Experimental Tests of a Physical Model for Lymph Flow in Anurans

这项工作的目的是通过实验来测试骨骼肌和呼吸的解剖和生理控制如何影响无尾两栖动物（青蛙和蟾蜍）的淋巴运动。淋巴是一种液体，它从循环系统的小血管（毛细血管）中过滤到组织中，这是心脏产生压力的结果。淋巴系统的主要作用是从毛细血管中逸出的液体回流到循环系统中。无脊椎两栖动物失去循环液，从而形成淋巴液的速度大约是哺乳动物的十倍。因此，它们将淋巴恢复到循环系统的能力是至关重要的，两栖动物比任何其他脊椎动物都能更快地用淋巴补充失去的血量。本研究项目的工作假设是，淋巴运动是对两种机制造成的淋巴囊压力差异的反应：肺通气和骨骼肌收缩。通过三个机构（波特兰州立大学、加州州立大学东湾分校、加州科学院）的研究人员的合作，将测量与肺压力变化和骨骼肌收缩在各种解剖途径相关的淋巴通量。此外，还将评估血容量状况对这些压力和活动的影响。将收集比较解剖学数据，以确定解剖学差异是否与淋巴流动和抗脱水能力的差异相关。这项研究将使我们对淋巴运动的机制有更深入的了解，并为第一批离开水生环境的脊椎动物成功定居陆地的适应提供见解。本科生和研究生的研究人员将得到培训，并从研究人员实验室之间的合作中受益。该项目的成果将通过隶属于加州科学院的教育推广工作进行传播。

The objectives of this work are to experimentally test how the anatomical and physiological control of skeletal muscles and breathing contributes to lymph movement in anuran amphibians (frogs and toads). Lymph is the fluid that filters from the small blood vessels (capillaries) of the circulatory system into the tissue as a consequence of the pressure generated by the heart. The principal role of the lymphatic system is to return this fluid that escapes from the capillaries back into the circulation. Anuran amphibians lose circulatory fluid, and hence form lymph, at about ten times the rate of mammals. Thus their ability to return lymph to the circulatory system is critical and amphibians can replace lost blood volume with lymph more rapidly than any other vertebrate. The working hypothesis for this research project is that lymph moves in response to pressure differences in lymph sacs created by two mechanisms: lung ventilation and skeletal muscle contractions. Through a collaboration of researchers at three institutions (Portland State University, California State University East Bay, California Academy of Sciences) lymph flux associated with lung pressure changes and skeletal muscle contraction in various anatomical pathways will be measured. In addition, the effect of blood volume status on these pressures and activities will be assessed. Comparative anatomical data will be collected to determine whether anatomical differences correlate with differences in lymph flow and the ability to withstand dehydration. This research will lead to a greater understanding of the mechanisms of lymph movement and provide insight into the adaptations that led to the successful colonization of land by the first vertebrate group that left the aquatic environment. Undergraduate and graduate students researchers will be trained and benefit from the collaboration between the researchers' laboratories. The results of this project will be disseminated via educational outreach efforts affiliated with the California Academy of Sciences.