Data from: Mouse vocal fold permeability in vivo: Effects of novel low-tech injury and instillation methods

Objectives: Vocal fold (VF) injury and instillation are emerging
techniques to study laryngeal pathologies in mouse models. Most approaches
require high-tech visualization and lengthy anesthesia. Intraperitoneal
(IP) naphthalene (NAPH) and topical polidocanol (PDOC) are two chemical
methods of injuring murine lower airways. Oropharyngeal aspiration (OA) is
used for murine lung instillation. We assessed whether these simple
low-tech methods could injure and instill mouse VFs, and whether injury
increased in vivo VF epithelial permeability. Methods: Mouse VFs were
injured using IP NAPH at 200, 250, 300, or 350 mg/kg, or OA of PDOC at
0.5% or 2% w/v. Twenty-four hours later, mice received Evans blue (EB) dye
OA instillation, then were sacrificed after 30 minutes. Coronal larynx
sections were assessed for VF injury. Permeability was measured by imaging
EB autofluorescence and quantifying percent positive area and signal
intensity. VFs were immunostained for basal cells (p63), tight junctions
(ZO-1), and basement membrane (laminin). Results: VF injury was 100% with
≥350 mg/kg NAPH or high-volume 2% PDOC and 0-40% with other treatments. EB
bound VF lamina propria in up to 100% of mice in a volume-dependent
manner. Permeability did not differ by injury. Basal cells and tight
junctions were decreased in injured VFs. Basement membrane was largely
intact. Conclusions: High-dose NAPH consistently injures mouse VFs. OA
reliably instills mouse VFs. Uninjured murine VF epithelium is highly
permeable to low molecular weight dye in vivo. Inherent permeability of
mouse VFs may facilitate targeted genetic engineering approaches and
studies of environmental hazards and drug treatments.