Ventilatory response to adjuvant arthritis in the rat.

This study examined ventilation in rats with arthritis induced by Mycobacterium butyricum. It was found that, 19 days after inoculation, the minute ventilation of arthritic rats breathing air was about two-fold higher than that of control animals. This increase resulted from an increase both in respiratory frequency and in tidal volume. Air-CO2 mixtures continued to stimulate ventilation in arthritic rats, and the minute ventilation of these animals on breathing 5 or 7% CO2 exceeded that of controls. The results are consistent with the hypothesis that arthritic rats hyperventilate and contribute to the validation of adjuvant arthritis as an animal model of chronic pain.