Abstract
It is unclear whether the filter has any effect on cigarette smoke toxicity. We investigated whether there are differences between filtered and nonfiltered cigarette smoke in biochemical markers in body fluids. Wistar rats were exposed to filtered (F) or nonfiltered (N) cigarette smoke for 3 mo, 6 cigarettes for 30 min/day, 5 days/wk. Nicotine and tar quantities were 25% and 30% less, respectively, for filter cigarettes than with nonfilter cigarettes. The control animals (C) inhaled clean room air. Cells and biochemical markers in blood and bronchoalveolar lavage fluid (BALF) were analyzed. The smoke-exposed groups showed decreases in weight gain, total protein, and vitamin E in blood, and increases of albumin/ globulin and vitamin C in serum. These findings were not observed for filter cigarettes except for vitamin C. The N group revealed a tendency for decrease in 1-globulin content. Greater increases in white blood cell counts and serum vitamin C were observed in the F group than in the N group. Serum elastolytic activity was not affected by cigarette smoke. In BALF, total cell and pulmonary alveolar macrophages (PAMs) increased, and total glutathione decreased in the smoke-exposed groups. Superoxide dismutase (SOD) activity increased significantly in the N group. Bronchoalveolar lavage elastolytic activity and O-2 generation of PAMs were unchanged in the smoke groups. Cigarette smoke affected antioxidant balance and globulin metabolite. However, there was no marked difference between the F and N groups. The effectiveness of a filter in preventing lung injury followed by the development of chronic bronchitis and emphysema should be clarified in a prospective study.