CORE--METABOLISM AND FUNCTION

该核心将评估项目所用的正常和转基因小鼠模型中的表面活性剂代谢和表面活性剂功能。该核心中使用的所有技术先前已在使用转基因小鼠的研究中发表。该核心中使用的四种技术先前已在使用转基因小鼠的研究中发表。项目将提供四种类型的表面活性剂代谢和功能测量： 1. 体内表面活性剂的代谢测量将包括 a) 肺泡灌洗液和肺组织中饱和磷脂酰胆碱 (Sat PC) 池大小； b) 用于选定研究的磷脂成分； c) 将放射性标记的前体掺入 St PC 并测量表面活性剂分泌的动力学； d) 通过气管内注射给出放射性标记的表面活性剂成分（Sat PC、SP-A、SP-B、SP-C）的清除动力学。这些测量提供了有关表面活性剂进出肺泡的通量的信息。 2. 表面活性剂的表面活性将通过测量 a) 最小和最大表面张力进行体外评估； b) 表面活性剂降低表面张力的特性对血浆蛋白抑制的敏感性； c) 吸收率。威廉米天平和/或气泡表面活性计将用于上述测量。 3.通过将从小鼠肺泡分离的表面活性剂给予缺乏表面活性剂的妊娠27天早产兔，体内测量表面活性剂功能。将量化测试表面活性剂对通气期间动态顺应性和早产兔肺静压容积曲线的影响。

This core will assess surfactant metabolism a and surfactant function in the normal and transgenic mouse models used for the projects. All techniques to be used in this Core have been previously published in studies using transgenic mice. Four techniques to be used in this core have been previously published in studies using transgenic mice. Four types of measurements of surfactant metabolism and function will be provided to the projects: 1. Metabolic measurements of surfactant in vivo will include a) pool sizes of saturated phosphatidylcholine (Sat PC) in alveolar lavage and lung tissue; b) phospholipid composition for selected studies; c) radiolabeled precursor incorporation into St PC and measurements of the kinetics of surfactant secretion; and d) clearance kinetics for radiolabeled surfactant components (Sat PC, SP-A, SP-B, SP-C) given by intratracheal injection. These measurements provide information on the flux of surfactant into and out of the alveolus. 2. The surface activity of surfactant will be evaluated in vitro by measurements of a) minimum and maximum surface tension: b) sensitivity of surface tension lowering properties of surfactant to inhibition by plasma protein; and c) absorption rate. The Wilhelmy balance and/or captive bubble surfactometer will be used for above measurements. 3. Surfactant function will be measured in vivo by giving surfactant isolated from alveolar laves of mice to be surfactant deficient 27 d gestation premature rabbits. The effects of the test surfactants on dynamic compliance during ventilation and static pressure volume curves of the premature rabbit lung will be quantified.