AIM To study the secretory activity and androgen regulation of glutathione peroxidase (GPx) in epithelial cell cultures from human epididymis. METHODS Tissue was obtained from patients undergoing therapeutic orchidectomy for prostatic cancer. Epithelial cell cultures were obtained from the caput, corpus and cauda epididymides. Enzymatic activity was measured in conditioned media by colorimetr...

Oxidative mechanisms of injury are important in many neurological disorders, including hypoxic-ischemic brain damage. Cerebral palsy after preterm birth is hypothesized to be caused by hypoxic-ischemic injury of developing oligodendrocytes (OLs). Here we examined the developmental sensitivity of OLs to exogenous hydrogen peroxide (H2O2) with stage-specific rat oligodendrocyte cultures. We found...

withania somnifera (l.) dunal is an erect evergreen shrub commonly known as ashwagandha. it is widely used in ayurvedic, and in the traditional pharmacopeia system of india. it is one of the major ingredients in many formulations prescribed for a variety of musculo-skeletal conditions including arthritis and rheumatism. in the present study, variations in the quality and quantity of proteins an...

Recently, we have put forward the hypothesis that a decreased concentration of reduced glutathione (GSH) may be implicated in the mechanisms of peroxidative damage to the liver and kidney caused by lead (Pb) and/or ethanol (EtOH). Thus, the aim of the present study was to assess the activities of GSH-related enzymes, such as glutathione peroxidase (GPx), glutathione reductase (GR), and glutathi...

There is a requirement for cellular defense against excessive peroxynitrite generation to protect against DNA strand breaks and mutations and against interference with protein tyrosine-based signaling and other protein functions due to formation of 3-nitrotyrosine. Here, we demonstrate a role of selenium-containing enzymes catalyzing peroxynitrite reduction using glutathione peroxidase (GPx) as...

Cellular glutathione peroxidase (GPx-1), a selenocysteine-containing enzyme, plays a central role in protecting cells from oxidative injury. GPx-1 is ubiquitously expressed in eukaryotic cells where it reduces hydrogen and lipid peroxides to alcohols. Adenosine, which is released from stressed or injured cells, protects against ischemia/reperfusion injury and apoptosis. In this study, we hypoth...

OBJECTIVE This study was designed to determine the relationship between Mycobacterium avium subspecies paratuberculosis (MAP) infection and selenium-dependent glutathione peroxidase (GPx) activity, in the blood of humans and cattle infected with MAP. DESIGN MAP infection status and GPx activity were determined in sera from 42 cattle, a group of 27 patients with Crohn's disease and 27 of their...

OBJECTIVE Lipid hydroperoxide, a marker of oxidative stress, is linked to the development of nephropathy and is reportedly higher in patients of African origin compared with Caucasians. This may be relevant to race-specific differences in susceptibility to nephropathy. We investigated whether alterations in antioxidant enzyme activity could account for this biochemical phenotype and examined th...

abstract background: the chemotherapeutic agents used for treatment of breast cancer are all shown to increase free oxygen radicals and generation of reactive oxygen species. the aim of this study was to evaluate effect of chemotherapy on plasma selenium (se) concentration and glutathione peroxidase (gpx) activity in breast cancer patients. materials and methods: seventeen women in stage ii and...

Esworthy, R. Steven, Jeffrey R. Mann, Mindy Sam, and Fong-Fong Chu. Low glutathione peroxidase activity in Gpx1 knockout mice protects jejunum crypts from g-irradiation damage. Am J Physiol Gastrointest Liver Physiol 279: G426–G436, 2000.—Gpx1 knockout (KO) mice had a higher number of regenerating crypts in the jejunum than did Gpx2-KO or wild-type mice analyzed 4 days after $10 Gy g-irradiatio...