Malnutrition impairs alveolar fluid clearance in rat lungs
Malnutrition impairs alveolar fluid clearance in rat lungs
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DOI：
10.1152/ajplung.00229.2003
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发表时间：
2004-06-01
影响因子：
4.9
通讯作者：
Matthay, MA
中科院分区：
文献类型：
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作者：
Sakuma, T;Zhao, YB;Matthay, MA
营养不足使危重患者的临床病程变得复杂，其中许多患者出现肺水肿。然而，人们对营养不良对解决肺泡水肿机制的影响知之甚少。因此，我们研究了营养不良大鼠肺泡液清除率降低的机制。 120 小时内允许大鼠喝水，但不能吃食物。然后，分离左肺和右肺，分别测量肺水量和肺泡液清除率。通过在 1 小时内用等渗 5% 白蛋白溶液滴注到远端空气空间中的伊文思蓝染料浓度的逐渐增加来测量肺泡液清除率。与对照组相比，营养不良使肺泡液清除率降低 38%。阿米洛利 (10(-3) M) 消除了营养不良大鼠的肺泡液清除率。营养剥夺 120 小时后重新喂食 120 小时，或营养剥夺 120 小时期间口服谷氨酸钠，可使肺泡液清除率分别恢复至正常值的 91% 和 86%。二丁酰-cGMP 是一种环核苷酸门控阳离子通道激动剂，可增加营养不良大鼠的肺泡液清除率，并补充谷氨酸钠。特布他林是一种 β(2)-肾上腺素能激动剂，在所有条件下（对照组、营养不良、重新喂养和谷氨酸治疗）均可增加大鼠的肺泡液清除率。这些结果表明，营养不良主要损害阿米洛利不敏感和二丁酰-cGMP敏感的肺泡液清除率，但这种影响可以通过重新进食、谷氨酸钠治疗或β-肾上腺素能激动剂治疗部分逆转。
Inadequate nutrition complicates the clinical course of critically ill patients, and many of these patients develop pulmonary edema. However, little is known about the effect of malnutrition on the mechanisms that resolve alveolar edema. Therefore, we studied the mechanisms responsible for the decrease in alveolar fluid clearance in rats exposed to malnutrition. Rats were allowed access to water, but not to food, for 120 h. Then, the left and right lungs were isolated for the measurement of lung water volume and alveolar fluid clearance, respectively. The rate of alveolar fluid clearance was measured by the progressive increase in the concentration of Evans blue dye that was instilled into the distal air spaces with an isosmolar 5% albumin solution over 1 h. Malnutrition decreased alveolar fluid clearance by 38% compared with controls. Amiloride (10(-3) M) abolished alveolar fluid clearance in malnourished rats. Either refeeding for 120 h following nutritional deprivation for 120 h or an oral supply of sodium glutamate during nutritional deprivation for 120 h restored alveolar fluid clearance to 91 and 86% of normal, respectively. Dibutyryl-cGMP, a cyclic nucleotide-gated cation channel agonist, increased alveolar fluid clearance in malnourished rats supplied with sodium glutamate. Terbutaline, a beta(2)-adrenergic agonist, increased alveolar fluid clearance in rats under all conditions ( control, malnutrition, refeeding, and glutamate-treated). These results indicate that malnutrition impairs primarily amiloride-insensitive and dibutyryl-cGMP-sensitive alveolar fluid clearance, but this effect is partially reversible by refeeding, treatment with sodium glutamate, or beta-adrenergic agonist therapy.