The purpose of this study was to quantitate cell populations recovered by lung lavage up to 6 weeks following thoracic irradiation (24 Gy) as an index of the acute inflammatory response within lung structures. Additionally, rats were treated five times weekly with intraperitoneal saline (0.3 cc) or methylprednisolone (7.5 mg/kg/week). Lung lavage of irradiated rats recovered increased numbers of total cells compared to controls beginning 3 weeks after irradiation (P < 0.05). The initial increase in number of cells recovered was attributable to an influx of neutrophils (P < 0.05), and further increases at 4 and 6 weeks were associated with increased numbers of recovered macrophages (p < 0.05). Lung lavage of steroid-treated rats at 6 weeks after irradiation recovered increased numbers of all cell populations compared to controls (P < 0.05); however, numbers of recovered total cells, macrophages, neutrophils, and lymphocytes were all significantly decreased compared to saline-treated rats (P < 0.05). The number of inflammatory cells recovered by lung lavage during acute radiation-induced lung injury is significantly diminished by corticosteroid treatment. Changes in cells recovered by lung lavage can also be correlated with alteration in body weight and respiration rate subsequent to treatment with thoracic irradiation and/or corticosteroids.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging