Circadian changes of the SIgA, lysozyme, albumin and copper content of saliva.

The authors investigated SigA, Lysozyme (muramidase), albumin and copper levels in the saliva of sixteen children in the course of the day. A total of nine blood samples was taken in three-hour intervals from each child. Statistically highly significant changes were found in SIgA with a minimal average at 11 a.m. and maximum at 5 a.m. In albumin the maximum was recorded already at 11 p.m., while the minumum was at 11 a.m. The changes of copper values were different, with the maximum at 11 a.m. and minimum at 2 a.m., with smallest individual differences of mean daily levels. Lysozyme displayed an individual variability of levels and the lowest correlation with the investigated rhythms. A statistically significant difference was found only between samples collected during day- and night time. The findings are discussed from the aspects of other relations which might influence the assessed values.