Basal release of urokinase plasminogen activator, plasminogen activator inhibitor-1, and soluble plasminogen activator receptor from separated and cultured endometriotic and endometrial stromal and epithelial cells.

Objective: To investigate whether separated and cultured endometriotic and endometrial stromal and epithelial cells release urokinase plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and soluble plasminogen activator receptor (suPAR) antigens in vitro.

Design: In vitro study.

Setting: University hospital clinic.

Patient(s): Regularly menstruating women with and without endometriosis.

Intervention(s): Tissue samples were collected at surgery performed for clinical reasons.

Main Outcome Measure(s): The antigen concentrations of uPA, PAI-1, and suPAR in culture medium were assayed by enzyme-linked immunosorbent assay.

Result(s): Both stromal and epithelial cells from endometriotic and endometrial tissue released the three types of antigens, but the release of PAI-1 was significantly higher from stromal cells in the three types of tissue than from epithelial cells. Furthermore, the release of PAI-1 was significantly higher from endometriotic cells than from endometrial stromal cells.

Conclusion(s): This study has demonstrated the basic capacity of separated epithelial and stromal cells from all three types of tissue to release uPA, PAI-1, and suPAR without any paracrine influence, as in vivo. The higher release of PAI-1 from endometriotic stromal cells might have importance for the invasive growth.