Studies On Neutron And γ Ray Radiation Injury On Gut-associated Lymphoid Tissues And Regulation Of IL-2 On Reepithlialization Of Enteric Epithelium

Objective: Compared to y ray injury, Neutron radiation injury of intestine always occur more rapidly and severely, have less curative effect and recover more difficultly. Now characteristics of neutron injury on gut-associated lymphoid tissues and effects of IL-2 on reepithlialization of enteric epithelium after neutron radiation have not yet been reported. It is very important for prevention, diagnosis and treatment of neutron injury to research characteristics of pathological changes of gut-associated lymphoid tissues and regulation of which on reepithlialization of enteric epithelium after neutron injury.Materials and methods: 350 BALB/C mice and IEC-6 (jejunum crypt epithelial cells of normal SD rats) was radiated by 2.5～5.5Gy neutron and 5.5～12Gy γ ray, and IEC-6 was treated by IL-2 (25 × 10~3～1×10~5U/L) and JAK, blocking agent (A77-1726) on 12h before radiation or immediately after radiation. The mice were sacrificed on 6h, 12h, 1～5d, 7d,14d, 21d and 28d after irradiation, IEC-6 were collected on 15min, 30min, 1h, 3h, 6h, 9h, 12h and 1～3d. Then the regularity of gut-associated lymphoid tissues injury and recovery and effects of IL-2 on reepithlialization of enteric epithelium could be studied with light microscope, electron microscope, histochemical stain, MTT colorimetry, FACS and immunoblot method and so on.Results: (1) Pathological changes of gut-associated lymphoid tissues: lymphocytes occurred apoptosis and necrosis within 3d, regenerated on 5d, and recovered during 14～21d after 2.5Gy neutron radiation, most lymphocytes appeared necrosis after 4.0 and 5.5Gy neutron radiation and no recovery. Pathological changes of 5.5Gy y ray group were similar to those of 2.5Gy neutron group, but were more slight, earlier regeneration and much more apoptosis. Degree of injury of 12Gy y ray was between 4.0 and 5.5Gy neutron group. (2) Changes of T, B lymphocytes in intestinal PP and plasmocytes: decreased progressingly within 5d after 2.5Gy neutron radiation, T/B ratio increased, and recovered after 14d. T lymphocytes and plasmocytes appeard dose-effect...