Protective effect of inhibiting the activation of nuclear factor-κB by dexamethasone on donor rat lung

Objective To observe the protective effect of dexamethasone, the inhibitor of nuclear factor-Kappa B, on the ischemia-perfusion injury of rat lung during the period of lung preservation. Methods Twenty-four rats were randomly divided into two groups: the control group and the trial group. The harvested lung blocks were flushed with and stored in the low-potassium-dextran (LPD) solution in control group, but in the trail group LPD containing dexamethasone solution was used. The lungs were stored at 4 ℃ for 16 h in both groups. The isolated rat lung reperfusion models were established and the donor lungs were perfused for 1 h. PaO_2 and PawP were measured at every 15 min intervals during reperfusion. After reperfusion, the lung tissue wet-to-dry (W/D) ratio and myeloperoxidase (MPO) activity were obtained. The protein and mRNA expression of intercellular adhesion molecule-1 (ICAM-1), nuclear factor-Kappa B (NF-κB) was also detected by using immunohistochemistry and semi-quantitative RT-PCR at the end of reperfusion. Results The levels of decreased PaO_2 and increased PawP in trail group were lower than in control group at the every interval time in the samples obtained 15 min after reperfusion (P0.01). After reperfusion the W/T, MPO, the protein and mRNA expression of ICAM-1, NF-κB were decreased evidently in trail group as compared with those in control group (P0.01). Conclusion Using dexamethasone during donor rat lung preservation can effectively inhibit the expression of NF-κB and ICAM-1, further improve lung respiratory functions.