[Effects of bite force lost on the expression of IL-6 in the rat periodontium].

OBJECTIVE: In order to explain the molecular mechanism of periodontium remodeling the expression of IL-6 in the rat periodontal ligament fibroblasts (PDLC) and the alveolar bone osteoblasts under normal and bite force lost was studied. METHODS: To establish a rat model of different bite force for the study, left maxillary molars of rats were extracted and the left mandibular molar area was used as the bite force lost. The animals were sacrificed after 6 hours, 1, 2, 3 days and 1, 2, 3, 4 weeks. The prepared tissue specimens were processed for the study of the change in the histologic morphology and the expression of IL-6 protein in PDLC and osteoblasts with HE staining and immunohistochemistry techniques. RESULTS: In the group of bite force lost, the loosely arrangement of periodontal ligaments and the resorption of alveolar bone were observed in histological study, the expression of IL-6 in PDLC and osteoblasts was enhanced apparently than that in the group of normal bite force by using immunohistochemistry techniques. In the group of lost bite force, the expression of IL-6 in PDLC enhanced with time regularly: The expression of IL-6 was strengthened after 3 days, and reached the peak after 2 weeks, then, decreased after that and restored to normality in 4 weeks. While in osteoblasts of the group of bite force lost, the expression of IL-6 was strengthened just after 2 weeks. CONCLUSION: Bite force lost induce the expression of IL-6 enhanced apparently in PDLC and osteoblasts, it suggests that IL-6 may play important roles in the effect of bite force on periodontium remodeling. It approaches initially the molecular mechanism of periodontium remodeling, demonstrates that the histologic morphology is closely related to the mechanical condition.