the progesterone treatment of the rat was found to be a prerequisite for such development and transformation of endometrial cells in vitro , since control experiments performed with nonhormonally injected castrated animals gave only isolated islets of epithelial cells and scattered fibroblast-like cells in culture , whereas the decidual transformation was still observed , although with some delay , with cells from progesterone ( but not estradiol ) -treated spayed rats .
C0016030
fibroblast
C0007634
cells