Alloxan and streptozotocin are widely used to induce experimental diabetes in animals. The mechanism of their action in B cells of the pancreas has been intensively investigated and now is quite well understood. The cytotoxic action of both these diabetogenic agents is mediated by reactive oxygen species, however, the source of their generation is different in the case of alloxan and streptozot...

Liquid flow in microchannels is completely laminar and uniaxial, with a very low Reynolds number regime and long mixing lengths. To increase fluid mixing and solubility of reactants, as well as to reduce reaction time, complex three-dimensional networks inducing chaotic advection have to be designed. Alternatively, turbulence in the liquid can be generated by active mixing methods (magnetic, ac...

Using FeOOH/Mg(OH)₂ as precursor and FeCl₂ as the treating solution, we prepared γ-Fe₂O₃ based nanoparticles. The FeCl₂ treating solution catalyzes the chemical reactions, dismutation and oxygenation, leading to the formation of products FeCl₃ and Fe₂O₃, respectively. The treating solution (FeCl₂) accelerates dehydration of the FeOOH compound in the precursor and transforms it into the initial ...

Superoxide dismutase (SOD, EC 1.15.1.1) is an important metal-containing antioxidant enzyme that provides the first line of defense against toxic superoxide radicals by catalyzing their dismutation to oxygen and hydrogen peroxide. SOD is classified into four metalloprotein isoforms, namely, Cu/Zn SOD, Mn SOD, Ni SOD and Fe SOD. The structural models of soybean SOD isoforms have not yet been sol...

Polbax, a water-soluble extract of fresh pollen grains and pistils, was tested for its ability to influence the accumulation of lipofuscin (age pigment) in cultured neonatal rat cardiac myocytes. Exposure for 3 weeks to Polbax at concentrations of 0.1, 1.0 or 10 mg/L decreased lipofuscin accumulation morphometrically assayed using laser scanning microscopy images (green excitation light) of for...

ions from deoxyribose produces thiobarbituric-reactive material. In addition, the quantitation of OH• radical by rhodamine must be considered a lower limit on the amount actually formed, since other OH• reaction pathways (e.g., reaction with buffer, self-quenching) have not been quantitated. Because active oxidants other than hydroxy radical (such as metal-oxo species) can lead to ribose degrad...

In contrast to the NADPH oxidases Nox1 and Nox2, which generate superoxide (O(2)(·-)), Nox4 produces hydrogen peroxide (H(2)O(2)). We constructed chimeric proteins and mutants to address the protein region that specifies which reactive oxygen species is produced. Reactive oxygen species were measured with luminol/horseradish peroxidase and Amplex Red for H(2)O(2) versus L-012 and cytochrome c f...

Copper-zinc superoxide dismutase (SOD) is of fundamental importance to our understanding of oxidative damage. Its primary function is catalysing the dismutation of superoxide to O(2) and H(2)O(2). SOD also reacts with H(2)O(2), leading to the formation of a strong copper-bound oxidant species that can either inactivate the enzyme or oxidise other substrates. In the presence of bicarbonate (or C...