Division of Vascular Surgery, University of Massachusetts Medical School, Worcester, Mass 01655, USA.
J Vasc Surg. 2010 Jan;51(1):165-73. doi: 10.1016/j.jvs.2009.08.045. Epub 2009 Oct 30.
The goals of this study were to determine if endothelial nitric oxide synthase (eNOS) affects both early and late collateral arterial adaptation and blood flow recovery after severe limb ischemia in a mouse model and to determine if eNOS-derived NO is necessary for recruitment of chemokine (C-X-C motif) receptor 4 (CXCR4)(+) vascular endothelial growth factor receptor-1 (VEGFR1)(+) hemangiocytes to the site of ischemia.
Two studies were completed. In the first, hind limb ischemia was induced by unilateral femoral artery excision in three groups: C57Bl6 (wild-type), eNOS(-/-), and C57Bl/6 mice treated with N(G)-nitro-L-arginine methyl ester (L-NAME) from 1 day before excision through day 3 after excision (early L-NAME group). These groups were studied on day 3 after induction of ischemia. In the second study, hind limb ischemia was induced in C57Bl/6 mice (wild-type) and C57Bl/6 mice treated with L-NAME from days 3 through 28 after induction of ischemia. These groups were studied day 28 after ischemia induction. Dependent variables included hind limb perfusion, collateral artery diameter, and the number and location of hemangiocytes within the ischemic hind limb.
In the first study, toe gangrene developed in the eNOS(-/-) and early L-NAME treatment groups by day 2. These groups demonstrated less blood flow recovery and smaller collateral artery diameter than the wild-type group. Hemangiocytes were present within the adventitia of collateral arteries in the wild-type group but were only sparsely present, in a random pattern, in the eNOS(-/-) and early L-NAME treatment groups. In the second study, the late L-NAME group showed less blood flow recovery and smaller collateral artery diameter on day 28 of ischemia than the wild-type group. Hemangiocytes were present in a pericapillary distribution in the wild-type group, but were present only sparsely in the late L-NAME treatment group.
Early (day 3) and late (day 28) adaptive responses to hind limb ischemia both require eNOS-derived NO. NO is necessary for normal hemangiocyte recruitment to the ischemic tissue.
本研究旨在确定内皮型一氧化氮合酶（eNOS）是否影响严重肢体缺血后小鼠模型的早期和晚期侧支动脉适应以及血流恢复，并确定 eNOS 衍生的一氧化氮（NO）是否对于趋化因子（C-X-C 基序）受体 4（CXCR4）（+）血管内皮生长因子受体 1（VEGFR1）（+）血管生成细胞招募到缺血部位是必需的。
完成了两项研究。在第一项研究中，通过单侧股动脉切除在三组中诱导后肢缺血：C57Bl6（野生型）、eNOS（-/-）和 C57Bl/6 小鼠，从切除前 1 天至切除后 3 天（早期 L-NAME 组）接受 N（G）-硝基-L-精氨酸甲酯（L-NAME）治疗。这些组在缺血诱导后 3 天进行研究。在第二项研究中，在 C57Bl/6（野生型）和 C57Bl/6 小鼠中诱导后肢缺血，并从诱导后肢缺血的第 3 天至第 28 天接受 L-NAME 治疗。这些组在缺血诱导后 28 天进行研究。因变量包括后肢灌注、侧支动脉直径以及缺血后肢内血管生成细胞的数量和位置。
在第一项研究中，eNOS（-/-）和早期 L-NAME 治疗组在第 2 天出现脚趾坏疽。这些组的血流恢复和侧支动脉直径较小，明显小于野生型组。野生型组的侧支动脉外膜中存在血管生成细胞，但在 eNOS（-/-）和早期 L-NAME 治疗组中仅以稀疏的随机模式存在。在第二项研究中，与野生型组相比，晚期 L-NAME 组在缺血后第 28 天的血流恢复和侧支动脉直径较小。在野生型组中，血管生成细胞呈毛细血管周围分布，但在晚期 L-NAME 治疗组中仅稀疏存在。
后肢缺血的早期（第 3 天）和晚期（第 28 天）适应性反应均需要 eNOS 衍生的 NO。NO 对于正常的血管生成细胞招募到缺血组织是必需的。
