The activity of the hepatic microsomal ethanol-oxidizing system (MEOS) was compared with the content of three forms of cytochrome P-450. Measurements were also made of the activity of microsomal reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the enzyme which generates H2O2 in microsomes and which has been considered by some to be the rate-limiting step of MEOS activity. Et...

Apocynin (4-hydroxy-3-methoxyacetophenone), isolated from the traditional medicinal plant Picrorhiza kurroa, is a naturally occurring methoxy-substituted catechol, experimentally used as an inhibitor of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase.1 Activated neutrophil NADPH oxidase, a multisubunit complex composed of membrane-associated gp91phox (Nox2) and p22phox and c...

Apocynin (4-hydroxy-3-methoxyacetophenone), isolated from the traditional medicinal plant Picrorhiza kurroa, is a naturally occurring methoxy-substituted catechol, experimentally used as an inhibitor of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase.1 Activated neutrophil NADPH oxidase, a multisubunit complex composed of membrane-associated gp91phox (Nox2) and p22phox and c...

The phagocyte NADPH oxidase system, as previously defined by cell-free reconstitution, is comprised of five essential components, three of which are produced during late phagocytic differentiation-namely, two cytosolic proteins, p47and p67-phox-and the large subunit of cytochrome bSs8, gp91-phox. To confirm that these are the only phagocyte-specific components necessary for oxidase activity in ...

The O2 generated by this enzyme serves as the starting material for the production of a vast assortment of reactive oxidants, including oxidized halogens, free radicals, and singlet oxygen. These oxidants are used by phagocytes to kill invading microorganisms, but they also cause a lot of what the military would call ‘‘collateral damage’’ to nearby tissues, so their production has to be tightly...

The contributing role of environmental factors to the development of Parkinson’s disease has become increasingly evident. We report that mesencephalic neuron-glia cultures treated with diesel exhaust particles (DEP; 0.22 μM) (5–50 μg/ml) resulted in a dose-dependent decrease in dopaminergic (DA) neurons, as determined by DA-uptake assay and tyrosine-hydroxylase immunocytochemistry (ICC). The se...

The leukocyte NADPH oxidase catalyzes the reduction of oxygen to O(2)(-) at the expense of NADPH. Extensive phosphorylation of the oxidase subunit p47(PHOX) occurs during the activation of the enzyme in intact cells. p47(PHOX) carrying certain serine-to-alanine mutations fails to support NADPH oxidase activity in intact cells, suggesting that the phosphorylation of specific serines on p47(PHOX)...

NADPH oxidase (Nox) is a unique, multi-protein, electron transport system that produces large amounts of superoxide via the reduction of molecular oxygen. Nox-derived reactive oxygen species (ROS) are known to be involved in a variety of physiological processes, including host defense and signal transduction. However, over the past decade, the involvement of (Nox)-dependent oxidative stress in ...

Increased expression of cyclooxygenase (COX) 2 and the production of PGs appear to provide a survival advantage to transformed cells through the inhibition of apoptosis, increased attachment to extracellular matrix, increased invasiveness and the stimulation of angiogenesis. The purpose of this study was to determine whether an angiogenic antagonist, SU5416, could inhibit endogenous and phorbol...

We have shown that intracellular superoxide (O(2)(*-)) production in CNS neurons plays a key role in the pressor, bradycardic, and dipsogenic actions of Ang II in the brain. In this study, we tested the hypothesis that a Rac1-dependent NADPH oxidase is a key source of O(2)(*-) in Ang II-sensitive neurons and is involved in these central Ang II-dependent effects. We performed both in vitro and i...