Decreased expression of tissue inhibitor of matrix metalloproteinases in follicular fluid from women with polycystic ovaries compared with normally ovulating patients undergoing in vitro fertilization.

Objective: To compare activity of matrix metalloproteinases (MMP) and expression of their tissue-specific inhibitor (TIMP) in the follicular fluid of normally ovulating women and women with the polycystic ovary syndrome (PCOS).

Design: Prospective study.

Setting: IVF unit and endocrine research unit.

Patient(s): Fourteen patients undergoing IVF treatment (seven with normal ovulation and seven with PCOS).

Main Outcome Measure(s): Activity of MMP-2 and MMP-9 and expression of MMP-1, TIMP-1, and TIMP-2 was measured in follicular fluid of the leading follicles by using gel zymography and immunoblot analysis.

Result(s): The activity of MMP-2 and MMP-9 and expression of MMP-1 was similar in follicular fluid of normally ovulating patients and patients with PCOS. Significantly lower expression of TIMP-1 was found in follicular fluid of patients with PCOS women compared with normally ovulating patients.

Conclusion(s): Because MMPs and TIMPs play a role in the physical and chemical structure of the follicular compartment, the decreased expression of TIMP in patients with PCOS may be part of a compensatory process to overcome the physical properties of the thick ovarian capsule.