“…Cell culture has provided a powerful tool for studying many aspects of cell growth and function under controlled conditions. Although hormone sensitivity of endometrial cells in primary culture is well documented (Gerschenson, Conner, Yang & Andersson, 1979;Chaminadas, Propper, Royez et al 1986;Alkhalaf, Chaminadas, Propper & Adessi, 1987 ), the effects of ovarian steroids on ultrastructural features of cultured endometrial cells have been rarely reported Propper & Adessi, 1987e). A direct action of oestrone sulphate on protein synthesis in rat and rabbit uterus has been demonstrated (Brooks, Leithauser, De Loecher & De Wever, 1969) and the prehormone role of oestrone sulphate has been established in different species and tissues (Payne, Laurence, Foster & Jaffe, 1973;Adessi, Tran & Vingler, 1982;Moutaouakkil, Prost, Dahan & Adessi, 1984;Prost, Turrel, Dahan et al 1984).…”