Clara Cell's Anti-inflammatory Protection In The Rabbits' Lungs That Received Ischemia/Reperfusion

Objective:We investigated the inflammatory reaction of the rabbits' lungs that received Ischemia/Reperfusion,and in some of the rabbits' lungs,Clara cells were selectively ablated in order to approach the effect of Clara cell in the lung Ischemia/Reperfusion injury about the inflame-matory.Method:24 adult rabbits of either sex were randomly divided into three equal groups,8 rabbitsin each group.The group A is the Control group;the rabbits of group B only recived Ischemia/Reperfusion in left lung;in the group C,rabbits' s Clara cells were selectively ablated by naphthalene treatment and they recived Ischemia/Reperfusion in left lung.In anesthetized rabbits,the groupA'animals' hilum of the left lung were not blocked,but in the rabbits of groupB,C,we ligated the hilum of left lung for 60 minutes,and to reperfusfor 120minutes.To draw the arterial blood at 120 minutes of reperfusion and measure the content of TNF-α(tumor necrosis factor-a)in surem.Wet/dry(W/D)ratio of lung,lung permeability index(LPI) and neutrophils percentage in bronchoalveolar lavage fluid(BALF) were detected as index of the lung injury.To examine the degree of lung tissue damage(LTD) by view of the histological appearances of lung under light microscope.The expression of CCSP in lung were detected immunohistochemically,to observe the distribution and number of Clara cell that CCSP~+ under light microscope.Result:After 60 minutes ischemic and 120 minutes reperfusion,the content of TNF-α(tumor necrosis factor-a) is the lowest in Control group(P＜0.01)and the highest in groupC;conferred to Control,the W/D,LPI,quantity of WBC in BALF were significantly higher in gropB,C than those of the control group(all P＜0.05,respectively),and those in groupC are higher than in groupB(all P＜0.05,respectively);Tissues demonstrated the degree of lung injury and the degree of inflammatory cell infiltration in groupC had been aggravated significantly than that in groupB,and in Control group those were normal.Rabbit exposed to naphthalene vapor at concentrations of 100ppm for 12hours could selectively ablated Clara cells.Conclusions:Clara cell of the terminal bronchioles can significantly inhibit the inflammatory reaction of the rabbits'lungs that received Ischemia/Reperfusion,so it can alleviate lung Ischemia/Reperfusion injury accordingly,Clara cell lighten the lung Ischemia/Reperfusion injury.