Angiotensin I-converting enzyme in foetal membranes and chorionic cells in culture.

Angiotensin I-converting enzyme (ACE) is found in human amniotic fluid and foetal membranes taken during Caesarean sections at term. ACE contents are higher in the chorion than in the amnion. Cells cultured from chorion contain ACE together with renin. Chorionic ACE was inhibited by captopril and by an excess of anti-ACE immuneserum. It is concluded that extravascular ACE is present in the uteroplacental complex during pregnancy.