Endothelin-renin-angiotensin-atrial natriuretic peptide system in ovaries: an intraovarian ERAANP system

In a recent investigation of the ovary, high levels of endothelin-1 (ET-1), the renin-angiotensin system (RAS), and atrial natriuretic peptide (ANP) were identified. It was determined that ET, RAS, and ANP, alone or together, affected ovarian function. It is important that mutual relationships of these vasoactive and hormonal peptides, which coexist in the ovary, are examined to determine their in vivo functions. This study, using immature rats treated with pregnant mare's serum gonadotropin (PMS), examined the effects of ET-1, angiotensin II (Ang II) and ANP, individually or in combination, on steroidogenesis by granulosa cells (GCs) cultured for 72 h. ET-1 Ang II, and ANP, alone or combined, also had a mutual effect on steroidogenesis. Concomitantly with previous findings on the ovary, the authors propose that the intraovarian endothelin-renin-angiotensin-ANP system (ERAANPS) functions as a novel intraovarian regulator system.