TRANSPORT OF I-125-LABELED ALBUMIN ACROSS NORMAL AND DEENDOTHELIALIZED RABBIT THORACIC AORTA INVIVO
TRANSPORT OF I-125-LABELED ALBUMIN ACROSS NORMAL AND DEENDOTHELIALIZED RABBIT THORACIC AORTA INVIVO
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DOI：
10.1161/01.atv.4.3.283
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发表时间：
1984-01-01
期刊：
影响因子：
--
通讯作者：
LEES, RS
中科院分区：
文献类型：
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作者：
RAMIREZ, CA;COLTON, CK;LEES, RS
在正常和球囊导管去内皮化的兔胸降主动脉上测量了体内125 I-白蛋白的浓度曲线，作为静脉注射后时间的函数。在去内皮化后5或60分钟注射示踪剂，并在循环时间为10、30或60分钟后处死动物。立即切除主动脉并在载玻片之间冷冻平坦。在冷冻切片机中平行于内膜表面连续切片样品，用三氯乙酸（TCA）洗涤并计数。对照组动物中TCA可沉淀放射性的相对组织浓度曲线显示从管腔和外膜侧进入，与先前在清醒正常家兔中发现的一样，但管腔和内外膜边界的空间梯度不太陡。球囊动物的相对浓度水平比对照动物高10- 40倍，曲线更平坦。与去内皮化后5分钟相比，在等效循环时间的实验中，60分钟开始的吸收率更高，这表明球囊损伤后可能发生了进行性中膜水肿。完整的内皮显然是125 I-白蛋白转运通过主动脉壁的主要传质阻力。数据还表明，不完整的单层血小板粘附到内皮下球囊去内皮化后，是不是一个实质性的阻力运输，相比，媒体，对流发挥了更重要的作用比扩散125碘-白蛋白运输通过内皮化的主动脉壁。
Transmural concentration profiles of 125I-albumin in vivo were measured across the normal and balloon catheter-deendothelialized rabbit descending thoracic aorta as a function of time following i.v. injection. A tracer injected 5 or 60 min after deendothelialization, and the animals were sacrificed after circulation times of 10, 30 or 60 min. The aorta was immediately excised and frozen flat between glass slides. Samples were serially sectioned parallel to the intimal surface in a refrigerated microtome, washed with trichloroacetic acid (TCA), and counted. Relative tissue concentration profiles of TCA-precipitable radioactivity from the media of control animals showed entry from both luminal and adventitial sides, as previously found with conscious normal rabbits, but spatial gradients at both luminal and medial-adventitial borders were less steep. Relative concentration levels in ballooned animals were 10- to 40-fold higher than in controls, and the profiles were flatter. Uptake rates at equivalent circulation times were greater in experiments initiated 60 min, as compared with 5 min, after deendothelialization, suggesting that progressive medial edema may have occurred following balloon injury. The intact endothelium evidently is the dominant mass transfer resistance for 125I-albumin transport across the aortic wall. The data also suggest that the incomplete monolayer of platelets adherent to the subendothelium after balloon deendothelialization is not a substantial resistance to transport, as compared to that of the media, and that convection plays a more important role than diffusion for 125I-albumin transport across the endothelialized aortic wall.