Evaluation of Alkaline Phosphatase Activity Alteration in Mouse Endometrium After Ovarian Hyperstimulation During Early, Pseudo and Natural Pregnancy Until Implantation Time

Purpose: The purpose of this study was to determine alkaline phosphatase (ALP) activity of uterus after ovarian induction using pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) in normal and pseudopregnancy during implantation periods. Materials and Methods: For this purpose, 240 female NMRI mice with the age of 6-10 weeks were selected and divided into control and hyperstimulated groups. These mice were rendered normal or pseudopregnant. Five mice per each group were sacrificed by cervical dislocation on the first day to sixth day of natural or pseudopregnancy. For biochemical assay, the samples were obtained from the uterin horns then were hemogenated using tris HCI buffered salin (pH 8.3) and centrifuged with14000 g. The activity of enzyme was determined using paranitrophenyle phosphate as substrate. Then specific activity of enzyme was calculated according to the total protein. The data were evaluated with Mann whithney test. For histochemistry the samples were cryosections (5mm thickness) and the ALP activity was determined by azo-coupling technique using alphanaphtole phosphate as substrate. Results: The pattern of ALP activity in the biochemical and hisotchemical study was the same in each group. The activity of the endometrial ALP increased during early pregnancy in the control and hyperstimulated natural pregnant groups. The endometrial ALP activity increased until 4th day in control and hyperstimulted pseudopregnant groups. The enzyme activity was observed on the apical border of surface and glandular epithelium and limina propria. Conclusion: Thus ovarion hyprstimulation alters the endometrial ALP activity during early pregnancy. This alteration may influence the endometrial receptivity and embryo implantation. However, it needs more investigation with complementary technique.