Plasma angiotensin I and serum placental leucine aminopeptidase (P-LAP) in pre-eclampsia.

A study was undertaken on serial measurements of plasma angiotensin I (A-I) and serum placental leucine aminopeptidase (P-LAP) activities in normal and pre-eclamptic pregnancy. There was the significant difference in A-I levels between normal and mild pre-eclamptic pregnancy at weeks 30, 35, 37, between normal and severe pre-eclamptic pregnancy at week 37. There were no differences in serum P-LAP between normal and mild pre-eclamptic pregnancy up to week 33, but thereafter the levels for the mild pre-eclampsia were significantly higher than for the normal pregnancy. The P-LAP activity for the severe pre-eclampsia reached its maximum level at week 31. Around this week, the levels for severe pre-eclampsia were significantly higher than in the normal pregnancy. After week 35, the activities decreased precipitously to week 40; the activities for severe pre-eclampsia in late pregnancy at weeks 39 and 40 were significantly lower than in normal pregnancy. The above data support the idea that P-LAP test is useful for prediction or diagnosis of pre-eclampsia.