Studies on the Acute and Accumulative Toxicity of Melamine in Mice

To evaluate the toxicity of melamine to mice,the acute toxicity and the accumulative toxicity tests were carried out.The acute toxicity test was designed to 7 experiment groups(r=0.65) and 1 control group,which consisted of 10 mice.Toxic manifestations,gross lesions and histopathological lesions of mice,were observed during 7 days acute exposure.LD50 and 95% LD50 confidence level of melamine were calculated by the modified Korbor method.The accumulative toxicity test was carried out by continuous exposure at a fixed dose(1/3 LD50),the accumulative coefficient was calculated to appraise the accumulative toxicity of melamine.The acute toxic symptoms of mice were actively decreased,respiratory distress and anorexia.The death time of mice was within 42 h-72 h.Except for kidney,lung,liver and spleen of dead mice showed gross lesions and histopathological changes.The LD50 of melamine to mice was 2 958.69 mg/kg,with 95% confidence interval of 2 187.00 mg/kg-3 981.07 mg/kg.The results of accumulative toxicity test showed that the accumulative coefficient K was 4.The results suggest that melamine is a kind of low toxic chemical according to food safety evaluation on toxicology in China,and possesses moderate accumulative toxicity in mice.The kidney,lung,liver and spleen are toxic targets of melamine in acute toxicity test.