Alteration of Swallowing and Ventilation Coordination in Respiratory Diseases in Small Mammals

In human and animal, swallowing and ventilation are coordinated to avoid laryngeal penetration or tracheal aspiration, and respiration is interrupted during swallowing and resumes in the expiratory phase. Some respiratory diseases may alter this coordination due to impaired lung function. The aim of this study was to evaluate swallowing–ventilation coordination in unrestrained rats with pulmonary emphysema or with pulmonary fibrosis. Two protocols were performed in 38 male Sprague–Dawley rats (2–3 months, 250–300 g): pulmonary emphysema and pulmonary fibrosis. Ventilation during swallowing and swallowing–ventilation coordination were recorded using a whole-body plethysmography and video recordings. The rats were free to take water after 24 h without drinking. Compared to control groups, swallowing frequency was significantly higher in rats with pulmonary emphysema and there was a decrease of swallows during expiration in rats with pulmonary emphysema and in rats with pulmonary fibrosis. In this study, we show that respiratory diseases are associated with changes in swallowing–ventilation coordination and hypothesize that they increase the risk of aspiration.