HYPOTHERMIA EFFECT ON PULMONARY SURFACTANT

低温对肺表面活性剂的影响

• 批准号: 2398207
• 负责人: ALLAN W SMITS
• 金额: $ 7.48万
• 依托单位: QUINNIPIAC UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2398207
• 关键词: Chiroptera; cholesterol; hypothermia; laboratory rat; phospholipids; pulmonary surfactants; respiratory function; surface property

DESCRIPTION (Adapted from the applicant's abstract): Pulmonary surfactant (PS), a complex mixture of lipids and proteins that forms an extremely thin (0.01 um) layer on the inner lining of the lung airways and alveoli (air-liquid interface), has the capacity to reduce surface tension of the air-liquid interface to nearly 0 dynes/cm. It enhances lung compliance and prevention of alveolar collapse and alveolar flooding. In mammals including humans, high proportions (50 percent) of the PS consists of saturated phospholipids, whose capacity to reduce surface tension are greatly compromised by body temperatures lower than 37 degrees C because saturated phospholipids undergo a structural phase change (gel to liquid crystalline) below normal body temperature. While this may not seem problematic for normothermic individuals, this relationship between surfactant function and body temperature in hypothermic individuals has not previously been recognized, and has direct implications in potential causes of Sudden Infant Death Syndrome (SIDS), the clinic treatment of accidental hypothermia, and the current widespread use of induced hypothermia for neuro and cardiovascular surgery. In contrast to human, certain mammal species (temperate bats, deer mice) display daily reductions in body temperatures (voluntary hypothermia or torpor) that are considered severely lethal by human standards, without any sign of respiratory distress. The capacity for rapid recovery from hypothermia in these animals strongly suggests an adaptation of their PS system to body temperature change (e.g., rapid adjustment of saturated/unsaturated phospholipid ratio, incorporation of cholesterol). The overall objective of the proposed study is to compare the PS system of a traditionally homeothermic mammal species (lab rat) with that of a renown heterothermic mammal (big brown bat). Specific goals of this comparison are to 1) measure the PS composition under normothermic and hypothermic conditions, 2) determine how hypothermia influences lung compliance, and 3) describe the surface tension properties of PS at a variety of temperatures in vitro. Compositional analysis of lavaged PS will focus on the degree of saturation of phospholipids and the amount of cholesterol. How the PS of each species responds to hypothermia to possibly compromise lung inflation and deflation will be measured by specific compliance. In vitro characterization of the surface tension properties of PS as affected by temperature will be evaluated using balance surfactometry and captive bubble analysis.

描述（改编自申请人的摘要）：肺部 表面活性剂（PS），脂质和蛋白质的复杂混合物，形成 在肺部内衬上极薄（0.01 um）层 和肺泡（空气界面），具有降低表面的能力 空气界面的张力到近0 dynes/cm。 它增强了 肺合规性和预防肺泡塌陷和肺泡 洪水。 在包括人类在内的哺乳动物中，高比例（50％） PS由饱和磷脂组成，其减少的能力 体温低于 37度C，因为饱和磷脂经历了结构相 将（凝胶变为液晶）低于正常体温。 尽管 对于常规的个体来说，这似乎不是问题的，这 表面活性剂功能与体温之间的关系 低温个体以前尚未得到认可，并且 猝死综合征的潜在原因的直接影响 （SIDS），意外体温过低的诊所治疗 在神经和心血管中广泛使用诱导的体温过低 外科手术。 与人类的某些哺乳动物物种相比（温带蝙蝠， 鹿小鼠）每天显示体温下降（自愿 体温过低或torpor）被人为严重致命 标准，没有任何呼吸窘迫的迹象。 能力 这些动物中的体温过低的快速恢复表明 将其PS系统适应体温变化（例如，快速 调整饱和/不饱和磷脂比的掺入 胆固醇）。 拟议的研究的总体目的是比较 传统疗法哺乳动物（实验室大鼠）的PS系统 带有著名的异性哺乳动物（大棕色蝙蝠）。 具体的 该比较的目标是1）测量下的PS组成 正常温度和低温条件，2）确定低温 影响肺依从性，3）描述表面张力 PS在各种温度下的特性。 组成 灌输PS的分析将集中于饱和度 磷脂和胆固醇量。 每个物种的PS如何 对体温过低的反应可能会妥协肺通胀和 放气将通过特定的依从性来衡量。 体外 PS的表面张力特性的表征受 将使用平衡表面测量法和圈养来评估温度 气泡分析。

项目成果

The effects of artificial lung inflation on pulmonary blood flow and heart rate in the turtle Trachemys scripta.

人工肺充气对粗龟肺血流和心率的影响。

• DOI: 10.1242/jeb.200.19.2539
• 发表时间: 1997
• 期刊: The Journal of experimental biology
• 作者: Herman,J;Wang,T;Smits,AW;Hicks,JW
• 通讯作者: Hicks,JW

Control of pulmonary surfactant secretion: an evolutionary perspective.

肺表面活性物质分泌的控制：进化的角度。

• DOI: 10.1152/ajpregu.2000.278.3.r611
• 发表时间: 2000
• 期刊: American journal of physiology. Regulatory, integrative and comparative physiology
• 作者: Wood,PG;Lopatko,OV;Orgeig,S;Joss,JM;Smits,AW;Daniels,CB
• 通讯作者: Daniels,CB