The erythrocyte uptake of 75Se as an indicator of selenium status in lambs.

The glutathione peroxidase activity (GSH-Px) and the in vitro erythrocyte uptake of 75Se (ESeU) was followed in blood samples from 31 lambs for 105 days. The lambs were divided into three groups; untreated (group U), vitamin E treated (group E) and selenium treated (group Se). The animals in group E were administered intramuscularly 250 mg vitamin E at two weeks interval and those in group Se 0.1 mg Se/kg as sodium selenite monthly. None of the lambs exhibited symptoms of muscular degeneration or any other disease during the trial. Vitamin E had no effect neither on the GSH-Px nor on the ESeU. Thirty days and later after the first Se treatment the GSH-Px was significantly higher in group Se than in the other two groups, but the most rapid increase of GSH-Px in this group was noticed after 44 days. On day 51 a significant decrease of GSH-Px was shown in groups U and E compared with day O. The lambs in groups U and E had significantly higher ESeU on day 36 and later compared with day 0. The administration of selenium in the mineral supplement (10 mg Se/kg) to the lambs in group U and E during the 26 latest days of the study gave an almost significant increase of GSH-Px and a decrease of ESeU. Our experience of the ESeU-test is that it is a simple method, and can be used to evaluate Se status of animals.