Effect of experimental leukopenia on chronic gingival inflammation in dogs

Leukopenia was induced in six beagle dogs with chronic gingivitis by the injection of heterologous anti-neutrophil scrum. During leukopenia, the number of neutrophils in the gingival crevice and within the gingival tissues was reduced. Concomitant with the reduction of neutrophils, the amount of gingival fluid decreased. The activity of acid phosphatase, hyaluronidase and protease in crevicular samples was determined and was found to decrease in parallel with the reduction in neutrophil number. All parameters returned to normal during the post-leukopenic period. The results of the present study support previous suggestions that neutrophils at the dento-gingival junction contribute to the enzyme milieu in the gingival crevice and that these cells, through their lysosomal enzymes, may induce vascular damage in periodontitis.