Mechanisms of surface tension reduction by pulmonary surfactant

肺表面活性剂是肺中的一种物质，它能使人以最小的努力呼吸。这在早产儿中很明显，由于缺乏表面活性剂而呼吸困难。我们实验室的目的是了解表面活性剂的工作原理。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表面活性剂功能的具体成分。在目前的应用中，我们使用了一种新型工具，即所谓的受限无底滴表面计，来评估表面活性剂的工作原理以及特定成分对其功能的影响。为了评估后一个问题，我们将比较具有不同呼吸生理的不同物种的表面活性剂。例如，我们将比较呼吸频率高的动物如小鼠和大鼠的表面活性剂和呼吸频率低的动物如猪和牛的表面活性剂，我们将比较冬眠时呼吸温度为5摄氏度的动物的表面活性剂和呼吸温度为37摄氏度的动物的表面活性剂。然后，我们将从这些动物身上改变表面活性剂的组成，观察我们是否能确定表面活性剂的哪些成分会对动物产生特定的影响。例如，我们将表面活性剂的一种成分从小鼠中改变为从奶牛中观察到的表面活性剂的水平，观察表面活性剂的行为是否相应发生变化。我们将重点关注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如何参与表面活性剂的功能，它存在于所有从不同种类分析的表面活性剂中。这项研究将作为两名新研究生研究训练计划的一部分进行，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呼吸特征的不同物种的肺是如何工作的。

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.