THE PLASMINOGEN-ACTIVATING SYSTEM IN GINGIVAL FLUID FROM ADULTS - AN INTRAINDIVIDUAL STUDY BEFORE AND AFTER TREATMENT OF GINGIVITIS

High concentrations of tissue plasminogen activator (t-PA) and placent al type plasminogen activator inhibitor (PAI-2) have previously been f ound in gingival crevicular fluid (GCF) of adults and children. In the present study, intra-individual comparisons were made of the concentr ations of t-PA, urokinase type plasminogen activator (u-PA), PAI-1, an d PAI-2 in GCF from the same sites before and after periodontal treatm ent in eight healthy male volunteers aged 35-46 yr. The gingival state was assessed by exudate measurement, bleeding on standardized probing , and the gingival index of Loe and Silness 3 days before the start of the trial and on the day after completing a 21-day preventive program consisting of instruction and professional cleaning once a week. Eigh t sites per subject were selected for enzyme analyses, all showing imp rovement in gingival state during the period. Sampling of GCF at the s tart and at the end of the trial was done with small disks of Millipor e-filter. t-PA and PAI-2 were analyzed with enzyme-linked immunosorben t assays with low method errors. The mean concentrations of t-PA were 0.73 mg/l before treatment and 0.49 mg/l after treatment. The mean con centrations of u-PA were 84.4 mu g/l before treatment and 101.6 mu g/l after treatment. PAI-1 was found in three subjects at the detection l evel. The mean PAI-2 concentrations were 2.19 mg/l before and 1.13 mg/ l after treatment. The mean molar ratio PAs/PAI-2 was 0.47 before and 0.48 after treatment. This insignificant change implies a maintained p roteolytic balance and indicates that PAI-2 is an important inhibitor of tissue proteolysis.