1 4 2 



The Inorganic Components of Saliva 



to 



O 



500 1 



400 



300- 



200' 



100- 



HO 



5 



5 10 15 



c/s 



Fig. 8.2. Dog parotid gland. 



20 25 



Secretion was produced by maximal stimulation of the auriculotemporal nerve at different 

 frequencies. Ordinate: rate of secretion in mg/g/min. Abscissa: frequency of stimulation (Burgen, 

 unpublished). 



unaltered in the face of major changes in structure occurring dur- 

 ing maturation. Lourie (1943) found that larger amounts of resting 

 saliva were produced in young children than in adults. 



TOTAL OSMOLYTE CONCENTRATION 



At maximum secretory rates, the osmolyte concentration in the 

 parotid saliva of the dog reaches a total of 200-260 milliosmols. 

 The osmolyte concentration is proportional to flow and reaches a 

 minimum of 50-1 00 milliosmols (15-30 per cent of the plasma osmo- 

 larity) at about 5-10 per cent of the maximum secretory rate. At 

 very low rates of secretion, the osmolyte concentration rises again 

 and may come close to the plasma concentration (Burgen, 1955; 

 Brusilow and Cooke, 1959; Burgen and Seeman, unpublished). 

 Similar relationships are evidently present in the dog and cat sub- 

 maxillary glands and the human parotid gland (Langstroth, McRae 

 and Stavraky, 1938a; Thaysen, Thorn and Schwartz, 1954). Cat 

 sublingual saliva and rat parotid saliva are not hypotonic and their 

 osmolarity at all rates of secretion is close to that of the plasma 

 (Lundberg, 1957; Schneyer and Schneyer, 1959). The secretion 

 from all the salivary glands in man is hypotonic but the relation- 

 ship of saliva osmolarity to the secretion rate has been established 

 only in the case of the parotid (Kostlin and Rauch, 1957). Saliva 



