Hypertension caused by angiotensin II is characterized by an increase in tissue oxidant stress as evidenced by increased quantities of reactive oxygen and nitrogen species. Manganese superoxide dismutase (MnSOD) is a key mitochondrial antioxidant enzyme that is inactivated in conditions of oxidant stress by reacting with peroxynitrite to form 3-nitrotyrosine in its active site. The increase in ...

Peripheral chemoreflex sensitivity is enhanced in both clinical and experimental chronic heart failure (CHF). Here we investigated the role of manganese superoxide dismutase (MnSOD), the SOD isoform specially targeted to mitochondria, and mitochondrial superoxide levels in the enhanced chemoreceptor activity and function of the carotid body (CB) in CHF rabbits. CHF suppressed MnSOD protein expr...

INTRODUCTION One of the causes of impaired antioxidant response in patients with type 1 diabetes might be decreased expression of mitochondrial manganese superoxide dismutase (MnSOD). OBJECTIVES The aim of this study was to evaluate the expression of MnSOD on transcript and protein levels in polymorphonuclear leukocytes (PMNLs) from patients with type 1 diabetes and analyze its association wi...

Manganese superoxide dismutase (MnSOD) protects cells against oxidative stress by eliminating superoxides. Hypothetically, decreased MnSOD levels in cancer might lead to increased oxidative stress and, thus, to increased sensitivity of cells to chemotherapy agents. Eighty-nine patients with acute myeloid leukemia (AML) were analyzed for a functional C to T polymorphism of MnSOD, which could pot...

Manganese superoxide dismutase (MnSOD) converts the superoxide anion into H(2)O(2), which, unless it is detoxified by glutathione peroxidase 1 (GPx1), can increase hepatic iron and can react with iron to form genotoxic compounds. We investigated the role of Ala/Val-MnSOD and Pro/Leu-GPx1 polymorphisms on hepatic iron accumulation and hepatocellular carcinoma development in patients with alcohol...

It has become increasingly clear that RNA-binding proteins play an important role in the regulation of gene expression. The presence in rat lung of a specific, redox-sensitive catalase RNA-binding protein was recently reported (Clerch, L. B., and D. Massaro, 1992. J. Biol. Chem. 267:2853). In order to determine if specific manganese superoxide dismutase (MnSOD) RNA-binding proteins exist, we te...

Manganese superoxide dismutase (MnSOD) activity falls ∼50% in lung during 48 h of exposure of adult rats to >95% O2 (L. B. Clerch and D. Massaro. J. Clin. Invest. 91: 499-508, 1993). We now show that hyperoxia also decreased MnSOD activity in lungs of adult baboons, making the phenomenon potentially more important to humans. In rats, a decrease in lung MnSOD activity during an initial 48 h of e...

BACKGROUND We investigated the relationship of the immunohistochemical expression status of manganese superoxide dismutase (MnSOD), catalase, glutathione peroxidase (GPx), and myeloperoxidase (MPO) in buccal mucosal squamous cell carcinoma (SCC) with clinicopathologic parameters and prognosis. METHODS The expression status of MnSOD, GPx, catalase, and MPO was evaluated by immunohistochemistry...