Abstract
Uterine luminal surface of the hamster was examined by scanning electron microscopy (SEM) to determine whether aging alters surface ultrastructure of the endometrium where implantation takes place. On Days 2 to 3, the epithelial cells of young hamsters were round and uniformly covered with microvilli. The cells of aged hamsters were polygonal in shape with microvilli of equal density. However, in about 15% of the aged uterine epithelium examined the cells had a reduced number of microvilli. The cellular protrusions appeared on the apical membrane in young uteri on Day 4, but fewer protrusions were observed in aged uteri on Day 5 and some of them were lost before implantation. Implantation was delayed in the aged females. These findings suggest that altered surface ultrastructure of the aged uterus may reflect age-related implantation failure.
