Effect of acidizing pretreatment in respiratory acidosis on neutrophil inflammatory infiltration in ischemic-reperfusion injury / 解放军医学杂志

ABSTRACT

[Abstracts] Objective To investigate the effect and mechanism of acidizing pretreatment in respiratory acidosis on ischemia-reperfusion (IR) lung injury in rats. Methods Forty-eight male Sprague-Dawley rats, weighted 250-300 g, were randomly divided into 6 groups (8 each). Rats in control group the left pulmonary hilum was dissociated without occlusion; in sham group the respiratory rate was adjusted to maintain the partial pressure of end-tidal carbon dioxide reached 56-65 mmHg for 5 min, the left hilar not blocked; in IR group the left pulmonary hilum was occluded for 45 min followed by reperfusion for 180 min; in group APC done as in sham group and blocked the left hilar as in group IR; in group SB+IR MMP-9 inhibitor SB-3CT 5 mg/kg was intraperitoneally injected, and then treated as in group IR 30 min after; in group SB+APC done as in group APC, and then SB-3CT 5 mg/kg was injected 30 min after. Rats in all the 6 groups were sacrificed by arterial bleeding when the experiments ended, and lung tissues were taken. HE staining was performed to observe the pathological changes of lung tissues, and immunohistochemistry was used to detect the infiltration of neutrophils (PMN) in lung tissue. Western blotting was used to detect the expression of NF-κB and MMP-9 proteins. Immunofluorescence staining was used to detect the co-expression of NF-κB and MMP-9 proteins. Results Statistically significant differences existed in each group (P0.05). The above indicators were significantly higher in group IR, group APC, group SB+IR and group SB+APC than those in control group and sham group (P0.05). Conclusions In the IR rat model, acidizing pretreatment in respiratory acidosis can alleviate PMN infiltration and IR lung injury. The mechanism may be related to inhibition of NF-κB/MMP-9 protein expression.