抄録
Parotid fluid was collected without exogenous stimulation from 513 healthy young male adults, and under rubber band and sour lemon drop stimulation from 271 subjects from the same population. The mean unstimulated parotid flow rate was 0.027 ml/min, the Na concentration mean was 2.61 mEq/1, and that for K was 36.7 mEq/1.
In six subgroups of the unstimulated subjects, flow rate did not exert a significant effect on Na concentration, but there was a highly significant negative correlation between K concentration and rate of flow; the mean for [K+] ranged from 25.5 mEq/1 at the highest rate of flow, to 46.3 mEq/1 at the lowest rate.
In the stimulated saliva samplings, the most dramatic effect was the marked increase in [Na+] and rate of secretion, the mean [Na+] at the highest rate of secretion (lemon drop stimulated) being 66.26 mEq/1. Potassium con-centration fell from the unstimulated level, and then remained constant at two different levels of stimulated flow (ca. 18 mEq/1).
The low Na and high K levels found in unstimulated saliva are felt to result from reabsorption of Na in excess of water and the secretion of K into the luminal fluid by ductal cells. The lack of effect of flow rate on Na con-centration within the flow rate range of the present study may result from a balanced outward diffusion of water from the luminal fluid caused by Na reabsorption.
