EPITHELIAL CELL ION TRANSPORT IN PERINATAL LUNGS

围产期肺中的上皮细胞离子转运

• 批准号: 2234896
• 负责人: RICHARD David BLAND
• 金额: $ 14.89万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-30 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2234896
• 关键词: aldosterone; baboons; disease /disorder model; glucocorticoids; histogenesis; immunocytochemistry; in situ hybridization; inhibitor /antagonist; ion transport; isolation perfusion; lung injury; messenger RNA; premature infant animal; pulmonary edema; pulmonary surfactants; radiotracer; respiratory airway clearance; respiratory distress syndrome of newborn; respiratory epithelium; sodium channel; sodium potassium exchanging ATPase

DESCRIPTION (adapted from the applicants' abstract) Pulmonary edema is a common cause of acute and chronic respiratory failure after premature birth. Protein-rich liquid enters the airspaces as a result of vascular and epithelial injury in lungs that are not yet fully developed. The major driving force for postnatal removal of liquid from the airspaces into the pulmonary circulation is active Na transport across the respiratory epithelium. Previous work with lungs from fetal and newborn rabbits suggested that abnormal Na-K-ATPase activity in the respiratory tract epithelium might slow liquid clearance from the lungs after premature birth. It is unknown how postnatal lung injury affects these processes, nor is it known how these processes operate to regulate lung liquid clearance after birth either in human infants or in non-human primates. The purpose of this project is to determine the effects of acute and chronic lung injury on ion transport in epithelial cells derived from the trachea and terminal air sacs of premature baboons, and to see how these effects influence liquid absorption from the lung lumen. This project takes advantage of a unique animal model of neonatal lung injury after premature birth in non-human primates that are delivered by cesarean section and treated with mechanical ventilation for up to 3 weeks after birth. Specific aims focus on the central hypothesis that absorption of liquid from the airspaces of the developing lung is driven by active Na transport across the respiratory tract epithelium, a process that is impaired after premature birth and subsequent lung injury induced by mechanical ventilation with oxygen enriched gas. The project uses complementary experimental approaches to study birth-related changes in respiratory epithelial ion transport and liquid movement, and the influence of postnatal lung injury on these processes: (1) airway and distal lung epithelial cells will be isolated from fetal and newborn baboons in order to measure fluxes of radiolabeled ions (86Rb, 36CJ, 22Na) in the presence or absence of various inhibitors of ion transport; (2) molecular techniques will be used to measure MRNA for the cc, and B, subunits of Na-KATPase and to quantify Na-K-ATPase protein abundance in tracheal and distal lung epithelial cells; (3) immunohistochemistry and in situ hybridization will be used to localize Na-K-ATPase and Na and Cl channels on respiratory epithelium of fetal and newborn baboons with and without postnatal lung injury; and (4) excised lungs will be used to measure net production (secretion and absorption) of luminal liquid under basal and experimental conditions (with and without preceding injury, treatment with glucocorticoids before birth, and treatment with surfactant). This investigation should provide new insight into the possible role of pulmonary epithelial dysfunction in the pathogenesis of lung edema that often occurs in newborn infants with acute and chronic respiratory distress syndromes.

描述(改编自申请人的摘要)肺水肿 早产后急性和慢性呼吸衰竭的常见原因 出生。富含蛋白质的液体进入空气空间是血管的结果 以及尚未完全发育的肺上皮损伤。这个 出生后从空气中排出液体的主要驱动力 进入肺循环的是活跃的钠跨膜转运 呼吸道上皮。先前对胎儿和新生儿肺的研究 兔提示呼吸系统Na-K-ATPase活性异常 肠道上皮可能会减缓液体在肺中的清除速度 早产。出生后肺损伤是如何影响这些的尚不清楚。 过程，也不知道这些过程如何运作来调节肺 人类婴儿或非人类婴儿出生后液体清除 灵长类动物。该项目的目的是确定 急、慢性肺损伤对上皮细胞离子转运的影响 来自早产狒狒的气管和末端气囊，以及 看看这些效应是如何影响肺部液体吸收的 流明。该项目利用了一种独特的新生儿动物模型 非人类灵长类动物早产后的肺损伤 剖宫产及机械通气治疗 出生后最多3周。具体目标聚焦中央 假设从星际空间吸收液体 发育中的肺是由活跃的钠跨呼吸道运输驱动的 肠道上皮，早产后受损的过程， 有氧机械通气致继发性肺损伤 浓缩气。该项目使用互补的实验方法来 研究与出生相关的呼吸道上皮离子转运和 液体运动及产后肺损伤对上述指标的影响 过程：(1)分离呼吸道和远端肺上皮细胞 从胎儿和新生的狒狒身上提取的 存在或不存在放射性标记离子(86Rb、36CJ、22Na) 各种离子转运的抑制剂；(2)分子技术将 用于测定Na-KATPase的CC和B亚基和TO的mRNA 气管和远端肺组织Na-K-ATPase蛋白丰度的定量研究 (3)免疫组织化学和原位杂交法 用来定位呼吸上的Na-K-ATPase和Na、Cl通道 具有和不具有出生后肺的胎儿和新生狒狒的上皮 损伤；以及(4)切除的肺将用于测量净生产量 基础和基础状态下的腔液(分泌和吸收) 实验条件(有无既往损伤、治疗 出生前使用糖皮质激素，并使用表面活性物质治疗)。这 调查应该提供对可能的作用的新的见解 肺上皮功能障碍在肺水肿发病机制中的作用 常见于新生儿的急性和慢性呼吸道疾病 窘迫综合症。