title: Repeated intranasal exposure to microcystin-LR affects lungs but not nasal epithelium in mice.
abstract: Microcystin-LR (MC-LR) is a harmful cyanotoxin able to induce adverse outcomes in the respiratory system. We aimed to examine the lungs and nasal epithelium of mice following a sub-chronic exposure to MC-LR. Swiss mice were intranasally instilled with 10 μL of distilled water (CTRL, n = 10) or 6.7 ng/kg of MC-LR diluted in 10 μL of distilled water (TOX, n = 8) during 30 consecutive days. Respiratory mechanics was measured in vivo and histology measurements (morphology and inflammation) were assessed in lungs and nasal epithelium samples 24 h after the last intranasal instillation. Despite the lack of changes in the nasal epithelium, TOX mice displayed an increased amount of PMN cells in the lungs (× 10(-3)/μm(2)), higher lung static elastance (cmH2O/mL), resistive and viscoelastic/inhomogeneous pressures (cmH2O) (7.87 ± 3.78, 33.96 ± 2.64, 1.03 ± 0.12, 1.01 ± 0.08, respectively) than CTRL (5.37 ± 4.02, 26.65 ± 1.24, 0.78 ± 0.06, 0.72 ± 0.05, respectively). Overall, our findings suggest that the nasal epithelium appears more resistant than lungs in this model of MC-LR intoxication.
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Vinícius R
authors.initials: VR
authors.lastname: Oliveira
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Viviane G L
authors.initials: VG
authors.lastname: Mancin
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Eliete F
authors.initials: EF
authors.lastname: Pinto
authors.affiliation: Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Raquel M
authors.initials: RM
authors.lastname: Soares
authors.affiliation: Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Sandra M F O
authors.initials: SM
authors.lastname: Azevedo
authors.affiliation: Laboratory of Experimental Atmospheric Pollution, Department of Pathology, School of Medicine, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Macchione
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Alysson R
authors.initials: AR
authors.lastname: Carvalho
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: wazin@biof.ufrj.br.
authors.forename: Walter A
authors.initials: WA
authors.lastname: Zin
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006098:Granulocytes / Q000166:cytology / Q000187:drug effects; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008387:Marine Toxins; D051379:Mice; D052998:Microcystins / Q000633:toxicity*; D009297:Nasal Mucosa / Q000187:drug effects* / Q000378:metabolism
chemical_list: D008387:Marine Toxins; D052998:Microcystins; C057862:cyanoginosin LR
keywords: Cyanobacteria; Lung inflammation; Lung mechanics; Microcystin-LR; Nasal epithelium histology; Sub-chronic exposure