DECREASED EXPRESSION OF PAI-2 MESSENGER-RNA AND PROTEIN IN PREGNANCIES COMPLICATED WITH INTRAUTERINE PETAL GROWTH-RETARDATION

An increase in plasma plasminogen activator inhibitors (PAIs), fundame ntally PAI type 2 (PAI-2) has been described in normal pregnancy proba bly because the placenta is the main source of the high plasma levels of this protein. Although we have previously described plasmatic alter ations of these inhibitors in pregnancies complicated with intrauterin e fetal growth retardation (IUGR), no reports have been published abou t placental PAI-2 mRNA expression. In the present study, the placental PAI-2 expression determined in pregnancies complicated with IUGR and in severe preeclamptic patients was compared with that of normal pregn ancies in order to identify the placental cell types expressing PAI-2 and to determine whether the production of PAI-2 is altered in placent as from IUGR. In situ hybridization analyses show that the syncytiotro phoblasts are the cells with the greatest PAI-2 expression in placenta . We report that the significant decrease in plasma and placental PAI- 2 levels in IUGR groups is fundamentally due to a diminished expressio n of PAI-2 mRNA in placenta.