RESISTANCE ARTERY REMODELING HYPERTENSION

描述（由申请人提供）：当大动脉肥大时， 实验性肾脏和人体高血压，外周阻力增加 通过小动脉的向内的富营养化重塑。我们长远的目标是 确定这两种血管重塑的机制。我们 先前的实验提出了这样的假设：圆周壁应力， 升高血压，是肥大的主要刺激因素， 大动脉，但这种肥大的刺激是防止在小动脉， 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。测试 这种假设，孤立的小肠系膜动脉（200 - 300 μ m）安装在 组织浴中的微量移液管将用于确定初始信号， 压力刺激的机械传导。粘着斑激酶的作用 (FAK)，c-Src，MAP激酶Erkl/2，iNK和p38将通过以下方法研究： 用对激酶活性形式特异的抗体进行蛋白质印迹。 共聚焦荧光显微镜将用于定位活性位点， FAK和Src的形式。抑制剂将用于确定初始 机械传导信号依赖于自由基的产生， PDGF-α受体，或识别RGD基序的整联蛋白。生产 超氧阴离子和PDGF-α受体的磷酸化也将被 测定了在某些动脉中，内皮将被剥脱，以确定其 对机械转导和所进行的测定结果的贡献 整个动脉。将使用离体股薄肌供血小动脉（150 μ m） 以确定慢性肌源性反应是否会导致向内的、富营养化的 在5天内重塑，以及这种重塑是否涉及 增殖或凋亡。PDGF-A的反义寡聚体将用于 确定PDGF-A是否是血管壁肥大所必需的， 一肾一夹高血压大鼠。墙的横截面积为 通过石蜡包埋动脉的视频图像分析确定。 将通过BrdU免疫组织化学检测增殖细胞 通过ApopTag hi sftu TUNEL方法检测细胞的掺入和凋亡。其他 动脉节段将通过RT-PCR分析PDGF-A和PDGF-B mRNA，或快速 冷冻用于SDS-PAGE和PDGF-A和PDGF-B的免疫印迹。这些结果 可以阐明大动脉和阻力血管在 发展高血压作为控制室壁应力的适应， 自动调节血液流动而不是高血压的原因。这 信息还可以成为更有效的逆转疗法的基础 动脉壁的结构变化，如果不加以控制， 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.