Heistad D D, Marcus M L, Law E G, Armstrong M L, Ehrhardt J C, Abboud F M
J Clin Invest. 1978 Jul;62(1):133-40. doi: 10.1172/JCI109097.
Morphologic observations suggest that the inner layers of the thoracic aorta in man and dog are avascular and the outer layers have vasa vasorum. It appears that vasa vasorum are essential in the thoracic aorta because their interruption produces medial necrosis. These experiments provide the first measurements of blood flow through aortic vasa vasorum and examine physiologic regulation of that flow. During control conditions the outer two-thirds of the media of the thoracic aorta received 10 ml/min per 100 g blood flow through vasa vasorum. Flow to the inner third of the aorta was 1 ml/min per 100 g. Flow to both the inner and outer media of the abdominal aorta was less than 1 ml/min per 100 g. Adenosine increased blood flow to vasa vasorum in the outer media of the thoracic aorta from 7 to 18 ml/min per 100 g, but did not increase flow to the inner layers of the aorta. Hemorrhagic hypotension decreased flow in the outer media of the thoracic aorta from 14 to 2 ml/min per 100 g. Acute hypertension failed to increase blood flow through vasa vasorum, as conductance decreased significantly. These studies indicate that vasa vasorum provide a considerable amount of blood flow to the outer layers of the thoracic aorta. The vessels are responsive to physiologic stimuli because they dilate during infusion of adenosine and constrict during both hemorrhagic hypotension and acute hypertension. We speculate that the failure of blood flow to the aortic wall to increase during acute hypertension might, if it were sustained, contribute to aortic medial necrosis.
形态学观察表明,人和狗的胸主动脉内层无血管,外层有滋养血管。滋养血管在胸主动脉中似乎至关重要,因为其阻断会导致中层坏死。这些实验首次测量了通过主动脉滋养血管的血流量,并研究了该血流的生理调节。在对照条件下,胸主动脉中层外三分之二通过滋养血管接受的血流量为每100克10毫升/分钟。流向主动脉内三分之一的血流量为每100克1毫升/分钟。腹主动脉内、外层的血流量均小于每100克1毫升/分钟。腺苷使胸主动脉外层滋养血管的血流量从每100克7毫升/分钟增加到18毫升/分钟,但未增加主动脉内层的血流量。出血性低血压使胸主动脉外层的血流量从每100克14毫升/分钟降至2毫升/分钟。急性高血压未能增加通过滋养血管的血流量,因为血管传导性显著降低。这些研究表明,滋养血管为胸主动脉外层提供了相当数量的血流量。这些血管对生理刺激有反应,因为在输注腺苷时它们会扩张,而在出血性低血压和急性高血压时会收缩。我们推测,如果急性高血压期间主动脉壁的血流量持续不增加,可能会导致主动脉中层坏死。