Prostaglandin E2 enhances alveolar bone formation in the rat mandible

Abstract

Prostaglandin E 2 (PGE 2 ) induces bone formation in stress-bearing bones. The mandible, a stress-bearing bone, is loaded daily during mastication. The aim of this study was to determine if PGE 2 delivered locally to the mandible over 20 days enhances alveolar bone deposition. In 18 Lewis rats, controlled-release pellets containing PGE 2 were implanted on the buccal aspect on the left-hand side of the mandible, mesial to the root of the first molar. Controlled-release pellets locally delivered 0.1, 0.05, or 0.025 mg/day of PGE 2 . The right side of the mandible was used as a matched control for each animal. Six sham-treated animals were implanted with a placebo pellet. On days 7 and 19, animals were injected with the bone markers tetracycline and calcein, respectively. On day 21, animals were sacrificed and undecalcified tissues obtained for morphometrical analysis. Morphometrical measurements were analyzed by paired t test to determine differences between the matched samples and one-way ANOVA to compare the different treatment groups. A significant increase in alveolar bone area was observed in mandibles treated with 0.1 and 0.05 mg/day when compared with matched controls and the placebo group. This was accompanied by a significant increase in alveolar bone height and width. The proportions of double-labeled surface (dLS), the mineral apposition rate (MAR), and bone formation rate (BFR) were significantly increased in mandibles treated with the two higher doses of PGE 2 . The proportion of resorptive surface (RS) was significantly reduced in these two groups. It is concluded that PGE 2 induces alveolar bone formation in the mandible when locally delivered at a dose of 0.1 or 0.05 mg/day for 20 days.

The use of live‐animal micro‐computed tomography to determine the effect of a novel phospholipase A2 inhibitor on alveolar bone loss in an in vivo mouse model of periodontitis

“…In addition, the species of subject may influence responses to prostaglandin E 2 (22). Our findings are consistent with a recent study which showed that locally applied prostaglandin E 2 could enhance the rate of bone formation in a rat mandible (24). Another possibility is that while this drug suppresses the inflammation, it may concurrently stimulate bone resorption in a manner similar to that proposed for cyclooxygenase‐2 inhibitors in rheumatoid arthritis (25).…”

Topical administration of simvastatin recovers alveolar bone loss in rats

“…The labeling lines of tetracycline and calcein were not detected in the low‐mineralized bone area in this study. In general, these fluorescent lines are known to be clearly visible in mature bone (24). Our results may indicate that newly formed alveolar bone is still immature and the rough surface is one phenotype showing such immaturity.…”

Identification of genes related to mechanical stress in human periodontal ligament cells using microarray analysis

“…It is well documented that compressive forces induce the expression of pro‐inflammatory mediators and that interleukin‐1β has been implicated as one of the major cytokines synthesized in response to compressive forces applied on the PDL (6,26–28). Interleukin‐1β stimulates PGE 2 synthesis, which is essential to induce an osteogenic response during bone resorption and formation (14,29).…”