In 149 persons-33 caries-immune, 69 caries-susceptible, and 47 having
” slight” caries—salivas of the caries-immunes contained more proteolytic enzymes (katepsin and trypsin) than salivas of the caries-susceptibles. Katepsin and trypsin—produced by salivary leucocytes—are not bactericidal. The total number of salivary leucocytes secreted in a given time was not larger in caries-immunes than in caries-susceptibles, indicating that the difference in salivary enzymes was due to greater activity of leucocytes in immunes than in susceptibles. Saliva destroyed various bacteria at different rates, dependent mainly upon the action of leucocytes. Saliva of caries-immunes compared with that of caries-susceptibles had a greater bactericidal effect upon B. krodigiosus. Rate of secretion of saliva was greater in caries-immunes than in caries-susceptibles.
References: Biochem. Z., 1935; Z. Stour., 1936, 1938; Wiener Klin. Woch., 1936.