Karstoft J, Bååth L, Jansen I, Edvinsson L
Department of Diagnostic Radiology, University Hospital, Malmö, Sweden.
Acta Radiol. 1995 May;36(3):312-6.
Angiographic contrast media (CM) may cause both vasodilatation and vasoconstriction, effects that can only be partly be explained by the media's hyperosmolality. The present study describes a CM-induced vasoconstriction of isolated rabbit coronary arteries that depends on chemotoxicity and ion content of the CM. Rings of arteries were mounted in tissue baths and the constrictions induced by different CM were measured. Iotrolan and iodixanol (non-ionic dimers) caused the most powerful constrictions followed by iohexol (non-ionic monomer) and mannitol. Ioxaglate (ionic dimer) and diatrizoate (ionic monomer) caused no or weak constrictions. By comparing these findings with previous studies, it is concluded that non-ionic media cause vasoconstriction due to depolarization of the smooth muscle cells, an effect that for iohexol can be counteracted by addition of 30 mM NaCl. The ionic media seem to cause hyperpolarization of the cells. This difference between non-ionic and ionic CM might be one of the reasons for the lower tendency of non-ionic CM to cause vasodilatation clinically.
血管造影剂（CM）可引起血管扩张和血管收缩，而这些效应仅部分可由造影剂的高渗性来解释。本研究描述了一种由CM诱导的离体兔冠状动脉血管收缩，该收缩取决于CM的化学毒性和离子含量。将动脉环安装在组织浴槽中，测量不同CM诱导的血管收缩。碘曲仑和碘克沙醇（非离子二聚体）引起的收缩最强烈，其次是碘海醇（非离子单体）和甘露醇。碘克沙酸盐（离子二聚体）和泛影酸盐（离子单体）未引起或仅引起微弱收缩。通过将这些发现与先前的研究进行比较，得出结论：非离子型造影剂由于平滑肌细胞去极化而导致血管收缩，对于碘海醇，这种效应可通过添加30 mM氯化钠来抵消。离子型造影剂似乎会导致细胞超极化。非离子型和离子型CM之间的这种差异可能是临床上非离子型CM引起血管扩张倾向较低的原因之一。
