Department of Surgery and Anatomy, Ribeirão Preto Medical School, São Paulo University, Ribeirão Preto, São Paulo, Brazil.
Cardiovasc Pathol. 2010 Nov-Dec;19(6):e211-20. doi: 10.1016/j.carpath.2009.11.002. Epub 2010 Jan 8.
The effect of short duration and different degrees of distension pressures was investigated by means of immunohistochemistry of the three nitric oxide synthase isoforms in the human saphenous vein conventionally harvested from 20 patients submitted to coronary artery bypass graft. The human saphenous vein distal portion was divided into four segments, each one allocated to a different group. In Group I (control group), the human saphenous vein segment was not exposed to distension pressure. In Groups II, III, and IV, the human saphenous vein segment was exposed to 100, 200, and 300 mmHg of distension pressure, respectively. The distension pressures were applied and maintained with Krebs solution for 15 s. The human saphenous vein of the control group presented endothelial nitric oxide synthase and neuronal nitric oxide synthase in both endothelial and smooth muscle cells, while the inducible nitric oxide synthase appeared predominantly in the medial layer. Neither 100 nor 200 mmHg of pressurization affected the immunostaining of any nitric oxide synthase isoform. However, the human saphenous vein segments exposed to 300 mmHg of distension pressure showed a reduction in endothelial nitric oxide synthase content in the endothelium, but not in the tunica media. This lower endothelial nitric oxide synthase immunostaining in the intimal cells was associated with endothelial denudation. Therefore, we conclude that care should be taken when handling the human saphenous vein since just a few seconds of distension pressure above the normal systemic pressure can be sufficient to disrupt the endothelium reducing the amount of endothelial nitric oxide synthase and impairing the graft quality.
通过对 20 例接受冠状动脉旁路移植术的患者常规采集的人隐静脉中的三种一氧化氮合酶同工型进行免疫组织化学染色，研究了短时间和不同程度扩张压力的影响。将人隐静脉远段分为四段，每段分配到一个不同的组。在 I 组（对照组）中，人隐静脉段不暴露于扩张压力。在 II 组、III 组和 IV 组中，人隐静脉段分别暴露于 100、200 和 300mmHg 的扩张压力，扩张压力应用和维持用 Krebs 溶液持续 15s。对照组的人隐静脉在血管内皮细胞和平滑肌细胞中均存在内皮型一氧化氮合酶和神经元型一氧化氮合酶，而诱导型一氧化氮合酶主要存在于中膜层。100mmHg 和 200mmHg 的加压均未影响任何一氧化氮合酶同工型的免疫染色。然而，暴露于 300mmHg 扩张压力的人隐静脉段显示内皮一氧化氮合酶在内皮中的含量减少，但中膜层没有。内膜细胞中这种较低的内皮型一氧化氮合酶免疫染色与内皮剥脱有关。因此，我们得出结论，在处理人隐静脉时应小心谨慎，因为仅几秒钟高于正常全身压力的扩张压力就足以破坏内皮，减少内皮型一氧化氮合酶的含量，并损害移植物的质量。
