Vasomotor responses of newly developed coronary collateral vessels.
Vasomotor responses of newly developed coronary collateral vessels.
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新发育的冠状侧支血管的血管舒缩反应。
DOI：
10.1152/ajpheart.1996.271.2.h490
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Bache,RJ
中科院分区：
文献类型：
--
作者：
Kinn,JW;Altman,JD;Chang,MW;Bache,RJ
发达的冠状动脉侧支血管含有丰富的肌层，可以进行主动的血管运动。然而，冠状动脉闭塞后早期，冠脉侧支血管壁薄，几乎没有平滑肌，提示血管运动能力可能是有限的。因此，这项研究确定了新形成的冠脉侧支血管是否具有活跃的血管运动活性，以及这些新形成的血管的内皮功能是否受到损害。在犬冠状动脉前降支闭塞后约2wk测量逆行血流量作为冠脉侧支血流量的指标。将激动剂注入左冠状动脉主干，以到达起源于左冠状动脉系统的侧支。基线逆行血流量为25.1+/-2.7ml/min，硝酸甘油(6微克·kg-1.min-1)治疗后上升至36.7+/-3.7ml/min(P<；0.05)。吲哚美辛5 mg/kg静脉注射阻断环氧合酶逆行侧支血流量降至16.8+/-2.3ml/min(P<；a 0.05)。随后给予乙酰胆碱使逆行血流增加到29.4+/-3.7ml/min(P<；0.05)，表明内皮介导的血管扩张是完整的。用NG-硝基-L-精氨酸抑制一氧化氮合酶可使冠脉侧支循环血流量进一步减少至12.0+/-2.8ml/min(P<；0.05)，并明显钝化对乙酰胆碱的反应。这些发现表明，即使在冠状动脉侧支循环发育的早期，也有很强的血管舒缩能力，并表明一氧化氮和环氧合酶依赖的内皮机制都是完整的。
Well-developed coronary collateral vessels contain an abundant muscular media and can undergo active vasomotion. However, early after coronary occlusion, coronary collateral vessels are thin walled with little smooth muscle, suggesting that vasomotor capability might be limited. Consequently, this study determined whether newly developed coronary collateral vessels have active vasomotor activity and whether endothelial function in these newly developed vessels is impaired. Retrograde blood flow was measured as an index of coronary collateral blood flow approximately 2 wk after embolic occlusion of the anterior descending coronary artery of dogs. Agonists were administered into the left main coronary artery to reach collaterals originating from the left coronary system. Baseline retrograde blood flow was 25.1 +/- 2.7 ml/min and increased to 36.7 +/- 3.7 ml/min after nitroglycerin (6 micrograms.kg-1.min-1, P < 0.05). Cyclooxygenase blockade with indomethacin (5 mg/kg i.v.) decreased retrograde collateral blood flow to 16.8 +/- 2.3 ml/min (P <a 0.05). Subsequent administration of acetylcholine increased retrograde flow to 29.4 +/- 3.7 ml/min (P < 0.05), indicating intact endothelium-mediated vasodilation. Inhibition of nitric oxide synthase with NG-nitro-L-arginine further decreased coronary collateral retrograde flow to 12.0 +/- 2.8 ml/min (P < 0.05) and markedly blunted the response to acetylcholine. These findings demonstrate substantial vasomotor capability even early during coronary collateral development and indicate that both nitric oxide and cyclooxygenase-dependent endothelial mechanisms are intact.