MECHANICAL EFFECTS ON CORONARY PRESSURE FLOW RELATIONS

对冠状动脉压力血流关系的机械效应

• 批准号: 2221459
• 负责人: Frank C Yin
• 金额: $ 34.05万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-09 至 1997-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2221459
• 关键词: blood pressure; dogs; heart circulation; heart contraction; interstitial; isolation perfusion; mechanical pressure; stretch reflex; vasomotion

Cardiac muscle contraction is one of the major influences on coronary flow -- flow decreases, dramatically during contraction. Despite this well-known observation, however, the precise underlying mechanisms are not well understood. Delineating the mechanisms is difficult in the intact heart partly because it is difficult to precisely measure the pertinent parameters and partly because there are transmural gradients of these parameters. Moreover, the phasic nature of cardiac contraction adds additional complications. The overall goal of this proposal is to delineate the mechanical effects of the muscle and surrounding tissue on coronary pressure flow relations. The specific aims of the proposal are to test the following hypotheses: Specific Aim #l: The passive effect of mechanical stretching on P-F relations of the vasodilated bed in cardiac muscular tissue is influenced by the extent and direction of stretching. Specific Aim #2: The effects of both phasic and steady (tetanized) contractions on P-F relations of the vasodilated bed are influenced by the level of contractility, the extent and direction of stretching, but not by the afterload. Specific Aim #3: The interaction between vessels and surrounding tissue is influenced by the interstitial fluid volumes. Specific Aim #4: The interaction between vessels and surrounding tissue is modulated by the presence of vessel tone. Specific Aim #5: The interaction between vessels and surrounding tissue is modulated by the curvature of the tissue with the effect being greater in active than passive states. By using the specific expertise of two laboratories these aims will be addressed using isolated microvessels, perfused rat papillary muscles, perfused isolated dog interventricular septum, and isolated supported hearts. By progressing from the very simple to the very complex and utilizing the advantages of each preparation to answer a question for which it is ideally suited, a better understanding of this important field will emerge.

心肌收缩是对冠状动脉的主要影响之一 流量 - 收缩期间流量大幅下降。 尽管如此 但是，众所周知的观察结果是，确切的潜在机制是 不太了解。 描绘机制很难 完整的心部分是因为很难精确地衡量 相关参数，部分是因为有传播梯度 这些参数。 此外，心脏收缩的阶段性 增加了其他并发症。 该提议的总体目标是 描述肌肉和周围组织对机械效应 冠状动脉流量关系。 该提案的具体目的是 测试以下假设： 特定的目标#L：机械拉伸对P-F的被动效应 心脏肌肉组织中血管扩张的床的关系受影响 在拉伸的程度和方向上。 特定的目标＃2：阶段和稳定的效果（四人） 血管扩张床的P-F关系的收缩受到 收缩水平，伸展的程度和方向，但 不是通过后负载。 特定目标＃3：血管与周围组织之间的相互作用 受间质流体体积的影响。 特定目标＃4：血管与周围组织之间的相互作用 由容器音调调节。 特定目标＃5：容器与周围组织之间的相互作用 通过组织的曲率调节，其影响更大 在主动状态下。 通过使用两个实验室的具体专业知识，这些目标将是 使用孤立的微血管，灌注大鼠乳头肌肉来解决 灌注孤立的狗室内隔膜，并孤立的支撑 心。 通过从非常简单到非常复杂的发展和 利用每项准备的优势来回答一个问题 它非常适合，对这一重要的更好理解 场将出现。