Inhalation exposure systems for the development of rodent models of sulfur mustard-induced pulmonary injury

Abstract

Sulfur mustard (SM) is a chemical threat agent for which its effects have no current treatment. Due to the ease of synthesis and dispersal of this material, the need to develop therapeutics is evident. The present manuscript details the techniques used to develop SM laboratory exposure systems for the development of animal models of pulmonary injury. These models are critical for evaluating SM injury and developing therapeutics against that injury. Iterative trials were conducted to optimize a lung injury model. The resulting pathology was used as a guide, with a goal of effecting homogeneous and diffuse lung injury comparable to that of human injury. Inhalation exposures were conducted by either nose-only inhalation or intubated inhalation. The exposures were conducted to either directly vaporized SM or SM that was nebulized from an ethanol solution. Inhalation of SM by nose-only inhalation resulted in severe nasal epithelial degeneration and minimal lung injury. The reactivity of SM did not permit it to transit past the upper airways to promote lower airway injury. Intratracheal inhalation of SM vapors at a concentration of 5400 mg · min/m³ resulted in homogeneous lung injury with no nasal degeneration.

Keywords::

• Aerosol
• inhalation
• rodents
• sulfur mustard

Acknowledgements

This work was funded by NIH NINDS #5U54NS058185-03. We would like to thank Dr Tom March from Lovelace Respiratory Research Institute for his pathology reviews and photomics of the exposure models and Dr Karen Ann Smith of the University of New Mexico for use of the NMR in confirming the identity of SM.