The effect of amino acids and related compounds on the metabolism of saliva

Abstract

Conventional Warburg techniques were used to assess the effect of amino acids and related compounds upon the metabolism of whole salivas and suspensions of washed salivary sediments. The study of such substances is releBANt to the search for the factor in salivary supernatant which enhances glycolysis ( Hartles and Wasdell, 1955) and to their presence as possible substrates in the oral environment. In no instance was the salivary metabolism stimulated by the addition of the nitrogenous compounds to an extent comparable with the addition of glucose. The mean increase upon the endogenous oxygen uptake of whole saliva on the addition on l-aspartic acid, l-asparagine, glutathione and phosphoethanolamine was 20, 24, 26 and 9 per cent respectively. In the presence of some nitrogenous compounds oxygen uptake and carbon dioxide output in the presence of glucose could be stimulated. Results for given substrates varied from person to person and also from day to day. This variation is discussed. l-Glutamic acid and l-glutamine (4.5–9.0 × 10 −3 M) enhanced glycolysis of salivary sediments to an extent comparable with salivary supernatant; slight stimulation occurred with choline chloride; no enhancing effect was observed with carnitine, γ-aminobutyric acid, orotic acid and pangamic acid.