Abstract
Whole saliva was collected from patients suffering from periodontal disease (diseased group) and from clinically healthy subjects (normal group), homogenized (homogenized with a Voltex mixer) and the homogenate separated by centrifugation (centrifuged at 3, 000rpm for 10 minutes). The activity and content of lysozyme in the homogenate, supernatant and precipitate were measured by a modified method of Kakizaki's turbidimetric assay and the enzyme immuno-assay method of Yuzuriha et al.. The relationships between these values and the clinical findings, such as the GI-score, the DI-score, the pocket depth and the bone loss score, were studied.
The following results were obtained:
1. In the precipitate, the activity and content of lysozyme were found to be 70-80% of those in the homogenate.
2. The activity of lysozyme in the homogenate and precipitate was most stable when measured by the turbidimetric method after 1.5% bovine serum albumin had been added to a 1/15M phosphate buffer having a 6.0 pH; however, the supernatant was not changed. Further the activity of lysozyme was inhibited by the addition of NaCl to the buffer.
3. Storage of the saliva at -20°C increased the activity of lysozyme in the precipitate and decreased it in the supernatant; however, in the homogenate it remained unchanged.
4. The addition of mucin to whole saliva slight increased the activity of lysozyme in the supernatant. The addition of plaque bacteria to whole saliva inhibited the activity of lysozyme in the homogenate by approximately 20%. The addition of human serum to whole saliva increased the activity of lysozyme in the supernatant approximately five fold.
5. The lysozyme content in the homogenate and precipitate from the diseased group as measured by the enzyme immuno-assay were statistically higher than that from the normal group (p<0.05).
6. No statistically significant correlation between all the measured values and the clinical findings could be found.
