Effects of passive inhalation of cigarette smoke on structural and functional parameters in the respiratory system of guinea pigs

OBJECTIVE: To evaluate the effects of passive inhalation of cigarette smoke on the respiratory system of guinea pigs. METHODS: Male guinea pigs were divided into two groups: control and passive smoking, the latter being exposed to the smoke of ten cigarettes for 20 min in the morning, afternoon and evening (30 cigarettes/day) for five days. After that period, inflammatory parameters were studied by quantifying mesenteric mast cell degranulation, as well as oxidative stress, in BAL fluid. In addition, we determined MIP, MEP, and mucociliary transport (in vivo), as well as tracheal contractility response (in vitro). RESULTS: In comparison with the control group, the passive smoking group showed a significant increase in mast cell degranulation (19.75 ± 3.77% vs. 42.53 ± 0.42%; p < 0.001) and in the levels of reduced glutathione (293.9 ± 19.21 vs. 723.7 ± 67.43 nM/g of tissue; p < 0.05); as well as a significant reduction in mucociliary clearance (p < 0.05), which caused significant changes in pulmonary function (in MIP and MEP; p < 0.05 for both) and airway hyperreactivity. CONCLUSIONS: Passive inhalation of cigarette smoke caused significant increases in mast cell degranulation and oxidative stress. This inflammatory process seems to influence the decrease in mucociliary transport and to cause changes in pulmonary function, leading to tracheal hyperreactivity.