Effect of peroxisome proliferator on extracellular glutathione peroxidase in rat.
Glutathione peroxidase (GPX) activity measured using tert-butyl hydroperoxide as a substrate detects solely cellular/classical GPX (cGPX) in rat liver and kidney, and extracellular/plasma glutathione peroxidase (EC-GPX) in rat serum. To investigate the effect of peroxisome proliferator on EC-GPX, we measured activities of GPX and catalase in rat liver, kidney and serum, and then we performed immunoblot and Northern blot analyses in the kidney. Rats were fed on a diet containing either 2% (w/w) di-2-ethylhexyl phthalate (DEHP) or 0.25% (w/w) clofibrate for two or three weeks, respectively. Catalase activity was increased 1.4-fold (p < 0.001) in the treated liver, but not in the kidney. GPX activity was decreased to 59.2% (DEHP) and 70.4% (clofibrate) of the control (p < 0.001) in the serum but was unaltered in the liver and kidney. The immunoreactivity for EC-GPX was also significantly decreased in the DEHP-treated kidney compared with the control. The mRNA levels of EC-GPX and cGPX were unaltered. The immunostaining for 4-hydroxy-2-nonenal, a maker of lipid peroxide, was more intense in the treated kidney compared with the control. These results suggest that EC-GPX is post-transcriptionally decreased by peroxisome proliferator through the oxidative stress in the renal tubules. This may be a new deleterious effect of an endocrine disruptor DEHP.
Dobashi
K
K
Department of Pediatrics, Yamanashi Medical University, Tamahocho, Japan. kdobashi@swallow.res.yamanashi-med.ac.jp
Asayama
K
K
Nakane
T
T
Hayashibe
H
H
Kodera
K
K
Uchida
N
N
Nakazawa
S
S
D000447:Aldehydes / Q000032:analysis; D000818:Animals; D015152:Blotting, Northern; D001835:Body Weight / Q000187:drug effects; D002374:Catalase / Q000187:drug effects / Q000378:metabolism; D002994:Clofibrate / Q000494:pharmacology; D004051:Diethylhexyl Phthalate / Q000494:pharmacology; D005109:Extracellular Matrix / Q000187:drug effects* / Q000378:metabolism*; D005609:Free Radicals / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015151:Immunoblotting; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008054:Lipid Peroxides / Q000032:analysis / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D020025:Peroxisome Proliferators / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods
D000447:Aldehydes; D005609:Free Radicals; D008054:Lipid Peroxides; D020025:Peroxisome Proliferators; D004051:Diethylhexyl Phthalate; D002374:Catalase; D005979:Glutathione Peroxidase; D002994:Clofibrate; C027576:4-hydroxy-2-nonenal