Lipopolysaccharide differently affects prostaglandin E₂ levels in fetal and maternal compartments of perfused human term placenta

The aim of the present study was to examine the effect of lipopolysaccharide (LPS) on the levels of prostaglandin E₂ (PGE₂) in the perfusates of the fetal and the maternal compartments of perfused human term placental tissue. Term placentas were perfused for 10 h in the absence [control, (n = 4)] and presence of LPS [LPS = 1 μg/kg perfused placental tissue, (n = 4)] in the maternal reservoir. Perfusate samples from the fetal and the maternal circulations were collected every 30 min and examined for PGE₂ levels by radio-immunoassay. PGE₂ levels in the fetal circulation were gradually increased reaching significant peak value of 479 ± 159 pg/ml, as compared to PGE₂ levels in the maternal circulation (140 ± 146 pg/ml) (p < 0.05). After 10 hours of perfusion with control medium, PGE₂ levels in the maternal circulation (347 ± 144 pg/ml) were significantly higher as compared to the fetal circulation (150 ± 57 pg/ml) (p < 0.05). In presence of LPS, PGE₂ levels in the fetal circulation increased reaching a peak value of 1028 ± 663 pg/ml after 240 min of perfusion. The levels of PGE₂ in the control group after 240 min of perfusion were significantly lower (156 ± 77 pg/ml) (p < 0.05). No significant differences were detected in the levels of PGE₂ in the perfusate of the maternal compartment in presence of LPS, as compared to control. Our results suggest that the placenta may play an important role in maintaining high levels of PGE₂ in the fetal circulation and low PGE₂ levels in the maternal circulation during normal pregnancy. Moreover, placental PGE₂ release into the fetal and the maternal circulations may be differently affected in presence of intra-uterine infection/inflammation.