Abstract: Objective To explore the protective mechanisms of sevoflurane against acute lung injury (ALI) induced by one-lung
ventilation (OLV) in view of cyclooxygenase-2 (COX2) and 5-lipoxygenase (5-LOX) pathways. Method Eighteen healthy
Japanese white rabbits were randomized into sham-operated group (S group), OLV group (O group) and OLV + sevoflurane
group (OS group). COX2 and 5-LOX protein and mRNA expressions in the lungs were detected by Western blotting and
real-time PCR, respectively. Prostaglandin I2 (PGI2), thromboxane A2 (TXA2) and leukotrienes B4 (LTB4) in the lung tissues were
quantified with ELISA. Histological scores and lung wet/dry weight (W/D) ratios were determined for lung injury assessment.
Results COX2 and 5-LOX protein and mRNA expressions and the contents of LTB4, TXA2 and PGI2 in the lungs, lung W/D ratio
and histological scores were significantly higher while PGI2/TXA2 ratio was significantly lower in O group and OS group than
in S group (P<0.05). Compared with those in O group, COX2 and 5-LOX expressions, pulmonary contents of LTB4, TXA2 and
PGI2, and lung W/D ratio all decreased significantly but PGI2/TXA2 ratio was significantly elevated in OS group (P<0.05).
Conclusion OLV may activate COX2 and 5-LOX pathways to result in increased production of arachidonic acid metabolites.
Sevoflurane protects against OLV-induced ALI probably by reducing AA metabolites and regulating PGI2/TXA2 ratio through
inhibitions of COX2 and 5-LOX pathways.