To test the hypothesis that 5'-nucleotidase activity during ischemia is attenuated by oxygen-derived free radicals, we measured ischemia-induced reactive hyperemic flow, adenosine release, and 5'-nucleotidase activity in dogs (n = 62). A 1-minute occlusion of the coronary artery caused reactive hyperemic flow (307 +/- 5 versus 92 +/- 1 ml.100 g-1.min-1 at baseline) with increased release of ade...

This study was carried out to assess the developmental pattern of copper- and zinc-containing superoxide dismutase (CuZnSOD), manganese-containing superoxide dismutase (MnSOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activity in rat brain. The enzymes studied were assayed in different brain regions (cerebral cortex, striatum, cerebellum and brainstem) and enzyme values were corrected...

Objective: Enzymes like oxalate oxidase (EC 1.2.3.4) and superoxide dismutase (EC 1.15.1.1) from germin family are known to generate active oxygen species. In the mammalian system, excess accumulations of oxalate causes kidney stones. Oxalate oxidase, an H2O2-generating enzyme, used for detection of oxalate. The aim of the present work is to screen out the activity of enzymes from all three sta...

Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from less than 10 min to 40 h, reduces immunogenicity, and decreases sensitivity to proteolysis. Because PEG has surface active properties and can induce cell fusion, we hypothesized that PEG conjugation could enhance cell binding and association of norm...

Superoxide dismutases might conceivably protect against both ionizing radiation and free radical-producing antibiotic antitumor drugs. Copper- and zinc-containing superoxide dismutase (CuZn superoxide dismutase) and manganese-containing superoxide dismutase (Mn superoxide dismutase) were specifically assayed in human malignant tumors and for comparison in human tissues. The tumors possessed les...

Superoxide dismutase, catalase, glutathione peroxidase and NAD(P)H cytochrome c reductase were quantitated in polymorphonuclear leukocytes (PMN) and alveolar macrophages (AM) obtained from guinea pigs exposed up to 90 h to 85% oxygen. PMN and AM were sonicated and separated into a 16,000-g pellet, a 100,000-g pellet, and a 100,00-g supernate. Superoxide dismutase activity increased in both cell...

An understanding of biochemical events of cold storage may lead to more effective methods of preventing apple fruits from ripening and keeping their quality. This study aimed at determining the level of reduced and oxidized forms of ascorbic acid, and the activity of ascorbate peroxidase, catalase, and superoxide dismutase enzymes changes in pulp of Golden delicious apple cultivar during cold s...

Pioglitazone (PG) is one of thiazolidinediones used for the treatment of type II diabetes mellitus. Some reports of its hepatotoxicity exist, but the mechanism of its hepatotoxicity is not well known. In the present study, the protective effect of some ATP suppliers are investigated against mitochondrial toxicity of PG in isolated rat mitochondria. Mitochondrial viability was investigated by MT...