RESUMO
<p><b>AIM</b>To investigate the dynamic changes of Egr-1 expression in the lungs of acute pulmonary embolism of rats by infusion of autoblood thrombs.</p><p><b>METHODS</b>The model of pulmonary embolism by infusion of autoblood thrombs in the pulmonary artery of rats was established and the mean pulmonary arterial pressure was continuously monitored by computer, and the results were evaluated by lung perfusion scan and pathological changes. Expression of Egr-1 proteinum and mRNA were measured by immunohistochemistry and reverse transcription polymerase chain reaction.</p><p><b>RESULTS</b>The mPAP of rats was increased significantly after infusion of autoblood thrombs at the half hour, and reached high level at the second hour, then remained the high level to four hours compared with group control at the same time point (P < 0.01). ECT image was showed significantly filling defect after infusion of autoblood thrombs at the first hour. The infused thromb was witnessed by hematoxylin and eosin stain. In the tracheal epithelium cells, alveolar epithelium cells and vascular smooth muscle cells of embolism rats, Egr-1 protein expression was increased significantly after embolization at the second hour compared with group control at the same time point (P<0.01), and was decreased slowly at the fourth hour. Egr-1 mRNA expression was showed the similar changes.</p><p><b>CONCLUSION</b>Expression of Egr-1 was low level in group control, but increased significantly after infusion of autoblood thromb at the second hour in the specificity of cells, suggesting that Egr-1 expression might be an important link of pathological changes in the acute pulmonary embolism.</p>