ANGIOTENSIN II-LIKE IMMUNOREACTIVITY IN HUMAN OVARIAN FOLLICULAR FLUID

Abstract

Human ovarian follicular fluid (hFF) has angiogenic activity, although the causative factors are unknown. We recently found that hFF contains renin activity which converts renin substrate to angiotensin I (AI). Since the enzymatic cleavage product of AI, angiotensin II (All), is a potent stimulator of new vessel formation, we have examined Sephadex G-25 column fractions of hFF and extracted hFF and plasma from individual patients forAll-like immunoreactivity (AII-IR). Eluent fractions from Sephadex G-25column chromatography of hFF had significant AII-IR which eluted in the same fractions as synthetic All. Individual, extracted FF samples contained approximately 10 times higher levels of AII-IR than extracts of plasma from the same patients. Serial dilutions of the Sephadex column fractions and extracted FF and plasma inhibited binding of (125)I-AII to rabbit anti-All serum in a manner parallel to the inhibition caused by synthetic All, indicating that the detected immunoreactivity was not dueto non-specific assay interference. In summary, the results indicate the presence of significant All-like immunoreactivity in hFF. Allmay now be considered as a potential mediator of the angiogenic activity present in hFF andmay play an important paracrine and/or autocrine role in physiologic events in the ovary.