Réparation cellulaire précoce du poumon et de l'intestin, chez la souris, après irradiation par neutrons rapides et rayons gamma

Lung tolerance is assessed from LD50 at 180 days after thoracic irradiation, in mice, with d(50) + Be neutrons and 60Co gamma rays. Early intestinal tolerance is assessed from LD50 at 7 days after abdominal irradiation. Additional dose (Dr) to reach LD50 when a single dose Ds is split into 2 equal fractions Di separated by different time intervals "i", is determined (Dr = 2Di - Ds), Dr is larger after gamma than after neutron irradiation, for lung and intestine. After thoracic irradiation with gamma rays, Dr reaches 3.36, 4.38, 5.12 and 5.37 Gy for "i" = 2, 6, 12 and 24 hours respectively; after neutron irradiation, Dr reaches 0.66, 0.9, 1.29, 1.95 and 1.50 Gy for "i" = 1, 2, 4, 12 and 24 hours. Dr is smaller for intestine; after abdominal irradiation with gamma rays, it reaches 1.99, 2.59, 2.74, 3.11, 3.34, 4.44 and 4.56 Gy for "i" = 1, 2, 3.5, 8, 12, 18 and 24 hours; after neutron irradiation, it reaches 0.13, 0.45, 0.42 and 1.33 Gy for "i" = 1.5, 3.5, 5.5 and 24 hours. After gamma irradiation, early repair is complete after 3.5 hours for intestine and needs 12 hours for lung.