[Changes in the pulmonary ventilation of cats with a combination of increased respiratory resistance and hypercapnia before and after vagotomy].

In cat+s, increased resistance against breathing at the background of hyperventilation with a hypercapnic mixture reduces the 1-min ventilation. However, the bioelectric activity of the diaphragmatic nerve becomes augmented, thus indicating an increase in the respiratory center inspiratory activity. Vagotomy was followed by a decreased ventilatory response to CO2. Suppression of ventilation and augmentation of the diaphragmatic nerve activity during additional resistance against breathing in vagotomized animals were preserved on account of a considerably greater activity of the respiratory center. The data obtained suggest that, in conditions of combination of increased resistance against breathing with hypercapnia, the lungs afferent system fulfills an optimization of activity of the ventilatory apparatus.