[Vagus nerves and pulmonary artery pressure in the conscious and anesthetized cats using different levels of oxygenation (author's transl)].

Pulmonary artery pressure (PAP systolic and diastolic) and heart rate (HR) have been recorded in conscious or anesthetized cats. Experiments have been carried out before and after bilateral vagotomy or section of vagal afferents at the level of the nodose ganglion. Animals were exposed to different levels of oxygenation using FIO2 from 0.11 to 1.00. The results show that: 1 Anesthesia with sodium pentobarbital did not affect PAP for a given level of FIO2 : changes in PAP caused by modifications of FIO2 were not affected by anesthesia. Heart rate was independent of FIO2, but remained always higher in the anesthetized animals (Fig. 4). 2 In anesthetized animals, pulmonary de-afferentation or vagotomy affected neither PAP, nor its variations with FIO2 nor HR (Fig. 5). 3 In conscious animals, PAP and its variations with FIO2 were not affected by vagotomy (Fig. 6 and 7) or pulmonary de-afferentation (Fig. 8). On the other hand, heart rate was always decreased after either vagotomy or pulmonary deafferentation. It is concluded that (1) PAP and its control by FIO2 are independent of the vagal innervation; (2) the pulmonary edema observed after vagotomy cannot be caused by an increase in lung vascular pressure; (3) anesthesia, on the one hand, and pulmonary afferents, on the other hand, can play a role in the control of the cardiovascular activity.