CENTRAL CARDIOVASCULAR CONTROL DURING BLOOD LOSS

失血期间的中央心血管控制

• 批准号: 6288290
• 负责人: James C. Schadt
• 金额: $ 25.38万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-15 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6288290
• 关键词: blood pressure; endogenous opioid; hemodynamics; hemorrhage; hypotension; laboratory rabbit; neuroendocrine system; neuroregulation; periaqueductal gray matter; serotonin; vasopressins

A thorough understanding of the physiological consequences of traumatic blood loss is essential to effective medical management of the problem and the associated complications. The response to blood loss in conscious animals (including humans) is biphasic. The pattern is characterized initially by sympathoexcitation and arterial blood pressure maintenance with little activation of humoral systems. This is followed later by sympathoinhibition, vasodilation, hypotension, and increased release of vasopressin, epinephrine and renin. Very little is actually known about the central nervous system networks controlling the onset of hypotension. The periaqueductal gray (PAG) is a brain area that may be important in the control of the cardiovascular and neurohumoral response to blood loss. Our general hypothesis is that the ventrolateral PAG is important in the central control of the integrated hemodynamic and neurohumoral response to hemorrhage and stressful sensory stimuli. We will use a combination of approaches to evaluate ventrolateral PAG involvement in cardiovascular control during acute hypotensive hemorrhage in conscious rabbits. The use of this combination of approaches is novel, and this will be one of the first studies to address ongoing central cardiovascular control mechanisms during a physiological event such as hemorrhage. The Specific Aims of this study are: 1) To define the role of the ventrolateral PAG in the hemodynamic response to blood loss and stress in the conscious rabbit. 2) To quantify the response of ventrolateral PAG neurons during hemorrhage and stress in the conscious rabbit. 3) To understand the role of serotonergic and opioidergic mechanisms in the ventrolateral PAG during blood loss in the conscious rabbit.

彻底了解创伤性失血的生理后果对于有效地处理这一问题及其相关并发症是至关重要的。有意识的动物(包括人类)对失血的反应是双相的。这种模式最初的特点是交感神经兴奋和维持动脉血压，几乎没有体液系统的激活。随后是交感神经抑制、血管扩张、低血压和增加血管加压素、肾上腺素和肾素的释放。人们对控制低血压发生的中枢神经系统网络知之甚少。中脑导水管周围灰质(PAG)是一个在控制失血引起的心血管和神经体液反应中可能起重要作用的大脑区域。我们的一般假设是，腹外侧部PAG在对出血和应激性感觉刺激的综合血流动力学和神经体液反应的中枢控制中起重要作用。在清醒兔急性低血压出血期间，我们将使用多种方法评估腹外侧PAG在心血管控制中的作用。这种方法的结合使用是新颖的，这将是第一批研究出血等生理事件期间正在进行的中枢心血管控制机制的研究之一。本研究的具体目的是：1)明确腹外侧方PAG在清醒兔失血和应激反应中的作用。2)定量观察清醒兔在出血和应激过程中腹外侧部PAG神经元的反应。3)了解清醒兔失血过程中5-羟色胺能和阿片能机制在腹外侧部PAG中的作用。