Ultrastructural Evaluation of the Protective Effect of Nitroglycerin in Preservation-Reperfusion Injury of Rat Lungs

Abstract

Aim of Study. Nitric oxide (NO) has been reported as a favorable protective supplement in donor lung preservation, but related ultrastructural studies are rare in the literature. This study was performed to assess the ultrastructural changes and to evaluate the protective effect of NO as donor nitroglycerin (NTG) treatment of ischemia-reperfusion injury in rat lungs. Materials and Methods. Fifteen Sprague-Dawley rats weighing 300 to 350 g were used in this study. The NTG group (n 5) used intravenous administration followed by mixture in the University ofWisconsin (UW) solution. For the non-NTG group (n 5), we injected the same amount of normal saline intravenously followed by admixture in the UW solution. The heart-lung blocks were removed, weighed, and kept in UW solution for 24 hours at 10°C. Reperfusion using human blood diluted in Krebs-Hensleit solution was done for 60 minutes. For the control group (n 5), we injected the same amount of normal saline intravenously, and removed the lungs with no preservation and reperfusion procedures. Results. The non-NTG group showed multiple patchy areas of alveolar collapse with marked swelling and destruction of type I epithelial cells, loss of type II cell surfactant granules, endothelial swelling and papillary projection, interstitial edema, and alveolar macrophages with active phagocytosis of the destroyed materials. The NTG group showed similar ultrastructural changes, but in a lesser severity compared with the non-NTG group. Conclusion. Administration of the NTG reduced the ischemia-reperfusion injury in the rat donor lungs. Ultrastructural examination was an effective tool to evaluate the protective effect of NTG in ischemia-reperfusion procedures of donor lungs.