Department of Surgery, The Chinese University of Hong Kong, Block B, 5A, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR, China.
World J Surg. 2010 Jul;34(7):1461-9. doi: 10.1007/s00268-010-0520-6.
Endothelial dysfunction related to the loss of nitric oxide (NO) production remains an important issue in cardiac surgery. We examined the hypothesis that AVE3085, a novel compound that enhances eNOS transcription, may protect coronary endothelium against hypoxia-reoxygenation (H-R) injury during cardioplegic arrest and the possible mechanism by which this occurs.
Porcine coronary small arteries (600-800-microm diameter) were subjected to hypoxia (PO(2) <5 mmHg) in St. Thomas cardioplegic (ST) solution with or without AVE3085 (10 microM) or L-arginine (10 mM) at either 37 or 4 degrees C for 60 min, followed by 30-min reoxygenation. Bradykinin (-10 to -6.5 LogM)-induced, endothelium-dependent relaxation was studied in a myograph in U(46619) precontraction before and after H-R. Protein expressions of eNOS and phosphorylated eNOS at Ser-1177 (p-eNOS(Ser1177)) were also determined.
Exposure to ST solution with H-R at both 37 and 4 degrees C markedly reduced bradykinin-induced relaxation in coronary small arteries. Addition of AVE3085 in ST solution at 37 degrees C preserved the vasorelaxant response to bradykinin (95.7 +/- 2.1% vs. 69.2 +/- 6.6%, p < 0.01), with the protective effect comparable to that of L-arginine (96.1 +/- 3.3% vs. 70.6 +/- 8.7%, p < 0.05). eNOS and p-eNOS(Ser1177) expressions in coronary endothelial cells were significantly increased by the addition of AVE3085 in ST solution during hypoxia (p < 0.05). Protection of endothelium-dependent relaxation from H-R by AVE3085 (70.3 +/- 7.2% vs. 90.5 +/- 2.4%, p < 0.05) also reached a level similar to that by L-arginine (69.9 +/- 9.0% vs. 94.7 +/- 3.9%, p < 0.05) at 4 degrees C.
We have demonstrated a new mechanism to protect coronary endothelium from H-R injury by using eNOS enhancers. This may form a new strategy in the future development of cardioplegic/preservation solutions with direct targeting of eNOS expression in coronary vasculature.
与一氧化氮（NO）产生损失相关的内皮功能障碍仍然是心脏手术中的一个重要问题。我们检验了这样一个假设，即 AVE3085 是一种新型化合物，可增强 eNOS 转录，可能在心脏停搏期间保护冠状内皮免受缺氧-复氧（H-R）损伤，以及发生这种情况的可能机制。
猪冠状动脉小动脉（600-800-µm 直径）在 Thomas 心脏停搏液（ST）中进行缺氧（PO（2）<5mmHg），在 37 或 4°C 下进行 60 分钟，然后进行 30 分钟复氧。在 U（46619）预收缩的肌动图中，在 H-R 前后，研究了缓激肽（-10 至-6.5 LogM）诱导的、内皮依赖性舒张。还测定了 eNOS 和磷酸化 eNOS 丝氨酸 1177（p-eNOS（Ser1177））的蛋白表达。
在 37 和 4°C 下，ST 溶液中的 H-R 明显降低了冠状动脉小动脉中缓激肽诱导的舒张反应。在 37°C 下，在 ST 溶液中添加 AVE3085 可保持对缓激肽的血管舒张反应（95.7 +/- 2.1% vs. 69.2 +/- 6.6%，p < 0.01），其保护作用与 L-精氨酸相当（96.1 +/- 3.3% vs. 70.6 +/- 8.7%，p < 0.05）。在缺氧期间，ST 溶液中添加 AVE3085 可显著增加冠状动脉内皮细胞中的 eNOS 和 p-eNOS（Ser1177）表达（p < 0.05）。AVE3085 对 H-R 引起的内皮依赖性舒张的保护作用（70.3 +/- 7.2% vs. 90.5 +/- 2.4%，p < 0.05）也达到了 L-精氨酸（69.9 +/- 9.0% vs. 94.7 +/- 3.9%，p < 0.05）在 4°C 时的水平。
我们已经证明了一种通过使用 eNOS 增强剂来保护冠状动脉内皮免受 H-R 损伤的新机制。这可能为未来发展直接针对冠状动脉血管中 eNOS 表达的心脏停搏/保存溶液提供一种新策略。
