Classical selenium-dependent glutathione peroxidase expression is decreased secondary to iron deficiency in rats.
While there are reports that classical selenium-dependent glutathione peroxidase (Se-GPX1) activity is decreased during iron deficiency, the relationship between tissue iron status and Se-GPX1 activity remains speculative. This study was undertaken to investigate the mechanism for the decrease in Se-GPX1 activity during iron deficiency. Male weanling Sprague-Dawley rats were given free access to either an iron-deficient or an iron-adequate diet for eight weeks, after which blood, livers, kidneys, hearts, brains and testes were surgically excised. During iron deficiency, Se-GPX1 mRNA levels in liver tissue were decreased by approximately 55%. Similarly, the concentration of immunoreactive Se-GPX1 protein and total selenium-dependent glutathione peroxidase (Se-GPX) activity were decreased by 55% and 60%, respectively. In kidney, heart and brain total Se-GPX activities were depressed as much as 33%. Selenium concentration in liver was reduced by 42%, whereas the decrease in Se concentrations in kidney, heart, and brain ranged from 17 to 25%. Concentrations of plasma Se also were reduced by 18%, but testes showed little change in either Se-GPX activity or Se concentration during iron deficiency. Results suggest that the synthesis of Se-GPX1 protein is decreased during iron deficiency possibly due to pretranslational regulation.
Moriarty
P M
PM
Graduate Program in Nutrition, College of Health and Human Development, Pennsylvania State University, University Park 16802.
Picciano
M F
MF
Beard
J L
JL
Reddy
C C
CC
D018798:Anemia, Iron-Deficiency / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D001921:Brain / Q000201:enzymology / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D000090463:Iron Deficiencies; D007668:Kidney / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012643:Selenium / Q000032:analysis / Q000097:blood / Q000502:physiology*; D013737:Testis / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism
D012333:RNA, Messenger; D005979:Glutathione Peroxidase; D012643:Selenium