Reflex tracheal contraction during pulmonary venous congestion in the dog.

1. The effect of pulmonary venous congestion on tracheal tone was studied in dogs anaesthetized with alpha-chloralose. Pulmonary venous congestion was produced by partial obstruction of the mitral valve to increase left atrial pressure by 10 mmHg. Tracheal tone was measured in vivo by an isometric force displacement method. 2. Tracheal tone increased by 6.3 +/- 0.3 g from a control level of 91.6 +/- 2.8 g when left atrial pressure was increased …