[Respiratory changes in rabbits during metabolic acidemia].

The authors investigated the hyperventilation reaction during acute metabolic acidaemia in anaesthetized rabbits with preserved vagi and after vagotomy. They assessed the respiratory pattern, partial CO2 pressure and pH of arterial blood [PaCO2, pHa]. The value of the minute ventilation [VE] did not differ in animals with intact vagi and those after vagotomy. In rabbits after vagotomy the VE was more effective, as apparent from pHa values. The protraction of the period of expiration [Te] by extension of the expiratory break in vagotomized animals suggests a facilitating action of the vagal pulmonary feedback on the expiration--inspiration activity [inspirium on-switch system].