PHYSIOLOGY OF THE MESENTERIC LYMPHATIC PUMP

拟议研究的目的是使用体内显微镜 系统分析生理控制的技术 的微透镜（直径为50 - 150 μ m）， 活体视频显微镜和淋巴内压（P）， 直径（D）连续监测。 淋巴管收缩 然后在心动周期之后对周期进行建模;即，基本心脏 函数参数（例如，收缩频率，每搏输出量， 射血分数）用于分析流动产生 淋巴"心脏"的能力。 淋巴肌力学是 通过监测平滑肌缩短率进行分析， (dD/dt）、压力发展速率（dP/dt）、张力 发展和收缩力（即，收缩性）。 的 拟议的研究将涉及6个具体目标：1）测试 假设淋巴收缩的开始完全是 取决于平滑肌伸展的程度（即，肌原性） 和独立的神经活动; 2）研究长度-张力 淋巴管平滑肌的关系; 3）确定 交感神经的变力和变时作用， 副交感神经系统对肠系膜神经系统的影响; 4） 评估收集数据的能力， 葡萄糖偶联引起的淋巴产生功能性增加 肠液吸收; 5）表征 肠系膜淋巴泵增加淋巴流量， 脂质摄入，并确定这种反应是否依赖于 吸收的脂质类型（例如，短链、中链或长链脂肪 酸）和6）确定胃肠道肽是否在胃肠道中释放， 对管腔内脂质反应增强淋巴管收缩 活动 这些研究的结果将提供一个坚实的基础 用于未来的胃肠动力学研究， 通过肠系膜淋巴心推进淋巴。

The purpose of the proposed studies is to use in vivo microscopic techniques to systematically analyze of the physiological control of lymphatics (50-150 mum in diameter) are viewed through an intravital videomicroscope and intralymphatic pressure (P) and diameter (D) are continuously monitored. The lymphatic contractile cycle is then modelled after the cardiac cycle; i.e., basic cardiac function parameters (e.g., contractile frequency, stroke volume, ejection fraction) are used to analyze the flow generating capabilities of the lymph "Hearts". Lymphatic muscle mechanics are analyzed by monitoring the rate of smooth muscle shortening (dD/dt), the rate of pressure development (dP/dt), tension development and force of contraction (i.e., contractility). The proposed studies will address 6 specific aims: 1) test the hypothesis that the initiation of lymphatic contraction is totally dependent upon the degree of smooth muscle stretch (i.e., myogenic) and independent of nervous activity; 2) study the length-tension relationship for lymphatic smooth muscle; 3) determine the inotropic and chronotropic effects of the sympathetic and parasympathetic nervous systems on mesenteric lymphatics; 4) evaluate the ability of collecting lymphatics to respond to functional increases in lymph production caused by glucose-coupled intestinal fluid absorption; 5) characterize the response of the mesenteric lymphatic pump to increases in lymph flow that follow lipid ingestion and determine if this response is dependent on the type of lipid absorbed (e.g., short, medium or long chain fatty acids) and 6) determine if gastrointestinal peptides released in response to intraluminal lipid augment lymphatic contractile activity. The results of these studies will provide a firm basis for future studies on gastrointestinal lymphatics and the propulsion of lymph by the mesenteric lymph hearts.