PURPOSE: This study was undertaken to determine the effects of intratracheal administration of endotoxin on hyperoxia-induced lung injury in neonatal rats. MATERIALS AND METHODS: Newborn Sprague Dawley rat pups were divided into four experimental groups: normoxia control (NC), normoxia with endotoxin treatment (NE), hyperoxia control (HC), and hyperoxia with endotoxin treatment (HE) groups. In HC and HE, rat pups were subjected to 14 days of hyperoxia (> 95% oxygen) within 12 hours after birth. In endotoxin treated group (NE and HE), Escherichia coli endotoxin (0.5microgram in 0.03mL of saline) was given intratracheally at the 1st, 3rd and 5th postnatal day. Radial alveolar count (RAC), mean linear intercept (MLI), RAC/MLI ratios, and degree of fibrosis were measured to assess the changes in lung morphology. RESULTS: During the research period, survival rates in both HC and HE were notably reduced 7 days after endotoxin was administered, but body weight gain was considerably reduced only in HC. On day 14, significant arrest in alveolarization, as evidenced by the decrease of RAC and RAC/MLI ratio and increase of MLI as well as increased fibrosis, were noted in HC. Although slight but significant arrest in alveolarization and increased fibrosis score were observed in NE compared to NC, the hyperoxia-induced lung damage observed in HC was significantly improved in HE. CONCLUSION: This study suggests that intratracheal administration of endotoxin significantly attenuated hyperoxia-induced lung injury in neonatal rats.
Animals ; Animals, Newborn ; Body Weight ; Drug Administration Routes ; Endotoxins/*administration & dosage ; Hyperoxia/*complications ; Lung Diseases/*chemically induced/*etiology/pathology ; *Lung Injury ; Rats ; Rats, Sprague-Dawley

Interstitial lung disease in children (chILD) is a group of disorders characterized by lung inflammation and interstitial fibrosis. In the past recent years, we noted an outbreak of child in Korea, which is possibly associated with inhalation toxicity. Here, we report a series of cases involving toxic inhalational injury-associated chILD with bronchiolitis obliterans pattern in Korean children. This study included 16 pediatric patients confirmed by lung biopsy and chest computed tomography, between February 2006 and May 2011 at Asan Medical Center Children's Hospital. The most common presenting symptoms were cough and dyspnea. The median age at presentation was 26 months (range: 12-47 months), with high mortality (44%). Histopathological analysis showed bronchiolar destruction and centrilobular distribution of alveolar destruction by inflammatory and fibroproliferative process with subpleural sparing. Chest computed tomography showed ground-glass opacities and consolidation in the early phase and diffuse centrilobular nodular opacity in the late phase. Air leak with severe respiratory difficulty was associated with poor prognosis. Although respiratory chemicals such as humidifier disinfectants were strongly considered as a cause of this disease, further studies are needed to understand the etiology and pathophysiology of the disease to improve the prognosis and allow early diagnosis and treatment.
APACHE ; Bronchi/pathology ; Child, Preschool ; Cough/etiology ; Cyclophosphamide/therapeutic use ; Disinfectants/*toxicity ; Dyspnea/etiology ; Enzyme Inhibitors/therapeutic use ; Humans ; Hydroxychloroquine/therapeutic use ; Immunoglobulins/therapeutic use ; Infant ; Inhalation ; Lung Diseases, Interstitial/chemically induced/drug therapy/*pathology ; Prognosis ; Retrospective Studies ; Steroids/therapeutic use ; Tomography, X-Ray Computed