Department of Pharmacology, Biosciences Institute of Botucatu, Sao Paulo State University (UNESP), Botucatu, Sao Paulo, Brazil.
J Cardiovasc Pharmacol. 2020 Dec;76(6):715-729. doi: 10.1097/FJC.0000000000000917.
Perivascular adipose tissue (PVAT) modulates the vascular tone. Hydrogen sulfide (H2S) is synthetized by cystathionine gamma-lyase (CSE) in brown PVAT. Modulation of vascular contractility by H2S is, in part, adenosine triphosphate (ATP)-sensitive potassium channels dependent. However, the role of PVAT-derived H2S in hypertensive pregnancy (HTN-Preg) is unclear. Therefore, we aimed to examine the involvement of H2S in the anticontractile effect of PVAT in aortae from normotensive and hypertensive pregnant rats. To this end, phenylephrine-induced contractions in the presence and absence of PVAT and endothelium in aortae from normotensive pregnant (Norm-Preg) and HTN-Preg rats were investigated. Maternal blood pressure, fetal-placental parameters, angiogenesis-related biomarkers, and H2S levels were also assessed. We found that circulating H2S is elevated in hypertensive pregnancy associated with angiogenic imbalance, fetal and placental growth restrictions, which revealed that there is H2S pathway activation. Moreover, under stimulated H2S formation PVAT, but not endothelium, reduced phenylephrine-induced contractions in aortae from HTN-Preg rats. Also, H2S synthesis inhibitor abolished anticontractile effects of PVAT and endothelium. Furthermore, anticontractile effect of PVAT, but not of endothelium, was eliminated by ATP-sensitive potassium channels blocker. In accordance, increases in H2S levels in PVAT and placenta, but not in aortae without PVAT, were also observed. In conclusion, anticontractile effect of PVAT is lost, at least in part, in HTN-Preg aortae and PVAT effect is ATP-sensitive potassium channels dependent in normotensive and hypertensive pregnant rat aortae. PVAT but not endothelium is responsive to the H2S stimulation in hypertensive pregnant rat aortae, implying a key role for PVAT-derived H2S under endothelial dysfunction.
血管周脂肪组织 (PVAT) 调节血管张力。硫化氢 (H2S) 是由棕色 PVAT 中的胱硫醚 γ-裂解酶 (CSE) 合成的。H2S 对血管收缩性的调节部分依赖于三磷酸腺苷 (ATP) 敏感性钾通道。然而,PVAT 衍生的 H2S 在高血压妊娠 (HTN-Preg) 中的作用尚不清楚。因此,我们旨在研究 H2S 在正常血压和高血压妊娠大鼠主动脉中 PVAT 产生的抗收缩作用中的作用。为此,研究了正常血压妊娠 (Norm-Preg) 和 HTN-Preg 大鼠主动脉中存在和不存在 PVAT 和内皮时,去甲肾上腺素诱导的收缩。还评估了母体血压、胎儿胎盘参数、血管生成相关生物标志物和 H2S 水平。我们发现,与血管生成失衡、胎儿和胎盘生长受限相关的高血压妊娠中循环 H2S 水平升高,表明 H2S 途径被激活。此外,在刺激 H2S 形成的情况下,PVAT 而非内皮,可减少 HTN-Preg 大鼠主动脉中去甲肾上腺素诱导的收缩。此外,H2S 合成抑制剂消除了 PVAT 和内皮的抗收缩作用。此外,ATP 敏感性钾通道阻滞剂消除了 PVAT 的抗收缩作用,但不消除内皮的抗收缩作用。同样,也观察到 PVAT 和胎盘的 H2S 水平增加,但没有 PVAT 的主动脉则没有增加。总之,至少部分 HTN-Preg 主动脉中 PVAT 的抗收缩作用丧失,并且正常血压和高血压妊娠大鼠主动脉中 PVAT 效应依赖于 ATP 敏感性钾通道。在 HTN-Preg 大鼠主动脉中,PVAT 而不是内皮对 H2S 刺激有反应,这表明在内皮功能障碍下,PVAT 衍生的 H2S 起关键作用。