title: Endocytosis of cigarette-smoke condensate by rabbit alveolar macrophages in vitro measured as fluorescence intensity.
abstract: It has previously been shown that alveolar macrophages (AMs) from smokers have increased fluorescence compared to AMs from nonsmokers. In the present investigation, AMs lavaged from rabbits were exposed to a cigarette-smoke condensate (CSC) in order to study its influence on the fluorescence of AMs. Flow cytofluorometry was used. Alveolar cells exposed to 0.01% of CSC showed a fluorescence which increased with higher concentrations of the CSC. Incubation with CSC for 5 min was enough to give a significant rise (p less than 0.001) in cell fluorescence compared to controls. After incubating fluorescent cells with untreated non-fluorescent AMs, fluorescent material was distributed to the non-fluorescent AMs within 30 min. Further more, fluorescence decreased when exposed cells were cultured in CSC-free medium. When incubating CSC with blood leucocytes, an almost threefold increase in fluorescence was observed among the phagocytic cells at 37 degrees C compared to 4 degrees C, whereas the fluorescence in the non-phagocytic cell population only showed a minor enhancement. Endocytosis of fluorescent material in CSC can explain the strong fluorescence seen in AMs from smokers. Exocytosis and re-endocytosis of the material by new AMs may explain the slow decline in the fluorescence of AMs observed after cessation of smoking.
authors.affiliation: Dept of Thoracic Medicine, Karolinska Hospital, Stockholm, Sweden.
authors.forename: C M
authors.initials: CM
authors.lastname: Sköld
authors.forename: A
authors.initials: A
authors.lastname: Eklund
authors.forename: J
authors.initials: J
authors.lastname: Hed
authors.forename: R
authors.initials: R
authors.lastname: Hernbrand
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004705:Endocytosis; D005260:Female; D005434:Flow Cytometry; D005453:Fluorescence; D066298:In Vitro Techniques; D016676:Macrophages, Alveolar / Q000502:physiology*; D008297:Male; D010947:Plants, Toxic; D011817:Rabbits; D012906:Smoke; D014026:Nicotiana
chemical_list: D012906:Smoke