Alteration of circulating Placental Leucine Aminopeptidase (P-LAP) activity in preeclampsia.
OBJECTIVE
Placental Leucine Aminopeptiadse (P-LAP) also known as oxytocinase, is secreted by syncytiotrophoblast and increases gradually during pregnancy until delivery. It is a regulator of uterine contractions, of vascular resistance and of volume of the retroplacental blood pool. Recently, it was shown that it could also regulate metalloproteinase 9 activity and thus, invasiveness of trophoblastic cells. Since development of preeclampsia could be initiated by decreased cytotrophoblastic invasion of spiral arterioles and a reduced uteroplacental perfusion, we speculate that circulating P-LAP activity could be decreased during preeclampsia.


METHODS
Case-control study was evaluated in 84 women. P-LAP activity was measured in n=51 healthy pregnant women at term, and compared with n=16 normotensive women delivering preterm and n=17 women diagnosed with pre-eclampsia. P-LAP activity was determined by colorimetry in plasma samples using L-Leucine-p-nitroanilide as substrate.


RESULTS
P-LAP activity was significantly lower in sera of preeclamptic women (0.91+/-0.122 mDO/min) as compared to normotensive controls (1.41+/-0.103 mDO/min; p=0.003) irrespective of time of delivery.


CONCLUSIONS
These findings confirm the probable involvement of P-LAP in trophoblast invasion and development of preeclampsia.
Department of Anesthesiology, University of Washington Medical Center, Seattle, WA , USA.
Ruth
R
Landau
Alexandra
A
Laverrière
Paul
P
Bischof
Olivier
O
Irion
Michel
M
Morales
Marie
M
Cohen
D016022:Case-Control Studies; D010122:Cystinyl Aminopeptidase / Q000097:blood* / Q000378:metabolism*; D015536:Down-Regulation; D004789:Enzyme Activation; D005260:Female; D005865:Gestational Age; D006801:Humans; D011225:Pre-Eclampsia / Q000097:blood* / Q000201:enzymology* / Q000378:metabolism; D011247:Pregnancy; D047928:Premature Birth / Q000097:blood / Q000201:enzymology / Q000378:metabolism; D012720:Severity of Illness Index; D047929:Term Birth / Q000097:blood / Q000378:metabolism
D010122:Cystinyl Aminopeptidase; C105964:leucyl-cystinyl aminopeptidase