Abstract: Objective:To investigate effects of the continuous administration o f Melatonin during 51 days on the anti-oxidation system and the growth of weigh t. Methods: The objects were Kunming mice (♂). The model was set up by continu o us administration of MT during 51 days. The indexes include the activity of Su pe roxide Dismutase(SOD) , Peroxidase(POD), Catalase(CAT),Total anti-oxidant Ca pab ility(T-AOC) and weight. Results: After continuous administration of MT, mi ce′ s weight and the increment of weight are significantly lower in MT group th an in control group(p< 0.05). Continuous administration of MT can significantly enhan ce the activity of SOD and T-AOC in kidney, T-AOC in heart, SOD and T-AOC in brain (p< 0.05～0.01),and significantly decrease the activity of CAT in brain an d the content of MDA in kidney, heart and brain(p< 0.05～0.01), but ins ignifican tly effect on the activity of POD and CAT in kidney, SOD, POD and CAT in heart a nd POD in brain(p >0.05). Conclusion: Experimental results suggest th at the stro ng anti-oxidation capability of MT can significantly assist anti-o xidation sys tem of body, and partly inhabit the growth of weight.

Key words: melatonin(MT), weight, kidney, brain, heart, chemical indexes