Micropipette measurement of airway submucosal gland secretion: laryngeal reflex

We used our microcollection technique to study the effect of mechanical stimulationof the larynx on tracheobrochial gland secretion. The basal secretory rate of 8 glands in 5 cats rose from 18.6 +/- 2.0 nl/min (mean +/- SE) to a maximum of 47.8 +/- 4.0 nl/min within 1 min of mechanical stimulationof the laryngeal mucosa(p < 0.005) and returned to prestimulation levels within 4 to 5 min after cessation of the stimulus. The effect of laryngeal stimulation on gland secretion was prevented by cooling both cerevical vagi to - 3 degrees C before and during stimulation, and was restored by warming both vagito 37 degrees C before stimulaltion. Atropine sulfate (0.5 mg/kg given intravaenously) also prevented the secretory response to laryngeal stimulation. Transsection of the sensory nerves to the larynx blocked this response as well. Electrical stimulation (7 V, 20 Hz, 15 s) of the central end of the cut superior layyngeal nerve increased the rate of secretion of 6 glands in 5 cats from 10.0 +/- 2.0 nl/min to 26.0 +/- 3.0 nl/min (p < 0.01); atropine also prevented this effect.