Most of the studies with isolated perfused lungs have been performed with lungs obtained from rats, guinea pigs, rabbits or dogs. The interaction of the immune system with the lung is currently an area of great interest. The mouse is the best characterized rodent species with respect to its immune system. Immunologic probes such as antibodies and cytokines are more widely available for mice versus other species. To facilitate studies on the interaction of the lung and the immune system, an apparatus for perfusing and ventilating mouse lungs has been developed. This apparatus is also suitable for studying the respiratory system of knock-out mice.
Ventilation
The lung is placed in the artificial thoracic chamber and ventilated at negative pressure. It is connected through the tracheal cannula to the pneumotachometer for measurement of respiratory flow. The respiration rate, the inspiratory and the end-expiratory pressure can be adjusted by separate controls (Positive ventilation using a regular Minivent ventilator is also possible).
Perfusion
The pulmonary artery is cannulated to provide perfusion. The perfusate is passed by means of a roller pump at constant flow through the heat exchanger, through a bubble trap to the pulmonary artery and finally into the lung vascular bed. The perfusate outflow is usually provided by cannulating the left atrium of the heart.