AUGMENTED PLACENTAL PRODUCTION OF LEPTIN IN PREECLAMPSIA - POSSIBLE INVOLVEMENT OF PLACENTAL HYPOXIA

Preeclampsia (PE) is a hypertensive disorder, which develops in late p regnancy and is usually associated with placental hypoxia and dysfunct ion. We have recently demonstrated that leptin is a novel placenta-der ived hormone in humans and suggested its significance in human pregnan cy (see Ref. 19). To explore the changes in the leptin production in p lacenta in PE, we measured the plasma leptin level and placental lepti n messenger RNA expression in pregnant women with PE. Plasma leptin le vels in preeclamptic women were elevated significantly, compared with gestational age- and body mass index-matched normal pregnant women (P < 0.0001). Plasma leptin levels in the severe PE group were significan tly higher than those in the mild PE group (P < 0.0001). Plasma leptin levels in preeclamptic women were reduced, soon after the placental d elivery, to those expected for their body mass indices. Northern blot analysis revealed that leptin messenger RNA levels are increased in th e placentas from preeclamptic women, compared with normal pregnant wom en. Leptin secretion was increased significantly in a human trophoblas tic cell line (BeWo cells) cultured under hypoxic conditions (5% O-2), compared with those cultured under standard conditions (20% O-2; P < 0.01). The present study demonstrated that placental production of lep tin is augmented in severe PE, probably because of placental hypoxia, thereby suggesting the possible significance of leptin as a marker of placental hypoxia in severe PE.