Evaluation the Effect of Nicotine Injection on the Lungs of Mice

Background: Nicotine is the chief addictive substance in cigarette smoking which conceder as the main cause of mortality worldwide. Aims: Through the current in vivo  study,  we  tried  to  evaluate  the harmful effect of nicotine injection on the lungs of mice. Materials and Methods: A total of 40 healthy male mice were divided into four groups of 10 mice each, injected subcutaneously with 0.1 ml  of  (1  mg/kg)  nicotine  for  5  days  a  week  for  (8,  12,  and  16)  weeks,  whereas  the  control  group  injected with 0.1 ml of normal saline. The mice were sacrificed, lungs were isolated and divided into two  parts,  the  first  for  measurement  malondialdehyde  (MDA)  and  glutathione  (GSH),  the  second  was subjected to histopathological examination. Results: The results showed that the levels of MDA were significantly elevated (P ≤ 0.01) in all work groups and the mice of Group D had the highest MDA  value  (23.13  ±  3.4  nmol/ml)  with  statistically  significant  difference  (P  ≤  0.01),  and  GSH  levels were significantly decreased (P < 0.01) in all workgroups, the Group D had the lowest value (6.77 ± 1.33 mM/ml) with statistically significant difference (P ≤ 0.01), also the results clarified that nicotine injection was caused a pathological effect in mice lung tissues such as alveoli damage and emphysema,  congestion  of  blood  vessels,  hemorrhage,  alveolar  edema,  lung  fibrosis,  lymphocytes  infiltration, and these effects were graded in terms of severity depending on the injection period of nicotine. Conclusion:  It  can  be  concluded  that  the  nicotine  injection  causes  significant  changes  in  lung tissues and oxidant markers levels (MDA and GSH).