RESUMO
Apoptosis is a process that plays an important role during early stage of implantation. The aim of this study was to investigate the incidence of apoptosis in mice endometrium after ovarian stimulation at implantation period. NMRI female mice were divided into two groups: 1] control group, which were rendered pseudopregnant by vaginal stimulation and 2] experimental group, which were stimulated using an intrapritoneal injection of 10 IU hMG followed by another injection of 10 IU hCG after 48 h. In the evening of the second injection, the mice were rendered pseudopregnant the same as control group. Samples were obtained from 1/3 middle part of uterine horns during implantation period. Apoptosis was assessed in two groups at implantation period using light and electron microscopic studies, TUNEL staining and semiquantitative RT-PCR. Our morphological and ultrastructural results showed apoptosis in both groups, while TUNEL analysis showed that the percentage of TUNEL-positive cells was higher in stimulated group than in the control group [P