RESISTANCE ARTERY REMODELING HYPERTENSION

描述(申请人提供)：当大动脉肥厚时 实验性肾脏和人类高血压，外周阻力增加 通过小动脉向内的富营养性重塑。我们的长期目标是 确定这两种血管重塑背后的机制。我们的 以前的实验表明，周向壁应力， 通过升高血压，是肥厚的主要刺激因素 大动脉，但这种肥大的刺激在小动脉中被预防 血管收缩。持续的血管收缩导致向内的富营养化 通过在较小的管腔周围重新排列相同的细胞来重塑。为了测试 这一假说，分离的肠系膜小动脉(200-300微米)安装在 组织浴中的微管将被用来确定 压力刺激的机械传递。粘着斑激酶的作用 (FAK)，c-Src，MAP激酶Erkl/2，Ink和p38将由 Western blotting用针对活性形式的激酶的抗体。 将使用共聚焦荧光显微镜来定位活性部位 FAK和Src的形式抑制剂将被用来确定最初的 机械转导信号依赖于自由基的产生、激活 PDGF-α受体，或识别RGD基序的整合素。生产 超氧阴离子和PDGF-α受体的磷酸化也将 量过了。一些动脉的内皮细胞会被剥离，以确定其 对机械转导和检测结果的贡献 在整个动脉上。将使用分离的股薄肌供血小动脉(150微米) 以确定慢性肌源性反应是否会导致内向、富营养化 5天内的重塑以及此重塑是否涉及 增殖或凋亡。PDGF-A反义寡聚体将用于 确定PDGF-A是否在大鼠血管壁肥厚中起重要作用 一肾一夹高血压大鼠。墙体横截面积将为 由石蜡包埋动脉的视频图像分析确定。 用免疫组织化学方法检测BrdU的增殖细胞 原位末端标记法检测细胞掺入和细胞凋亡其他 动脉节段将通过RT-PCR分析PDGF-A和PDGF-B mRNA，或QUICK 冰冻，用于PDGF-A和PDGF-B的SDS-PAGE和免疫印迹这些结果 可以阐明大动脉和阻力血管在动脉粥样硬化中的作用 高血压的发展成为控制室壁应力和 自动调节血流，而不是作为高血压的原因。这 信息也可以成为更有效的逆转治疗的基础 动脉壁的结构变化，如果不加以控制可能会导致血管 靶器官的病理学。

DESCRIPTION (provided by applicant): While large arteries hypertrophy in experimental renal and human hypertension, peripheral resistance is increased by inward, eutrophic remodeling of arterioles. Our long-term objective is to determine the mechanisms behind these two types of vascular remodeling. Our previous experiments suggest the hypothesis that circumferential wall stress, elevated by increasing blood pressure, is a major stimulus for hypertrophy of large arteries but this hypertrophic stimulus is prevented in arterioles by vasoconstriction. Sustained vasoconstriction leads to inward, eutrophic remodeling by rearrangement of the same cells around the smaller lumen. To test this hypothesis, isolated small mesenteric arteries (200-300 urn) mounted on micropipets in a tissue bath will be used to determine the initial signals in mechanotransduction of a pressure stimulus. The role of focal adhesion kinase (FAK), c-Src, the MAP kinases Erkl/2, iNK and p38 will be investigated by Western blotting with antibodies specific for the active form of the kinase. Confocal fluorescence microscopy will be used to locate the site of active forms of FAK and Src. Inhibitors will be used to determine if the initial mechanotransduction signal depends upon free radical production, activation of the PDGF-alpha receptor, or integrins recognizing the RGD motif. Production of superoxide anion and phosphorylation of the PDGF-alpha receptor also will be measured. The endothelium will be denuded in some arteries to determine its contribution to mechanotransduction and to the results of the assays performed on whole arteries. Isolated gracilis feeding arterioles (150 urn) will be used to determine if a chronic myogenic response can lead to inward, eutrophic remodeling over a 5-day period and whether this remodeling involves proliferation or apoptosis. Antisense oligomers for PDGF-A will be used to determine whether PDGF-A is essential for vascular wall hypertrophy in the one-kidney, one-clip hypertensive rat. Wall cross-sectional area will be determined by video-based image analysis of paraffin-embedded arteries. Proliferating cells will be detected by immunobistochemistry for BrdU incorporation and apoptotic cells by the ApopTag hi sftu TUNEL method. Other artery segments will be analyzed by RT-PCR for PDGF-A and PDGF-B mRNA, or quick frozen for SDS-PAGE and immunoblotting for PDGF-A and PDGF-B. These results could clarify the role of large arteries and resistance vessels in the development of hypertension as being adaptations to control wall stress and autoregulate blood flow rather than as a cause of hypertension. This information could also form the basis for more effective therapy to reverse structural changes in arterial walls that if unchecked can lead to vascular pathologies in target organs.