GLANDULAR SECRETION OF ELECTROLYTES 

 JoRN Hess Thaysen 



Medical Department A, Rigshospitalet, Copenhagen 



The ducts or tubules of glands with external secretion are 

 usually quite complex in structure and morphologically they 

 differ to a considerable extent from gland to gland. It is, 

 therefore, reasonable to assume that the ducts do not merely 

 serve as pathways for the secretion formed in the acini, but 

 that they contribute somehow to the elaboration of the final 

 secretory product. This possibility has already been considered 

 in the past century by Merkel (1883), mainly on morphological 

 grounds, and by Werther (1886), who made a comparative 

 investigation of the concentration of salt in various types of 

 saliva. The results of these experiments were, however, 

 inconclusive, and in 1950 Babkin restated the need for a 

 study of the physiology of the glandular ducts. Since then, 

 certain advances have been made through comparative work, 

 by the application of concepts from modern renal physiology 

 and with the use of electrophysiological methods, relating 

 changes in membrane potentials to ionic transport. It is the 

 purpose of the present paper to review this work and to 

 present a theory of the mechanism of glandular electrolyte 

 secretion based on the available data. 



Fig. 1 shows a comparison between the concentrations of 

 the main electrolytes in sweat, parotid saliva, tears and 

 pancreatic juice in relation to secretory rate, calculated in 

 milligrams per gram gland per minute. The following simil- 

 arities and differences between the four secretory products 

 are apparent from Fig. 1 : 



The Excretion of Sodium: 



In sweat and in parotid saliva the concentration of sodium 

 is smaller than the concentration of sodium in plasma and 



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