Department of Vessel Physiology Group, Institute of Vegetative Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Invest Radiol. 2010 Aug;45(8):453-7. doi: 10.1097/RLI.0b013e3181d77eed.
Iodinated contrast media (CM) can potentially cause contrast-induced nephropathy (CIN). It is not clear, however, whether particular types of CM are more prone to cause CIN than others. In this study we compare 4 types of CM (ionic vs. nonionic; monomer vs. dimer) on their effects on the microvessels that supply the area at risk for renal damage in CIN (outer medullary descending vasa recta-DVR).
Using microdissection techniques, single DVR were isolated from rats and perfused using a set of concentric pipettes. After stabilization, perfusate was exchanged for a buffered solution containing either vehicle, or amidotrizoate (an ionic/monomeric CM), ioxaglate (an ionic/dimeric CM), iopromide (a nonionic/monomeric CM), and iodixanol (a nonionic/dimeric CM). The final iodine concentration was 23 mg iodine/mL, a concentration similar to that expected for coronary interventions. At this dilution, properties of CM solutions like viscosity and osmolarity are similar to the vehicle solution. To rule out further influence of CM-osmolarity and viscosity, the DVR bath solution was kept isoosmolar to the perfusate. Angiotensin II dose response curves were performed after the 20 minutes of perfusion. Digital videomicroscopy was used for measurements of luminal diameter.
All types of CM reduced luminal diameter of perfused DVR in a similar manner. After 20 minutes of perfusion, size of DVR were: 45% +/- 7% of initial diameter for the amidotrizoate-group; 53% +/- 6% for the ioxaglate-group; 63% +/- 11% for the iopromide-group; and 49% +/- 8% for the iodixanol-group. Control group remained at 96% +/- 4% of initial diameter. The angiotensin II dose response curves showed greater reactivity for amidotrizoate, iopromide and iodixanol, when compared with controls.
Under conditions where effects of osmolarity and viscosity are kept insignificant, perfusion of DVR using different types of iodinated CM leads to similar constriction of DVR. The response to angiotensin II was enhanced in 3 of the tested CM. This may be an important mechanism in the pathophysiology of CIN.
碘造影剂（CM）可能会导致对比剂肾病（CIN）。然而，目前尚不清楚特定类型的 CM 是否比其他类型更容易引起 CIN。在这项研究中，我们比较了 4 种 CM（离子型与非离子型；单体与二聚体）对供应 CIN 中易损区（外髓下降直小血管-DVR）的微血管的影响。
使用显微解剖技术，从大鼠中分离出单个 DVR，并使用一组同心管进行灌注。稳定后，将灌流液交换为含有载体、氨甲蝶呤（一种离子/单体 CM）、碘海醇（一种离子/二聚体 CM）、碘普罗胺（一种非离子/单体 CM）和碘克沙醇（一种非离子/二聚体 CM）的缓冲溶液。最终碘浓度为 23 毫克碘/毫升，该浓度与预期的冠状动脉介入治疗相似。在这种稀释度下，CM 溶液的粘度和渗透压等特性与载体溶液相似。为排除 CM 渗透压和粘度的进一步影响，将 DVR 浴液保持与灌流液等渗。在灌注 20 分钟后进行血管紧张素 II 剂量反应曲线。数字视频显微镜用于测量管腔直径。
所有类型的 CM 均以相似的方式减少了灌注的 DVR 的管腔直径。灌注 20 分钟后，DVR 的大小为：氨甲蝶呤组为初始直径的 45% +/- 7%；碘海醇组为 53% +/- 6%；碘普罗胺组为 63% +/- 11%；碘克沙醇组为 49% +/- 8%。对照组保持在初始直径的 96% +/- 4%。血管紧张素 II 剂量反应曲线显示，与对照组相比，氨甲蝶呤、碘普罗胺和碘克沙醇的反应性更强。
在保持渗透压和粘度影响无足轻重的条件下，使用不同类型的碘造影剂灌注 DVR 会导致 DVR 相似的收缩。在测试的 3 种 CM 中，对血管紧张素 II 的反应增强。这可能是 CIN 病理生理学中的一个重要机制。
