Neutrophil Elastase and its Inhibitors in Human Gingival Crevicular Fluid during Experimental Gingivitis

The relative concentrations and absolute amounts of neutrophil elastase and its two inhibitors, α2-macroglobulin (α2-M) and alantitrypsin (α1-AT), were determined in gingival crevicular fluid (GCF) collected from six dental students who refrained from brushing the upper left or right quadrant during three weeks. Plaque and gingival indices and flow of GCF were measured before, during, and after the three weeks of no brushing. Functional elastase, representing the enzyme complexed with a2-M, was measured by use of a low-molecular-weight fluorogenic substrate. Elastolytic activity in GCF was also assayed by use of elastin as substrate. Antigenic elastase, representing the enzyme complexed with a 1-AT, as well as the inhibitors a2-M and al-AT were measured by ELISA. After three weeks of plaque accumulation, the concentrations of both functional and antigenic elastase increased by a factor of about 3, whereas the concentrations of the inhibitors increased in a much higher proportion. No free elastase could be detected in GCF, as evidenced by the Sephadex G-75 elution profile of GCF, by the negative results obtained when elastin was used as substrate, and by the demonstration that pure enzyme kept its activity against the low-molecular-weight substrate after being saturated by a2-M.

Elastase release from gingival crevicular and peripheral neutrophils in periodontitis and health

The activity of elastase increases significantly in the gingival sulcus during inflammation. The release of this enzyme from crevicular and peripheral polymorphonuclear leucocytes (PMNs) was studied in seven patients with gingivitis, six with adult periodontitis, seven with rapidly progressive periodontitis and in nine healthy subjects. Peripheral PMNs were isolated from blood and crevicular PMNs from gingival washings. After preincubation with cytochalasin B, the same numbers of crevicular and peripheral cells were incubated either in phosphate-buffered saline (spontaneous release) or in the same buffer containing formyl methionyl-leucyl-phenyl-alanine (stimulated release). Elastase activity was measured in the supernatant by a fluorimetric technique. The results confirm that compared to peripheral PMNs, crevicular cells show a higher spontaneous release of elastase and a lower stimulated release. The activity of elastase released either spontaneously or after stimulation of crevicular cells was significantly lower in the controls as compared with cells obtained from patients with gingivitis or periodontitis. Crevicular PMNs collected from patients with deeper pockets appear to release larger amounts of elastase than those from controls.

The recovery efficiency of various materials for sampling enzymes and polymorphonuclear leukocytes from gingival crevices

The present investigation was designed to assess the effects of strips made of different materials on the recovery of enzymes in gingival crevicular fluid (GCF) (Experiment 1), and to examine a possible relationship between lysosomal enzyme activities and number of crevicular polymorphonuclear leukocytes (PMNs) (Experiment 2). In Experiment 1, GCF was collected with capillaries from 14 patients with periodontal disease, and applied on various test strips in microcentrifuged tubes or directly into tubes (controls). Strips were then shaken and centrifuged to elute GCF enzymes. The supernate was used for determinations of alkaline phosphatase (ALP), beta-glucuronidase (BG) and aspartate aminotransferase (AST) activities. The % recoveries were calculated as relative percentages to controls. When using saline as eluent, 90% or more ALP, BG and AST were found to be recovered from strips of durapore and papers. More than 35% of ALP and BG was found to remain on paper points. However, the % recoveries from paper points were improved using eluent with 0.1% (w/v) cetyl pyridinium chloride. In Experiment 2, 54 GCF samples were collected from 3 periodontitis patients by using durapore strips, in order to measure both PMN numbers and BG activities in the same samples. The 2 parameters showed strong and positive correlation with 0.847 (p < 0.001) of the Pearson's correlation coefficient. These findings suggest that durapore is a useful material not only for counting PMNs but also for measuring activities of GCF enzymes. Elevation of BG activities in GCF can be due to increasing numbers of PMNs.