Objectives: Placenta is a known source of some fibrinolytic components in p
regnancy. The aim of the present study is to find out whether myometrium ca
n be a parallel source. Study Design: The study group consisted of 34 women
(16 primaparas and 18 multiparas, 39.0 +/- 0.2 years) in the 36-40th week
of gestation with some obstetric complications: preeclampsia - 11, fetal di
stress - 9, breech presentation - 3, placenta previa - 1, repeat caesarean
birth - 10 cases (20 women were the control group). The strips of myometriu
m as well as samples of venous blood and placenta were collected at the tim
e of caesarean section. The tissue extracts were prepared. The components o
f the plasminogen activator system were measured, i.e. tissue plasminogen a
ctivator (tPA), urokinase plasminogen activator (uPA), plasminogen activato
r inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2). An imm
unoenzymatic method (ELISA) was used. Spearman and Pearson's correlation co
efficients were the main tools of the statistical analysis. Results: The co
ncentration of the fibrinolytic components in blood plasma, placenta and my
ometrium were as follows (ng/mg of total protein): tPA: 0.15 +/- 0.07 blood
plasma), 0.12 +/- 0.05 (placenta), and 1.42 +/- 1.02 (myometrium); uPA: 0.
01 +/- 0.005 (blood plasma), 1.09 +/- 0.25 (placenta), and 0.52 +/- 0.13 (m
yometrium); PAI-1: 2.86 +/- 0.90 (blood plasma), 30.67 +/- 9.31 (placenta),
and 22.29 +/- 11.29 (myometrium); PAI-2: 2.86 +/- 0.90 (blood plasma, 750.
89 +/- 170.29 (placenta), and 24.84 +/- 8.03 (myometrium). Conclusion: Besi
des placenta, myometrium is another important source of fibrinolytic compon
ents in pregnancy. Copyright (C) 2001 S. Karger AG, Basel.