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.
Redlich
C A
CA
Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
Rockwell
S
S
Chung
J S
JS
Sikora
A G
AG
Kelley
M
M
Mayne
S T
ST
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