Abstract
Sidestream smoke evolves from the smoldering end of a cigarette while the smoker is not puffing, and contributes substantially to environmental tobacco smoke (ETS). In contrast, main stream smoke emerges from the butt end of the cigarette and is mainly inhaled by the smoker. This study was performed to compare the effects of short-term exposure to cigarette smoke condensates prepared from sidestream (CSCSS) and mainstream cigarette smoke (CSC-MS) on macrophage basal metabolism and responsiveness to two different stimuli, bacterial lipopolysaccharide (LPS) and interferony (IFNy). Despite their generation at different temperatures and their different chemical composition, CSC-SS and CSC-MS had similar effects on macrophages. Both enhanced macrophage basal metabolism and responsiveness to LPS. Macrophage responsiveness to IFNy, assessed by their expression of four functional capacities, was suppressed by both CSC-SS and CSC-MS. The four assessed IFNy-inducible functional capacities were: enhanced phagocytosis of immuoglobulin-opsonized sheep red blood cells, TPAinduced peroxide production, class II major histocompatibility complex expression, and nitric oxide synthesis with LPS co-stimulation. The effects of CSCSS and CSC-MS were similar qualitatively; they differ quantitatively in some cases, with CSC-MS generally effective at lower concentrations (expressed as cigarette-equivalents) than CSCSS. Considering dilution of sidestream smoke in room air and loss during passage through the respiratory system, we expect to deliver the maximal dose to lung macrophages
