Role of polymorphonuclear leukocytes in collagenase production in chronic otitis media

The effect of polymorphonuclear leukocytes on collagenase production by fibroblast-like cells was studied in an in vitro cell culture system. An extract of rat intraperitoneal polymorphonuclear leukocytes induced significant collagenase production by rat skin fibroblast-like cells. Fibroblast-like cells cultured in the presence of polymorphonuclear leukocytes had many conspicuous microspikes on their surface and contained bundles of actin filaments in their cytoplasm. Polymorphonuclear leukocytes appears to be involved in bone resorption by inducing collagenase production by fibroblast-like cells, as well as by releasing their own enzymes involved in bone resorption.