Laboratório de Tecnologia em Produção de Fármacos, Centro Universitário Estadual da Zona Oeste, Rio de Janeiro, Brazil.
Am J Hypertens. 2012 Apr;25(4):498-504. doi: 10.1038/ajh.2011.253. Epub 2012 Jan 19.
The purpose of this study was to investigate the contribution of renin-angiotensin system (RAS) and oxidative status on the maternal cardiovascular regulation at the end of pregnancy in normotensive and spontaneously hypertensive rats (SHR).
Blood pressure (BP), mesenteric arterial bed (MAB) reactivity, mesenteric oxidative damage, protein expression, and antioxidant activities were compared between four groups: SHR (SHR-P) and normotensive Wistar controls (W-P) in the 20th day of pregnancy or age-matched nonpregnant rats (SHR-NP and W-NP).
BP in W-P and SHR-P was reduced at the end of pregnancy. The vasodilator effects of angiotensin II (Ang II) and angiotensin 1-7 (Ang-(1-7)) were higher in SHR-P than in other groups. Endothelial nitric oxide synthase (eNOS) expression was increased in W-P and SHR-P compared to nonpregnant groups. Angiotensin-converting enzyme (ACE) and AT(1) receptor expressions were increased in SHR-NP compared to normotensive groups and pregnancy reduced their expressions in SHR. No difference was observed in AT(2) receptor expression among the groups. ACE2 expression was higher in hypertensive than normotensive groups. The levels of thiobarbituric acid-reactive substances (TBARS) were reduced in pregnant compared to nonpregnant groups. Superoxide dismutase (SOD) activity was reduced in SHR-P compared to SHR-NP. However, pregnancy increased catalase (CAT) and glutathione peroxidase (GPx) activities in normotensive rats and SHR, respectively.
The results suggest that the reduction of BP to normal values at the end of pregnancy in SHR may be related to an increased NO production and vasorelaxation to Ang II and Ang-(1-7) associated with decreased expression of vascular ACE and AT(1) receptors and oxidative status.
本研究旨在探讨肾素-血管紧张素系统（RAS）和氧化应激状态对正常血压和自发性高血压大鼠（SHR）妊娠末期母体心血管调节的影响。
比较了 4 组大鼠的血压（BP）、肠系膜动脉床（MAB）反应性、肠系膜氧化损伤、蛋白表达和抗氧化活性：妊娠第 20 天的 SHR（SHR-P）和正常血压 Wistar 对照组（W-P）以及年龄匹配的非妊娠大鼠（SHR-NP 和 W-NP）。
W-P 和 SHR-P 的血压在妊娠末期降低。与其他组相比，SHR-P 对血管紧张素 II（Ang II）和血管紧张素 1-7（Ang-（1-7））的血管舒张作用更强。与非妊娠组相比，W-P 和 SHR-P 的内皮型一氧化氮合酶（eNOS）表达增加。与正常血压组相比，SHR-NP 的血管紧张素转换酶（ACE）和 AT1 受体表达增加，而妊娠则降低了 SHR 中的表达。各组间 AT2 受体表达无差异。与正常血压组相比，高血压组 ACE2 表达更高。与非妊娠组相比，妊娠组丙二醛（TBARS）水平降低。与 SHR-NP 相比，SHR-P 的超氧化物歧化酶（SOD）活性降低。然而，妊娠分别增加了正常血压大鼠和 SHR 中的过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GPx）活性。
研究结果表明，SHR 妊娠末期血压降至正常水平可能与 NO 生成增加和 Ang II 和 Ang-（1-7）的血管舒张作用增强有关，这与血管 ACE 和 AT1 受体表达减少和氧化应激状态有关。
