Glandular Secretion of Electrolytes 



63 



varies with the rate of secretion. With increasing secretory 

 rate the concentration of sodium rises to about 60 m-equiv./l. 

 in the sweat and to about 90 m-equiv./l. in the parotid sahva, 

 but no definite maximum is reached in either secretion. This 

 finding conforms with the old work of Heidenhain (1868), 

 Langley and Fletcher (1889), Kittsteiner (1911, 1913), and 

 Hancock, Whitehouse and Haldane (1929). 



120 



o 



Ui 



2 160 



SWEAT (1) 



PAROTID SALIVA (2) 



PANCREATIC JUICE (6) 



20 AO 60 80 

 SECRETORY RATE 



100 20 AO 60 60 100 



(MG PER GRAM GLANO PER MINUTE) 



Fig. 1. The concentration of the main electrolytes in sweat, 

 parotid saliva, tears and pancreatic juice in relation to secretory 

 rate (in milligrams per gram gland per minute). From the data of 

 1 : Schwartz and Thaysen (1956) ; 2 : Thaysen, Thorn and Schwartz 

 (1954); 3: Thaysen and Thorn (1954); and 4: Bro-Rasmussen, 

 Killmann and Thaysen (1956). 



In tears and in pancreatic juice the concentration of sodium 

 in secretion water is about equal to the concentration of 

 sodium in plasma water and is independent of the rate of 

 secretion. 



The Excretion of Potassium: 



The concentration of potassium in all four secretions 

 independent of wide ranges of variation in secretory rate. 



is 



