An improved respiratory system for curarized rats

A respiratory system is described in which peak expired CO₂ is continuously monitored from curarized rats. Another alteration from previous systems is that an endotracheal tube is used to minimize dead air space. The adequacy of the system was tested by maintaining curarized rats at one level of peak expired CO₂ for varying periods of time and by keeping rats at different peak expired CO₂ levels for a fixed period of time. Results of blood gas analyses indicated that values obtained with this system are similar to values in noncurarized rats, and that manipulation of expired CO₂ is an effective means of altering blood gas values.