Increase in Gingival Tissue Volume in High-cholesterol Diet Rats

Objectives:High dietary cholesterol induces proliferation of periodontal ligament fibroblasts at 8 weeks. Transforming growth factor (TGF)-beta 1 stimulates fibroblast proliferation. There is an association between high dietary cholesterol and TGF-beta 1 production in various organs. The present study examined the effects of high dietary cholesterol on TGF-beta 1 expression in rat periodontal tissues. Methods:Sixty rats were randomly divided into 6 groups: 3 experimental groups, for analysis during 4, 8 and 12 weeks feeding with a high cholesterol diet containing 1% cholesterol (w/w) and 0.5% cholic acid (w/w), and 3 control groups feeding with a regular diet. Results:In the periodontal ligament, the experimental group showed higher densities of TGF-beta 1 positive fibroblasts, TGF-beta receptor type I (TGF-RI) positive fibroblasts and total fibroblasts than the control group at 8 weeks. In the connective tissue subjacent to the junctional epithelium, the experimental group showed higher densities of TGF-RI positive fibroblasts and total fibroblasts than the control group at 12 weeks. Width of the free gingivae for the experimental group was also greater than that for the control group at 12 weeks. Conclusion:High dietary cholesterol enhances expression of TGF-beta 1 and its receptor in rat periodontal tissues, which contributes to a net increase in tissue volume via proliferated fibroblasts.