title: Tobacco smoke modulates ozone-induced toxicity in rat lungs and central nervous system.
abstract: Adult Sprague-Dawley (SD) male rats were exposed for a single 3 h period to air, ozone (O₃) or O₃) followed by tobacco smoke (O₃/TS). For pulmonary effects, bronchoalveolar lavage (BAL) cells and fluid were analyzed. Data revealed a significant increase in polymorphonuclear leukocytes (PMN), total protein and albumin concentrations in the O₃ group, reflecting inflammatory and toxic responses. A subsequent exposure to TS attenuated PMN infiltration into the airspaces and their recovery in the BAL. A similar reduction was observed for BAL protein and albumin in the O₃/TS group, but it was not statistically significant. We also observed a significant increase in BAL total antioxidant capacity following O₃ exposure, suggesting development of protective mechanisms for oxidative stress damage from O₃. Exposure to TS attenuated the levels of total antioxidant capacity. Lung tissue protein analysis showed a significant reduction of extracellular superoxide dismutase (EC-SOD) in the O₃ or O₃/TS group and catalase in the O₃/TS group. TS further altered O₃-induced EC-SOD and catalase protein expression, but the reductions were not significant. For effects in the central nervous system (CNS), we measured striatal dopamine levels by HPLC with electrochemical detection. O₃ exposure produced a nonsignificant decrease in the striatal dopamine content. The effect was partially reversed in the O₃/TS group. Overall, the results show that the toxicity of O₃ in the lung is modulated by TS exposure, and the attenuating trend, though nonsignificant in many cases, is contrary to the synergistic toxicity predicted for TS and O₃, suggesting limited cross-tolerance following such exposures.
authors.affiliation: Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA.
authors.forename: Vanitha
authors.initials: V
authors.lastname: Bhoopalan
authors.forename: Sung Gu
authors.initials: SG
authors.lastname: Han
authors.forename: Mrudang M
authors.initials: MM
authors.lastname: Shah
authors.forename: David M
authors.initials: DM
authors.lastname: Thomas
authors.forename: Deepak K
authors.initials: DK
authors.lastname: Bhalla
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D015153:Blotting, Western; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D004298:Dopamine / Q000378:metabolism; D004347:Drug Interactions; D019570:Inhalation Exposure / Q000009:adverse effects*; D007958:Leukocyte Count; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D009504:Neutrophils / Q000187:drug effects; D010083:Oxidants, Photochemical / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010126:Ozone / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014028:Tobacco Smoke Pollution
chemical_list: D000975:Antioxidants; D010083:Oxidants, Photochemical; D014028:Tobacco Smoke Pollution; D010126:Ozone; D004298:Dopamine