EFFECT OF DIETARY SELENIUM ON SELENOPROTEIN-W AND GLUTATHIONE-PEROXIDASE IN 28 TISSUES OF THE RAT

The influence of deficient (0.004 mu g/g), adequate (0.1 mu g/g), and excessive (4.0 mu g/g) levels of dietary selenium (se) on the selenopr otein W (Se-W) content and glutathione peroxidase (GPX) activity was i nvestigated in 28 tissues of the rat. GPX activity was found in all 28 tissues examined, and dietary selenium resulted in increased activiti es in all tissues, except for the spinal cord. Except for the brain, 0 .1 mu g Se per g diet resulted in significantly greater GPX activity i n all tissues as compared with rats fed the deficient diet. When 4.0 m u g Se per g diet was fed, however, this resulted in significantly gre ater activity in the brain as compared with the rats fed the deficient diet. Se-W was nondetectable in liver, thyroid, pancreas, pituitary, and eyes regardless of the level of Se fed. Se-W was not detected in h eart, lungs, prostate, esophagus, small intestine, tongue, skin, diaph ragm, and skeletal muscle from Se-deficient rats, but was present in t hese tissues when the two higher levels of Se were fed. In other tissu es such as the kidney and seminal vesicles Se-W was detected only in r ats fed 4.0 mu g Se per g diet. These results indicated that the distr ibution of Se-W among rat tissues is more widespread than thought, and suggest that the regulation of Se-W by Se is markedly different betwe en various tissues. (C) Elsevier Science Inc. 1998.