Fig. 5.

Osteoprotegerin (OPG) production in human gingival fibroblasts (HGF) stimulated with lipopolysaccharide (LPS), indomethacin (IND) and prostaglandin E₂ (PGE₂). (a) HGF stimulated with 1 μg/ml of Actinobacillus actinomycetemcomitans LPS in the presence or absence of 1 μM IND and 1 μM PGE₂ for 24 h. (b) HGF stimulated with 1 μg/ml of Porphyromonas gingivalis LPS in the presence or absence of 1 μM IND and 1 μM PGE₂ for 24 h. (c) HGF stimulated with 1 μg/ml of Escherichia coli LPS in the presence or absence of 1 μM IND and 1 μM PGE₂ for 24 h. The OPG levels in the culture supernatants were measured using enzyme-linked immunosorbent assay. The results are representative of three experiments. **P < 0·01.