Endometrial response to sexual steroids as assessed by prostaglandin F-2 alpha output in explant culture and hormone receptor expression

The objective of this study was to evaluate the endometrial response to sex ual steroids in organ culture using two mea ns: prostaglandin (PG) F-2 alph a output in medium culture and steroid receptor immunoexpression in tissue. Human endometrium samples were classified in homogeneous and heterogeneous proliferative or secretory subsets. In proliferative endometrium explant c ulture, progesterone (10(-7) M) induced a significant decrease in PGF(2 alp ha) output, but this was not the case in secretory endometrium, whereas no significant effect of estradiol (10(-8) M) was observed. Before culture, ho mogeneous and heterogeneous proliferative endometrium presented the same pa ttern of estradiol receptor (ER) and progesterone receptor (PR) expression evaluated by quantitative immunocytochemistry. After culture, immunoreactiv e ER and PR were detected on the explant. PR immunoexpression rates after c ulture were lower than before culture in glands on homogeneous proliferativ e and in stroma on heterogeneous proliferative endometrium explants without in vitro steroid addition. In secretory endometrium, no significant differ ence was observed between ER or PR immunoexpression rates before culture an d after culture. These results provided the hormonal receptivity status of endometrium after culture and will thus serve as a reference for evaluating in vitro steroid effects an endometrium explants. Our preliminary results suggest that cultures of endometrium explants are a valid model for studyin g the effects of hormonal treatment on homogeneous as well as heterogeneous endometrium. These data could be particularly relevant for evaluating the potential response to hormone stimulation and treatment of endometria sampl ed in perimenopausal patients. Copyright (C) 2000 S. Karger AG, Basel.