Ojbective: To study the anti ionizing radiation ability of
metallothionein (MT) by oral administration. Methods:
MT were given to mice for 30 days by stomach feeding, and then the mice received 7 Gy or 8 Gy 60 Co γ radiation, or received 1 Gy 60 Co γ small dose radiation once a day. The experiment lasted for 8 weeks. The number of leucocytes and lymphocytes were counted at different time after radiation. Results: (1)7 Gy radiation was the most appropriate condition used for the experiments. After 7 Gy 60 Co γ radiation, the decrease of lymphocytes paralleled with that of leucocytes. Thus lymphocytes could be used as an indicator for evaluating the anti radiation effect of functional food. (2)After 30 days feeding of MT (0.6 mg/(kg bw·d) or 3.0 mg/(kg bw·d), the leucocytes and lymphocytes were significantly higher than that of control. (3)The survival time of MT accepted mice after 8 Gy 60 Co γ radiation was longer 72% than that of control (P<0.05). (4)After 1 Gy 60 Co γ radiation once a week for 7 or 8 weeks, the leucocytes and lymphocytes were significantly higher than that of control. Conclusion: Oral administration of MT can elongate the survival time of mice which accepted large dose of radiation, and reduce the damage on immunity system induced by large or multiple small dose radiation.