Premium
Knockout of cellular glutathione peroxidase affects selenium‐dependent parameters similarly in mice fed adequate and excessive dietary selenium
Author(s) -
Cheng WenHsing,
Combs Gerald F.,
Lei Xin Gen
Publication year - 1998
Publication title -
biofactors
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 94
eISSN - 1872-8081
pISSN - 0951-6433
DOI - 10.1002/biof.5520070403
Subject(s) - gpx1 , selenoprotein , glutathione peroxidase , selenium , gpx3 , endocrinology , medicine , gpx4 , knockout mouse , chemistry , kidney , phospholipid hydroperoxide glutathione peroxidase , peroxidase , biology , biochemistry , superoxide dismutase , oxidative stress , enzyme , receptor , organic chemistry
Abstract This study was to determine whether or not effects of the cellular glutathione peroxidase (GPX1) knockout on several Se‐dependent parameters in mice were tissue, dietary Se concentration, and selenoprotein specific. A 2×3 factorial experiment was conducted with 18 GPX1 knockout mice [GPX1(‐)] and 18 controls (3 weeks old, half males and females). These mice were fed a torula yeast diet supplemented with all‐rac‐α‐tocopheryl acetate (50 mg/kg of feed) and Se (sodium selenite) at 0, 0.5, or 3.0 mg/kg of feed for 6 weeks. Both kidney GPX1 mRNA levels and liver, kidney, lung, and testis total GPX activities, assayed using hydrogen peroxide, were affected (p< 0.001) by the GPX1 knockout and dietary Se concentrations, whereas kidney extracellular or plasma GPX (GPX3) mRNA levels and phospholipid hydroperoxide GPX (GPX4) activities in the four tissues were affected (p< 0.001) by only dietary Se concentrations. Total GPX activity in testis was reduced approximately 90% (p< 0.01) by the GPX1 knockout. Neither the GPX1 knockout nor the dietary Se concentrations affected mRNA levels of GPX4 in testis or selenoprotein P in kidney. Total liver Se concentrations were not different between the GPX1(‐) and control mice at 0 mg Se/kg of feed, but were reduced (p< 0.01) by 61 and 64% in the GPX1(‐) mice at 0.5 and 3.0 mg Se/kg of feed, respectively. These results not only confirm the independent expression of GPX3, GPX4, and selenoprotein P from that of GPX1, but also show similar effects of the GPX1 knockout on Se‐dependent parameters in mice between different dietary Se concentrations, tissues, and selenoproteins.