Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
Microcirculation. 2012 May;19(4):360-72. doi: 10.1111/j.1549-8719.2012.00172.x.
In this paper, we describe the histological and contractile properties of the thoracodorsal artery (TDA), which indirectly feeds the spinotrapezius muscle.
We used immunolabelling techniques to histologically characterize the TDA while the contractile properties were assessed using pressure arteriography.
Our results demonstrate that the TDA is composed of approximately one to two layers of smooth muscle cells, is highly innervated with adrenergic nerves, and develops spontaneous tone at intraluminal pressures above 80 mmHg. The reactivity of the TDA in response to various contractile agonists such as phenylephrine, noradrenaline, angiotensin II, serotonin, endothelin 1, and ATP, as well as vasodilators, shows that the TDA exhibits a remarkably comparable reactivity to what has been observed in mesenteric arteries. We further studied the different components of the TDA response to acetylcholine, and found that the TDA was sensitive to TRAM 34, a blocker of the intermediate conductance potassium channel, which is highly suggestive of an endothelium-dependent hyperpolarization.
We conclude that the TDA exhibits comparable characteristics to other current vascular models, with the additional advantage of being easily manipulated for molecular and ex vivo vasoreactivity studies.
本文描述了间接为斜方肌提供营养的胸背动脉（TDA）的组织学和收缩特性。
我们使用免疫标记技术对 TDA 的组织学特征进行了描述，同时使用压力动脉造影术评估了其收缩特性。
我们的结果表明，TDA 由大约一层到两层平滑肌细胞组成，高度受肾上腺素能神经支配，在管腔内压力超过 80mmHg 时会产生自发张力。TDA 对各种收缩激动剂（如苯肾上腺素、去甲肾上腺素、血管紧张素 II、血清素、内皮素 1 和 ATP）以及血管扩张剂的反应性表明，TDA 表现出与肠系膜动脉相似的反应性。我们进一步研究了 TDA 对乙酰胆碱的不同反应成分，发现 TDA 对 TRAM 34 敏感，TRAM 34 是一种中间电导钾通道阻断剂，这高度提示存在内皮依赖性超极化。
我们得出结论，TDA 表现出与其他现有血管模型相似的特征，并且具有易于进行分子和离体血管反应性研究的额外优势。
