Pathological observation of toxic effect of melamine on important organs of digestive system of mice

In order to investigate the toxicity of stomach,small intestine and liver caused by melamine,32 KM mice were randomly divided into 4 groups of 8 mice(male∶female=1∶1) in each group.All the mice were administrated orally with different doses(0,175,350,700mg/kg) of melamine(MA),and the clinical response was observed.When the mice died during the experiment,an autopsy was carried out instantly.The pathological changes of stomach,small intestine and liver were observed.Result showed that all the mice in experimental group died within 48h,and diffuse necrosis in mucosa of stomach and small intestine was observed.In liver injury,fatty changes in hepatocytes and diffuse congestion in lobule occurred,with local hemorrhage in some mice.Moreover,many small yellow crystalline solids were observed in the blood vessels of stomach,intestine and liver in 700mg/kg group.Under transmission election microscopy,the cytoplasm was loose and the mitochondria were swelling in the 175mg/kg and 350mg/kg group,while in the 700mg/kg group,the cytoplasm were full with lipid droplet and the mitochondria diffusely shrinked.In conclusion,melamine can induce acute necrosis of stomach and small intestine,liver congestion,fatty degeneration and necrosis.High concentration of melamine can form crystalline solids in the interstitial of stomach,small intestine and liver.