Effect of topically applied neutrophil leukocyte extract on normal gingiva of dogs

Seven beagle dogs were used to study the gingivitis-inducing potenial of a topically applied neutrophil leukocyte extract and to compare the vascular and cellular reactions with those induced by plaque extract applied in an identical manner. In four dogs neutrophil extract was applied onto the marginal gingiva in one jaw quadrant while Gey's medium was applied to the contralateral gingival units. In the remaining three dogs plaque extract and Gey's medium, respectively, were applied in the same way. After 6.5 h of topical application colloidal carbon (1 ml/kg bodyweight) was injected into a leg vein and after a further 1.5 h biopsies were obtained from the experimental regions. The results show that topical application of an extract from neutrophils induces both an increase in the number of crevicular leukocytes and an enhanced vascular permeability. As in previous studies plaque extract was found to promote the emigration of leukocytes and to alter the permeability of the dentogingival vessels. The vascular and cellular reactions were, however, more pronounced after application of plaque extract than after neutrophil extract.