A METHOD FOR UNIFORM STIMULATION OF THE SALIVARY GLANDS IN THE UNANESTHETIZED DOG BY EXPOSURE TO A WARM ENVIRONMENT, WITH SOME OBSERVATIONS ON THE QUANTITATIVE CHANGES IN SALIVARY FLOW DURING DEHYDRATION

Abstract

Uniform stimulation of the salivary glands in the unanesthetized dog may be obtained by exposing the animal to a warm atmosphere of constant temperature, thereby producing always the same rate of panting (polypnea). As panting dries the mouth and tongue, the salivary glands are reflexly stimulated to secrete a thin, watery saliva which may appropriately be called the "polypnea secretion." Holding the dog''s mouth closed or spraying the mouth with water promptly lessens the polypnea secretion. In a warm room (40 degrees C.) the polypnea secretion reaches a definite level within 10 to 15 min. and has been observed to stay constant for over 2 hrs. On a normal water intake the polypnea secretion remains nearly the same from day to day, but after 24 hrs. without water it is often reduced to 1/2 the normal rate, and after 3 days'' water deprivation it may fall to 1/5 normal. This method of uniform stimulation of the salivary glands is being used in an attempt to uncover the physiological mechanism responsible for the reduction in salivary flow that accompanies dehydration.