Monitoring of Endometrial Changes in Rat in Simulation to Programs of Assisted Reproduction: Histological Immunohistochemical Studies

Background; Successful embryo implantation is a crucial event in natural and assisted reproduction. The development of a receptive endometrium and subsequent differentiation into decidua is a principal event in implantation. Decidualization includes differentiation of stromal fibroblasts into unique secretory tissue. Osteopontin is considered to be a marker for decidualization. Endometrial proliferation and apoptosis is important for successful embryo implantation. Proliferating cell nuclear antigen PCNA,is a well established proliferation marker. Aim of the work: the present work was planned to highlight the rat endometrial changes in simulation to programs of assisted reproduction with the impact on stromal proliferation and decidualization at immunohistochemical level, using the markers OPN and PCNA. Material and Methods: Thirty adult female albino rats weighing 150-200 grams were used in the present study, they were equally divided into three groups. Group I (a b): control group in which ovulation and pseudopregnancy was induced by mechanical vagino-cervical stimulation. Group II (a b): Rats were subjected to ovarian hyperstimulation by two intraperitoneal injections of human chorionic gonadotrophin (HCG) 350 IU/kg rat, with 48 hours apart. On the evening of the second injection, rats were subjected to mechanical vagino-cervical stimulation as in the control group (day zero). Group III (a b): they were treated in the same way as group II, followed by a daily subcutaneous injection of progesterone, 35mg/Kg rat till the time of sacrification. Rats were sacrificed on fourth day (subgroups la, Ha Ilia) and fifth day (subgroups lb, lib Illb) of ovulation and pseudopregnancy induction. Sections were subjected to H E stain and immunohistochemical staining for PCNA and osteopontin. This was followed by morphometric study and statistical analysis for the height of luminal epithelial cells, stromal thickness, area percent of FCNA immunoreactivity, optical density and area percent of osteopontin immunoreactivity. Results: Endometrium following HCG hyperstimulation with progesterone injection favours for decidualization, as indicated by strong osteopontin immunoexpression, low columnar epithelium lining the endometrium, proliferation of stromal cells and increased stromal thickness with proliferated endometrial glands. The decidualization marker, osteopontin was more, obvious on day 4 than day 5 in hyperstimulated progesterone injected group denoting the premature receptivity of endometrium. Conclusion:. It was concluded that endometrium following HCG hyperstimulation with progesterone injection favours for decidualization with premature endometrial receptivity.