[Biochemical analysis of free amino acids in human parotid secretions (author's transl)].

Parotid secretion was obtained under standardized conditions from 17 male students by stimulation with citric acid. The average flow rate was 0.65 ml/min. The free amino acids in these samples were determined with the aid of two-dimensional thin layer microchromatography of the dansyl derivatives and TV densitometric determination of the blackening of photographic negatives. Apart from glutamic acid, only amino acids with nonpolar residues such as glycine, alanine, leucine, isoleucine, phenylalanine and proline occurred in all 17 samples. The mean values of the concentrations lay between 0.2 mumol/l for isoleucine and 1.2 mumol/l for proline. There were great interindividual variations. (SD between 40% ad 110%). In the present range of 0.3 to 1.1 ml/min, no dependence of the concentrations on the flow rate could be demonstrated. It was attempted to draw up a standard profile by elimination of greatly deviating samples.