The Establishment Of Toxicology Animal Model Of Cigarette Smoke And The Tobacco Specific Nitrosamines (TSNA)

To examine the possibility of developing an animal model of whole smoke and theTobacco-specific nitrosamines (TSNA)-induced body injury in Kunming mice according tothe producers and methods of tobacco smoke and TSNA-induced lung injury model inhome and abroad. One hundred and twenty Kunming strain mice were divided into4groups randomly：the smoke group, the NNK group, the NNN group and the control group.The smoke group except normal control were exposed to tobacco smoke for4months（2hours per day,10cigarettes,12minute per cigarette,1time per minute and6days perweek). The NNK and NNN group were injected intraperitoneally at a dose of0.2mg/mL,one time a day,6days a week, and last4months. The control group without the wholesmoke and the TSNA treatment, and other conditions were the same with the experimentalgroup. After treatment with cigarette smoke、NNK and NNN, dissecting the mice andcollected their organs（trachea, lung, liver, kidney, spleen, stomach, small intestine, bladderand testicular). After that, histologic sections were performed to observe the changes of thetissues. Screening the abnormal tissue and detecting the expression of proliferating cellnuclear antigen (PCNA) and p53protein with immunohistochemical staining，Proteinelectrophoresis and antioxidant gene Nrf2and GCLC relative expression with quantitativeReal-time PCR. The major conclusions are described as follows:（1）During the modeling, the smoke group mice skin drying and yellowing. In themodeling late, the frequency of the mice breath quickening and deepening, compared thecontrol group, the smoke group’s weight growth was significantly lower (P<0.05). TheNNK and NNN group mice tail appeared erosion, the weight gain and other aspects haveno significant change compared the control group. The above results show that the cigarettesmoke has a certain artificial effect on the growth of mice, but the TSNA has a little effecton the growth of mice.（2）HE staining result showed that the mice lung and liver of the experimentalgroup had obvious changes, there was significant inflammatory cells infiltration in the micelung, the alveolar spaces of different sizes, some of them thinning or breakage, and thepresence of significant sediment compared with the control group. The mice liver enlargeand cells degeneration with widespread, the number of liver cells increased significantly,showed inflammatory cell infiltration mildly. Other tissues have not found significantabnormalities.（3）Immunohistochemical results: the PCNA and p53positive expression rate inlung of the experimental group is respectively the smoke group80%and66.7%, the NNK （4）group66.7%and70%, the NNN group70%and76.7%, the PCNA and p53positive expression rate of the control group is10%and6.7%; In the mice liver, the PCNAand p53positive expression rate of the experimental group is the smoke group73.3%and60%, the NNK group60%and66.7%, the NNN group56.7%�'�56.7%respectively, thePCNA and p53positive expression rate of the control group is16.7%and10%.（5）The SDS-PAGE electrophoresis results showed that the water-soluble totalprotein expression of the experimental group mice lung and liver has little difference withthe control group.（6）Quantitative Real-time PCR test results showed that the antioxidant gene Nrf2and GCLC relative expression in the mice lung of the experimental group was about2.044and1.708times、1.939and1.334times、1.997and1.695times respectively that of thenormal group, it is significantly higher than the control group; However, the antioxidantgene Nrf2relative expression in the mice liver of the experimental group was about0.1203times、0.2087times and0.2552times respectively that of the normal group, that issignificantly lower than the control group.