[Changes in pulmonary ventilation after shafts in acid-base equilibrium in the skeletal muscles of the cat].

In anesthetized cats, perfusion of the m. gastrocnemius with solutions simulating metabolic acidosis produces a reflex enhancement of breathing proportional to the acidosis degree. Perfusion with solutions having pH 7.0, 6.8 and 6.3 induced 4.6 +/- 1.0, 6.3 +/- 0.5 and 10.3 +/- 1.2% increases of the minute volume of ventilation, resp. These increases were mainly due to increases of the tidal volume rather than of respiratory rate. An increase of the mean blood pressure also occurred whereas heart rate did not change significantly. Hindlimb perfusion experiments revealed that reflex changes of the blood pressure and breathing depended on the muscle mass perfused. Possible participation of the muscle receptors sensitive to changes of metabolism in exercise hyperpnea, is discussed.