动物造模 z-bio 2023-03-02 663

　　Objective: To investigate the internal exposure level of cigarettes in vivo by measuring the plasma nicotine and cotinine contents in smoking rats.

　　Methods: A total of 160 clean-grade SD male rats were randomly divided into 2, 4, 6, 8, and 12-week low-, medium-, and high-dose groups and a control group, with 10 rats in each group. Static exposure to the respiratory tract was used, once a day, and the exposure cycle was 2, 4, 6, 8, and 12 weeks. The general toxic effects of rats were observed, and the contents of nicotine and cotinine in the plasma of smoking rats were detected by gas chromatography-mass spectrometry.

　　Results: After the third week, the rats in the cigarette smoke exposure group gradually began to have intermittent cough, increased abdominal breathing, nasal noise and other symptoms. The longer the exposure time, the more obvious the symptoms; the higher the exposure dose, the longer the exposure period, The body weight of rats decreased more obviously, and the difference was significant compared with the blank control group (P < 0.01). The retention time of plasma nicotine in rats was 7.5-8.5 min. The nicotine content in plasma increased compared with the blank control group (155±56.65) ng/mL; the retention time of cotinine in rat plasma was 11.5-12.5 min; with the prolongation of exposure time and the increase of exposure dose, the concentration of cotinine in rat plasma increased. Compared with the blank control group (340±41.97) ng/mL, the content of cotinine increased, and there was a dose-response relationship. There was a significant difference in the content of cotinine between different exposure periods (P < 0.05). There was an interaction effect between exposure doses (P < 0.05).

　　CONCLUSION: Cigarette smoke exposure can cause different degrees of damage in rats. The plasma cotinine concentration in rats can effectively reflect the exposure to cigarette smoke, and it shows a good dose-response relationship.