Effect of platelet-derived growth factor on endometrial stromal cell proliferation in vitro: a model for endometriosis?

OBJECTIVE

To assess the direct effects of platelet-derived growth factor (PDGF), a macrophage secretory product structurally and functionally similar to substances released by peritoneal macrophages isolated from endometriosis patients, on endometrial cell proliferation.

DESIGN

Prospective analysis of cell proliferation in vitro.

SETTING

Proliferative phase endometrial stromal cells isolated from biopsy specimens were grown in short-term culture and served as a model for stromal components of endometriotic implants.

PATIENTS: Biopsies were obtained from regularly cycling volunteers without endometrial pathology.

INTERVENTIONS: Platelet-derived growth factor was added to nutrient medium in both the presence and absence of suboptimal (2.5%) calf serum (CS) supplements and a physiological estradiol (E2) concentration (10(-9) M).

MAIN OUTCOME MEASURES: Cumulative [3H]-thymidine incorporation as a reflection of cell proliferation.

RESULTS

Platelet-derived growth factor exerted a significant dose-dependent effect on stromal cell proliferation in both the presence and absence of CS (P less than 0.01). This effect was enhanced in, at best, an additive but not synergistic manner by E2 10(-9) M.

CONCLUSION

These data imply that macrophage secretory products such as PDGF may play a significant role in the maintenance or proliferation of endometriosis.