Factors affecting human placental transfer of anesthesia-related drugs.

异丙酚在人胎盘中的双通道传递研究利用人胎盘双通道传递（单通道模式），研究了子宫血流量、脐静脉血流量和白蛋白浓度（蛋白结合）对异丙酚胎盘传递的影响。根据不同流量或不同白蛋白浓度的母体和胎儿灌注液的胎盘清除率评价胎盘转移。将安替比林添加到母体灌注液中作为参考。结果表明：（1）在母体白蛋白水平不变的情况下，随着胎脑灌注液中白蛋白浓度的增加，胎脑灌注液中丙泊酚浓度和丙泊酚清除率均增加，而游离丙泊酚浓度和安替比林清除率均不变。(2)随着母体灌流液中白蛋白浓度的增加，胎儿流出液中丙泊酚浓度和胎盘清除率降低。(3)随着母体血流量的增加，胎儿流出液中丙泊酚浓度增加，丙泊酚和安替比林的清除率增加（清除率不变）。(4)随着胎血流量的增加，丙泊酚的血药浓度无明显变化，而丙泊酚的清除率呈流量依赖性增加，安替比林的清除率有上限。(5)结论：本模型能准确描述药物在胎盘组织中的转运，而传统的母体和胎儿血药浓度（F/M）的测定受子宫血流量、脐静脉血流量以及母体和脐静脉血中蛋白结合的影响较大

Placental transfer of porpofol in human dually per fused cotyledon in vitro.We investigated the effects of uterine and umbilical blood flow and albumin concentration (protein binding) on the placental transfer ofpropofol by using the dually per fused human placental cityledon(single pass mode). Placental transfer was evaluated on the basis ofplacental clearaces at various flow rates or albumin concentrations of maternal and fetal perfusates. Antipyrine was added to the maternal perfusate as a reference. As results, (l) With increasing albumin concentrations of the fetal perfusate at constant maternal albumin level, propofol concentrations of fetal perfusate and its clearance were increased while both unbound propofol concentration and antipyrine clearance were unchaged. (2) With increasing albumin concentrations of maternal perfusate, propofol concentration of fetal outflow and placental clearance were decreased. (3) With increasing maternal blood flow, the propofol concentration of fetal out flow was increased while both clearance ofpropofol and antipyrine were increased (clearance ratio was constant). (4) With increasing fetal blood flow, the propofol concentration of fetal out flow was unchanged while clearance of propofol was flow-dependency increased but clearance of antipyrine showed ceiling.(5) Propofol significantly partitioned to placental tissues and the placenta would act as a condenser.In summary, our model could exactly denote the placental transfer of drug using the parameter of clearance while traditional determination of maternal and fetal blood concentration (F/M ratio) was extremely influenced with uterine blood flow, umbilival blood flow, and protein binding in maternal and umbilical blood