Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
Clin Exp Hypertens. 2011;33(4):223-30. doi: 10.3109/10641963.2011.583967.
Angiotensin (Ang)-(1-7) Ang-(1-7) is formed from angiotensin II by angiotensin-converting enzyme 2 (ACE2) and modulates the renin-angiotensin system. We evaluated whether the Ang-(1-7)-Mas axis in the rostral ventrolateral medulla (RVLM) contributes to neural mechanisms of blood pressure (BP) regulation. We microinjected Ang-(1-7), Ang-(1-7)-Mas receptor antagonist A-779, and ACE2 inhibitor DX600 into the RVLM of anesthetized Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHRs). Unilateral Ang-(1-7) microinjection induced a significantly greater increase in AP (arterial blood pressure) in SHR than in WKY. Bilateral A-779 microinjection induced a significantly greater decrease in AP and renal sympathetic nerve activity in SHR than in WKY. Bilateral DX600 microinjection induced a significantly greater decrease in AP in SHR than in WKY. Our results suggest that endogenous Ang-(1-7) in the RVLM contributes to maintain AP and renal sympathetic nerve activity both in SHR and WKY and that its activity might be enhanced in SHR.
血管紧张素（Ang）-（1-7）血管紧张素（Ang）-（1-7）由血管紧张素转换酶 2（ACE2）从血管紧张素 II 形成，并调节肾素-血管紧张素系统。我们评估了延髓头端腹外侧区（RVLM）中的 Ang-（1-7）-Mas 轴是否有助于血压（BP）调节的神经机制。我们将 Ang-（1-7）、Ang-（1-7）-Mas 受体拮抗剂 A-779 和 ACE2 抑制剂 DX600 微注射到麻醉的 Wistar-Kyoto 大鼠（WKY）和自发性高血压大鼠（SHR）的 RVLM 中。单侧 Ang-（1-7）微注射诱导 SHR 的动脉血压（AP）显著增加，而 WKY 则没有。双侧 A-779 微注射诱导 SHR 的 AP 和肾交感神经活动显著降低，而 WKY 则没有。双侧 DX600 微注射诱导 SHR 的 AP 显著降低，而 WKY 则没有。我们的结果表明，RVLM 中的内源性 Ang-（1-7）有助于维持 SHR 和 WKY 的 AP 和肾交感神经活动，并且其活性可能在 SHR 中增强。
