title: Species differences in impairment and recovery of alveolar macrophage functions following single and repeated ozone exposures.
abstract: Effects of single (0.4 ppm for 3, 6, or 12 hr) and repeated (0.4 ppm, 12 hr/day for 3 or 7 days) in vivo ozone exposures on rat and mouse alveolar macrophage functions and cell number were investigated. Single ozone exposure of rats resulted in a small (approximately 15%) decrease in Fc-receptor-mediated phagocytosis and phorbol ester-induced superoxide production by the alveolar macrophages and was followed by recovery above control levels within 12 hr of exposure. Repeated exposures of rats for up to 7 days did not alter alveolar macrophage functions, with the exception of the effects of 3 days of exposure on superoxide production (71 +/- 9% as compared with the controls). In mice, significant changes in alveolar macrophage functions were not observed until 12 hr of exposure (at that timepoint phagocytosis was 74 +/- 2%). Repeated ozone exposures of mice did not cause a further decrease in phagocytosis (at Day 7, 74 +/- 14%). Both after 3 and 7 days of repeated ozone exposure of mice, superoxide production by the alveolar macrophages was inhibited approximately 50%. In rats and mice, repeated ozone exposures led to an increase in the number of alveolar macrophages. In mice, this increase appeared at a later time point (at Day 7 vs Day 3) and was less pronounced (at Day 7, 139 +/- 9% vs 179 +/- 17%) as compared with rats. In summary, our data show that rat and mouse alveolar macrophages have different susceptibilities to both single and repeated in vivo ozone exposures.
authors.affiliation: Laboratory for Toxicology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
authors.forename: R S
authors.initials: RS
authors.lastname: Oosting
authors.forename: L M
authors.initials: LM
authors.lastname: van Golde
authors.forename: J
authors.initials: J
authors.lastname: Verhoef
authors.forename: L
authors.initials: L
authors.lastname: Van Bree
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000378:metabolism; D002452:Cell Count; D007958:Leukocyte Count; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D009504:Neutrophils; D010126:Ozone / Q000008:administration & dosage / Q000494:pharmacology*; D010587:Phagocytosis / Q000187:drug effects; D011650:Pulmonary Alveoli / Q000166:cytology; D051381:Rats; D011919:Rats, Inbred Strains; D011961:Receptors, Fc / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
chemical_list: D011961:Receptors, Fc; D013481:Superoxides; D010126:Ozone