Changes in expression of aquaporin 1 and aquaporin 4 in lung tissues during one-lung ventilation in patients undergoing pulmonary lobectomy

Abstract

Objective To evaluate the changes in the expression of aquaporin 1 (AQP1) and aquaporin4 (AQP4) in lung tissues during one-lung ventilation in patients undergoing pulmonary lobectomy.Methods Forty ASA physical status Ⅰ or Ⅱ patients,aged 30-64 yr,weighing 45-79kg,undergoing pulmonary lobectomy,were randomly divided into 2 groups(n=20 each):two-lung ventilation group (group T) and one-lung ventilation group (group O).Anesthesia was induced with iv injection of midazolam,fentanyl,vecuronium and propofol.In group T,the patients were intubated with a single-lumen endotracheal tube and two-lung ventilation was performed.In group O,double-lumen endobranchial tube was inserted,and two-lung ventilation was performed followed by onelung ventilation after chest opening.PET CO2 was maintained at 5.3-24.0 kPa and SpO2 was maintained ＞ 92％.Anesthesia was maintained with iv infusion of remifentanil,propofol and vecuronium.The normal lung tissues were obtained from the site near the pathologic changes for microscopic examination (with light microscope) and examination of the ultrastructure (with transmission electron microscope),and for determination of W/D lung weight ratio,the expression of AQP1 mRNA and AQP4 mRNA (by RT-PCR) and the expression of AQP1 protein and AQP4 protein (by Western blot).Results Compared with group T,W/D lung weight ratio was significantly increased,the expression of AQP1 mRNA and protein was down-regulated in group O (P ＜ 0.05),and no significant changes were found in the expression of AQP4 mRNA and protein in group O (P ＞ 0.05).Pathological changes were observed in group O.Conclusion Down-regulation of AQP1 expression may be involved in the acute lung injury induced by one-lung ventilation in patients undergoing pulmonary lobectomy,however,AQP4 has no such effect. Key words: Aquaporin 1 ; Aquaporin 4; Respiration, artificial