A SIMPLIFIED METHOD FOR THE ESTIMATION OF GLUTATHIONE-PEROXIDASE ACTIVITY AND SELENIUM CONCENTRATION IN BOVINE BLOOD

Twelve hybridoma clones were established that produced mouse monoclona l antibodies to bovine erythrocyte glutathione peroxidase. In these mo noclonal antibodies, GPF-1, GPI-8, and GPJ-1, which showed marked reac tion to this enzyme, were examined for reactivity to erythrocyte lysat es from 12 different species of animals and from humans and for the in hibition of glutathione peroxidase activity. GPF-1 and GPJ-1 reacted m arkedly with glutathione peroxidase in erythrocyte lysates from rumina nts and pigs and inhibited enzymatic activity. Conversely, GPI-2 showe d positive reaction to hemolysate from all mammals used, except for mi ce, and did not inhibit enzymatic activity. To determine the concentra tion of bovine glutathione peroxidase in erythrocyte lysates, a sandwi ch ELISA was developed using GPJ-1, both as a coated antibody and as a peroxidase-labeled antibody. This ELISA system was a sensitive proced ure with a detection limit of 6 ng/ml for glutathione peroxidase prote in. Using blood samples from 121 cows, optical density by this ELISA w as well correlated with the glutathione peroxidase activity and with t he selenium concentration in bovine whole blood. The sandwich ELISA us ing GPJ-1 is a rapid and simple screening method to estimate glutathio ne peroxidase activity and selenium concentration in bovine whole bloo d.