Exocytosis of polymorphonuclear leukocyte lysosomal contents induced by dental plaque

Rabbit polymorphonuclear leukocytes were incubated with a sonically treated suspension of pooled dental plaque to determine if the plaque would induce release of lysosomal enzymes from the polymorphonuclear leukocytes. Cells incubated with plaque at 37 degrees C released significantly greater amounts of the lysosomal enzymes, beta-glucuronidase and lysozyme, than did cells incubated with plaque at 0 degrees C or without plaque at 37 degrees C. This response was both dose and time dependent. Release of the cytoplasmic enzyme lactate dehydrogenase was minimal, and there were no significant differences in lactate dehydrogenase release between cells at 0 and 37 degrees C, or without plaque. These results indicate that dental plaque can induce the selective release of lysosomal enzymes, which could be involved in the periodontal injury produced by dental plaque.