Angiotensin II immunoreactivity is elevated in ascites during severe ovarian hyperstimulation syndrome: implications for pathophysiology and clinical management.

OBJECTIVE: To investigate the ovarian renin-angiotensin system (RAS) during severe ovarian hyperstimulation syndrome (OHSS).
DESIGN: Simultaneous sampling of blood and ascitic or peritoneal fluid (PF) during therapeutic paracentesis or laparoscopy.
SETTING: University Hospital. PATIENTS: Twelve patients were investigated: three patients presenting severe OHSS, three patients with a spontaneous first trimester pregnancy, three normally cycling women during the early luteal phase, and three patients with ascites of nonovarian origin. MAIN OUTCOME MEASURE: Renin-like activity and angiotensin II (ANG II) immunoreactivity were measured simultaneously in the plasma and the ascites or PF.
RESULTS: Angiotensin II immunoreactivity was much higher in the ascites or PF than in corresponding plasma during severe OHSS, first trimester pregnancy, and in the early luteal phase, while it was lower in ascites of nonovarian origin. Renin-like activity and ANG II immunoreactivity were the highest in the ascites of severe OHSS and in the PF from part of the patients with a spontaneous first trimester pregnancy.
CONCLUSIONS: The present findings argue for the ovarian origin of the elevated renin-like activity and ANG II immunoreactivity in the ascites of severe OHSS and suggest a stimulatory role of hCG on the ovarian RAS whether during severe OHSS or first trimester spontaneous pregnancy. The vasoactive peptide ANG II may contribute to the maintenance of the ascites in severe OHSS but is probably not responsible for the formation of the ascites. The efficiency of paracentesis during severe OHSS could be explained at least partially by the removing of great amounts of ANG II from the peritoneal cavity.