低剂量辐射对小鼠蛋白质代谢的影响

目的 :　了解一次性低剂量辐射对小鼠蛋白质代谢是否有影响 ,为辐射防护提供参考。方法 :　选用生长期和成年期小鼠各 3 0只 ,随机分成 3组 ,雄雌各半。分别接受 0 ,2 5 0 m Gy,5 0 0 m Gy60 Coγ射线一次全身照射 ,剂量率为 78.6 c Gy/min。每只动物每天定量给予 4g饲料 ,照射后第 7d起恢复自由进食 ,测定动物照射后连续 3 d的氮平衡 ,每 3 d称一次体重。照射后 1 0 d测定血红蛋白 (Hb) ,血清总蛋白 (TP)和血清非蛋白氮 (NPN)。结果 :　成年期小鼠在照射后 6 d时体重显著减少 (P<0 .0 1 ) ,恢复自由进食后体重减轻得到恢复。氮平衡试验中生长期小鼠 5 0 0 m Gy组 ,成年期 2 5 0 m Gy和 5 0 0 m Gy剂量组的正氮平衡低于相应的对照组 (P<0 .0 5 )。照射 5 0 0 m Gy使 Hb和 TP有所下降 ,同时 NPN升高 ,但未达到统计学显著差别。结论 :　一次性暴露于 2 5 0m Gy电离辐射对氮代谢有不良效应。

EFFECTS OF LOW DOSE RADIATION ON PROTEIN METABOLISM IN MICE

Objective: To understand whether low dose radiation has effect on protein metabolism in mice. Methods: Nitrogen balance (NB) test was carried out in 30 young and 30 adult mice. Mice were irradiated at the dose of 0, 250 mGy, 500 mGy by 60 Co γ-ray with the dose rate of 78.6 cGy/min. Each group had 5 mice in both sexes. Four grams of animal feeds were given to each mouse every day. Weight was recorded in each other two days. Urine and feces were collected in the first 3 days after irradiation. On day 7 feeds were given ad libitum, and on day 10, mice were killed and the levels of hemoglobin (Hb), serum total protein (TP) and serum nonprotein nitrogen (NPN) were measured. Results: On day 6 after irradiation the body weight in 500 mGy group in adult mice was lower than control (P<0.01). However, the weight was regained on day 9. The 500 mGy group in young and both 250 mGy and 500 mGy groups in adult mice had lower values in NB test (P<0.05). No difference was found in the levels of Hb, TP and NPN. Conclusion: Low dose irradiation at 250 mGy will give some adverse effects on nitrogen metabolism.