The effects of changes in the proportion and type of dietary carbohydrate on the amylase and protein concentrations in rat saliva

Abstract

Amylase activity, total protein concentration and patterns obtained by paper electrophoretic separation of proteins were compared in pilocarpine-stimulated saliva from 80-day-old rats of the Harvard caries-resistant and caries-susceptible strains, fed a 67 per cent sucrose diet from weaning, and from rats of the latter strain fed similar diets except that the sucrose was replaced either by corn starch or an isocaloric mixture of protein and fat. Male rats had higher salivary flow rates than females but the concentrations of amylase and total protein appeared to be independent of sex or flow rate. Total protein concentration tended to be higher in rats fed the high protein diet and differences occurred in electrophoretic patterns among the groups. Since the concentration of salivary amylase was not significantly different among the four groups, the conclusion was drawn that the presence of carbohydrate in the diet was not required to induce the synthesis of salivary amylase.