Vitamin A inhibits radiation-induced pneumonitis in rats.
Radiation-induced lung injury frequently limits the total dose of thoracic radiotherapy that can be delivered, and the determinants of host susceptibility are poorly understood. To test the hypothesis that vitamin A status may be an important, modifiable host determinant of radiation-induced lung injury, we determined the effect of altered vitamin A status on radiation-induced lung inflammation in rats. WAG-Rij Y rats were fed a diet deficient in or supplemented with vitamin A (0 units/kg or 80,000 units/kg diet). After 5 wk of consuming the prescribed diet, rats were irradiated with 15 Gy of 250 kV X-rays to the whole thorax. At 4-5 wk post-irradiation, there were significantly fewer neutrophils on bronchoalveolar lavage in rats fed the vitamin A-supplemented diet (8.8 +/- 1.2% neutrophils) compared with those fed the vitamin A-deficient diet (20.8 +/- 3.4% neutrophils, P < 0.01). At the termination of the experiment, 4-5 wk postradiation, lung retinol levels of the vitamin A-supplemented group were 19.6 +/- 1.8 nmol/g, whereas those in the vitamin A-deficient group were significantly lower, 1.7 +/- 0.5 nmol/g (P < 0.01). These findings suggest that supplemental vitamin A may reduce lung inflammation after thoracic radiation and be an important modifiable radioprotective agent in the lung.
Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
C A
CA
Redlich
S
S
Rockwell
J S
JS
Chung
A G
AG
Sikora
M
M
Kelley
S T
ST
Mayne
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004032:Diet; D004305:Dose-Response Relationship, Drug; D008168:Lung / Q000528:radiation effects; D008297:Male; D009752:Nutritional Status; D017564:Radiation Pneumonitis / Q000517:prevention & control*; D051381:Rats; D014801:Vitamin A / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D014802:Vitamin A Deficiency / Q000097:blood / Q000378:metabolism; D014810:Vitamin E / Q000097:blood
D014801:Vitamin A; D014810:Vitamin E