Effects of cigarette smoke on lung antioxidant defences, induction of goblet cell metaplasia and micropapillomatosis in DBA/2 and ICR mice

The role of strain differences in the response to cigarette smoke was investigated in mice. Basal total antioxidant capacity of bronchoalveolar lavage (BAL) fluids assessed as “Trolox equivalent antioxidant capacity” in DBA/2 mice was 61±12 nmolTrolox/ml BAL. After acute exposure to cigarette smoke (5 cigarettes within 20 min) the total BAL fluids antioxidant capacity of the DBA/2 mice decreased by 32% (p<0.01). Basal total antioxidant capacity of BAL fluids in ICR mice was similar to that of the DBA/2 mice (63±22 nmolTrolox/ml BAL). However, after acute cigarette smoke ICR mice increased their BAL antioxidant capacity by 57 % (p<0.01). Mice of these two strains were then exposed either to room air or to chronic cigarette smoke (3 cigarettes/day, 5 days/week) for 7 months. The animals were then sacrificed, the lungs stained with periodic acid-Schiff and the peripheral airways examined. The airways of both strains exposed to room air were normal. The peripheral airways of ICR mice exposed to cigarette smoke (N=5) showed no abnormalities and their epithelium was devoid of goblet cells. All DBA/2 mice exposed to cigarette smoke (N=8) exhibited a large number of goblet cells (goblet cell metaplasia) in their peripheral airways. Additionally, 7/8 mice had a diffuse micropapillomatosis in some cases with infiltrating character. All these results indicate that the response and sensitivity to the effects of cigarette smoke is strain-dependent.