Cadmium-induced alterations in the antioxidant defense system of the rat eye in relation to dietary selenium intake.
Cytosolic activity of glutathione peroxidase (GSH-Px), selenium-independent GSH-Px, and catalase, thiobarbituric acid reactive substances (TBARS), and glutathione and selenium (Se) concentration were measured in ocular tissues of rats maintained on a low (0.05 ppm) or adequate (0.10 ppm) Se diet and treated with 0 or 25 ppm cadmium (Cd) in their drinking water for fourteen weeks. Feeding rats a low Se diet resulted in a significant decrease in GSH-Px activity when compared to rats maintained on adequate dietary Se, irrespective of Cd treatment. Se-independent GSH-Px activity of rats maintained at 0.05 ppm Se decreased 27% when compared to Se-adequate controls, whereas activity increased 38% in the Cd-treated low-Se group. When comparisons were made between ocular TBARS in rats maintained at either level of dietary Se and treated with 0 or 25 ppm Cd, a trend toward decreased amounts of TBARS in Cd-treated groups was observed. A significant decrease in ocular Se concentration occurred in rats fed 0.05 ppm Se when compared to the Se-adequate group. Administering Cd to the low-Se group increased ocular Se levels 100%. A negative correlation between ocular Se concentration and TBARS was observed, suggesting a possible alternate role for Se as an antioxidant in the eye.
Sinno
J A
JA
Department of Pharmaceutical Sciences, St. John's University, Jamaica, NY 11439.
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002104:Cadmium / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D004032:Diet; D005123:Eye / Q000187:drug effects / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012643:Selenium / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D013858:Thiobarbiturates
D000975:Antioxidants; D013858:Thiobarbiturates; D002104:Cadmium; D002374:Catalase; D005978:Glutathione; D012643:Selenium