Ultrastructural study of cultured human gingival fibroblasts exposed to endotoxin

Our current concept of periodontal disease is that some mediators found in the gingival sulcus are able to penetrate the epithelial barrier and produce tissue destruction in the periodontium. Endotoxin, one such mediator, recently has been the subject of considerable study. The purpose of this investigation was to substantiate the role of endotoxin in the pathogenesis of periodontal disease by ascertaining its action on cellular and subcellular components. In order to accomplish this, cultured human gingival fibroblasts were exposed to media containing either 300 micrograms/ml or 500 micrograms/ml of endotoxin and untreated medium for a period of 24 hours. Cells were harvested and prepared for electron microscopy by conventional methods. Electron microscopic examination revealed alterations in mitochondria, Golgi apparatus, lysosomal-like bodies, cytofilaments and plasma membrane. Relationship of these alterations to pathologic processes is discussed.