Baile E M, Mayo J R, Sasaki F, Bai T R, Paré P D
University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, British Columbia, Canada.
Acad Radiol. 1995 Nov;2(11):980-4. doi: 10.1016/s1076-6332(05)80700-7.
Contrast agents have been shown to produce vasodilatory responses in several vascular beds. To our knowledge, however, their effect on the bronchial vasculature has not been examined. Clinically, contrast-induced bronchial vasodilation could potentially exacerbate life-threatening pulmonary hemorrhage during bronchial angiography for hemoptysis. In the current study, we systematically measured the bronchial vasodilatory response to diatrizoate meglumine 66% and diatrizoate sodium 10% (MD-76) and examined whether vasodilation would be mediated by nitric oxide (NO).
We measured bronchial blood flow in seven anesthetized, ventilated, open-chested sheep using an ultrasonic flow probe placed around the bronchial artery. Bronchial blood flow was recorded before and after injection of 2 ml MD-76 into the bronchial artery. The protocol was repeated after 20 min infusion of N omega-nitro-L-arginine (L-NA; 10(-2) mol/l), an NO-synthase inhibitor, into the bronchial artery.
There was a 45 +/- 8 ml/min increase (p < .01) in bronchial blood flow after injection of MD-76, which was reduced to 20 +/- 6 ml/min (p < .01) after infusion of L-NA.
Bronchial arterial injection of MD-76 results in a consistent increase in bronchial blood flow that is mediated partly by NO.
造影剂已被证明能在多个血管床产生血管舒张反应。然而，据我们所知，其对支气管血管系统的影响尚未得到研究。在临床上，造影剂诱发的支气管血管舒张可能会在咯血的支气管血管造影过程中加重危及生命的肺出血。在本研究中，我们系统地测量了支气管对66%泛影葡胺和10%泛影酸钠（MD - 76）的血管舒张反应，并研究血管舒张是否由一氧化氮（NO）介导。
我们使用置于支气管动脉周围的超声流量探头，测量了7只麻醉、通气、开胸绵羊的支气管血流量。在向支气管动脉注射2 ml MD - 76之前和之后记录支气管血流量。在向支气管动脉输注20分钟的NO合酶抑制剂Nω - 硝基 - L - 精氨酸（L - NA；10⁻²mol/L）后重复该方案。
注射MD - 76后支气管血流量增加45±8 ml/min（p <.01），输注L - NA后降至20±6 ml/min（p <.01）。
支气管动脉注射MD - 76可导致支气管血流量持续增加，且部分由NO介导。
