聚乙二醇对不同浓度肺表面活性物质活性的影响

The effect of polyethylene glycol on activation of different concentrations of pulmonary surfactant

目的观察非离子聚合物聚乙二醇(PEG)对不同浓度肺表面活性物质(PS)活性的影响。方法(1)体外实验:利用闭泡式表面张力仪测量PEG、不同浓度PS(Curosurf)、血浆及混合物的最大表面张力(γmax)和最小表面张力(γmin),并计算其稳定系数(S.I.)。(2)体内实验:大鼠经气管滴入3mg/ml的3×109CFU/ml大肠杆菌,24～36h后,对大鼠行气管插管并左侧颈动脉插管术,机械通气15min。然后将PaO2≤26.6kPa的大鼠随机分为三组,经气管分别滴入2ml/kg生理盐水(NS组),Curosurf(PS组)、Curosurf与5%PEG混合物(1/2PS+PEG组)。另设正常对照组(不给细菌)。大鼠机械通气180min后,用生理盐水[20ml/(kg.次)]灌洗大鼠右肺三次,测定灌洗液的γmin。结果(1)体外实验:1.25mg/ml的PSγmin<2mN/m,S.I.>1.6,而0.62mg/ml和0.31mg/ml的PSγmin>10mN/m,S.I.<0.8;加入5%PEG后,混合物γmin<2mN/m,S.I.>1.6;血浆存在时,不同浓度PS与PEG混合物不同程度地降低了γmin,提高了S.I.。存在1%血浆时,1.25、0.62mg/mlPS与PEG混合物γmin<2mN/m,S.I.>1.6,并且组间差异无显著性(P>0.05)。(2)体内实验:1/2PS+PEG组和PS组大鼠肺泡灌洗液γmin与正常对照组比较差异无显著性(P>0.05),与NS组比较显著降低,差异有显著性(P<0.05);组间比较差异无显著性(P>0.05)。结论PEG可以在一定程度上提高不同浓度PS的活性,逆转因血浆蛋白引起的失活。

Objective To investigate the effect of polyethylene glycol（PEG） on activation of different concentrations of pulmonary surfactant（PS）.Methods （1） In vitro experiment：The maximum（ymax） and minimum surface tension（ymin） of PEG, different concentrations of PS（Curosurf）, plasma and their mixtures were measured by captive bubble surfactometer, respectively. Values of stability index（S. I. ） were also calculated. （2） In vivo experiment：Rats received a dose（3 ml/kg, 3 × 10^9CFU/ml） of E. coli via the airways. After 24-36 h, the animals were ventilated for 15 min and treated via the tracheal cannula with 2 ml/kg saline（NS group）, Curosurf（PS group） or a mixture of Curosurf and 5 % PEG（1/2 PS ＋ PEG group） when PaO2≤ 26.6 kPa. Control animals were not received bacteria. After 180 min ventilation with 100 % O2, animals were sacrificed. The right lungs were washed for three times with saline[20 ml/（ kg, time）]. The lung lavage fluid was centrifuged and measured. Results （1） In vitro： The ymin of 1.25 mg/ml PS was 〈 2 mN/m and S. I. 〉 1.6. The ymin of 0.62 and 0.31 mg/ml PS was 〉 10 mN/m and S. I. 〈 0.8. When 5 % PEG added, ymin was 〈2 mN/m and S. I. 〉1.6. PEG significantly enhanced the ability of curosurf in reducing the ymin and elevating S. I.in the presence of plasma. （2） In vivo： There were no significant difference in ymin of lung lavage fluid between PS, 1/2PS ＋ PEG, and control group; The ymin values in PS and 1/2PS ＋ PEG group were less than that of NS group（ P 〈 0.05）, and there were no significant difference between PS and 1/2PS ＋ PEG group. Conclusion PEG enhanced the ability of different concentrations of PS to reduce surface tention and reversed the inactivation of PS induced by plasma.