Elastase activity was found to be significantly increased in
periodontitis (0.872±0.4270 absorbance units/mg
protein, mean±S. D., 1.05±0.61 units/ml saliva),
gingivitis (0.772±0.416 units/mg
protein, 1.515±0.952 units/ml) and diabetes (0.549±0.286 units/mg
protein, 1.20±0.769 units/ml) compared to normals (0.255±0.089) units/mg
protein, 0.264±0.079 units/ml). Chymotryptic activity was not found to be increased in these disease conditions over the normal level (0.284±0.096 units/mg
protein).
Aminopeptidase activity was elevated only in
periodontitis (0.670+0.140 units/mg
protein) compared to normals (0.349±0.100 units/mg
protein).
Trypsin-like activity was also found to be significantly raised in
periodontitis compared to normals when
Pro-Phe-Arg-p-nitroanilide (0.666±0.204 units/mg protein), Ile-Pro-Arg-p-nitroanilide (1.59±0.260 units/mg protein) and Pyroglu-Pro-Arg-p-nitroanilide (1.82±0.380 units/mg
protein) were used as substrates. The normal values with these three substrates were respectively, 0.454±0.110, 1.04±0.231 and 1.15±0.312 units/mg
protein. Total
protein level in saliva was found to be significantly elevated in
gingivitis (209±66.8 mg/dl) and diabetes (204±68.0) compared to normal values (107±20.7). Increase in
periodontitis was marginal (127±28.3 mg/dl). Expression of proteolytic activities normalized to
protein level was useful in differential diagnosis. Increase in
elastase level in saliva is not a specific marker for
periodontal diseases.