PHYSIOLOGY OF THE MESENTERIC LYMPHATIC PUMP

拟议研究的目的是使用活体显微镜 生理调控技术的系统分析 淋巴管(直径50-150微米)通过 活体内视频显微镜和淋巴内压(P)和 持续监测直径(D)。淋巴管收缩 然后在心跳周期之后模拟心跳周期；即基本心脏循环 功能参数(例如，收缩频率，每搏量， 射出分数)用来分析流动的产生 淋巴“心脏”的功能。淋巴肌力学是 通过监测平滑肌缩短率进行分析 (dd/dt)、压力发展速度(dp/dt)、张力 发展和收缩的力量(即收缩能力)。这个 拟议的研究将涉及6个具体目标：1)测试 假设淋巴收缩的启动完全是 取决于平滑肌的伸展程度(即肌源性) 与神经活动无关；2)研究长度-张力 淋巴平滑肌的相互关系；3)确定 交感神经和交感神经的变力和变时作用 肠系膜淋巴管上的副交感神经系统； 评估收集淋巴管的能力，以应对 葡萄糖偶联引起的淋巴产生的功能性增加 肠道液体吸收；5)表征 肠系膜淋巴泵以增加随之而来的淋巴流量 并确定这种反应是否依赖于 吸收的脂肪类型(例如，短链、中链或长链脂肪 酸)和6)确定胃肠肽是否在体内释放 腔内脂质增强淋巴管收缩的反应 活动。这些研究的结果将提供坚实的基础 未来对胃肠道淋巴管和 肠系膜淋巴心对淋巴的推进作用。

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.