ABSTRACT
<p><b>AIM</b>To investigate the role of endothelin-1 in the pathogenesis of neurogenetic pulmonary edema.</p><p><b>METHODS</b>The levels of endothelin-1 in plasma and lung were measured in rats which suffered from diffuse brain injury on Marmarous' model. The changes of endothelin-1 in the lungs were also detected using an immunohistochemical method.</p><p><b>RESULTS</b>After heavy diffuse brain injury in rats, the levels of endothelin-1 in plasma and lung began increasing at 1 hour, and peaked at 6 hour. Though a little declining at 24 hour, it maintained a higher level within 48 hours (P < 0.05). Pulmonary pathology showed that after brain injury there were congestion, swelling in pulmonary microvessels with broadened pulmonary interstitial tissue, and leucocyte infiltration was dominated by neutrophils and monocytes from 1 hour on, which peaked at 6 hour. More serious congestion, swelling and protein effusion in pulmonary alveoli were observed at both 24 h and 48 h. Immunohistochemically, endothelin-1 had more significant expression and higher levels of OD in the experimental groups than that in the control's, the most significance of which was at 6 hour.</p><p><b>CONCLUSION</b>The inflammatory injury mechanism caused by endothelin-1 may play an important role in neurogenic pulmonary edema.</p>