Plethysmograph chamber

Report 30 minutes following the dosing, rats returned to the plethysmographic chamber and respiratory parameters measured continuously for 5 minutes After 1,2, and 4 hours, each animal returned to its designated plethysmographic chamber and respiratory parameters are measured continuously for 5 minutes following a 5-min stabilization period One copy of the draft final report One bound and unbound copy of the final and an electronic copy in Word and PDF... 

Fig. 1. Tracings of lung airflow and lung volume changes during spontaneous breathing in a conscious rat. Airflow was measured directly using a head-out plethysmograph chamber. The functional endpoints can be automatically calculated for each breath using a data acquisition and analysis software system.

To provide a direct measure of ventilatory parameters, a head-out plethysmograph chamber is used, while measurement of pleural pressure is used to provide a direct measure of airway resistance and compliance. 

Fig. 4. Plethysmograph chambers for the direct measurement of ventilatory parameters. The rat and dog are in head-out chambers, while the monkey is in a head-enclosed chamber. For all chambers, an air tight seal is made around the neck using a 1/8 inch thick neoprene collar.

Fig. 1. Buxco whole body plethysmograph for measuring lung function. The mouse is placed in a plexiglas chamber, where it is free to move. A port at the top of the chamber is connected to a nebulizer to allow administration of aerosolized chemicals. A transducer linked to an amplifier monitors the pressure changes within the chamber, which correspond to the animal s breathing rates and depths. These raw data are converted to a value called Penh, which is a measure of BHR. Readout consists of change in Penh over time. An increase in Penh indicates that the mouse is hyperresponsive.

In the barometric (whole body) chamber design, the animal is completely contained within the plethysmograph and has no limitation to movement within the chamber. The use of an unrestrained system allows for longer-duration evaluatiOTis and repeated evaluations with minimal disturbance to the animals, primarily rats and mice (Delaunois et al. 2009). 

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