布比卡因在人离体肺脏液体清除中的作用

Effect of bupivacaine on alveolar fluid clearance in ex vivo human lungs

目的探讨布比卡因在人离体肺段肺泡液体清除中的作用。方法选取临床外科手术肺切除患者的肺段标本，采用随机数字表法分为对照组（6例）、布比卡因组（6例）、阿米洛利组（5例）、布比卡因＋阿米洛利组（6例），将不同药物通过插管注入远端肺组织，其中对照组为单纯10ml用0．9％氯化钠注射液配制的5％小牛血清白蛋白，余3组分别另加入对应药物。应用考马斯亮蓝法测定肺泡液体内小牛血清白蛋白浓度的方法测定人离体肺段肺泡液体清除率（AFC）。用蛋白质印迹法和实时定量聚合酶链反应（PCR）的方法测定人H441细胞上皮钠通道α亚单位的蛋白和mRNA表达水平。结果阿米洛利组、布比卡因组、布比卡因＋阿米洛利组AFC均低于对照组，差异有统计学意义[（6．6±1．2）％、（9．6±0．9）％、（7．9±2．1）％比（14．0±0．7）％]（P〈0．05）；布比卡因＋阿米洛利组与2种药物单独使用组比较差异均无统计学意义（均P〉0．05）。蛋白质印迹法和实时定量PCR结果显示布比卡因能够时间依赖性降低H441细胞中上皮钠通道α亚单位的蛋白和mRNA表达水平，与对照组比较，24、48h的表达差异均有统计学意义[（0．55±0．09）、（0．49±0．09）比（1．00±0．00），（0．28±0．06）、（0．26±0．04）比（1．00±0．00）]（均P〈0．01）。结论布比卡因能够抑制与阿米洛利敏感性上皮钠通道有关的AFC，降低其表达水平，从而阻碍肺泡上皮液体的清除。

Objective To explore the effect of bupivacaine on alveolar fluid clearance（AFC） in ex vivo human lungs. Methods Segmental bronchi separated from patients who had lobectomy were divided into amiloride group（5 cases）, bupivacaine group （6 cases）, amiloride plus bupivacaine group （6 cases） and control group （6 cases） by random number table to have corresponding drug interventions; the control group had 10 ml, 5% calf serum albumin prepared with 0.9% sodium chloride injection, the other 3 groups were added corresponding medicines. Ex vivo AFC was measured by Coomassie brilliant blue method. Expression levels of epithelial sodium channel（ENaC）-α protein and mRNA in H441 cells were tested by western blot and real-time polymerase chain reaction（PCR）. Results The value of AFC in amiloride group, bupivacaine group and bupivacaine plus amiloride group were significantly lower than that in control group [ （ 6. 6 ± 1.2 ） %, （ 9. 6 ± 0. 9 ） %, （ 7. 9 ± 2. 1 ） % vs （ 14. 0 ± 0. 7 ） % ] （ P 〈 0. 05 ） ; there were no significant differences of AFC among amiloride group, bupivacaine group and bupivacaine plus amiloride group （ P 〉 0.05 ）. Western blot and real-time PCR results showed that protein and mRNA expression levels of ENaC-α in H441 cells in bupivacaine group after 24, 48 h of bupivacaine intervention were significantly lower than those in control group [ （ 0. 55 ± 0. 09 ） , （ 0. 49 ± 0. 09 ） vs （ 1.00 ± 0.00） ; （0. 28 ± 0. 06）, （0. 26 ± 0. 04） vs （ 1.00 ± 0. 00） ] （ P 〈 0. 01 ）. Conclusion The inhibition of lung fluid clearance caused by application of bupivacaine may be associated with the decrease of amiloride-sensitive ENaC expression.