Structural and functional alterations in the rat lung following whole thoracic irradiation with moderate doses: injury and recovery.
OBJECTIVE
To characterize structural and functional injuries following a single dose of whole-thorax irradiation that might be survivable after a nuclear attack/accident.


METHODS
Rats were exposed to 5 or 10 Gy of X-rays to the whole thorax with other organs shielded. Non-invasive measurements of breathing rate and arterial oxygen saturation, and invasive evaluations of bronchoalveolar lavage fluid, (for total protein, Clara cell secretory protein), vascular reactivity and histology were conducted for at least 6 time points up to 52 weeks after irradiation.


RESULTS
Irradiation with 10 Gy resulted in increased breathing rate, a reduction in oxygen saturation, an increase in bronchoalveolar lavage fluid protein and attenuation of vascular reactivity between 4-12 weeks after irradiation. These changes were not observed with the lower dose of 5 Gy. Histological examination revealed perivascular edema at 4-8 weeks after exposure to both doses, and mild fibrosis beyond 20 weeks after 10 Gy.


CONCLUSIONS
Single-dose exposure of rat thorax to 10 but not 5 Gy X-irradiation resulted in a decrease in oxygen uptake and vasoreactivity and an increase in respiratory rate, which paralleled early pulmonary vascular pathology. Vascular edema resolved and was replaced by mild fibrosis beyond 20 weeks after exposure, while lung function recovered.
Zhang
Rong
R
Department of Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, China.
Ghosh
Swarajit N
SN
Zhu
Daling
D
North
Paula E
PE
Fish
Brian L
BL
Morrow
Natalya V
NV
Lowry
Timothy
T
Nanchal
Rahul
R
Jacobs
Elizabeth R
ER
Moulder
John E
JE
Medhora
Meetha
M
D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005260:Female; D008168:Lung / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects*; D011651:Pulmonary Artery / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects; D011652:Pulmonary Circulation / Q000528:radiation effects*; D011654:Pulmonary Edema / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D011833:Radiation Injuries, Experimental / Q000473:pathology* / Q000503:physiopathology*; D051381:Rats; D012119:Respiration / Q000528:radiation effects; D013909:Thorax; D014598:Uteroglobin / Q000378:metabolism
C556391:Scgb1a1 protein, rat; D014598:Uteroglobin