Progestin regulation of human endometrial function.

A well-orchestrated sequence of events enables the human endometrium to become receptive to embryo implantation during a defined period in the menstrual cycle. Ovarian steroids, oestradiol and progesterone, regulate many of these functions in a highly co-ordinated manner. There are no experimental systems for critically examining the regulation of endometrial functions by steroid hormones, especially those responses restricted to the epithelium. Using an experimental xenograft model where the steroid responses of normal endometrium could be predictably recapitulated, the role of progesterone in the regulation of alpha crystallin B in the glandular epithelial cells of human endometrium was established.