The roles of Weibel-Palade bodies in processing and release of endothelin-1

1)通过电镜观察培养的人脐静脉内皮细胞（HUVEC）在缺氧条件下的动态变化，并制备培养液上液，采用三明治- eia法测定ET-1浓度。与常氧组相比，缺氧HUVEC中webel - palade （WP）数量显著增加，ET-1浓度显著升高。采用电镜、免疫细胞化学和原位杂交技术对缺氧条件下的大鼠腹主动脉进行了观察。WP小体数量的显著增加只发生在缺氧样品中。同时，与常氧组相比，低氧组细胞对ET-1的免疫反应程度和ET-1 mRNA信号的免疫反应程度显著增强。这些结果表明，缺氧内皮细胞中WP小体的增加与ET-1的合成和释放增加之间存在相关性。对镉给药后的大鼠胸主动脉进行了电镜观察和免疫细胞化学染色。镉处理大鼠内皮细胞中WP小体数量显著增加。ET-1和ECE-1的免疫反应性优先定位于内皮对照组，镉处理组ET-1和ECE-1的免疫反应强度显著增强。免疫电镜观察发现，ET-1的免疫反应金颗粒优先定位于WP小体，ECE-1的免疫反应金颗粒在对照组WP小体内以及沿内皮细胞膜分布。经镉处理后，ET-1和ECE-1的免疫反应性增强，与内皮细胞膜密切相关的WP小体中ET-1的免疫反应性更加明显。因此，目前的研究结果表明，增加的WP体与增加的ET-1释放之间存在相关性，ET-1在WP体中由ECE-1处理，以镉管理的方式释放。少

1) Dynamic changes in cultured human umbilical vein endothelial cells (HUVEC) after exposure to hypoxic condition were investigated by electron microscopy, and surpernants of the cultured media ware prepared for assays of ET-1 concentration by sandwich-EIA method. A remarkable increase in number of Weibel-Palade (WP) and elevation of ET-1 concentration in the media were confirmed in the hypoxic HUVEC, when compared to the normoxic one. The rat abdominal aorta under the hypoxic condition was investigated by electron microscopy, immunocytochemistry and in-situ hybridization. The significant increase in number of WP bodies uniquely occurred in the hypoxic samples. At the same time, the degree of immunoreactivity for ET-1 and that of ET-1 mRNA signal were significantly enhanced in the hypoxic samples when compared to the normoxic ones. These findings suggest that the correlation exists between increased WP bodies and enhanced synthesis and release of ET-1 in the hypoxic endothelial cells.2 … More ) The rat thoracic aorta after cadmium administration was prepared for electron microscopy and immunocytochemistry. A remarkable increase in number of WP bodies occurred in the endothelia of cadmium-treated rat. Immunoreactivity for ET-1 and ECE-1 was preferentially localized along the endothelium control groups, and the immunoreactive intensities of ET-1 and ECE-1 were significantly enhanced in the cadmium-treated groups. By immunoelectron microscopy, immunoreactive gold particles for ET-1 were preferentially localized in WP bodies and those for ECE-1 were in WP bodies as well as along the endothelial cell membrane in control groups. By cadmium administration, immunoreactivity for ET-1 and ECE-1 appeared to be enhanced, and immunoreactivity for ET-1 in WP bodies, which are closely associated with the endothelial cell membrane became more pronounced. Thus, the present findings suggest that the correlation exists between increased WP bodies and enhanced release of ET-1, which is processed by ECE-1 in WP bodies, in a manner of a regulated release by cadmium administration. Less