SELENIUM CONTENT AND GLUTATHIONE-PEROXIDASE ACTIVITY IN TISSUES OF YOUNG CATTLE FED SUPPLEMENTED WHOLE MILK DIETS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 42  (10) , 1718-1723
Abstract
Three groups of 5 calves each were fed (from birth to 12 wk of age) 3 vitamin-mineral supplemented whole milk diets differing only in their Se content (0.03, 0.23 and 0.53 .mu.g/g of solids). Glutathione peroxidase (GSH-Px) activities and Se concentrations were determined in blood at weekly intervals and in selected tissues after 12 wk. There were marked differences among the tissues in GSH-Px activity, most notably in the liver, lungs and adrenal glands, depending on whether H2O2 or cumene hydroperoxide was used to assay the enzyme. Tissues having the highest GSH-Px activity on a weight basis, when assayed with the H2O2 substrate, were erythrocytes and testes. Enzyme activity in thymus, brain, striated muscle, adipose tissue and blood plasma was lowest among the tissues analyzed. The Se concentration on a fresh tissue-weight basis was highest in kidney cortex, intermediate in kidney medulla, testes, liver and spleen, and lowest in striated muscle, adipose tissue and blood plasma. The Se concentration was increased in liver, kidney cortex, spleen and heart, with increasing increments of dietary Se; differences were not observed in testes and adipose tissue.