Changes in Blood Levels of Selenium and Tocopherol after Administration in the Horse

Abstract

In order to clarify changes in blood levels after administration of selenium and tocopherol, oral administration of premix A and B and intramuscular injection of E·SE were carried out in the horse.
Oral administration of 50 g/day of premix A and 25 g/day of premix B for 8 weeks, resulted in marked increases of two weeks later, while serum tocopherol level and blood glutathioneperoxidase (GSH-Px) activity did not increase. However, in a horse administered premix B only, blood GSH-Px activity increased slightly eight weeks later.
When injected with 2 to 2.5 ml/100 kg of E·SE one of four times at 2 or 4 weeks interval, serum selenium levels increased rapidly one day later and a high concentration was maintained over two to four weeks. In particular, serum selenium remained at high levels above 100 ppm after two injections. Serum tocopherol levels increased markedly the next day after E·SE injection and high concentrations continued from two to three weeks after injection. Blood GSH-Px activity increased slightly to about 30 i.u six or eight weeks after injection.
In newborn foals from mares injected with E·SE prior to parturition, serum tocopherol and selenium levels and blood GSH-Px activity were below the levels found in their respective mothers. Tocopherol levels in the colostrum just after parturition were higher than serum tocopherol levels in newborn foals, suggesting that the newborn foals might have received tocopherol mainly from colostral milk.