Effects of safflor injection on expression of cyclooxygenase-2 mRNA during lung ischemia/reperfusion injury in rabbits

AIM: To investigate the effects of safflor injection(SI) on expression of cyclooxygenase-2 mRNA during lung ischemia/reperfusion injury(PIRI) in rabbits.METHODS: Rabbit lung model of ischemia/reperfusion injury was constructed in vivo.The rabbits were randomly divided into three groups: sham-operation group(group S),ischemia-reperfusion group(group I/R) and ischemia/reperfusion plus safflor injection group(group SI).The lung tissue sampled at the end of the experiment was assayed for wet/dry weight ratio(W/D),injured alveoli rate(IAR) and observed ultrastructure changes under electron microscope.The expressions of COX-1 and COX-2 were measured by immunohistochemistry(IHC).The expression of COX-1 mRNA and COX-2 mRNA were observed by in situ hybridization(ISH).RESULTS: The value of W/D and IAR was much higher in I/R group,but decreased in SI group.Electron microscope showed obvious ultrastructure injury brought by PIRI in I/R group,which was greatly attenuated in SI group.The IHC and ISH demonstrated that COX-2 and COX-2 expressions in pulmonary tissue of I/R group were significantly higher than those in S group(P0.01).The difference of COX-1 and COX-1 expressions in pulmonary tissue was not observed among three groups.CONCLUSION: The lung ischemia-reperfusion insult induces the upregulation of COX-2 in lung.Safflor injection may attenuate lung ischemia-reperfusion injury through inhibiting COX-2 expression.