DYNAMICS OF POLYPNEIC SALIVATION IN A DOG

1. The dynamics of polypneic salivation and its relation to respiration and to masticatory movements were investigated in dogs. The polypnea was developed by locomotion of animals on a treadmill or by increasing environmental temperature. 2. The secretion of saliva during polypnea occurs in jerks from the parotid and submaxillary glands. The salivary jerk continues about 3.5 sec with 27 sec intervals on the average. During every jerk each gland secreted 3-12 drops of saliva; depending on the intensity of polypnea. The submaxillary gland secreted about one third of saliva more than the parotid gland. 3. The jerky character of polypneic salivation differentiates it specifically from alimentary, defensive or drug-induced secretion of saliva which occurs regularely without jerks. During polypnea even this regular secretion acquires a jerky character. 4. During salivary jerks the polypnea is suddenly interrupted, the animal withdraws its tongue, closes the oral cavity and makes 2-4 chewing and licking movements, as well as a swallowing movement. Later it opens the oral cavity and the polypneic respiration suddenly starts, continuing until the next salivary jerk. 5. Jerkiness of polypneic salivation is an economic way of salivation since it saves by about ten times body fluids and electrolytes, thus rendering possible a prolonged maintainance of homoiothermia during increased requirements for heat dissipation from organism. © 1969 Springer-Verlag.