Evaluation of Pinopodes Expression on the Mouse Endometrium Immediately before Implantation by Treatment with HMG/HCG and Sildenafil Citrate Administration

Sildenafil citrate is a new drug and has special properties that bring about nitric oxide effects on vascular smooth muscle. The aim of this study was to assess the effects of ovarian stimulation and sildenafil citrate injection on pinopode expression in mice.Thirty adult female mice were randomly divided into three groups: control, hyperstimulated and hyperstimulated +sildenafil citrate injection. In experimental groups mice received 7.5 IU human menopausal gonadotropin (HMG) and then after 48 hr received 7.5 IU human chorionic gonadotropic (HCG) hormones. After that every two females were put with one male in one cage for mating. Hyperstimulated +sildenafil citrate group were injected with sildenafil citrate (3 mg/mouse) every 24 hr for three days, after HMG injection. The animals were sacrificed by cervical dislocation 96 hr after HMG injection, and their uterine specimens (the middle one-third) were prepared for transmission electron microscope studies. Electron microscopy observations showed that in the control group there were long and short microvilli while no developed pinopodes were observed, however, in the two other groups, well developed pinopodes were expressed 4 days after HMG injection.The results showed that hyperstimulation of mice with sildenafil citrate may be more helpful in formation of pinopodes and implantation.