Inorganic selenite supplementation and protection against hyperoxic injury in neonates

This study was designed to determine if oral sodium selenite supplementation to Se-depleted rat pups furnishes protection against hyperoxic lung injury. Twelve female rats were bred and fed a Se-deficient (0.04 ppm Se) diet during pregnancy and lactation. Pups were supplemented either with 0 or 3.2 ng Se/g body weight daily from days 2 to 7. On day 4, two litters were mixed, with half of the pooled litter assigned to an air environment and the other half to an oxygen environment. Dams cross-fostered pups for 4 d. Selenite supplementation increased pup plasma and liver selenium concentration and the liver activity of glutathione peroxidase (GPx). However, lung GPx activity was more affected by oxygen exposure than selenite supplementation. While oral Se supplementation of the pups showed a tendency for decreased incidence of lung injury with oxygen exposure, this apparent effect was not statistically significant. Selenium-supplemented pups also showed a trend toward larger internal surface area and lung volume than selenium-depleted pups. These data indicate that early postnatal selenium repletion via direct oral selenite supplementation may be beneficial to rat pups against hyperoxic lung injury.