Piana R N, Banitt P F, Nunez B N, Dai H B, Sellke F W
Cardiovascular Division, Harvard Medical School, Boston, Massachusetts.
Invest Radiol. 1994 Oct;29(10):877-81. doi: 10.1097/00004424-199410000-00003.
Iodinated contrast media can cause a number of well-described acute hemodynamic and vascular effects including vascular spasm, hypotension, and arrhythmias. Coronary microvessels were studied in vitro after high-dose exposure to an ionic, high-osmolar contrast agent diatrizoate meglumine in vivo. The aim of this study was to examine the endothelium-dependent and endothelium-independent vasodilator responses of the microvessels after previous contrast media administration in a clinically relevant setting.
Left coronary angiography was performed on six pigs using a cumulative dose of 60 mL (5 mL/injection) of diatrizoate meglumine. After 1 hour of reperfusion, epicardial coronary microvessels were studied in vitro in a pressurized, no-flow state with video microscopy. The vasodilators bradykinin, calcium ionophore A23187, and sodium nitroprusside were sequentially applied extraluminally after preconstriction. Serotonin and the thromboxane A2 analog U46619 were studied without preconstriction.
Microvessels exposed to diatrizoate meglumine had normal relaxation responses to the endothelium-dependent vasodilators bradykinin and calcium ionophore A23187 when compared to control vessels. The vasoconstrictor responses to U46619 and serotonin were not significantly altered compared to control vessels. Responses to the endothelium-independent vasodilator sodium nitroprusside were not reduced or were slightly enhanced after exposure to contrast media.
Coronary resistance vessels responses to the endothelium-dependent vasodilators bradykinin and calcium ionophore A23187 are not diminished after previous exposure to diatrizoate meglumine. The vasoconstrictor responses to U46619 and serotonin were similarly unaffected by previous exposure to contrast media. This suggests that, when used in clinically relevant amounts, diatrizoate meglumine does not cause functional endothelium or vascular smooth muscle impairment.
碘化造影剂可引发多种已被充分描述的急性血流动力学和血管效应，包括血管痉挛、低血压和心律失常。在体内高剂量暴露于离子型高渗造影剂泛影葡胺后，对冠状动脉微血管进行了体外研究。本研究的目的是在临床相关环境中，检查先前给予造影剂后微血管的内皮依赖性和非内皮依赖性血管舒张反应。
对6头猪进行左冠状动脉造影，使用累积剂量为60 mL（每次注射5 mL）的泛影葡胺。再灌注1小时后，在体外使用视频显微镜在加压无血流状态下研究心外膜冠状动脉微血管。在预收缩后，依次在管腔外应用血管舒张剂缓激肽、钙离子载体A23187和硝普钠。在未预收缩的情况下研究了5-羟色胺和血栓素A2类似物U46619。
与对照血管相比，暴露于泛影葡胺的微血管对内皮依赖性血管舒张剂缓激肽和钙离子载体A23187具有正常的舒张反应。与对照血管相比，对U46619和5-羟色胺的血管收缩反应没有显著改变。暴露于造影剂后，对非内皮依赖性血管舒张剂硝普钠的反应没有降低或略有增强。
先前暴露于泛影葡胺后，冠状动脉阻力血管对内皮依赖性血管舒张剂缓激肽和钙离子载体A23187的反应并未减弱。对U46619和5-羟色胺的血管收缩反应同样不受先前暴露于造影剂的影响。这表明，当以临床相关剂量使用时，泛影葡胺不会导致功能性内皮或血管平滑肌损伤。
