Organ-related cigarette smoke-induced oxidative stress is strain-dependent

Cigarette smoke (CS) is associated with oxidative stress in several organs because it contains high concentrations of free radicals and reactive oxygen species. Experimental models, using different strains, provide important insights into the genetic basis of diseases. This study sought to identify, in different mouse strains, the organ that is most-susceptible to CS-induced oxidative stress to obtain an optimized experimental animal model of oxidative injury induced by CS.

Male Swiss, DBA/2, C3H, BALB/c, and C57BL/6 mice were exposed to CS 3 times a day (4 cigarettes per session) for 60 consecutive days. Control groups from the same strains were sham-treated. Protein content, malondialdehyde level, myeloperoxidase activity, and nitrite level were assayed in lung, liver, kidney, and brain from all strains. Catalase and glutathione peroxidase activities were measured. Analyses of data were done by using a 1-way ANOVA with Bonferroni's post-test (P<.05).

Cigarette smoke exposure resulted in distinct, organ-specific responses among strains. The survival rate of DBA/2 mice was lowest. BALB/c and C57BL/6 strains were more-susceptible to oxidative damage in the lung and liver. C3H and C57BL/6 mice were more-susceptible to oxidative damage in the brain. No renal oxidative damage was seen.

Mouse strains and individual organs display a range of susceptibilities to CS-induced oxidative stress. BALB/c and C57BL/6 strains appear to be the best choices as experimental models for studying CS effects on liver and lung, and C3H and C57BL/6 strains for CS-effects on the brain.