Effects of parecoxib pretreatment on pneumocyte apoptosis during lung ischemia-reperfusion injury in rats

Objective To investigate the effects of parecoxib on pneumocyet apoptosis during lung ischemia-reperfusion(I/R)injury in rats. Methods Seventy-two male SD rats were randomly divided into 3 groups(n= 24 each): sham operation group(S group); I/R group and parecoxib group(P group).The lung I/R was induced by occlusion of hilum of the right lung for 60 min followed by 120 min of reperfusion.In P group, parecoxib(5 mg/kg) was injected intravenously at 30 min before occlusion of hilum of the right lung. The rats were sacrificed at 2 h of reperfusion and then the lungs were removed for measurement of lung wet/dry weight ratio, apoptosis index, B cell lymphoma/leukemia-2(bcl-2)and B cell lymphoma/leukemia-2 associated X protein(bax) protein expression, and microscopic examination.Bcl-2/bax ratio was calculated. Results Parecoxib preconditioning significantly attenuated the I/R-induced changes in lung wet/dry weight ratio(6. 34 ±0. 19 vs.5. 28±0. 17, P< 0. 05), apoptosis index[(21. 5±2. 1)% vs.(11. 6±0. 8)%, P< 0. 05], bcl-2 protein expression(0. 29±0. 07 vs.0. 45±0. 09, P< 0. 05)and bax protein expression(0. 34±0. 05 vs.0. 18±0. 04, P< 0. 05), and bcl-2/bax ratio(0. 85±0. 05 vs.2. 50±0. 03, P< 0. 05)in P group as compared with I/R group.Parecoxib preconditioning also ameliorated I/R-induced lung damage. Conclusion Parecoxib can inhibit pneumocyte apoptosis through regulating the expression of bcl-2 and bax protein, and ameliorate lung I/R injury. Key words: Parecoxib; Reperfusion injury; Lung; Apoptosis