Construction and evaluation of a graded rat model for smoke inhalation lung injury

Abstract

Objective: To address the critical impact of smoke inhalation lung injury on burn patient prognosis and the lack of animal models simulating varying injury severity, we established a graded rat model to facilitate research into its pathological mechanisms and treatments. Methods: Eighteen male Wistar rats were divided into a control group and groups exposed to smoke for 5, 10, 15, 30 minutes (n=3 per group). A custom smoke chamber and specific materials (50 g pine wood chips + 10 mL kerosene) were used. Post-exposure assessments included lung function, lung coefficient (wet weight), histopathology (H&E staining), and leukocyte count and IL-6 levels in alveolar lavage fluid. Results: Lung function declined significantly in all exposure groups versus controls, with progressive worsening over time. The lung coefficient increased significantly in the 15- and 30-minute groups. Histology revealed intact structure at 5 and 10 minutes, alveolar rupture and neutrophil infiltration at 15 minutes, and hyaline membranes at 30 minutes. Leukocyte count and IL-6 levels rose markedly after 15 and 30 minutes of exposure. Statistical comparisons confirmed progressive injury severity with longer exposure. Conclusions: Graded rat models of mild, moderate, and severe inhalation lung injury were successfully established following 5, 15, and 30 minutes of smoke exposure, respectively. Injury and inflammation intensified significantly with exposure duration, providing a valuable foundation for further research.

Keywords

Animal models / Inhalation lung injury / Lung function / Lung coefficient / IL-6

Conflict of interest statement

The authors report no conflict of interest.

Funding

This study was supported by the Medical Development Research Fund of Emergency General Hospital (KY202201) and the National Key Research and Development Program of China (2023YFC3011805).

Data availability statement

The data supporting the findings of this study are available from the corresponding authors upon request.

Authors’ contributions

Study concept and design: ZYQ, ZYZ; Analysis and interpretation of data: SF, ZY, DYY, XYH; Drafting of the manuscript: ZYQ, SF, XYH; Critical revision of the manuscript for important intellectual content: ZYZ, ZJL, GYP; Statistical analysis: ZYQ, SF, XYH.

Publisher’s note

The Publisher of the Journal remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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