Factors affecting pH rise of suspended salivary sediment.

Abstract

The effect of some salivary constituents on pH rise was studied. A solution simulating salivary supernatant in buffer capacity and inorganic composition was used. Mixing this solution with glucose and salivary sediment resulted in a pH rise similar in magnitude and shape to that of the salivary supernatant control, demonstrating a significant contribution of buffer capacity to in vitro pH rise of salivary supernatant. Arginine peptides also showed pH rise activity, but only at concentrations not found in saliva. The salivary buffers are therefore the major contributors to pH rise in saliva. Additional studies demonstrated that the activity of arginine was diminished by attaching groups to the α-amino or guanidino functional group, but was not affected by esterification. Within the limits of the molecules tested, arginine peptides increased in activity with increasing number of arginyl groups, but were unaffected by varying the size of the peptide. Little difference was seen between a C- and N-terminal peptide.