| BackgroundHepatocellular carcinoma(HCC,hepatocellular carcinoma)is one of the most common and highly malignant tumors in humans.It is the fifth place in the global incidence of malignancy,the third is the death of the tumor and the second tumor in China.Therefore,early diagnosis and treatment to improve the survival and prognosis of patients with liver cancer is extremely important.Therefore,the establishment of liver cancer model of liver cancer research is of great significance.Sausage,salted fish and other animal pickled food is a favorite food for our residents,but its food safety has attracted more and more attention.China's newly issued dietary guidelines(2016)Article 4,recommended appropriate amount of fish,poultry,eggs,lean meat,smoked and pickled meat due to the processing process vulnerable to some carcinogenic contamination,clearly made less or not eat.At present,a large number of epidemiology that often eat bacon food and other processed meat products will increase liver cancer,gastric cancer,colorectal cancer and other digestive system cancer risk,and analysis is likely and sausage,salted fish and other animal pickled food intake increased May lead to N-nitroso compounds(English abbreviation),benzopyrene(BaP)and other carcinogenic substances increased,but the relevant laboratory research data is very small.Therefore,this study was conducted to study the effect of bacon products on the digestive system of rats by long-term feeding rats.The effects of different bacon products on the liver,esophagus,stomach and stomach of experimental rats were observed and compared.Rectal and other digestive system damage,and analysis to determine whether this damage is mainly caused by nitrosamines.Objective1.Us NDMA as a chemical inducer,the establishment of rat liver cancer model.2.To study the long-term intake of sausage on the rat digestive system damage.3.Analysis of the intake of sausage on the rat digestive system damage is mainly caused by nitrosamines.Methods1.6-week-old male SD rats were randomly divided into experimental group(42 rats)and control group(42 rats).The experimental group was treated with 30?g/L dimethylnitrosamine(NDMA))Drinking water allowed to drink for 12 weeks,12 weeks after the change to sterile tap water,the control group has been given sterile tap water.The rats were sacrificed at 36th week,and all rats were sacrificed at 36 weeks,and all rats were sacrificed at 36,6,6,10,12,16,20,24,28,Take the liver and serum samples,the liver immediately do pathological sections,observe the pathological changes.2.Sausage feeding experiment:180 weeks of male clean grade SD rats 180,weight 200.8 ± 23.9g,according to body weight were randomly divided into 5 groups,were blank control group(fed with AIN-93G feed),experimental group A[fed(180g/kg)in the diet,the experimental group B[the content of sausage(NDMA content exceeded)was 18%(180g/kg)],and the experimental group C[(300 g/kg)and the positive control group(fed with basic feed,given 30?g/L NDMA drinking water for 12 weeks of free drinking,12 weeks after the change to sterile tap water),continuous feeding The rats were sacrificed at the 7th,17th,25th and 33th week,and the rats were sacrificed at 36 weeks.The liver,colon,rectum,esophagus and stomach were taken and the pathological changes were observed immediately.3.Statistical methods:all data using Excel to establish a database,the original data using SPSS 20.0 statistical software for entry,sorting and analysis.Data collation analysis using frequency,mean and standard deviation,such as statistical description.Hepatitis score and liver fibrosis score between the experimental groups were compared by t test or analysis of variance.Result1.Liver cancer model establishment experiment:the experimental group of liver tissue sections at the first 6,16,24,32 weeks positive group were three rats were typical of hepatitis,liver fibrosis,cirrhosis,liver cancer changes,And the trend of the whole induction process is obvious,showing a significant time gradient.2.Sausage feeding experiment:The scores of hepatitis B in the control group,the experimental group A,the B group,the C group and the positive control group were as follows:blank control group:0±0?0±0?0.55±0.73?1.31 ±0.94;Group A:0.25±0.71?0.34±0.68?0.73±0.98?2.43±0.89;Group B:3.88±0.83?7.36±0.79?10.42±0.76?13.64±0.83;Group C:7.92±0.87?9.99±0.93 ?12.91 ±0.98?15.51 ±0.98;Positive control group:11.11±0.96?14.32±0.87?15.43±0.92?17.65±0.99.The hepatitis B scores of experimental groups 7,17,25 and 33 were compared with those of the control group at the corresponding time points.The scores of hepatitis in experimental group B and group C were higher than those in blank control group(P<0.01).The scores of hepatitis B in group C were higher than those in group B.The scaffolds of liver tissue of experimental group A and group B were different in four different periods(P<0.01),and the scores of hepatitis B in group B were higher than those in group A.The histopathological changes of liver tissue in experimental group A were compared with blank control at 7th,17th and 25th week(P<0.01),but there was no significant difference between the two groups(P>0.05).The difference between the two groups was statistically significant(P<0.01).At the 33th week of the experiment,3(37.5%)rats in the blank control group were hepatitis and 5(62.5%)rats in the experimental group A had hepatitis;6(75%)mice in the experimental group B(25%)rats showed mild hepatic fibrosis;2(25%)rats in the experimental group C had hepatitis,5(62.5%)had mild hepatic fibrosis,1(12.5%)has developed cirrhosis.In the positive control group,2(25%)rats developed cirrhosis,6(75%)had only liver cancer.The pathological sections of the esophagus,stomach,colon and rectal tissues of the blank control group,the experimental group A,the B group and the C group were normal throughout the experimental stage.Only positive control group showed colonic mucosal inflammation,lymphoid tissue hyperplasia,intestinal epithelial atrophy and other pathological changes.Conclusion1.With 30?g/L NDMA aqueous solution for a long time free drinking water,in the first 32 weeks to induce rat to form hepatocellular carcinoma.2.The toxicity of NDMA-induced hepatocarcinoma and the degree of liver injury were similar to those of natural pathogenesis of human hepatocellular carcinoma,suggesting that NDMA had obvious affinity for liver,high rate of carcinogenesis and more specificity drug.3.Long-term intake of NDMA excessive sausage will lead to the occurrence of hepatitis,liver fibrosis,liver cirrhosis increased risk,and then develop into liver cancer,and the more the higher the risk of sausage intake.Long-term intake of NDMA excessive sausage on the esophagus,stomach,colon and rectal tissue without significant damage.4.Long-term sausage intake caused by liver damage and accompanied by excessive intake of sausage nitrosamine(NDMA)intake is closely related. |
PDF Full Text Request