Correlation Between Glutathione Peroxidase Activity and The Quantity of Selenium in The Whole Blood of Beef Calves

Abstract

The aim of the study was to establish concentration of selenium and the pertinent activity of glutathione peroxidase (GSH-Px) in whole blood that could be used as reference values in future research. The first part of study was carried out on clinical healthy beef calves (n = 35), fed a basal diet and a ready-made fodder mix that contained 0.1 mg.kg(-1) selenium. In the second part of our research, we investigated the GSH-Px activity in a group of calves (n = 47) that had not received supplements added to the basal diet. The research was carried out in the north-west Croatia, in the region known to be poorer in selenium. We determined GSH-Px activity in whole blood by the Ransel method adapted to a Technicon RA-1000 at 37 degrees C. Determination of Se concentration was done with a modification of the method given by Perkin-Elmer HGGS. The mean value of the Se concentration in the whole blood of the first group of calves was 200.22 +/- 45.2 mu g.l(-1) and pertinent average GSH-Px activity was 764.6 +/- 197.8 mu kat.l(-1). From the results obtained, a correlation between Se and GSH-Px was calculated (r = 0.82 ; P < 0.001). The mean values of the GSH-Px activity in herd that did not receive a supplement were 435.3 +/- 155.76 mu kat.l(-1). Out of 47 animals of the second herd, four animals (8.51%) had lower values than those recommended as sufficient. This study confirmed that after the calculation of the correlation between Se and GSH-Px, glutathione peroxidase activity determination can be used as a rapid and simple proxy for the determination of selenium concentration in whole blood.