Classical selenium-dependent glutathione peroxidase expression is decreased secondary to iron deficiency in rats
Moriarty, P.M.; Picciano, M.F.; Beard, J.L.; Reddy, C.C.
Journal of Nutrition 125(2): 293-301
1995
ISSN/ISBN: 0022-3166 PMID: 7861256 Document Number: 442725
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.