Marin M L, Gordon R E, Hardy M A, Reemtsma K, Benvenisty A I
Department of Surgery, Columbia University College of Physicians & Surgeons, New York, New York.
J Surg Res. 1990 Feb;48(2):134-43. doi: 10.1016/0022-4804(90)90205-g.
Immunologic function of endothelial cells is especially important in consideration of vein allografting for arterial reconstruction and in organ allotransplantation. Ultraviolet B radiation (UVB) has previously been shown to modulate graft immunogenicity, and to alter cell surface receptor function. In this study, superficial epigastric veins were UVB irradiated with 10, 24, 40, 80, and 150 mJ/cm2 while control veins were not irradiated; all specimens were examined for endothelial ultrastructural changes. Veins were perfuse-fixed at 1, 3, 7, 14, and 28 days after irradiation, and were evaluated by transmission electron microscopy and scanning electron microscopy. Control veins had a normal appearing endothelial lining, composed of elongated, attenuated endothelial cells. Veins irradiated with more than 24 mJ/cm2 displayed injured endothelial cells characterized by altered microvilli, defects in the cell surface, and a change in cell shape. The degree of cell damage correlated closely with increasing UVB dose. At doses of 80 mJ/cm2 or greater there was moderate to severe endothelial cell separation from the underlying basement membrane and an increase in cellular lysosomes. The effects of UVB were maximal at 3 days with virtual recovery in resurfacing of all specimens with endothelium 28 days after irradiation. These data suggest that UVB has a dose-dependent effect on venous endothelium that is morphologically reversible with time. Cell membrane changes seen following exposure to UVB may contribute to altered cell surface receptor function.
考虑到用于动脉重建的静脉移植和器官同种异体移植，内皮细胞的免疫功能尤为重要。先前已表明，紫外线B辐射（UVB）可调节移植物的免疫原性，并改变细胞表面受体功能。在本研究中，对腹壁浅静脉进行10、24、40、80和150 mJ/cm² 的UVB照射，而对照静脉不进行照射；检查所有标本的内皮超微结构变化。在照射后1、3、7、14和28天对静脉进行灌注固定，并通过透射电子显微镜和扫描电子显微镜进行评估。对照静脉的内皮衬里外观正常，由细长、变薄的内皮细胞组成。照射剂量超过24 mJ/cm² 的静脉显示内皮细胞受损，其特征为微绒毛改变、细胞表面缺陷和细胞形状改变。细胞损伤程度与UVB剂量增加密切相关。在80 mJ/cm² 或更高剂量下，内皮细胞与下方基底膜出现中度至重度分离，细胞溶酶体增加。UVB的作用在3天时最大，照射后28天所有标本的内皮重新覆盖几乎恢复。这些数据表明，UVB对静脉内皮有剂量依赖性作用，随着时间的推移在形态上是可逆的。暴露于UVB后观察到的细胞膜变化可能导致细胞表面受体功能改变。
