INTERACTION BETWEEN PREGNANCY-INDUCED BIOACTIVE PEPTIDES AND THE PLACENTAL PROTEASES

Studies have shown that placental proteases metabolize vasoactive pept ides, possibly derived from the fetus, and protect the exchange of pep tide hormones across the placenta in order to maintain fete-placental homeostasis. Changes in maternal serum protease activities were useful for monitoring pre-eclampsia and predicting the onset of labour. The study showed the possible role of oxytocinase in the maintenance of ge station and the possible involvement of angiotensinase in the attenuat ed presser responses to angiotensin II during pregnancy, respectively. In addition, the ratio of peak systolic over least diastolic pressure (S/D) of uterine or umbilical artery assessed by the Doppler techniqu e was closely correlated with the concentrations of maternal serum pro teases in pre-eclampsia, which suggested that placental proteases migh t control utero-placental circulation via the regulation of concentrat ions of vasoactive peptides in uteroplacental circulation.