Phosphate 161 



CALCIUM AND MAGNESIUM 



In human parotid saliva there is a positive correlation between 

 flow rate and calcium concentration (Chauncey, Lisanti and Winer, 

 1958) which ranges from i-o mEq/1. at low flows up to 3-4 mEq/1. 

 at high flows. Values of 1-3 mEq/1. for resting parotid saliva and 

 3-6 mEq/1. for resting submandibular saliva have been reported 

 (Rauch, 1956; Henriques and Chauncey, 1958). de Beer and Wilson 

 (1932) also found in the dog parotid excited by pilocarpine that 

 there was a positive correlation with secretion rate and, further, 

 that the saliva calcium was increased by raising the plasma level. 

 Andreyev and Pugsley (1933) also found the saliva calcium to fol- 

 low the plasma calcium. Kesztyus and Martin (1937) found that 

 the submaxillary saliva of the dog contained 4-6 mEq/1. calcium 

 after chorda stimulation, showed no appreciable rest transient and 

 was practically independent of rate of flow in the range tested. 



The concentration in sympathetic saliva is much higher (n-32 

 mEq/1.) and considerably above the normal plasma level of 4-6 

 mEq/1. Baxter (1933) found approximately 11 mEq/1. in dog 

 parotid saliva and 5 mEq/1. in mixed saliva produced by reflex 

 stimulation. 



Levels of 0-6-1-4 mEq/1. of magnesium have been found in 

 parasympathetic saliva (Rauch, 1956; Kesztyus and Martin, 1937) 

 compared with 1-5-2-5 mEq/1. in plasma. Sympathetic submaxil- 

 lary saliva, however, may have concentrations as high as 3-2 mEq/1. 



PHOSPHATE 



The total phosphate of saliva is usually about twice the plasma 

 level and, of this, at least 80 per cent is present as inorganic 

 phosphate (Chauncey and Weiss, 1958; Clark and Shell, 1927; 

 White and Bunting, 1946; Becks and Wainwright, 1946; Hildes, 

 1955; Kostlin and Rauch, 1957; Eggers-Lura, 1947; Krasnow, 

 1945). Stevens (1953) found a similar relation in mixed saliva 

 after injection of inorganic phosphate as P 32 but Wills (1943) 

 found in the cat a saliva/plasma ratio of only 0-28-0-40 with 

 chorda stimulation and lower figures with pilocarpine. 



The concentration is relatively flow independent but shows some 

 upswing at low secretion rates (Hildes, 1955). The organic phos- 

 phate of saliva is acid-soluble and partially split by phosphatases 

 (Eggers-Lura, 1947). Rose and Kerr (1958) have presented 



