维生素D对不同剂量X射线照射小鼠免疫功能的保护作用

目的 观察维生素D对不同剂量X射线照射小鼠免疫功能的影响。方法 将小鼠采用随机数字表法分为5组:健康对照组、2 Gy和5 Gy照射组、2 Gy+药物(维生素D)组和5 Gy+药物(维生素D)组。给药组小鼠在不同剂量X射线照射后,连续7 d腹腔注射6 IU维生素D[1,25(OH)₂D₃]/g体重,于给药后第8天,5组小鼠均处死。测定小鼠体重、胸腺和脾脏指数,ConA诱导的脾脏T淋巴细胞增殖能力,ELISA法检测脾细胞IL-2的分泌量。结果 与健康对照组相比,2和5 Gy照射组小鼠脾脏T淋巴细胞增殖能力、脾细胞IL-2的分泌量均显著降低(F=36.20、7.13,P<0.05);与2 Gy照射组相比,2 Gy+药物组小鼠胸腺指数、脾脏指数、脾脏T淋巴细胞增殖能力均显著增高(t=-2.54、-2.24、-2.84,P<0.05);与5 Gy照射组相比,5 Gy+药物组小鼠的胸腺指数、脾细胞IL-2的分泌量显著增高(t=-5.02、-2.64,P<0.05)。结论 维生素D能够改善受照小鼠的免疫功能,但随照射剂量增大,改善作用减弱。

Protective effect of vitamin D on the immune function of mice in response to radiation

Objective To investigate the effect of vitamin D on the immune function of mice irradiated with different doses of X-rays. Methods The mice were randomly divided into five groups: controls, 2 and 5 Gy irradiated groups, 2 and 5 Gy X-rays combined with vitamin D groups. Vitamin D (6 IU/g) was intraperitoneally injected into the mice after irradiation for 7 days. On day 8, all mice were killed, and body, thymus and spleen of each mouse were weighed. The thymus and spleen indexes, and proliferation of spleen T lymphocytes were assessed. The level of IL-2 in the supernatant of spleen cells was measured by ELISA. Results Compared with control group, proliferation of spleen T lymphocytes and the level of IL-2 in the supernatant significantly decreased in 2 and 5 Gy groups (F=36.20,7.13, P<0.05). Compared with 2 Gy group, the thymus index, spleen index and proliferation of spleen T lymphocytes were significantly increased in the 2 Gy plus vitamin D group (t=-2.54,-2.24,-2.84, P<0.05). Compared to the 5 Gy group, the thymus index and the level of IL-2 in the supernatant significantly increased in the 5 Gy plus vitamin D group (t=-5.02,-2.64, P<0.05). Conclusions Vitamin D could restore the immune function of mice after radiation, while the restore capacity was decreased along with the increase of radiation dose.