摘要
目的：观察X线造影剂（radiographiccontrastmedia，RCM）对肺阻力血管（直径0．3～0．6mm的微动脉）张力的影响。材料与方法：肺阻力动脉从Wistar大鼠肺中分离而得，制备成条状浸于生理盐溶液（Phsiologiocalsaltsolution，PSS）中，并供给95％O2/5％CO2的混合气体。动脉条给予17.5mmHg被动跨壁压力，动脉条的张力通过力传感仪自动记录。实验包括下述部分：（1）浸于PSS中的动脉条暴露于各种浓度（10、20、40、80、150、200、250mgI／ml）的RCM及其甘露醇渗透压对照溶液中20分钟，观察动脉条的张力改变，RCM包括Diatrizoate，Ioxaglate、Iopromide及4种；（2）浸于PSS中的动脉条先由前列腺素F2α引起收缩，再暴露于80mgI／ml上述RCM及其甘露醇对照溶液中20分钟，观察动脉条的张力改变；（3）浸于PSS中的动脉条暴露于250mgI／ml上述RCM及其甘露醇对照溶液2分钟后即将血管槽内溶液再换成RSS，观察动脉条的张力改变。结果：（1）所有RCM均引起动脉条张力的观相性改变，包括初始短暂的舒张相和随后持续的收缩相，甘露醇溶液只引起收缩相；（2）RCM的血管收缩效果与其种类和浓度有关，Diatrizoate＞Io-promide＞Ioxaglate＞Iotrolan，Diatrizoate在40mgI／ml时其收缩作用最强，Iopromide在150mnI／ml时最强?
Objective:To study the effects of radiographic contrast media (RCM) on the tension of isolated pulmonary resistant arteries (PRA).Materials and Methods: PRAs (small arteries with diameter of 0. 3 ～ 0. 6mm) were dissected off from Wistar rat lungs and mounted as rings preparations bathed in normal saline, which was gassed with 95 % O2 and 5 % CO2. A passive transmural pressure of 17. 5mmHg was added and the tension of the rings was recorded automatically using a force transducer. The following experiments were Conducted: (1) Arterial rings bathed in normalsaline were exposed to Diatrizoate, Ioxaglate, Iopromide and Iotrolan with various concentration (10, 20, 40, 80, 150, 200, and 250mgI/ml) and totheir osmolar-controlled solutions of mannitol for 20min. The change of tension was observed. (2) Arterial rings, which were bathed in normal salineand Pre-constricted by 1O-5mol/L or 1O-4mol/L PGF2α, were exposed to 80mgI/ml of above listed RCM and mannitol control Solutions for 20 minutes. (3) Arterial rings, which were bathed in normal saline, were exposed to 250mgI/ml of above listed RCM and their mannitol control solutionsfor 2 minutes. After being tested with each RCM, the rings were washed with normal saline, then left to relax to base tension. Results: (1 ) All tested RCM caused biphasic change of tension of artery rings, with initial temporal Phase of dilatation and followed by a sustained phase of constriction.The mannitol control solutions caused only a vasoconstriction. (2) The magnitude of vasoconstriction effects was dose and RCM dependent in the fol-lowing orders: Diatrizoate > Iopromide > Ioxaglate > Iotrolan. Diatrizoate reached its peak response at 40mgI/ml, Iopromide at 80mgI/ml,Ioxaglate at 150mgI/ml, and Iotrolan at 200mgI/ml. At higher doses their vasoconstriction effects started to decrease. (3) The biphasic responses ofartery rings to RCM were reproduced when Pre-constricted by PGF2α, the dilatation response was more apparent, the largest vasodilatation was ob-served with Ioxaglate and the smallest vasodilatation was seen with Iotrolan. Mannitol solutions caused only a vasoconstriction. (4) A rebound vaso-constriction was observed when the bath solution changed to pure normal saline after 2 minutes exposure to 250mgI/ml Diatrizoate. The vasoconstric-tion lasted for about 20 minutes before it retumed to base line. This response was not apparent with the other RCM, but it was observed with saturatedmannitol solutions. Conclusion: RCM can induce alterations of the tension of isolated resistant pulmonary arteries, Diatrizoate is the most vasoactiveagent, and Iotrolan is the least vasoactive agent. The vasorelaxant property of RCM is not dependent on their high osmolarity.
出处
《临床放射学杂志》
CSCD
北大核心
1999年第12期768-771,共4页
Journal of Clinical Radiology
关键词
肺阻力血管
X线造影剂
Contrast media Experiment Pulmonary resistant artery
