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Transfer of aspirin across the perfused human placental cotyledon

1991; Elsevier BV; Volume: 165; Issue: 4 Linguagem: Inglês

10.1016/0002-9378(91)90444-v

1097-6868

Robert L. Jacobson, Anthony S. Brewer, Annie Eis, Tariq A. Siddiqi, Leslie Myatt,

Cardiovascular Issues in Pregnancy

Pregnancy-induced hypertension is associated with a reduction in prostacyclin synthesis that is relative to normotensive pregnancy, whereas thromboxane A2 synthesis is unchanged or increased. The net effect is a decreased prostacyclin/thromboxane ratio that may result in the reduced fetal-placental blood flow seen in pregnancy-induced hypertension because thromboxane is known to constrict this circulation. Low-dose aspirin (acetylsalicylic acid), which is used to treat pregnancy-induced hypertension, selectively inhibits thromboxane synthesis and therefore may alter fetal-placental blood flow. We have investigated the transfer of acetylsalicylic acid in the perfused human placental cotyledon and its effects on fetal-placental perfusion pressure. Human placental cotyledons were perfused with tissue culture medium 199 plus 5% polyvinylpyrrolidone that was gassed with 95% oxygen/5% carbon dioxide at flow rates of 10 ml/min (maternal) and 4 ml/min (fetal). Acetylsalicylic acid (10-5 mol/L) was added to the maternal circuit, and cotyledons were perfused for 1 hour with aliquots taken from a closed fetal circuit every 5 minutes. Acetylsalicylic acid was assayed by spectrofluorometry at 306/412 nm. Our data indicate an initial rapid transfer of ascetylsalicylic acid during the first 5 minutes into the fetal-placental circulation, the concentration then decreased to a steady state at 0.4 x 10-5 mol/L Resting perfusion pressure of both maternal and fetal circulation did not change after the addition of acetylsalicylic acid to maternal perfusate and transfer to the fetal circulation.