Murohara T, Asahara T, Silver M, Bauters C, Masuda H, Kalka C, Kearney M, Chen D, Symes J F, Fishman M C, Huang P L, Isner J M
Department of Medicine (Cardiology) and Department of Cardiothoracic Surgery and Biomedical Research, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02135, USA.
J Clin Invest. 1998 Jun 1;101(11):2567-78. doi: 10.1172/JCI1560.
We tested the hypothesis that endothelial nitric oxide synthase (eNOS) modulates angiogenesis in two animal models in which therapeutic angiogenesis has been characterized as a compensatory response to tissue ischemia. We first administered L-arginine, previously shown to augment endogenous production of NO, to normal rabbits with operatively induced hindlimb ischemia. Angiogenesis in the ischemic hindlimb was significantly improved by dietary supplementation with L-arginine, compared to placebo-treated controls; angiographically evident vascularity in the ischemic limb, hemodynamic indices of limb perfusion, capillary density, and vasomotor reactivity in the collateral vessel-dependent ischemic limb were all improved by oral L-arginine supplementation. A murine model of operatively induced hindlimb ischemia was used to investigate the impact of targeted disruption of the gene encoding for ENOS on angiogenesis. Angiogenesis in the ischemic hindlimb was significantly impaired in eNOS-/- mice versus wild-type controls evaluated by either laser Doppler flow analysis or capillary density measurement. Impaired angiogenesis in eNOS-/- mice was not improved by administration of vascular endothelial growth factor (VEGF), suggesting that eNOS acts downstream from VEGF. Thus, (a) eNOS is a downstream mediator for in vivo angiogenesis, and (b) promoting eNOS activity by L-arginine supplementation accelerates in vivo angiogenesis. These findings suggest that defective endothelial NO synthesis may limit angiogenesis in patients with endothelial dysfunction related to atherosclerosis, and that oral L-arginine supplementation constitutes a potential therapeutic strategy for accelerating angiogenesis in patients with advanced vascular obstruction.
内皮型一氧化氮合酶（eNOS）调节血管生成，在这两种模型中，治疗性血管生成已被表征为对组织缺血的一种代偿反应。我们首先给手术诱导后肢缺血的正常兔子给予L-精氨酸，此前已证明L-精氨酸可增加内源性一氧化氮的产生。与给予安慰剂的对照组相比，通过饮食补充L-精氨酸可显著改善缺血后肢的血管生成；口服L-精氨酸补充剂可改善缺血肢体血管造影显示的血管状况、肢体灌注的血流动力学指标、毛细血管密度以及依赖侧支血管的缺血肢体的血管舒缩反应性。使用手术诱导后肢缺血的小鼠模型来研究编码ENOS的基因靶向破坏对血管生成的影响。通过激光多普勒血流分析或毛细血管密度测量评估，与野生型对照相比，eNOS基因敲除小鼠缺血后肢的血管生成明显受损。给予血管内皮生长因子（VEGF）并不能改善eNOS基因敲除小鼠受损的血管生成，这表明eNOS在VEGF的下游发挥作用。因此，（a）eNOS是体内血管生成的下游介质，（b）通过补充L-精氨酸促进eNOS活性可加速体内血管生成。这些发现表明，内皮一氧化氮合成缺陷可能会限制与动脉粥样硬化相关的内皮功能障碍患者的血管生成，口服L-精氨酸补充剂构成了一种加速晚期血管阻塞患者血管生成的潜在治疗策略。
