COMPARISON OF CHANGES IN THE pH OF ARTERIAL BLOOD AND SALIVA DURING VARIATIONS OF PULMONARY VENTILATION

Abstract

PH determinations were made by means of the glass electrode on arterial blood and pilocarpine stimulated saliva of anesthetized dogs. During resting conditions the saliva pH showed large variations while blood pH remained constant. The administration of low oxygen mixtures or of NaCN produced an increase in blood pH immediately. Saliva usually showed a slight increase in pH at the beginning of these administrations which was attributed to the blowing off of CO2. The initial increase in pH of saliva was followed by a decrease which was attributed to disturbances of cellular metabolism. During recovery saliva pH increased and blood pH decreased. Thus saliva may show a pH change in the same direction or inversely with that of blood. The evidence indicates that the metabolic changes within the gland cells are more important factors in determining the pH of saliva than is the pH of arterial blood.