Benter I F, Diz D I, Ferrario C M
Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC, USA.
Hypertension. 1995 Dec;26(6 Pt 2):1138-44. doi: 10.1161/01.hyp.26.6.1138.
We have suggested that angiotensin-(1-7) [Ang-(1-7)] may oppose the pressor activity of angiotensin II (Ang II). This hypothesis was supported by the fact that long-term intravenous infusion of Ang-(1-7) transiently lowers blood pressure in spontaneously hypertensive rats (SHR). We now investigated whether the pressor sensitivity to bolus injections of either phenylephrine (PE) or Ang II was altered on day 12 of an Ang-(1-7) infusion when blood pressure in the SHR had returned to hypertensive levels. SHR (n = 10) and WKY rats (n = 8) were given Ang-(1-7) intravenously via osmotic minipumps at a dose of 24 micrograms/kg per hour for 2 weeks. On day 12 of the infusion, mean arterial pressure and heart rate in halothane-anesthetized rats were similar in Ang-(1-7)-treated SHR (142 +/- 6 mm Hg; 388 +/- 9 beats per minute) and those infused with vehicle (146 +/- 5 mm Hg; 392 +/- 13 beats per minute). Pressor responsiveness to PE in Ang-(1-7)-treated SHR was 22% less at a dose of 10 micrograms, while pressor responses to Ang II decreased by 20% and 25% at doses of 0.05 and 0.1 micrograms, respectively, compared with the vehicle-treated SHR (P < .05). There were no effects of the Ang-(1-7) infusion on pressor responses to Ang II or PE in WKY rats.(ABSTRACT TRUNCATED AT 250 WORDS)
我们曾提出血管紧张素 -（1 - 7）[Ang -（1 - 7）]可能会对抗血管紧张素II（Ang II）的升压活性。这一假说得到了以下事实的支持：长期静脉输注Ang -（1 - 7）可使自发性高血压大鼠（SHR）的血压短暂降低。我们现在研究了在Ang -（1 - 7）输注第12天，当SHR血压恢复到高血压水平时，对去氧肾上腺素（PE）或Ang II推注的升压敏感性是否发生改变。将SHR（n = 10）和WKY大鼠（n = 8）通过渗透微型泵以每小时24微克/千克的剂量静脉给予Ang -（1 - 7），持续2周。在输注第12天，接受Ang -（1 - 7）治疗的SHR中，氟烷麻醉大鼠的平均动脉压和心率（142±6毫米汞柱；每分钟388±9次心跳）与输注溶媒的大鼠（146±5毫米汞柱；每分钟392±13次心跳）相似。与接受溶媒治疗的SHR相比，接受Ang -（1 - 7）治疗的SHR在剂量为10微克时对PE的升压反应性降低了22%，而在剂量为0.05和0.1微克时对Ang II的升压反应分别降低了20%和25%（P <.05）。Ang -（1 - 7）输注对WKY大鼠对Ang II或PE的升压反应没有影响。（摘要截断于250字）
