Abstract
This study aims to investigate the effect of lung ischemia reperfusion injury（LIRI） on expression of transient receptor potential vanilloid 1（TRPV1） in the lung and brainstem of rats. Sixteen adult male Sprague Dawley rats weighing 250-320 g were randomly divided into Sham group and ischemia reperfusion group（IR group）. Before ischemia,0.5 hour and 4 hours after the reperfusion, respectively, arterial partial pressure of oxygen（PaO2） and arterial-alveolar oxygen pressure gradient（A-a DO2） were recorded and calculated, respectively. Left lung tissues and the brainstems were obtained at the end of the experiment. Lung tissue malondialdehyde（MDA）, myeloperoxidase（MPO） activities, calcitonin gene related peptide（CGRP） and substance P（SP） levels were assessed. The m RNA and protein expressions of TRPV1 in the lung and brainstem were measured by q RT-PCR and Western blot. Compared with in the Sham group, rats in the IR group had a poorer blood gas exchange（P<0.05） and the MPO activity and MDA level of lung tissues in the IR group were significantly higher than those in the Sham group（P<0.05）. CGRP level in the IR group increased remarkably（P<0.05）,while SP level did not differ statistically between the two groups（P>0.05）. The m RNA and protein expressions of TRPV1 in the lung tissue were upregulated in the IR group（P<0.05）, but there were no differences of those in the brainstem between the two groups（P>0.05）. The results suggest that LIRI could upregulate the expressions of TRPV1 and evoke CGRP release in the lung.