Mechanisms of surface tension reduction by pulmonary surfactant

肺表面活性物质是肺中的一种物质，允许人们以最小的努力进行呼吸。这一点在早产婴儿中很明显，由于缺乏表面活性物质，他们呼吸困难。我们的实验室旨在了解表面活性剂是如何起作用的。虽然以前的研究已经阐明了表面活性剂功能的许多一般方面，但一些技术限制使我们无法研究特定成分对表面活性物质功能的影响细节。在目前的应用中，我们使用一种新的工具，即所谓的约束固着液滴表面测定仪，来评估表面活性剂是如何工作的，以及特定的成分是如何对其功能做出贡献的。为了评估后一个问题，我们将比较来自不同种类、具有不同呼吸生理学的表面活性物质。例如，我们将比较小鼠和大鼠等呼吸频率高的动物的表面活性物质与猪和牛等呼吸速度慢的动物的表面活性物质，我们还将比较冬眠期间呼吸温度为5摄氏度的动物的表面活性物质与呼吸温度为37摄氏度的动物的表面活性物质。然后，我们将改变这些动物的表面活性物质的组成，以观察我们是否可以确定导致动物特异性效应的表面活性物质的成分。例如，我们将把老鼠表面活性物质的一种成分改变为牛表面活性物质中观察到的水平，并观察表面活性物质的行为是否相应地发生变化。我们将重点研究表面活性剂的一个特定成分是胆固醇，因为目前尚不清楚这种化合物存在于从不同种类分析的所有表面活性剂中，如何对表面活性剂的功能做出贡献。这项研究将作为两名新研究生研究培训计划的一部分，将为肺表面活性物质的功能提供新的科学信息，并帮助我们了解不同物种和不同呼吸特征的肺是如何工作的。

Pulmonary surfactant is a material in the lung that allows people to breathe with minimal effort. This is evident in babies born prematurely which due to the lack of surfactant have trouble breathing. Our laboratory aims to understand how surfactant works. Although previous research has elucidated many general aspects of surfactant function, some technical limitations have prevented us from studying the details by which specific components contribute to surfactant function. In the current application we use a novel tool, the so-called constrained sessile drop surfactometer, to assess how surfactant works and how specific components contribute to its function. To assess the latter question, we will compare surfactants from different species that have different respiratory physiology. For example, we will compare surfactant from animals with a high breathing rate like mice and rats with surfactant from animals with a slow breathing rate like pigs and cows, and we will compare surfactant from animals that breathe at 5OC during hibernation to surfactant from animals that were breathing at 37oC animals. We will then make changes to the composition of the surfactant from those animals to observe if we can determine the components of the surfactant that are responsible for the animal-specific effects. For example, we will change the one of the ingredients of the surfactant from mice to the level observed in surfactant from cows and observe if the behavior of the surfactant changes accordingly. One specific component of surfactant that we will focus on is cholesterol, as it is still unclear how this compound, which is present in all surfactants analyzed from different species, contribute to the function of surfactant. This research, which will be performed as part of the research training program for two new graduate students, will provide new scientific information on the function of pulmonary surfactant and help us understand how the lung works in different species with different breathing characteristics.