Berssenbrugge A D, Goodfriend T L, Ball D L, Rankin J H
Am J Obstet Gynecol. 1980 Mar 15;136(6):762-7. doi: 10.1016/0002-9378(80)90453-6.
The pressor response to angiotensin II was measured in unanesthetized, chronically catheterized pregnant and nonpregnant rabbits. Angiotensin II was infused intravenously for 10 minutes at a dose of 50 and 124 ng/kg/min. No difference in control mean arterial blood pressure was observed between pregnant and nonpregnant rabbits. The pressure change in response to angiotensin II was significantly greater in nonpregnant rabbits than in pregnant rabbits (P less than 0.002). Plasma samples were analyzed for angiotensin II concentration by radioimmunoassay. The results showed that there was no difference in plasma angiotensin II concentration between pregnant and nonpregnant rabbits following angiotensin II infusions. In a separate series we observed the effect of 5 mg of phenoxybenzamine on the pressor response to angiotensin II. After phenoxybenzamine treatment the control mean arterial blood pressure was significantly greater in nonpregnant rabbits than in pregnant rabbits, but the change in pressure in response to angiotensin II in nonpregnant rabbits was not significantly different from that of pregnant rabbits. These results show (1) that pregnant rabbits have a decreased sensitivity to angiotensin II, (2) that this decreased sensitivity is not due to differences in plasma concentration of angiotensin II, and (3) that this differential sensitivity to angiotensin II can be prevented by alpha-receptor blockade.
在未麻醉、长期插管的怀孕和未怀孕兔子中测量对血管紧张素II的升压反应。以50和124 ng/kg/分钟的剂量静脉输注血管紧张素II 10分钟。怀孕和未怀孕兔子之间的对照平均动脉血压未观察到差异。未怀孕兔子对血管紧张素II的压力变化明显大于怀孕兔子（P小于0.002）。通过放射免疫分析法分析血浆样本中的血管紧张素II浓度。结果表明，血管紧张素II输注后，怀孕和未怀孕兔子的血浆血管紧张素II浓度没有差异。在另一个系列中，我们观察了5毫克酚苄明对血管紧张素II升压反应的影响。酚苄明治疗后，未怀孕兔子的对照平均动脉血压明显高于怀孕兔子，但未怀孕兔子对血管紧张素II的压力变化与怀孕兔子没有显著差异。这些结果表明：（1）怀孕兔子对血管紧张素II的敏感性降低；（2）这种敏感性降低不是由于血管紧张素II血浆浓度的差异；（3）这种对血管紧张素II的差异敏感性可以通过α受体阻断来预防。
