Renin and Inactive Renin in Human Amnion at Term Pregnancy

Immunofluorescent analysis using antiserum to human kidney renin revealed the presence of renin in epithelial cells from human normal term amnion. Enzymatic analysis showed that both active and inactive renin are present. Renin activity was increased by either trypsin or acid treatment. The results suggest that epithelial cells of the amnion may be a source of active and inactive renin known to be present in amniotic fluid. The origin of the renin in the amniotic cells remains to be determined. It may function in physiological or pathological states as a regulator of membrane permeability, placental vascular control, or uterine contractility.