中文摘要：

目的 评价丙泊酚对呼吸机所致急性肺损伤和水通道蛋白5（AQP-5）表达的影响.方法 健康雄性Wistar大鼠50只,采用随机数字表法,将其随机分为5组,每组10只：常规潮气量通气组（A组,VT=8 mL/kg）、大潮气量通气组（B组,VT=30 mL/kg）、丙泊酚不同时点给药组（C～E组,VT=30 mL/kg）.C组、D组和E组分别于给予大潮气量通气前1 h、给予大潮气量通气即刻和给予大潮气量通气后1 h时静脉注射丙泊酚5 mg/kg,随后以10 mg/（kg·h）速率输注至机械通气4 h结束.测定肺泡灌洗液蛋白、肺通透指数（LPI）及肺组织湿/干重量比（W/D）;HE染色光镜下观察肺损伤程度;采用Western blot和RT-PCR法分别测定肺组织AQP-5的蛋白及mRNA表达.结果 与A组比较,B～E组W/D、LPI增加,AQP-5表达下调（P〉0.05）;与B组比较,C组、D组W/D、LPI下降,AQP-5表达上调（P〉0.05）,HE染色肺损伤程度减轻.结论 丙泊酚早期给药能减轻呼吸机所致肺损伤,其保护机制与上调肺组织AQP-5的表达有关.

英文摘要：

Objective To investigate the effects of propofol on ventilator - induced lung injury and the expression of aqnaporin 5 （ AQP - 5 ） in rats. Methods Fifty male Wistar rats were randomly divided into 5 groups ： standard venti- lation group （ Group A, VT = 8 mL/kg） ; high - tidal volume ventilation group （ Group B, Vr = 30 mL/kg） ; propofol trea- ted groups （ Group C, D, and E, in which propofol 5 mg/kg 1 h before, immediately after and 1 h after high - tidal vol- ume ventilation （30 mL/kg） was given, respectively, followed with infusion of propofol at 10 mg/（ kg ~ h） until 4 h after ventilation）. Lung tissues were collected for calculation of wet/dry lung weight ratio （W/D）, lung permeability index （LPI）, and lung pathologic change. The expressions of AQP- 5 mRNA and protein were also assessed. Results When compared with Group A, significant increase in W/D and LPI, with down - regulation in AQP - 5 mRNA and protein were observed in the other 4 groups （ P 〈 0. 05 ）. When compared with Group B, significantly lower W/D and LPI, with up - regulation in AQP - 5 were observed in Group C and D （ P 〈 0. 05 ）. Morphological changes and neutrophil sequestration were also less in Group C and D. Conclusion Early propofol administration provides protective effects on the lung injury induced by ventilator, which may be related to the up - regulation of AQP - 5.