Age dependence of selenite uptake in rat eye lenses.

75Se-selenite was administered to young and adult rats in subcutaneous injection or added into the medium in which eye lenses were incubated. The 75Se uptake in lenses of the young was significantly higher in comparison with adults both in vivo and in vitro. The in vivo 75Se uptake, referred to unit of lens weight, was almost 500 times higher in young animals while in vitro it was only five times higher, which apparently reflects the age-dependent differences in the structure and function of membranes and/or system barriers.