EXPERIMENTAL RADIATION PNEUMONITIS

Technical Report · Sun Jan 01 04:00:00 EST 1961

OSTI ID:4716991

Smith, J C

The pathological features of radiation pneumonitis were studied in rats. Autopsy examinations were performed on rats at intervals of 2 weeks to 5 months after irradiation of the right hemithorax with 3000 r. The morphological reaction sequence included atrophy, hyalinization, accumulation of macrophages in alveoli, depopulation of alveolar lining surfaces, and hyalinization of alveolar walls. The pathologic changes were generally progressive, the reaction developed in the absence of exudative inflammation, and the tissue changes were not detectably modified by cortisone or terramycin, alone or in combination. The reaction of pulmonary tissue to x irradiation may be more appropriately regarded as an induced atrophy due to mitogenic arrest than as an inflammatory response due to ionizing injury. A suggested concept of pathogenesis is that ionizing radiation induces mitotic arrest in the alveolar lining cells which subsequently detach from the alveolar surfaces and either accumulate in the air sacs or are transported out of the lung depending on the capacity of the pulmonary clearance mechanism. This concept is based on a known biologic effect of irradiation, it does not require the process of inflammation, and it is consistent with a temporal account of the events that transpire. (auth)

• Research Organization: Western Reserve Univ., Cleveland
• NSA Number: NSA-17-023215
• OSTI ID: 4716991
• Report Number(s): TID-16982
• Country of Publication: United States
• Language: English

Related Subjects

BIOLOGY AND MEDICINE