryo ◽  
Embryo Production ◽  
Reactive Material

The substrates used in in vitro embryo production (IVP) mimic the in vivo fluids in which oocytes mature, oocytes are fertilized, and the early embryos develop (follicular and oviductal fluid). It is well established that oxidative stress negatively affects in vitro culture (IVC) outcomes. Guaiazulene (G) is a component of chamomile species oil with known antioxidant properties. In the present study, all IVP media were modified by the addition of G solutions so that the former exhibited a total protection against induced lipid peroxidation (TPaLP) similar to that of the respective in vivo environment. The IVP outcomes were then compared between G-processed and control oocytes. Bovine preovulatory follicular (BF) and oviductal (BO) fluid samples were collected from 10 Holstein 4- to 5-year-old cows in estrus. TPaLP was assessed according to the samples&apos; ability to inhibit rat hepatic microsomal lipid peroxidation, by determination of the 2-thiobarbituric acid reactive material. TPaLP (mean % � SEM) of the BF and BO were 70.63 � 10.03 and 16.33 � 4.33, respectively, whereas those of the IVP [in vitro-matured (IVM), in vitro-fertilized (IVF), and IVC] media were lower (17.94 � 1.66, -1.82 � 0.78, and 14.57 � 1.26, respectively). TPaLP of the 0.1 mM G-modified IVP medium increased to 67.2 � 5.85, 19.98 � 2.49, and 69.19 � 6.22, respectively. A total of 2041 class A oocytes were used. The proportion of cleavage, early embryo development (embryos with more than 4 cells), or both after IVP (18 h IVM–5% CO2 in air, and 18 h IVF, 48 h IVC–5% CO2, 10% O2, 85% N) in the presence of G (n = 1237) during each of the IVP phases or any possible combination of IVP phases was compared with the respective control (C, n = 804). Statistical analysis was performed by a chi-squared test; P &lt; 0.05 was considered significant. G improved cleavage and embryo development rates when present during IVM (79.4 and 57.8% vs. 64.5 and 38.2% for C) or both IVM and IVC (78.0 and 60.7% vs. 57.8 and 36.5%, respectively). When present only during 18 h of IVF, G had no effect on embryo production. However, an increased embryo development rate resulted from the combined exposure to G during IVF and IVM (56.4 vs. 29.6%), during IVF and IVC (55.3 vs. 35.5%), or at all IVP phases (56.6 vs. 34.9%). The latter effect resembled the one obtained after G addition only to the IVC medium (62.5 vs. 39.7%, respectively). We concluded that the addition of G to IVP substrates, at concentrations that mimic the in vivo TPaLP conditions, could promote bovine IVP efficiency.

Postischemic oxygen radical production varies with duration of ischemia

1993 ◽  
Vol 264 (5) ◽  
pp. H1478-H1484 ◽  
Author(s):  
T. D. Henry ◽  
S. L. Archer ◽  
D. Nelson ◽  
E. K. Weir ◽  
A. H. From
Keyword(s):  
Oxygen Radicals ◽  
Myocardial Injury ◽  
Mechanical Damage ◽  
Oxygen Radical ◽  
Nondestructive Measurement ◽  
Intermediate Period ◽  
Enhanced Chemiluminescence ◽  
Oxygen Radical Production ◽  
Radical Generation ◽  
Function Peak

Oxygen radicals have been implicated in the pathogenesis of myocardial injury. Enhanced chemiluminescence is a sensitive technique for continuous nondestructive measurement of oxygen radical generation. Using an isolated perfused rat heart model, we studied the effect of variable durations of ischemia on oxygen radical generation and postischemic myocardial function. Peak postischemic oxygen radical generation was higher with an intermediate period of ischemia (11.5 min; 528 +/- 53 counts/s) than with either a shorter period (5 min; 328 +/- 21 counts/s) or a prolonged period (40.8 min; 286 +/- 53 counts/s). The magnitude of oxygen radical generation did not correlate with postischemic mechanical function, although it was related to the duration of ischemia with regard to brief and intermediate periods of ischemia (both associated with limited mechanical damage). The increased reperfusion chemiluminescence seen with the intermediate versus the brief ischemic insults can be explained by time-dependent enhancement of the mechanisms present during ischemia that serve to increase oxygen radical generation during reperfusion. In contrast, the longer period of ischemia, resulting in severe mechanical dysfunction, was associated with lower levels of chemiluminescence than observed with an intermediate ischemic duration. This most likely results from the irreversible myocardial injury associated with prolonged ischemia and the consequent inability to generate oxygen radicals. We conclude that, although reperfusion-associated enhancement of myocardial free radical generation may be related to mild to moderate postischemic mechanical dysfunction (stunning), this mechanism may not be of importance in the generation of irreversible reperfusion myocardial injury.

Influence of hypothyroidism on lipid peroxidation, erythrocyte resistance and antioxidant plasma properties in rabbits

2003 ◽  
Vol 51 (3) ◽  
pp. 343-351 ◽  
Author(s):  
Ewa Brzezińska-Ślebodzińska
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Thiobarbituric Acid ◽  
Organic Radicals ◽  
Plasma Properties ◽  
Phospholipid Liposomes ◽  
Chain Breaking ◽  
Erythrocyte Resistance ◽  
Radical Damage

The effect of hypothyroidism on some oxidative stress parameters is reported. Moderate hypothyroid state was induced in two groups of female rabbits (3 and 12 months old) by giving 50 mg/kg body weight (BW) of propylthiouracil (PTU) per os for 6 days and 20 mg/kg BW of methimazole (MMI) for further 14 days. Serum T4 and T3 concentrations decreased by about 38-40 and 32-36%, respectively. The induced hypothyroidism resulted in a significant decrease in the serum concentration of the lipid peroxidation end-product malondialdehyde, as measured by the thiobarbituric-acid assay. Erythrocytes of hypothyroid animals exhibited higher resistance to oxidative stress, while submitted to free radicals generator 2,2'-azo-bis(2-amidinopropane) hydrochloride (AAPH) in vitro. Using two detector systems (phospholipid liposomes and deoxyribose), sensitive to either organic or inorganic oxygen radical damage, the ability of euthyroid and hypothyroid rabbit plasma to protect against oxygen radicals was evaluated. The plasma of hypothyroid animals showed about 20% higher ability to protect against iron-binding organic radicals, but about 50% lower chain-breaking antioxidant activity. The antioxidant capacity of plasma against inorganic radicals was not affected by hypothyroidism. In conclusion, the results show that thyroid hormones modulate the free-radical-induced oxidative damage of lipids and that hypothyroidism offers some protection against lipid peroxidation.

HPLC Analysis of Tissue Thiobarbituric Acid-Reactive Material during Endotoxic Shock in Rats

2015 ◽  
pp. 42-45 ◽  
Author(s):  
M. Maiorino ◽  
L. Bordi ◽  
G. Consales ◽  
F. Ursini ◽  
G. P. Novelli
Keyword(s):  
Hplc Analysis ◽  
Endotoxic Shock ◽  
Thiobarbituric Acid ◽  
Reactive Material
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