Nonsteroidal anti-inflammatory drugs are used extensively in clinical medicine. In spite of their therapeutic utility, however, they are known to cause significant gastrointestinal and renal toxicities, circumstances that limit their use. The side effects produced in these organs have been attributed mainly to the inhibitory effect of these drugs on the activity of cyclooxygenase, a key enzyme ...

This study aimed to assess the role of oxygen free radicals in acute pancreatitis. Acute pancreatitis was induced in rats by infusion of the CCK-analogue cerulein (5 micrograms/kg per hour) for 30 minutes, 3.5 hours, and 12 hours. After the infusion, serum enzymes and conjugated tissue dienes and malondialdehyde were measured and tissue samples were subjected to electron and light microscopy. E...

High performance liquid chromatography with TSK 5000 PW or TSK 6000 PW size exclusion columns combined with a 125I labelled hyaluronic acid binding protein assay was used to study the effects of oxygen derived free radicals on synovial fluid hyaluronate. A continuous flux of free radicals was generated by the xanthine oxidase/hypoxanthine system. When the free radical flux was generated with xa...

reactions of free radicals and reactive oxygen species (ros) with biological molecules in vivo play an important physiological role in many diseases. 2,2-diphenyl-1-picrylhydrazyl (dpph) is a stable free radical and often used as a routine reagent to evaluate the antioxidant capacity of an antioxidant. this study was undertaken to investigate the free radical-scavenging and antioxidant activiti...

Oxygen toxicity was first described in laboratory animals in 1878 and was further established in 1899. The first experiment regarding a free radical reaction was reported in 1894. However, it was not until the late 1940s to early 1950s that retrolental fibroplasia in premature newborns was recognized as being due to oxygen toxicity and not until the late 1960s to early 1970s that newborn bronch...

Pyrogallol (a generator of superoxide anions) caused 50% increase in platelet aggregation induced by 400 microM of arachidonic acid. Dipyridamole did not produce a statistically significant inhibition of arachidonic-acid induced platelet aggregation, but it caused 100% inhibition of pyrogallol-stimulated platelet aggregation. Ferrous salts (Fe2+) induced 34% platelet aggregation which was inhib...

Hydrogen peroxide destroyed the Na+/Mg2+ antiport in Mg(2+)-loaded human and rat erythrocytes and increased the leakage of intracellular Mg2+ and K+. These effects are opposite to the increase of Na+/Mg2+ antiport and unchanged Na(+)-independent Mg2+ efflux from erythrocytes of patients with cystic fibrosis score 3. Thus, the increase of Na+/Mg2+ antiport in these patients is not caused by incr...

Autooxidation of Chlorophyll, Free Radicals, Carotenoids, Photosynthesis It is shown that the allomerization of chlorophylls a and b is effectively inhibited by carotenoid pigments. In the light of this finding, two possible mechanisms are considered for the allomerization. One assumes the addition of singlet oxygen to the 9,10-double bond of the chlorophyll (Chi) enolate anion to yield a C-10 ...

on the basis of experimental data a kinetic model for the heterogeneous interaction between alkylperoxyradicals and organic compounds in langmuir- hinshelwood approach at room temperature has been offered.the effect of oxygen on the kinetics of process in the presence, [o2]o = 1 x 1011 – 1.6 x 1012 molecules.cm-2, and absence of oxygen has been analyzed. over time the chain degenerate branching...