Wang Y X, Emery C J, Laude E, Morcos S K
Department of Experimental Medicine, Sheffield University Medical School, UK.
Br J Radiol. 1997 Dec;70(840):1229-38. doi: 10.1259/bjr.70.840.9505841.
The aim of the study was to establish the direct effects of radiographic contrast media (RCM) on the tension of isolated small pulmonary arteries and to investigate any mediation by nitric oxide (NO) and endothelin (ET). Small pulmonary arteries (0.3-0.6 mm in diameter) from male Wistar rats were mounted in a Cambustion vessel myograph and vessel wall tension recorded. The effects of 10, 20, 40, 80, 150, 200 and 250 mgl mI-1 of diatrizoate, ioxaglate, iopromide and iotrolan and their mannitol osmolar control from basal condition, and when the vessels were preconstricted with prostaglandin F2 alpha (PGF2 alpha) either submaximally (10 microM) or maximally (100 microM), were studied. The constrictor response to diatrizoate (40 mgI ml-1) was tested in the presence of non-selective endothelin receptor antagonist (10 microM SB209670). The dilator response to ioxaglate (80 mgI ml-1) was tested in the presence of L-nitroarginine methyl ester (L-NAME, 100 microM). All RCM caused biphasic changes in tension, a small transient fall (dilatation) followed by a sustained rise (constriction). Mannitol caused constriction only. The potency order of constrictions at 10-40 mgI ml-1 was diatrizoate > iopromide > ioxaglate > iotrolan. When the vessels were preconstricted with PGF2 alpha, RCM caused predominantly dilatation; ioxaglate produced the largest effect (-42.1 +/- 3.1%, n = 12). Mannitol caused constriction only. SB209607 had no effect on the constrictor effect of diatrizoate [41.9 +/- 2.3 alone, 42.1 +/- 2.7 with SB209670, n = 10]. L-NAME had no effect on the dilator response to ioxaglate [-38.2 +/- 1.6 alone, -43.6 +/- 2.2 with L-NAME, n = 8]. It is tempting to postulate that dimeric RCM may cause the least changes in the pulmonary circulation during angiography.
本研究的目的是确定放射造影剂（RCM）对离体小肺动脉张力的直接影响，并研究一氧化氮（NO）和内皮素（ET）的任何介导作用。将雄性Wistar大鼠的小肺动脉（直径0.3 - 0.6毫米）安装在Cambustion血管肌动描记器中，并记录血管壁张力。研究了10、20、40、80、150、200和250毫克/毫升的泛影葡胺、碘克沙酸、碘普罗胺和碘曲仑及其甘露醇渗透压对照在基础状态下以及当血管用前列腺素F2α（PGF2α）亚最大程度（10微摩尔）或最大程度（100微摩尔）预收缩时的作用。在非选择性内皮素受体拮抗剂（10微摩尔SB209670）存在的情况下，测试了对泛影葡胺（40毫克/毫升）的收缩反应。在L - 硝基精氨酸甲酯（L - NAME，100微摩尔）存在的情况下，测试了对碘克沙酸（80毫克/毫升）的舒张反应。所有RCM均引起张力的双相变化，先是短暂的小幅下降（扩张），随后是持续上升（收缩）。甘露醇仅引起收缩。在10 - 40毫克/毫升时收缩作用的强度顺序为泛影葡胺＞碘普罗胺＞碘克沙酸＞碘曲仑。当血管用PGF2α预收缩时，RCM主要引起扩张；碘克沙酸产生的作用最大（-42.1±3.1%，n = 12）。甘露醇仅引起收缩。SB209607对泛影葡胺的收缩作用无影响[单独时为41.9±2.3，与SB209670共同作用时为42.1±2.7，n = 10]。L - NAME对碘克沙酸的舒张反应无影响[单独时为-38.2±1.6，与L - NAME共同作用时为-43.6±2.2，n = 8]。很诱人推测二聚体RCM在血管造影期间可能对肺循环引起的变化最小。
