Effect of glucocorticoid on MIP-1a and NF-kb expressing in the lung of rats undergoing mechanical ventilation with a high tidal volume

Abstract

Ventilator induced lung injury (VILI) is a serious complication in the treatment of mechanical ventilating patients, and it is also the main cause that results in exacerbation or death of patients. In this study, we produced VILI models by using glucocorticoid in rats with high tidal volume mechanical ventilation, and observed the content of macrophage inflammatory protein-1α (MIP-1α) in plasma and bronchoalveolar lavage fluid (BALF) and the expression of MIP-1α mRNA and nuclear factor-kappa B (NF-κB) p65 mRNA in the lung so as to explore the role of glucocorticoid in mechanical ventilation. Thirty-two healthy Wistar rats were randomly divided into a control group, a ventilator induced lung injury (VILI) group, a dexamethasone (DEX) group and a budesonide (BUD) group. The content of MIP-1α in plasma and BALF was measured with ELISA and the level of MIP-1α mRNA and NF-κBp65 mRNA expressing in the lung of rats were detected by RT-PCR. The data were expressed as mean±SD and were compared between the groups. The content of MIP-1α in plasma and BALF and the level of MIP-1α mRNA and NF-KBp65 mRNA in the lung in the DEX and BUD groups were significantly lower than those in the VILI group (P<0.001). Although the content of MIP-1α in plasma and BALF and the level of MIP-1α mRNA and NF-κBp65 mRNA in the lung in the BUD group were higher than those in the DEX group, there were no significant differences between them (P>0.05). Glucocorticoid could down-regulate the expression of MIP-1α by inhibiting the activity of NF-κB in the lung and may exert preventive and therapeutic effects on VILI to some extent. The effect of local use of glucocorticoid against VILI is similar to that of systemic use, but there is lesser adverse reaction.