Effects of postovulatory aging on leucine uptake and incorporation in mouse eggs. A brief note

In order to delineate biochemical alterations during gamete senescence leucine uptake and incorporation in aging mouse eggs were investigated. One hour after ovulation eggs were removed from the oviducts and labeled (unaged) or incubated for 24 hours before labeling (in vitro aged) with [3H]leucine. In vivo aged eggs were removed from the oviducts 25 hours after ovulation and incubated in medium containing [3H]leucine. Aging of eggs for 24 hours resulted in a significant increase in the accumulation of [3H]leucine. The observed increase was larger in ova aged in vitro than in vivo, indicating that culture conditions affect leucine accumulation. Comparison of in vitro aged and unaged eggs revealed no significant difference in net leucine incorporation in to acid-insoluble material. In addition to previously documented morphological alterations, the data presented herein describe some of the biochemical changes that accompany aging of the mouse ovum. These results are discussed in light of theories of aging proposed for somatic cells.