Human Reproduction, Vol. 4, No. suppl_1, pp. 115-120, 1989
© 1989 European Society of Human Reproduction and Embryology
Contribution to the physiology and pathology of endometrial receptivity: the determination of protein patterns in human uterine secretions
Department of Anatomy and Reproductive Biology, Medical Faculty RWTH Aachen D-5100 Aachen 2 Department of Obstetrics and Gynaecology, Medical Faculty, University of Ulm D-7900 Ulm, FRG
Correspondence: 1To whom correspondence should be addressed
In this study, the uterine protein patterns of >200 patients of the sterility treatment programme of the Department of Obstetrics and Gynaecology, University of Ulm were analysed by the technique of uterine secretion electrophoresis (USE) of minute quantities. These analyses reveal three protein patterns, typical for the equivalent phases of the menstrual cycle: intermediate phase-, proliferative phase- and secretory phase. There appear up to 63 protein bands, most of which represent proteins <68 kd. Those separation areas below 68 kd show characteristic ‘families’ of protein bands, which typically constitute the three phase patterns. As a result of our study, a secretory phase pattern lasting 10 days is demonstrated, suggesting a remarkably long ‘receptive phase’ for the initiation of implantation. The fully expressed secretory phase pattern appears from day 15 to day 25 of the ideal menstrual cycle (28 days length). The ‘implantation window’ of the endometrium seems to remain open for a surprisingly long period of time. This insight sheds light on the success of embryo transfer after IVF when the cleavage stage embryo arrives in the uterine cavity several days earlier than after normal fertilization. Such early exposure to the uterine milieu nevertheless does not preclude implantation.
Key words: endometrial receptivity/protein pattern analyses/regulation of endometrial secretion/SDS–PAGE/uterine secretion