Copper deficiency affects selenoglutathione peroxidase and selenodeiodinase activities and antioxidant defense in weanling rats.
Copper deficiency has been postulated result in low selenoglutathione peroxidase (Se-GSHPx) activity, secondary to alterations in the antioxidant defense system. Type I iodothyronine 5'-deiodinase contains selenium; because it is not part of the antioxidant defense system its measurement provides a way to evaluate the influence of copper on selenoenzymes independent of the antioxidant system. Weanling rats were fed the control diet (125.9 nmol Cu/g diet), copper-deficient diet (7.9 nmol Cu/g diet), or the control diet restricted to the intake of the deficient rats (restrict-fed), for 21 d. Rats fed the copper-deficient diet had cardiomegaly, low hematocrit values, and low tissue copper concentrations, but normal liver selenium concentrations. Liver and plasma Se-GSHPx activities were lowest in the deficient rats. Non-Se-GSHPx activity was similar between control and copper-deficient groups. Liver selenodeiodinase activity was lowest in the copper-deficient rats; this reduction was functionally significant as evidenced by low plasma 3,3',5-triiodothyronine and high plasma 3,3',5'-triiodothyronine concentrations.
Olin
K L
KL
Department of Nutrition, University of California, Davis 95616-8669.
Walter
R M
RM
Keen
C L
CL
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006332:Cardiomegaly; D003300:Copper / Q000172:deficiency* / Q000378:metabolism / Q000494:pharmacology*; D004032:Diet; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism; D019803:Glutathione Disulfide; D005979:Glutathione Peroxidase / Q000378:metabolism*; D007453:Iodide Peroxidase / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D014131:Trace Elements / Q000378:metabolism; D014886:Weaning
D000975:Antioxidants; D014131:Trace Elements; D003300:Copper; D007453:Iodide Peroxidase; D005979:Glutathione Peroxidase; D005978:Glutathione; D019803:Glutathione Disulfide