Experimental Studies Of Injury To The Liver Tissue By Mixture Of Melamine And Cyanuric Acid

Objective:This study is to investigate the mixture of melamine and cyanuric acid toxicity injury in the mouse liver tissue, and to identify its mechanism, to round out its toxicity studies and a comprehensive and objective assessment of melamine and cyanuric acid toxicity for the production of safe animal feed to provide a theoretical reference.Method:This experiment uses 25 to 30 days aged mice as test object.30 days after gavage melamine and cyanuric acid poisoning attack, broken cervical vertebrae were killed, eyes and take out the liver blood test as follows:Use conventional method for melamine and cyanuric acid on liver function; Detection of liver superoxide dismutase (SOD) activity and malondialdehyde (MDA) content; with production of pathological liver biopsy and pathological examination of liver biopsy pathological changes;using RT-PCR, regulation of apoptosis related genes Bax, Bcl-2, Caspase-3 expression; by TUNEL assay of liver cell apoptosis and whether the rate of change, and by immunohistochemical detection of melamine and three poly cyanate on the regulation of apoptosis related genes Bax, Bcl-2, Caspase-3 protein expressionResults:After injection, melamine and cyanuric acid were mixed each dose group there are different degrees of liver cell degeneration, necrosis, nuclear condensation, fragmentation and disappear, some serious or even necrosis. As the infection dosage gradually increasing the content of MDA increased, while SOD activity decreased. Liver function tests, each dose group ALT, AST activity with the mixture of melamine and cyanuric acid dose increased gradually, TP content decreased correspondingly. TUNEL test results show:the mixed dose groups have different levels of apoptosis, and with the concentration, the more obvious apoptosis. RT-PCR results showed that Bax and caspase-3 expression was significantly increased, Bcl-2 gene expression was decreased, mixed high-dose group compared with the control group were significantly lower OD values were significantly different (P <0.01).Immunohistochemistry results showed that:Bax and caspase-3 are involved in the melamine and cyanuric acid induced apoptosis of liver cells, while Bcl-2 has not involved with melamine and cyanuric acid induced liver cell. Conclusion:Mixture of melamine and cyanuric acid on liver injury in mice, with the mixture showed a definite increase in dose effect relationship, the higher the dose the more serious injury. The separate melamine and cyanuric acid in the mouse liver without significant injury. And the mixture of melamine and cyanuric acid can induce apoptosis in mouse liver cells, Bax and caspase-3 involved in the melamine and cyanuric acid induced apoptosis of liver cells.