Effect of selenium deficiency on cellular and extracellular glutathione peroxidases: immunochemical detection and mRNA analysis in rat kidney and serum.
To determine the effect of selenium (Se) deficiency on expression of glutathione peroxidase (GSH-Px) 1 and 2, we measured GSH-Px activity in rat serum, liver and kidneys, serum immunoreactive GSH-Px 2, and the mRNAs of kidney GSH-Px 1 and 2. We purified rat GSH-Px 2 and raised polyclonal antibodies. Immunoreactive GSH-Px 2 was measured by rocket immunoelectrophoresis. GSH-Px 2 was purified 1470-fold with a specific activity of 250 units/mg. Immunoblotting detected only GSH-Px 2 in rat serum, and much less GSH-Px 2 than GSH-Px 1 in kidney. Immunoblot signal of kidney GSH-Px 1 and 2 decreased progressively in Se deficient rats. Serum GSH-Px activity in Se deficient rats at 1, 2, 3, and 4 weeks declined to 33, 20, 10, and 9% of the control, while the serum level of immunoreactive GSH-Px 2 was 58, 24, 15, and 10% of the control, suggesting the presence of an inactive protein at week 1. GSH-Px activity declined to 4 and 11% of the control in the liver and kidney at 4 weeks. The mRNAs of kidney GSH-Px 1 and 2 showed similar decreases, and were 24 and 23% of the control at 4 weeks. GSH-Px mRNA levels were better preserved than GSH-Px activity, suggesting that GSH-Px expression was regulated at both pre-translational and translational levels.
Nakane
T
T
Department of Pediatrics, Yamanashi Medical University, Tamahocho, Japan.
Asayama
K
K
Kodera
K
K
Hayashibe
H
H
Uchida
N
N
Nakazawa
S
S
D000818:Animals; D005979:Glutathione Peroxidase / Q000032:analysis* / Q000097:blood / Q000235:genetics*; D015151:Immunoblotting; D007122:Immunoelectrophoresis; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000097:blood / Q000235:genetics; D007668:Kidney / Q000201:enzymology*; D008099:Liver / Q000201:enzymology; D008297:Male; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012643:Selenium / Q000172:deficiency*
D007527:Isoenzymes; D012333:RNA, Messenger; D005979:Glutathione Peroxidase; D012643:Selenium