Prophylactic anti-inflammation inhibits cigarette smoke-induced emphysema in guinea pigs

In this study, the effect of prophylactic anti-inflammation on the development of smoke-induced emphysema was investigated. Young male guinea-pigs aged 1.5-2 months (weighing 198.3+/-26.9 g) were randomly divided into 4 groups: group A (cigarette smoke exposure only), group B (cigarette smoke exposure plus pentoxifylline-rich (PTX, 10 mg/d) forage feeding), group C (cigarette smoke exposure plus intermittent cortical steroid injection (Triamcinolone acetonide, 3 mg, i.m., every three weeks) and control group (group D: animals with sham smoke exposure, raised under the same conditions). Animals in group A, B and C were exposed to smoke of cigarettes for 1 to 1.5 h twice a day, 5 days a week. All animals were killed at the 16th week and followed by morphometrical analysis of the midsagittal sectioned lung slices. Smoke exposure of 16 weeks resulted in visible emphysematous development in Group A but not in Group B and C. It was evidenced by the indicator of air-space size, mean linear intercept (Lm): 120.6+/-16.0 microm in Group A; 89.8+/-9.2 microm in Group B and 102.4+/-17.7 microm in Group C. The average Lm in either group B or group C was shorter than that in Group A (ANOVA and Newman-Keuls test, F=8.80, P=0.0002) but comparable to that (94.8+/-13.2 microm) in group D (P>0.05). It is concluded that long-term prophylactic anti-inflammation inhibits pulmonary emphysema induced by cigarette smoking in the guinea pigs.