For a better understanding of the mechanism of action of the nitrofurans in the mammalian organism, studies of their metabolism have been initiated. Excretion studies (1) have revealed that only a small part of most ingested nitrofurans appears unchanged in the urine. Bender and Paul (2) in preliminary studies have shown that 5-nitro-2-furaldehyde semicarbazone (Furacin’) undergoes degradation ...

At the 661st Meeting of the Biochemical Society, held at Bath, the Host Colloquium, a joint meeting with the Society for Free Radical Research, took place on 10th and 11th April 1997. Its title was ‘Xanthine oxidase: enzymology and pathophysiology’. The two aspects of xanthine oxidase research specified in the Colloquium title have developed remarkably separately, and, for a number of reasons, ...

In this issue of Circulation,' Hori and colleagues report the results of using three antioxidant agents in an attempt to reduce ischemic injury in a coronary microembolization model. Repeated injections of 15-,um microspheres resulted in progressive microvascular obstruction, decreased function , and edema until the extent of embolization decreased flow to nearly zero (less than 0.08 ml/min/ g)...

Interactions between rat pulmonary artery endothelial cells and hydrogen peroxide or toxic oxygen products from phorbol ester-activated human neutrophils result in endothelial cell killing defined by 51Cr release. It has been shown that this cytotoxic reaction can be blocked by the presence of catalase, iron chelators, or scavengers of the hydroxyl radical. Evidence shows that products from xan...

BACKGROUND The effect of reactive oxygen species (ROS) on platelet function in coronary heart disease (CHD) is complex and poorly defined. Platelet aggregation studies in healthy volunteers have demonstrated contrasting results when platelets are exposed to ROS. We investigated the effect of ROS on whole blood aggregation (WBA) and the endothelial cell-platelet interaction in patients with CHD....

In vitro assembly or complementation of a hybrid assimilatory nitrate reductase was attained by mixing a preparation of nitrate-induced N. crassa mutant nit-1 specifically with acid-treated (pH 2.5) bovine milk or intestinal xanthine oxidase, rabbit liver aldehyde oxidase, or chicken liver xanthine dehydrogenase. The complementation reaction specifically required induced nit-1, the only nitrate...

Oxygen free radicals generated by xanthine oxidase have been implicated in cardiac damage. The activity of xanthine oxidase/reductase in adult rat heart is considerable. Its assay gives controversial results for other species, for example, rabbits and humans. Therefore, we perfused isolated hearts of various species, including explanted human hearts, to measure the conversion of exogenous hypox...