Related Experiment Video
Updated: Apr 6, 2026
Noninvasive Intratracheal Intubation to Study the Pathology and Physiology of Mouse Lung
Published on: November 8, 2013
Repeated intranasal exposure to microcystin-LR affects lungs but not nasal epithelium in mice
Vinícius R Oliveira1, Viviane G L Mancin1, Eliete F Pinto1
1Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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.
Insights
Sub-chronic exposure to microcystin-LR (MC-LR) caused lung inflammation and impaired respiratory mechanics in mice. The nasal epithelium showed resistance to MC-LR toxicity in this study.
Area of Science:
- Toxicology
- Respiratory Medicine
- Environmental Health
Background:
- Microcystin-LR (MC-LR) is a cyanotoxin known to cause respiratory issues.
- Understanding the specific effects of MC-LR on different respiratory tissues is crucial for risk assessment.
Purpose of the Study:
- To investigate the impact of sub-chronic intranasal exposure to MC-LR on mouse lungs and nasal epithelium.
- To assess changes in respiratory mechanics and histological parameters following MC-LR exposure.
Main Methods:
- Swiss mice were exposed intranasally to MC-LR (6.7 ng/kg) or distilled water for 30 days.
- Respiratory mechanics were measured in vivo.
- Lung and nasal epithelium histology were analyzed for inflammation and morphology.
Main Results:
- No significant changes were observed in the nasal epithelium.
- Mice exposed to MC-LR showed increased lung PMN cells and elevated lung static elastance.
- MC-LR exposure led to higher resistive and viscoelastic/inhomogeneous pressures in the lungs.
Conclusions:
- The lungs are more susceptible to MC-LR toxicity than the nasal epithelium in this mouse model.
- Sub-chronic MC-LR exposure induces lung inflammation and alters respiratory function.
- Findings suggest differential susceptibility within the respiratory system to cyanotoxin exposure.
More Related Videos
12:27The Utilization of Oropharyngeal Intratracheal PAMP Administration and Bronchoalveolar Lavage to Evaluate the Host Immune Response in Mice
Published on: April 2, 2014
08:00Intubation-mediated Intratracheal IMIT Instillation: A Noninvasive, Lung-specific Delivery System
Published on: November 17, 2014