RADIAL AND LONGITUDINAL MICROVASCULAR COMMUNICATION

径向和纵向微血管通讯

• 批准号: 2685508
• 负责人: HANS H DIETRICH
• 金额: $ 9.99万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2685508
• 关键词: adenosine triphosphate; arterioles; calcium flux; cell cell interaction; laboratory mouse; laboratory rat; membrane potentials; nitric oxide; nitric oxide synthase; purinergic receptor; tissue /cell culture; vascular endothelium; vascular smooth muscle; vasomotion; video microscopy

DESCRIPTION: (Adapted from the application) Propagated vasomotor responses have been shown to be important in regulating microvascular blood flow in response to hyperaemia and to be impaired following ischemia. The investigators found that extraluminally applied purines, including adenosine-triphosphate (ATP), caused a vasoconstriction in cerebral arterioles which surprisingly was converted to a propagated vasodilation. Inhibition of the endothelial nitric oxide (NO) greatly attenuated ATP-induced propagation in these vessels. It is unknown if and how endothelial (EC) and smooth muscle cells (SMC) interact to locally release purines nor is the mechanism of longitudinal communication caused by purines completely understood. The goal of this proposal is to elucidate the mechanism and interdependence of radial (locally between EC and SMC) and longitudinal (along the EC and SMC of a vessel) communication in response to purinergic vasomotor stimulation. The investigator will test three hypotheses: 1) Cellular cross talk between EC and SMC exists in response to purinergic stimulation. Using both isolated arterioles and EC and SMC cultures, the investigator will examine the role of the purinoceptors in the initiation of local responses in both EC and SMC. 2) The endothelium is the medium for propagation in cerebral arterioles. The investigator will investigate whether the endothelium is essential for propagation of vasomotor responses and if this propagation depends on gap junctions to allow for longitudinal cross talk. 3) Nitric oxide availability is necessary for propagation of vasomotor responses. Using cerebral arterioles from normal and endothelial NO synthase deficient (eNOS-) mice, the investigator will examine the importance of NO in the propagation of vasomotor responses. The experiments will be performed in rat isolated cerebral arterioles and eNOS- mouse arterioles in vitro as well as in cultured rat EC and SMC. Local micropressure ejection will be used for stimulation of isolated vessels and cells in culture. Video microscopy will be used for all observations. In blood vessels, the investigator will measure local and propagated diameter and membrane potential responses as well as cellular dye transfer. In cell culture, the investigator will measure local and propagated membrane potential, intracellular calcium activity, and dye transfer. The role of purinoceptors, gap junctions, and EC and SMC in local and propagated response will be revealed with pharmacological intervention as well with endothelial ablation. The significance of NO in the propagation will be demonstrated by supplementing NO in eNOS deficient mouse arterioles.

描述：（从应用程序改编）传播的血管舒适反应 已显示在调节微血管血流中很重要 对高血症的反应并受到缺血后的损害。 这 调查人员发现，脑外施用的嘌呤，包括 腺苷 - 三磷酸（ATP），引起脑血管收缩 令人惊讶地转化为繁殖血管舒张的小动脉。 抑制内皮一氧化氮（NO）极大地减弱 ATP诱导的这些血管中的传播。 未知是否以及如何 内皮（EC）和平滑肌细胞（SMC）相互作用以局部释放 嘌呤也不是由嘌呤引起的纵向交流的机制 完全理解。 该提议的目的是阐明 径向的机理和相互依赖性（在EC和SMC之间局部）和 纵向（沿着船舶的EC和SMC）响应 嘌呤能血管舒缩刺激。 研究者将检验三个假设：1） EC和SMC响应嘌呤能刺激而存在。 两者都使用 孤立的小动脉以及EC和SMC培养物，研究人员将检查 purinoceptors在两者中启动局部反应中的作用 EC和SMC。 2）内皮是大脑传播的介质 小动脉。 调查人员将调查内皮是否是 血管舒适反应的传播至关重要的 取决于间隙连接以进行纵向交叉谈话。 3）一氮 氧化物的可用性对于血管舒适反应的传播是必需的。 使用来自正常和内皮NO合酶的脑小动脉 （Enos-）小鼠，调查人员将检查NO的重要性 血管舒缩反应的传播。 实验将在大鼠分离的脑小动脉和 eNos-小鼠小动脉在体外以及培养的大鼠EC和SMC中。 局部微压弹射将用于刺激分离的 培养中的血管和细胞。 视频显微镜将用于所有人 观察。 在血管中，研究人员将测量本地和 传播直径和膜电位反应以及细胞染料 转移。 在细胞培养中，研究人员将衡量局部和 传播的膜电位，细胞内钙活性和染料 转移。 Purinoceptors，Gap连接器以及EC和SMC在本地的作用 并将通过药理学干预揭示传播的反应 以及内皮消融。 NO在 通过补充eNOS缺乏鼠标中的NO来证明传播 小动脉。