Production of tumor necrosis factor alpha by rat alveolar macrophages collected after acute cigarette smoking

In this study we evaluated the effect of cigarette smoke on the activation of alveolar macrophages of the rat lungs exposed to an episode of acute passive cigarette smoking. Our experiments were carried out in rats that, after undergoing smoking (3 cigarettes within 1 h) showed a COHb increase of about 16%. The evaluation of the kinetics of alveolar and peritoneal macrophages, indicated that the number of alveolar macrophages in the bronchoalveolar lavage fluids significantly increased 8 h after the smoking session, whereas the number of peritoneal macrophages remained practically constant. Alveolar macrophages collected 0.8 and 24 h after smoking and incubated for 24 h at 37 degrees C in an atmosphere of 5% CO2 in air spontaneously released 5 +/- 1, 48 +/- 14 and 15 +/- 9 units of TNF-alpha per 10(6) cells, respectively. Moreover, neither alveolar macrophages collected from smokers, nor those collected from controls, released IFN, and both cytokines were also absent either in bronchoalveolar lavage and peritoneal lavage fluids or in plasma. Alveolar macrophages collected from controls rats, when challenged with lipopolysaccharide (LPS), released more TNF than those collected from smoke exposed rats. Thus, it seemed that macrophages of experimental animals were activated but at the same time were somewhat depressed and responded less well to LPS.