Lundgren Y, Karlsson K, Ljungblad U
Acta Obstet Gynecol Scand Suppl. 1984;118:85-90. doi: 10.3109/00016348409157130.
Clinical as well as experimental studies have demonstrated a 70% reduction in utero-placental blood flow in pregnancies affected by severe hypertension (13, 19). In pregnant renal hypertensive rats, propranolol administration causes a further 50% reduction in utero-placental blood flow (16). The present study on renal hypertensive rats was performed in order to explore the acute effects on central haemodynamics and utero-placental blood flow of the non-selective beta-blocker pindolol, which also has an intrinsic beta-stimulatory effect. Renal hypertension was induced by partial clamping of both renal arteries in female Wistar rats 4 weeks before pregnancy. Some 2-4 days before expected parturition, cardiac output was determined with the dye-dilution technique and blood flow to the reproductive organs with the microsphere technique, both before and after acute pindolol administration. Mean arterial pressure and heart rate were recorded continuously during the experiment. After pindolol injection, mean arterial pressure fell by 22% due to a 38% reduction in total peripheral resistance. No significant changes in cardiac output, stroke volume or heart rate were found. Placental blood flow was significantly reduced, by 30%, whereas myometrial and ovarian blood flows were reduced by only 18 and 9%, respectively. Thus, the reduction in blood supply to the reproductive organs in renal hypertensive rats after acute pindolol administration was most pronounced in the placenta. This reduction in placental flow was, however, only about half as pronounced as after propranolol, which lacks intrinsic beta-stimulatory effects. This may suggest that vasodilating beta-receptors may play an important role in the maternal placental vascular bed.
临床研究以及实验研究均表明，患有严重高血压的孕妇，其子宫 - 胎盘血流量会减少70%（参考文献13, 19）。在妊娠肾性高血压大鼠中，给予普萘洛尔会使子宫 - 胎盘血流量进一步减少50%（参考文献16）。本研究以肾性高血压大鼠为对象，旨在探究具有内在β - 刺激作用的非选择性β受体阻滞剂吲哚洛尔对中心血流动力学及子宫 - 胎盘血流量的急性影响。在雌性Wistar大鼠怀孕前4周，通过部分夹闭双侧肾动脉诱导产生肾性高血压。在预计分娩前约2 - 4天，分别于急性给予吲哚洛尔前后，采用染料稀释技术测定心输出量，采用微球技术测定生殖器官血流量。实验过程中持续记录平均动脉压和心率。注射吲哚洛尔后，由于总外周阻力降低38%，平均动脉压下降了22%。心输出量、每搏输出量或心率未发现显著变化。胎盘血流量显著减少了30%，而子宫肌层和卵巢血流量仅分别减少了18%和9%。因此，急性给予吲哚洛尔后，肾性高血压大鼠生殖器官的血液供应减少在胎盘中最为明显。然而，这种胎盘血流量的减少程度仅约为缺乏内在β - 刺激作用的普萘洛尔给药后的一半。这可能表明血管舒张性β受体在母体胎盘血管床中可能起重要作用。
