Delayed embryonic development and implantation in senescent golden hamsters.

Abstract

Early embryonic stages from young (3–5 months) and senescent (14–15 months) golden hamsters were compared after 3, 3½, 4, 4½, 5, and 5½ days of pregnancy. Sections of epoxy resin-embedded uteri from 22 young (89 embryos) and 18 senescent (33 embryos) animals were examined using light microscopy. Morphologically, embryos from senescent hamsters exhibited a 12-h delay in the time of uterine attachment, orientation of the inner cell mass, formation of giant trophoblastic cells, reduction of uterine epithelium, and early embryonic development. The Pontamine Blue reaction in older uteri was delayed, sporadic, and less intense than in younger animals. Decidual cells first appeared in the uteri of senescent animals 12 h later, in accordance with the delay of the implanting blastocyst. The extent of the decidual cell reaction in the majority of senescent hamsters appeared similar to that in younger animals 12 h earlier.