[In vitro study of prolactin secretion by ectopic endometrial stromal cells].

OBJECTIVE: To investigate the relationship between prolactin (PRL) secretion by ectopic endometrial stromal cells and elevated PRL concentrations of peritoneal fluid in patients with endometriosis. METHODS: Twelve samples of each ectopic endometrium and normal endometrium were separated and cultured in vitro. After stimulated with progesterone(10(-8) mol/L) for 6 days, PRL levels in the media of cultured stromal cells from both tissue types were measured by enzyme-labeled immunosorbent assay(ELISA). A study of correlation between PRL level in culture supernatant of stromal cells from ectopic endometrium and American Fertility Society (AFS) classification of endometriosis score was performed. The expression of PRL protein of stromal cells from both tissue types were determined by immunocytochemical method. RESULTS: PRL was secreted in similar concentrations by stromal cells from both tissue types. The mean levels of PRL in ectopic and normal endometria were (21.8 +/- 8.0) and (24.5 +/- 7.9) micrograms.L-1.6 d-1 per, respectively (P > 0.05). There is significant positive correlation between PRL secretion by ectopic endometrial stromal cells and the scoring of endometriosis (P < 0.05). There were no significant difference in the immunostaining integral score of PRL between the two groups. CONCLUSION: Production of PRL by ectopic implants of endometriosis is likely to be a contributing factor of the elevated peritoneal fluid PRL in patients with endometriosis.