Angiopoietin 1 and angiopoietin 2 in follicular fluid of women undergoing a long protocol

Abstract

To determine the concentrations of angiopoietin 1 (ANGPT1) and ANGPT2 in individual human preovulatory follicles in relation to their diameter or volume to clarify the role of these molecules in folliculogenesis. Prospective study. Research laboratory at Kansai Medical University, Osaka, Japan. Twenty-three women undergoing IVF. On the day of oocyte retrieval, serum samples and follicular fluid (FF) from individual follicles were collected. We analyzed 348 follicles. ANGPT1 and ANGPT2 concentrations in FF and serum and oocyte recovery rates. On average, ANGPT1 concentrations in FF were 150 times lower than those in serum, whereas ANGPT2 concentrations in FF were 8 times higher than those in serum. The concentrations of ANGPT1 in follicles with a diameter ≤17 mm were significantly higher than those in follicles with a diameter ≥18 mm. On the other hand, the concentrations of ANGPT2 in follicles with a diameter ≤17 mm were significantly lower than those in follicles with a diameter ≥18 mm. The ANGPT2/ANGPT1 ratio increased with enlargement of follicular diameter. ANGPT1 concentrations in FF decreased with follicular volume. ANGPT2 concentrations and the ANGPT2/ANGPT1 ratio in FF rose with follicular volume. The ANGPT2/ANGPT1 ratio in FF from the oocyte recovery group was significantly higher than that from the nonrecovery group. Our data suggested that the change in ANGPT1 and ANGPT2 levels may be associated with follicular growth and angiogenesis during the preovulatory period.