Correlations between total protein, lysozyme, immunoglobulins, amylase, and albumin in stimulated whole saliva during daytime

The correlations between salivary proteins and the daytime variations are n ot known. The present study investigated the within-subject variation of co rrelations and concentrations between lysozyme, IgA, IgG, IgM, albumin, amy lase, and total protein in stimulated whole saliva of healthy adults in the course of a 12-h period. After several practise sessions, unstimulated and stimulated whole saliva samples were collected five times daily (at 8 a.m. , 11 a.m., 2 p.m., 5 p.m., and 8 p.m.) from 30 healthy university students, mow rate and total protein concentration were used as covariates, and gend er as a between-subject factor in the MANOVA analysis. After this adjustmen t, there was significant within-subject variation in salivary IgA (P < 0.00 1), albumin (P < 0.01), amylase (P < 0.05), and total protein (P < 0.001) c oncentrations. Total protein correlated significantly with amylase albumin and IgA through different samplings. In addition, IgG correlated with album in and lysozyme in the course of 12 h. On the whole, the correlations betwe en variables remained stable during repeated samplings. In addition, rankin gs of subjects for the variables tended to be maintained across different s amplings (P < 0.001). However, the observed within-subject variations in sa livary IgA, albumin, amylase, and total protein concentrations suggest that these proteins are subject to short-term variation.