Repeated intranasal exposure to microcystin-LR affects lungs but not nasal epithelium in mice

Toxicon. 2015 Sep 15:104:14-8. doi: 10.1016/j.toxicon.2015.07.331. Epub 2015 Jul 26.

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.

Keywords: Cyanobacteria; Lung inflammation; Lung mechanics; Microcystin-LR; Nasal epithelium histology; Sub-chronic exposure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intranasal
  • Animals
  • Dose-Response Relationship, Drug
  • Granulocytes / cytology
  • Granulocytes / drug effects
  • Inflammation / chemically induced
  • Inflammation / pathology
  • Lung / drug effects*
  • Lung / metabolism
  • Male
  • Marine Toxins
  • Mice
  • Microcystins / toxicity*
  • Nasal Mucosa / drug effects*
  • Nasal Mucosa / metabolism

Substances

  • Marine Toxins
  • Microcystins
  • cyanoginosin LR