title: Inflammatory response and pneumocyte apoptosis during lung ischemia-reperfusion injury in an experimental pulmonary thromboembolism model.
abstract: Lung ischemia-reperfusion injury (LIRI) may occur in the region of the affected lung after reperfusion therapy. The inflammatory response mechanisms related to LIRI in pulmonary thromboembolism (PTE), especially in chronic PTE, need to be studied further. In a PTE model, inflammatory response and apoptosis may occur during LIRI and nitric oxide (NO) inhalation may alleviate the inflammatory response and apoptosis of pneumocytes during LIRI. A PTE canine model was established through blood clot embolism to the right lower lobar pulmonary artery. Two weeks later, we performed embolectomy with reperfusion to examine the LIRI changes among different groups. In particular, the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2), serum concentrations of tumor necrosis factor-α (TNF-α), myeloperoxidase concentrations in lung homogenates, alveolar polymorphonuclear neutrophils (PMNs), lobar lung wet to dry ratio (W/D ratio), apoptotic pneumocytes, and lung sample ultrastructure were assessed. The PaO2/FiO2 in the NO inhalation group increased significantly when compared with the reperfusion group 4 and 6 h after reperfusion (368.83 ± 55.29 vs. 287.90 ± 54.84 mmHg, P < 0.05 and 380.63 ± 56.83 vs. 292.83 ± 6 0.34 mmHg, P < 0.05, respectively). In the NO inhalation group, TNF-α concentrations and alveolar PMN infiltration were significantly decreased as compared with those of the reperfusion group, 6 h after reperfusion (7.28 ± 1.49 vs. 8.90 ± 1.43 pg/mL, P < 0.05 and [(19 ± 6)/10 high power field (HPF) vs. (31 ± 11)/10 HPF, P < 0.05, respectively]. The amount of apoptotic pneumocytes in the lower lobar lung was negatively correlated with the arterial blood PaO2/FiO2, presented a positive correlation trend with the W/D ratio of the lower lobar lung, and a positive correlation with alveolar PMN in the reperfusion group and NO inhalation group. NO provided at 20 ppm for 6 h significantly alleviated LIRI in the PTE model. Our data indicate that, during LIRI, an obvious inflammatory response and apoptosis occur in our PTE model and NO inhalation may be useful in treating LIRI by alleviating the inflammatory response and pneumocyte apoptosis. This potential application warrants further investigation.
authors: Division of Respiratory & Critical Care Medicine, Scientific Research Department of the First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005, Fujian, People's Republic of China, jasonsci7333@163.com.
authors: Chaosheng
authors: C
authors: Deng
authors: Zhenguo
authors: Z
authors: Zhai
authors: Dawen
authors: D
authors: Wu
authors: Qichang
authors: Q
authors: Lin
authors: Yuanhua
authors: Y
authors: Yang
authors: Minxia
authors: M
authors: Yang
authors: Haibo
authors: H
authors: Ding
authors: Xiaoming
authors: X
authors: Cao
authors: Qiaoxian
authors: Q
authors: Zhang
authors: Chen
authors: C
authors: Wang
mesh_terms: D056809:Alveolar Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D004285:Dogs; D018836:Inflammation Mediators / Q000097:blood*; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D011655:Pulmonary Embolism / Q000097:blood* / Q000473:pathology; D015427:Reperfusion Injury / Q000097:blood* / Q000473:pathology
chemical_list: D018836:Inflammation Mediators