Role of macrophage inflammatory protein-1α in ventilator induced acute lung injury rats

Abstract

Objective To evaluate the role of macrophage inflammatory protein-1α (MIP-1α) in the acute lung injury rats induced by mechanical ventilation of different tidal volume.Methods Twenty-four health male Wistar rats were randomly divided into control group,low tidal volume group and high tidal volume group.The neutrophil count in bronchoalveolar lavage fluid (BALF), myeloperoxidase (MPO) activity and MIP-1α content in BALF and plasma,and the expression of MIP-1α protein in lung tissue were detected respectively.Results The neutrophil count, MPO activity and MIP-1α content in BALF of high tidal volume group were significantly higher than those of control group and low tidal volume group (all P <0.01).The expression of MIP-1α protein in alveolar and bronchiole epithelial ceils of high tidal volume group was obviously higher than that of control group and low tidal volume group (all P <0.01).There was no statistical significance between control group and low tidal volume group.Correlation analysis indicated that MIP-1α content was positively correlated with neutrophil count and MPO activity in BALF of all groups(r =0.802, r =0.791 ,all P<0.05).Conclusions The neutrophil recruition and activation induced by chemotatic factor MIP-1α in the lung is one of the important factors of ventilator induced lung injury.The diseased region of ventilator induced lung injury is not limited to pulmonary alveoli, and the bronchiole can also been involved. Key words: Mechanical ventilation; Acute lung injury; Macrophage inflammatory protein-1α