Variation of the mitotic and apoptotic index in the rabbit uterine epithelium during previous days of implantation

Abstract

Anzaldúa ASR, Pérez MM, Castro RJI. Téc Pecu Méx 2001,39(1):59-68. During the first days of pregnancy the rabbit endometrium experiencies multiple morphologic and functional changes, that provide to the blastocyst adequate environmental conditions necessary for the establishment of pregnancy. The present study was performed in order to know the proliferation index and apoptosis index of epithelial cells in the endometrium during the preimplantation period. In days 2 and 4 postcoitus, an increase (P<0.05) in the mitotic index was observed in the luminal and glandular epithelium with respect to the control group (not pregnant). Between days 2 and 5 a decrease of the apoptotic index was observed in the luminal and glandular epithelia. These results indicate that during the preimplantation period in the rabbit, the cellular proliferation and apoptosis are a coordinated process, in such a way that when one of them increases, the other is inhibited. This behavior was observed in both, the coating and the glandular epithelia. The proliferation of cells observed at glandular and luminal epithelia level during the 2nd and 4th day of pregnancy is along with a process of cellular differentiation wich ends up in a secretory epithelium that is necessary for nestling of embryos on day 7.