Early structural changes in sheep lung following thoracic irradiation
Using a large animal model of radiation lung injury--the sheep exposed to bilateral thoracic irradiation--we have recently shown the development of sustained pulmonary hypertension during the first 4 weeks following radiation. This is the period prior to the onset of pneumonitis and pulmonary fibrosis. In the present study, we have examined biopsy and autopsy lung tissue from these same sheep and assessed the sequential changes in lung morphology. Six unanesthetized sheep received bilateral thoracic irradiation (a total of 15 Gy); control sheep were sham irradiated. Lung biopsy tissue was taken prior to and at weekly or biweekly intervals during the 4 weeks immediately following radiation. The lungs were also removed at autopsy for light and electron microscopic examination. Our results show early (Week 1) interstitial and progressive intraalveolar edema accompanied by endothelial and epithelial injury. A gradual increase in number of interstitial mononuclear cells was evident from Week 1, both in the lung tissue and in perivascular cuffs. The number of peripheral lung interstitial mononuclear cells was twice baseline from Week 3 and included accumulation of lymphocytes, fibroblasts, and intravascular macrophages. The increased numbers of mononuclear cells paralleled the development of chronic pulmonary hypertension, perhaps suggesting their involvement in the pathogenesis of this disease. Alternatively, it may be that increased mononuclear cell number represents a stage of lung repair.
- Research Organization:
- Vanderbilt Univ. Medical Center, Nashville, TN (USA)
- OSTI ID:
- 7195045
- Journal Information:
- Radiat. Res.; (United States), Vol. 114:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HYPERTENSION
PATHOGENESIS
LUNGS
BIOLOGICAL RADIATION EFFECTS
PATHOLOGICAL CHANGES
BIOLOGICAL MODELS
ELECTRON MICROSCOPY
ENDOTHELIUM
EPITHELIUM
MACROPHAGES
MONOCYTES
SHEEP
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CARDIOVASCULAR DISEASES
CONNECTIVE TISSUE CELLS
DISEASES
DOMESTIC ANIMALS
LEUKOCYTES
MAMMALS
MATERIALS
MICROSCOPY
ORGANS
PHAGOCYTES
RADIATION EFFECTS
RESPIRATORY SYSTEM
RUMINANTS
SOMATIC CELLS
SYMPTOMS
TISSUES
VASCULAR DISEASES
VERTEBRATES
560152* - Radiation Effects on Animals- Animals