Morphological changes in the mammalian vas deferens during aging. I. The occurrence of binuclear cells in the mouse

The number of nuclei per principal cell was determined in the vas deferens of sexually immature, young sexually mature and old male mice. The incidence of binucleation increased with age. In 21-day-old mice approximately 99% of the principal cells were mononucleated and 9%-20% of the principal cells were binucleated. In the oldest animals, the ampulla and testis end of the vas usually had more binuclear cells than the middle segment. The biological significance and the mechanism of this phenomenon are not known; however, binucleation may prove to be a useful indicator of aging in the vas of this species. In addition, the mouse vas may provide a useful model for studies of binucleation and mitosis.