The Relation between the Composition of Parotid Saliva and. Mixed Saliva in Sheep during the Induction of Sodium Deficiency

Abstract

Samples of parotid saliva were taken from sheep with the parotid duct cannulated. At the same time, mixed saliva samples were taken by sponging the mouth. During progressive sodium depletion, the sodium of the mixed and parotid saliva was progressively replaced by potassium. A relationship between the potassium concentrations in mixed and parotid saliva was established. This shows that the parotid saliva is unlikely to contain more potassium than 20 m-equiv/l. if the mixed saliva contains 17 m-equiv/l. or less; conversely, the potassium concentrations of parotid saliva will not be less than 20 m-equiv/l. if the concentration in mixed saliva is 32 m-equiv/l. or more. This allows the onset of the change of parotid saliva from a high sodium to a high potassium concentration — which is assumed to take place at a potassium concentration of 2.0 m-equiv/l. — to he detected under field conditions. The implication of this change is discussed with reference to changes in adrenal secretions. The phosphate concentration in parotid saliva is related to the (Na++K+) concentration.