Role of Clara cells in lung ischemia-reperfusion injury in rabbits / 中华麻醉学杂志

ABSTRACT

Objective To investigate the role of Clara cells in lung ischemia-reperfusion (I/R) injury in rabbits.Methods Twenty-four healthy 10-12 month old rabbits of either sex weighing 1.5-2.0 kg were randomly divided into 3 groups ( n = 8 each) ; group A sham operation (group S) ; group B lung I/R and group C Clara cell elimination+ lung I/R. The animals were anesthetized with iv pentobarbital 30 mg/kg , tracheostomized and mechanically ventilated. In group B and C lung I/R was induced by clamping the left hilum of lung for 60 min followed by 120 min repeffusion. In group C Clara ceils were eliminated by ventilating the lungs with 89.28 mg/m2 naphthalin vapor for 12 h before lung I/R. The animals were killed by iv KCI at the end of 120 min reperfusion after lung isehemia. The left lung was immediately removed for microscopic examination, determination of W/D lung weight ratio and serum TNF-α level and MDA content. The percentage of neutrophi] in bronchoalveolar lavage fluid (BALF) was detected as index of lung injury. The expression of Clara cell secreting protein (CCSP) in the lung was detected by immuno-histoebemistry to indicate the number and distribution of Clara cells in the lung.Results Microscopic examination showed that there were severe leukocyte infiltration in alveolar spaces, alveolar edema and destroyed alveolar structure in group B and C. The serum TNF-u leve],W/D ratio and MDA content in the left lung and neutrophil percentage and WBC counts in BALF were significantly higher in group C than in group B. Conclusion Clara cells can protect the lungs against I/R injury through inhibiting inflammatory responses.