Dexamethasone and thyroid hormone pretreatment upregulate alveolar epithelial fluid clearance in adult rats
Dexamethasone and thyroid hormone pretreatment upregulate alveolar epithelial fluid clearance in adult rats
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DOI：
10.1152/jappl.2000.88.2.416
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发表时间：
2000-02-01
影响因子：
3.3
通讯作者：
Matthay, MA
中科院分区：
文献类型：
--
作者：
Folkesson, HG;Norlin, A;Matthay, MA
研究糖皮质激素和甲状腺激素3,3'，5-三碘- l -甲状腺原氨酸（T-3）预处理48 h对成年大鼠肺泡上皮液转运的影响。等压5%白蛋白溶液灌注1小时，观察肺泡液清除率。与对照组相比，地塞米松预处理可使肺泡液清除率提高80%。T-3预处理刺激肺泡液清除率65%，地塞米松和T-3有相加效应（132%）。心得安对两组肺泡液清除均无抑制作用，表明刺激并非继发于内源性β -肾上腺素能刺激。使用溴脱氧尿苷在体内标记，没有细胞增殖的证据。所有组的肺泡液清除均被阿米洛利部分抑制。地塞米松和地塞米松+ t -3预处理大鼠的部分阿米洛利抑制作用大于对照动物，但t -3预处理大鼠的部分阿米洛利抑制作用较小。总之，地塞米松、T-3或两者联合预处理可上调体内肺泡液清除率，类似于短期β -肾上腺素能刺激。这种影响部分是由增加的阿米洛利敏感的Na+转运介导的，因为刺激的肺泡液清除比对照大鼠对阿米洛利更敏感。这些观察结果可能具有临床相关性，因为糖皮质激素治疗通常用于急性肺损伤。
The in vivo effect of 48-h glucocorticoid and thyroid hormone 3,3',5-triiodine-L-thyronine (T-3) pretreatment on alveolar epithelial fluid transport was studied in adult rats. An isosmolar 5% albumin solution was instilled, and alveolar fluid clearance was studied for 1 h. Compared with controls, dexamethasone pretreatment increased alveolar fluid clearance by 80%. T-3 pretreatment stimulated alveolar fluid clearance by 65%, and dexamethasone and T-3 had additive effects (132%). Propranolol did not inhibit alveolar fluid clearance in either group, indicating that stimulation was not secondary to endogenous beta-adrenergic stimulation. With the use of bromodeoxyuridine in vivo labeling, there was no evidence of cell proliferation. Alveolar fluid clearance was partially inhibited by amiloride in all groups. Fractional amiloride inhibition was greater in dexamethasone- and dexamethasone-plus-T-3-pretreated rats than in control animals, but less in T-3-pretreated rats. In summary, pretreatment with dexamethasone, T-3, or both in combination upregulate in vivo alveolar fluid clearance similarly to short-term beta-adrenergic stimulation. The effects are mediated partly by increased amiloride-sensitive Na+ transport, because the stimulated alveolar fluid clearance was more amiloride sensitive than in control rats. These observations may have clinical relevance because glucocorticoid therapy is commonly used with acute lung injury.