P-120: The Impact of Progesterone and Sildenafil on Endometrial Ultrastructure in Superovulated Mice

Background: Implantation is proceeded by a process referred as adhesion. Adhesion requires maturation of endometrium and blastocyst to confer adherence ability to them. During IVF cycles, endometrial maturation is facilitated by progesterone administrating. Considering vasodilatory effect of Sildenafild, in genital organs, it appears that Sildenafil may have similar effect as progestrone. The aim of the present study is to compare ultrastructural characteristics of mice uterine endometrium in natural cycle with those at superovulated cycle received progesterone or Sildenafild. Materials and Methods: For this purpose, 60 adult female and 30 adult male mice were used. The female mice were divided into 4 groups as: controls, gonadotropin, gonadotropin + Sildenafil and gonadotropin + progesterone. In experimental groups the mice received 7.5 IU HMG as intra peritoneal injection and 48 hours later 7.5 IU HCG. Then in all groups, 2 female and one male mouse were placed in a cage for mating. In the gonadotropin + progesterone and gonadotropin + Sildenafil groups, the mice respectively received 1mg progesterone and 3mg sildenafil citrate at 24 , 48 and 72 hours after HMG injection. 96 hours after HMG injection, the mice were sacrificed and their uterine specimens were fixed in 10% formalin, embedded in paraffin and 5 μm thick sections were stained with H & E and studied with light microscope. For electron microscopic studies the specimens were fixed in 2% glutaraldehyde, embedded in araldite and thin sections studied with LEO 906 transmission electron microscope. Statistical analysis was performed using ANOVA. Results: Microscopy revealed that in control group the cells had numerous apical microvilli and some granules were found in basal portion. In gonadotropin + progesterone group, the granules were found in basal and apical portions and their microvilli appeared shorter than the control and gonadotropin groups. In this group, the apical membrane also contained some pinopodes projecting toward the lumen. In gonadotropin + Sildenafil group the granules were found in both apical and basal portions and the microvilli appeared shorter than the control and gonadotropin groups. In this group, pinopodes appeared slightly numerous than the other groups. Conclusion: Superovulatory drugs in mice stimulate endometrial maturation but injection of Sildenafil and progesterone has a negligible effects on it.