PLASMINOGEN ACTIVATORS AND PLASMINOGEN-ACTIVATOR INHIBITORS IN PLASMAOF PREMATURE AND TERM NEWBORNS

Objective: To compare the plasminogen activators (tPA, uPA) and their inhibitors (PAI-1, PAI-2) at different gestational ages, related to le vels in women at term and non-pregnant women. Methods: Blood samples w ere obtained by puncture of the umbilical cord vein? in gestational we eks 39-40 (n = 21), 30-32 (n = 15), and 27-29 (n = 9). Analyses of PA and PAI antigen concentrations and of PAI-1 activity were performed. R esults: The mean tPA antigen level in term newborn infants was 14.5 mu g/l compared to the premature newborns (7.0 mu g/l), women at term (7 .5 mu g/l) and non-pregnant women (2.3 mu g/l). PAI-1 activity and PAI -2 antigen concentrations were also higher in term newborn than in pre mature infants. Conclusions: The plasma levels of the plasminogen acti vators and inhibitors are higher in term newborn compared with prematu re newborn infants, reflecting maturation of protein synthesis.