Laboratory animals
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Intratracheal instillation (ITI) of a test compound is an alternative method to inhalation methods that require complex aerosol generation, exposure chambers and airflow monitoring instruments for exposing the lungs of animals to a test compound. For ITI in the rat, a laryngoscope is generally used for endotracheal intubation, and the procedure is difficult to perform. Therefore, we designed and constructed an automatic video instillator (AVI) for the accurate delivery of a dose of a test compound into the trachea of rats. ⋯ After a 2 h training session on the use of the AVI in an anaesthetized rat, we assessed the utility of the device by ITI of 0.25% (w/v) solution of Evans Blue dye into the lungs of 30 isoflurane-anaesthetized rats. Necropsy examinations were performed on 20 rats immediately after the completion of the procedure, and on 10 rats three days after the procedure. Based on the results of these examinations, we concluded that the device could be used for rapid, reproducible and successful ITI of a test compound into the lungs of a rat by one operator.