Anderson D F, Phernetton T M, Rankin J H
Am J Obstet Gynecol. 1980 Mar 15;136(6):814-8. doi: 10.1016/0002-9378(80)90461-5.
The placental transfer of acetylsalicylic acid was studied in five near-term ewes and fetuses. The total clearance (Ctot) of acetylsalicylic acid from the fetal compartment was determined by bolus injection of 14C-acetylsalicylic acid into the fetal compartment. Ctot = Cp + Cf where Cp is the placental clearance and Cf is the fetal tissue clearance. 14C-acetylsalicylic acid was then infused into the ewe. Fetal (F) and maternal (M) steady-state concentrations of acetylsalicylic acid were measured. During steady-state conditions, the influx of acetylsalicylic acid into the fetal compartment will equal the efflux, or Cp X (M - F) = Cf X F. Combining these two equations yields the following description of placental clearance: Cp = Ctot x F/M. Using this equation, we calculated Cp = 0.57 +/- 0.12 ml/min . kg and Cf = 1.93 +/- 0.22 ml/min . kg. Maternal and fetal placental flows were also measured using radioactively labeled microspheres. From these flows, a 99% degree of diffusion limitation was determined for the placental transfer of acetylsalicylic acid.
在五只近足月母羊和胎儿身上研究了乙酰水杨酸的胎盘转运情况。通过向胎儿体内一次性注射(^{14}C)-乙酰水杨酸来测定胎儿体内乙酰水杨酸的总清除率（(C_{tot})）。(C_{tot}=C_p + C_f)，其中(C_p)是胎盘清除率，(C_f)是胎儿组织清除率。然后将(^{14}C)-乙酰水杨酸注入母羊体内。测量了胎儿（(F)）和母体（(M)）中乙酰水杨酸的稳态浓度。在稳态条件下，乙酰水杨酸进入胎儿体内的流入量将等于流出量，即(C_p×(M - F)=C_f×F)。将这两个方程结合起来得到胎盘清除率的以下描述：(C_p = C_{tot}×F/M)。使用这个方程，我们计算出(C_p = 0.57 ± 0.12)毫升/分钟·千克，(C_f = 1.93 ± 0.22)毫升/分钟·千克。还使用放射性标记微球测量了母体和胎儿的胎盘血流量。根据这些血流量，确定乙酰水杨酸胎盘转运的扩散限制程度为(99%)。
